The Parker Guitars Forum

General Discussion => TECH TALK => Topic started by: vjmanzo on March 26, 2018, 09:32:59 AM

Title: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 26, 2018, 09:32:59 AM
Hi everyone.

I am looking at the notion of converting a Fly into a "12-string Concert” of sorts; more info on that soon. At this stage, however, I have a question about string tension. I’ve modified the bridge and saddles of a Fly to physically accommodate 12 strings (6 two-string courses), and intend to “fix” the bridge by replacing the tension spring with a wood block.

My question is:
what are the limits on overall tension that a Fly can handle?

I’d like to use D'Addario EJ38 12-String Phosphor Bronze Acoustic Guitar Strings, (10-47), which have the following gauges:
Plain Steel .010/.10, .014/.014, Phosphor Bronze Wound .023/.008, .030/.012, .039/.018, .047/.027

I’ve never used 12s on my Fly, but, in principle, a Fly with a 12 spring could handle the below string tension of about 150 lbs. of tension (with D’Addario EJ21 12s) as follows:

String Note Gauge     Tension
1   E 4   0.0120 in.  23.36 lbs                                                                             
2   B 3   0.0160 in.  23.31 lbs                                                                             
3   G 3   0.0240 in.  28.02 lbs                                                                             
4   D 3   0.0320 in.  27.63 lbs                                                                             
5   A 2   0.0420 in.  25.60 lbs                                                                             
6   E 2   0.0520 in.  21.15 lbs

Total 149.07 lbs. of tension


For the 12-string idea I’m proposing, with a wood block used instead of a spring, the guitar (truss rod, bridge, etc.) would need to support about 250 lbs. of tension in total resulting from a set of 10-gauge 12-strings. D’Addario lists the tension for 12-String 10’s (EJ38 set) as follows:

String Note Gauge       Tension
1   E 4   0.0100 in.   16.22 lbs                                                                             
2   E 4   0.0100 in.   16.22 lbs                                                                             
3   B 3   0.0140 in.   17.85 lbs                                                                             
4   B 3   0.0140 in.   17.85 lbs                                                                             
5   G 3   0.0230 in.   27.90 lbs                                                                             
6   G 4   0.0080 in.   14.68 lbs                                                                             
7   D 3   0.0300 in.   26.71 lbs                                                                             
8   D 4   0.0120 in.   18.54 lbs                                                                             
9   A 2   0.0390 in.   24.66 lbs                                                                             
10   A 3   0.0180 in.   23.41 lbs                                                                             
11   E 2   0.0470 in.   19.91 lbs                                                                             
12   E 3   0.0270 in.   26.91 lbs

Total 250.86 lbs. of tension

I know that the carbon fiber exoskeleton is strong, but I don’t want to push it beyond its limits. I also don’t want the bridge to pull up from where it’s secured. If anyone is knowledgeable about long-terms effects of having this added tension, please let me know. At this stage, I haven’t done any modifications to the guitar itself that are irreversible. Ideally, if successful, I’d like to continue this project and document how this 12-strong mod was executed.

Thanks for the help!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: ParkerPlayer on March 26, 2018, 11:20:39 AM
Hi,
this sounds like an ambitious, challenging project !  I like the idea, and if works I bet it will be a very cool guitar indeed.
Though I have not ever heard of anyone doing this before.  My first inclination would be to do this kind of modification on a hard tail version instead of a tremolo version because the hard tail has 3 points of attachment whereas floating bridge has only two.  I have read about some instances where the floating bridge mounts have migrated over time under string tension (AKA the "leaning post issue").  You might want to search the forum to read up on that issue before you continue. 
good luck!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 26, 2018, 11:39:57 AM
Thanks for the reply and the information. Yes, I'd considered doing this on a hardtail, and, besides the hardtail models being somewhat rare, my thought was that either bridge (hardtail or floating) might need to be reinforced, so, if that's the case, I might be better off trying this on a non-hardtail Fly since they can be found in abundance. I'm also drawn to the idea that, if these problems can be solved, others with the interest can try it on Flys that are more readily available on the second-hand market.

Thanks again for the info and the thoughts!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Patzag on March 26, 2018, 12:08:32 PM
I believe that your main issue is not going to be the neck but the bridge posts.  @ParkerPlayer is right IMO.  The hardtails are a little more rare but would definitely be more suitable to this project.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 26, 2018, 12:23:43 PM
Thanks, Patzag. I appreciate the info.

Do you happen to know what kind of reinforcement a hardtail bridge might need (if any) in order to compensate for the added tension? It's unclear to me just how much tension the hardtail bridge (or the floating bridge) can handle.

I believe that your main issue is not going to be the neck but the bridge posts.
Thanks for your thoughts on the neck strength; do you feel the neck (and truss) could handle the added tension as a result of the carbon fiber? If I'm going to focus my attention to reinforcing the bridge, I'd like to be confident that there isn't something I should also be addressing with the neck hence my original question about how much tension (in lbs.) a Fly can handle.


Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Patzag on March 26, 2018, 05:24:27 PM
I'm no expert on the subject of string tension, but if you look at the construction of the hardtail, the bridge is anchored by 3 ferrules the allow the bridge to be adjusted in height. If the ferrules are solidly anchored in the wood, as they are, you should have no tension issue. I've never heard of a bridge moving on a hardtail.  I have one and it has maintained its position for the last 20 years.  It is well designed and well anchored.
The deluxe however has occasionally suffered from bridge posts that move forward ever so slightly.  The tolerance of the bridge cavity is so tight that any forward motion would cause friction.  There being only two posts anchoring the bridge, any relaxing on either one caused that problem.  It's not widespread and only a few reported the issue out of the many thousands of guitars produced.  But this leads me to believe that that bridge would not be well suited to a near doubling of the tension on it.

As far as the neck, it is very strong.  Much stronger than it appears to be, because of the carbon fiber skin.  But I think the you're going to have to be willing to try and accept any consequences including trashing the guitar if it can't take it.  Maybe some of the very knowledgeable wood workers on the forum will chime in soon.  Give them a couple of days to see the thread.  There are some very smart and able people on this forum.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Big Swifty on March 26, 2018, 06:02:53 PM
Wasn't there a change in truss rod design at some point in the Fly evolution, from wire to solid?

At any rate, pre-refined Fly have a piano wire truss rod, and that will only go so far..but no, don't know how far exactly.

And i THINK that it was replaced with a typical solid rod at some point in the refined series.

Might be a different series of Parkers, but worth checking.

And yeah, agree with Patzag... don't know if you're going to get a definitive answer on this one.

Maybe try contacting Ken Parker himself?...

Good luck!

B.S.

(Hey, my 333 post, thats halfway to The Beast!)
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Patzag on March 26, 2018, 06:34:31 PM

Maybe try contacting Ken Parker himself?...


Brilliant.  Try that!  kensarchtopguitars@gmail.com
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: sybersitizen on March 26, 2018, 07:02:50 PM
It'll be interesting to find out what the definitive answer is.

In the meantime, I became curious about what Gibson did when designing the 12-string part of the EDS-1275. I found a couple of photos that I could manipulate and position in order to compare its necks against the regular 6-string SG neck. Have a look:

(http://thesybersite.com/public/Gibson-12-String-Neck.jpg)

Evidence suggests that the Gibson guys did not trust the standard 6-string neck to bear the stress of the extra strings. What they did there was to 'slide' the fretboard deeper into the body, thereby shortening the overall length of the neck, presumably reducing the risk of any issues. You can see that the bridge was correspondingly pushed deeper to maintain the same scale length. In order to maintain consistency between the 12- and 6-string parts of the EDS 1275, the 6-string neck and bridge were restructured as well. A side effect is that the upper frets of the EDS 1275 are harder to reach.

It's well known that the SG neck joint was pretty minimalistic and pushed the limits of reliability. One might call it vulnerable to breakage if mishandled, so caution was probably well justified. This is of course not the same situation with a Fly ... but I guess we shall see.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 26, 2018, 08:22:31 PM
Thanks, sybersitizen. Good information for sure. I’ve been reading what others have written on a variety of guitar forums with regard to converting guitars into 12-strings. The general consensus is to buy a reinforced neck. I guess the SG required similar forethought. I wonder what the Fly neck can handle.

Thanks again for chiming in.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 26, 2018, 08:51:09 PM
Thanks Patzag again for the info. Okay, so it looks like hardtail is the way to go. Is there any sense in trying to secure a floating bridge in some way? Adding another anchor point?

Yes Big Swifty, I think I’d have to look for a refined hardtail for this to take advantage of the actual truss rod.

Thanks everyone for the continued input. I mean, I could also just look into other non-Parker electric 12-strings, but where’s he fun in that?! :)
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Big Swifty on March 27, 2018, 12:02:40 AM
There's actually a pretty cool and remarkably well made 8 string Fly inspired guitar on the Facebook "Parker guitar owners and lovers" page at the moment.

Worth a look.

B.S.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 27, 2018, 12:17:18 AM
Very cool indeed! Thanks for pointing that out!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on March 27, 2018, 12:45:41 PM
Cool project VJ!

A few thoughts:

1. the posts will be fine.  The leaning post issue, once again, has nothing to do with wood or wood compression or wood failure.  (It is a diameter mismatch between post and bushing- the more the post extends outward from the bushing, the more the post can lean.  Variations in body thickness and action preference determine how far the posts extend out.)  If you have the delrin stabilization rings, you will not have an issue.  A hard tail is probably better for this in most ways, but I also think it will be more prone to binding from added tension when adjusting the bridge height .

2.  The neck should also be fine, though for sure you'll have to tweak the truss rod.  That said, a maple neck is more likely to crack, which is why the SG probably needed reinforcing (though those changes might have as much to do with aesthetics or even getting the guitar to fit into a certain size case/box). 

3.  The truss rod itself should be fine.  However, this is one place where I'd worry about wood compression:  If you have lots of tension on the truss rod (or wire), the points where the anchors contact the wood could become an issue over time.  Given the soft bass wood of most fly necks, wood compression near the anchors is in my mind the greatest risk.  A mojo might be a good choice if possible.  Another potential issue is having enough "adjustment" available in the rod.

4.  The neck joint to the body would be the next risky thing, though I don't think you'll have an issue unless you somehow violently shock the joint under high tension.  A floating bridge could actually help in this regard, imho.   

IMHO the most difficult things functionally are the realtively narrow width at the nut, and getting more tuning machines on the headstock.  You could downtune your new 12 string a full step and lower tension a bit that way too.  Small tradeoff there I think.

Keep us posted, looking forward to seeing your results!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 27, 2018, 01:41:35 PM
Thanks, Billy. Excellent info.

Good to know about the leaning post issue--I was worried about that one! I suppose that if I do look for a Mojo for this mod, I can look for a 2005+-ish version that have the delrin rings already installed? Otherwise, "some guy on this forum" wrote a really detailed guide (https://drive.google.com/file/d/0B7zMxEP10BlwYVA2WHVUcHA1Wlk/view) :) Thanks for that! Hardtail Flys seem so rare these days, and I'd really hate to take one out of the second-hand marketplace while so many more (relatively speaking) floating bridge models exist.

I'm open to detuning the guitar at first as I test the waters, great suggestion. I also think I can avoid violently shocking the neck joint; though, nothing makes me emote like a rock god more than playing a 12-string  ;D Good to note a few positives for trying this on a floating bridge versus a fixed.

I'm working on the bridge modification now with some of my students; we'll tackle the nut afterward--good points on that, Billy! For the headstock, here's the concept I'm going to try to pull off (practicing on some spare wood several times first):
(http://www.vjmanzo.com/clients/forums/parker/12-string_fender.jpg)

Far out right?! The idea would be to try stagger another set of Sperzels in between with holes (gulp) straight through the headstock to allow the string to pass into the locking mechanism. That particular modification, given how permanent it is, will require some intestinal fortitude!

Thanks for the continued help, Billy, and everyone. I'll try to post a picture of the bridge modification soon!



Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 27, 2018, 09:16:23 PM
@billy
Also, just to clarify:
Given the soft bass wood of most fly necks, wood compression near the anchors is in my mind the greatest risk.  A mojo might be a good choice if possible.
You're suggesting the Mojo because of the strength of mahogany vs. basswood, correct?
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on March 28, 2018, 09:20:32 AM
Yeah, mahogany is still relatively soft in the hardwoods category, but basswood is just slightly harder than balsa.  Its a balancing act between ability to flex without splitting and resisting compression. Both have the benefits of being easy to work and retain great dimensional stability.

I was thinking that the floating bridge might lead to some tuning issues, so hardtail is still probably the way to go.  There's probably a very good reason you don't see 12 string floyds.  lol   :P

One other thought is that it might make sense to do a filler block mod like I did on my mojo TOM project- I don't think a TOM is the right way to go but there are other 12 string bridges that might make life a lot easier.  (If you did want to try adding a filler block, let me know, I'm sure I can help.)

This might also be an easy thing with a parker hardtail- possibly no cnc work or wood filler blocks, much like the kahler mod Patzag did a while ago.  And as I think about it, there is probably an easy way to mod the fly hardtail bridge's mounting features if you had to, ie beefier hardware or something. 

Are you going to CNC new saddles?  Or mod existing?

You might want to add a thin aluminum (or similar) plate under the tuning machines- the carbon fiber is good but the extra 6 holes will probably take away a lot of rigidity.  cool idea there.

The last thing is that all these comments are my opinions only- I like to think they're relatively informed, but opinion all the same, lol.   ;D  Feel free to contact me directly if you want, though always great to see things like this on the forum.

You'll get a much better sense of things once you have parts in hand and make some practice pieces.

Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 28, 2018, 10:58:26 AM
Thanks, Billy. I appreciate the info and will most likely reach out to you offline.

Thanks for the recommendation about the tuning peg reinforcement. My plan is to mod existing saddles, but I’m also 3D scanning/modeling/CNCing saddles as well, so I’ll hopefully make a decision on those two options in the next few weeks. I’ll, of course, keep everyone posted; I’m actually 3D modeling quite a few Parker parts.

I’m on the lookout, now, for a suitable guitar to work with; looks like a hardtail Mojo would be ideal, but probably like trying to find a unicorn. :) I’ll keep an eye open for any hardtail, but if anyone has any leads beyond Reverb and eBay, please PM me.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Patzag on March 28, 2018, 02:47:29 PM
You guys can talk privately as much as you want to but please keep the thread alive!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 28, 2018, 02:50:49 PM
Definitely!! No worries!! Pics and videos to come!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Big Swifty on March 28, 2018, 03:47:52 PM
Yeah!

Love a good build thread.

B.S.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: ParkerPlayer on March 28, 2018, 04:38:45 PM
I agree !   It's fun to hear about new, creative stuff being done with Parkers. 
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on March 28, 2018, 05:00:07 PM
Thanks guys! When I got my first Parker back 2005, I knew I never wanted to play anything else! I think many of us share that sentiment.

I’m fortunate to, now, have a bunch of talented engineering students working with me who can help execute some of these ideas. I will definitely keep everyone posted and share detailed information if/when we’re successful!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Mossman on March 28, 2018, 08:31:40 PM

Evidence suggests that the Gibson guys did not trust the standard 6-string neck to bear the stress of the extra strings. What they did there was to 'slide' the fretboard deeper into the body, thereby shortening the overall length of the neck, presumably reducing the risk of any issues. You can see that the bridge was correspondingly pushed deeper to maintain the same scale length. In order to maintain consistency between the 12- and 6-string parts of the EDS 1275, the 6-string neck and bridge were restructured as well. A side effect is that the upper frets of the EDS 1275 are harder to reach.

I think the design decision to 'shorten' the Gibson doubleneck fretboards was because of the balance problem, not so much to accommodate extra string tension.  As it stands, the 1275 is neck heavy and tends to dive... if they had extended the necks out another inch, it would have been unplayable.  I think most doubleneck designs struggle with this.  I have had Carvin, Carparelli, BC Rich and Gretsch doublenecks and they all tend to neck dive when on the strap if the neck attaches at the usual, six string, location.  The BC Rich was probably the best balanced because its 12 string headstock weighed no more than a six (because six strings tuned at the body).
Title: Fly 12-String Hybrid Project
Post by: vjmanzo on April 25, 2018, 08:17:42 PM
Hi everyone! Here’s an update on my 12-string Fly project.

The bridge:
The 12-string bridge prototype is complete. My students here at WPI have been working with me and have modeled both the fixed bridge and the floating bridge. Here is a 3D model CAD view of the floating bridge with 12 custom saddle pieces:

(http://www.vjmanzo.com/clients/forums/parker/Bridge_saddle_prototype_1.JPG)
Note: the tremolo bushing hole shown in this image will be removed from the final version we fabricate

Bridge Hole Spacings
The hole spacings for the 12-string were calculated using this tool that my students also developed this term:

12-String Spacing Calculator (https://docs.google.com/spreadsheets/d/1Z5gs234OT1yuwp6gYoxPmAN28yYx_YxSOC3z2rRk-NY/copy) | mirror link (https://docs.google.com/spreadsheets/d/1NYeQbonzznN1AaIwFBgukT8YYq67BKyxIsZdNGaR1IA/copy)
Note: in order to allow you to use the spreadsheet, but not overwrite it, the links above will open a Google Doc link, which will prompt you to copy the file to your own Google Drive

We’ll use these same spacings for the nut once we get to that point.

The neck:
The neck requirements for the added tension suggested that I’d have to go with a mahogany or redwood neck as opposed to the more common basswood necks. Since RP Flys are very rare and limited, a Mojo is probably best suited for this mod since the mahogany, I suspect, has the best chance of tolerating the added tension (though, if this works, I’d like to try this with a Deluxe).

Floating bridge:
Since a hardtail Mojo is also rare, I’ve decided to proceed with the trying to make the floating bridge mod we made work with the notion that, if properly blocked, it will operate like a fixed bridge in terms of tuning stability. I have no concerns about post-leaning or too few points of contact.

The saddles:
We modeled the original saddles and then decided to come up with a variation that provides the original support concept and mounting screw concept with a reduced profile. As shown in the image, 12 stainless steel saddles (a pair of a "left" and a "right" saddle) will be screwed into the new bridge using a similar mechanism as the original bridge, but with a small screw. The idea, then, is that we will desolder the piezo sensors from the Graphtec ghost saddles and solder them into the underside of these new saddles.

Next Steps:
My students and I are actively working on this and will have an actual version of the bridge and saddles to show in a few weeks! At this point, as described in this Classified request (http://forums.parkerguitars.com/index.php/topic,17010.0.html), I am looking to buy a Fly Mojo (or possibly an RP) to begin modifying toward this end. I have an eye open on Reverb and eBay, but if you have any leads or even if you have a gutted shell or a beater (as long as there are no structural issues or factory rejects), please PM me; it’s okay if it has no internal parts as long as it’s got all of the holes in the right spots, all frets, working truss rod, etc. The main requirement here is that it's a Mojo and that you have no sentimental attachments to the guitar in case the guitar accidentally ends up “detached” from itself! :) Bad joke.

When this is all done, I’ll be happy to share the CNC files with anyone interested in performing this mod.

More soon!

V.J.

Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on April 26, 2018, 12:41:44 PM
Vj, this is great stuff!

one thing to mention before I forget:  http://www.ekips.org/tools/guitar/fretfind2d/

There are a few small tweaks you could consider:

* a little more clearance at the end of the saddles, where the strings pass through the "tailpiece."  This will make it a lot easier to change the strings and prevent any potential pinching.
* a little more clearance between saddles just to cover machining tolerances
* a small radius around the edge of the saddles' top edges, and the pocket too.
* if there's going to be any paint or powder coating, make sure there's an allowance for that, though the polished aluminum looks pretty cool

I can help with any cad surfacing or fine tweaks if you need it.

btw agree with the mossman balance theory
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on April 26, 2018, 12:52:16 PM
Thanks, Billy, for the good suggestions and resource. I’ll pass these on to the guys in my lab.

We’re probably not going to do any sort of surface coating on the bridge, but I’m curious if you know what that black material is?  We did it density test to confirm that the bridge is aluminum, but we didn’t know about that coating.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on April 26, 2018, 03:00:09 PM
you bet, lots of cool stuff you guys did there. 

I don't know for sure, but I believe that coating is powder coat.  Which means it's either polyester, epoxy, or ceramic.  I'm leaning towards polyester.  Powder coating is a ton of fun, and by far my favorite way to finish metals.

The bridge is definitely aluminum, possibly 6061 or 7075.

Might be cool to think about diy anodizing- it's not the simplest thing in the world to do, but doesn't add any thickness.  The colors can be pretty cool.

You will want some kind of protective coating on there, oxidized aluminum can be pretty nasty.  Some kind of chromate, alodine, etc. at a minimum if you don't powder coat.

For the 3d cad, try to be sure the radii are at least G1 continuous or it can add some unwelcome artifacts in CNC.  Not critical for a one off, but G2 & G3 are best if you can do it.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on April 26, 2018, 03:46:16 PM
Excellent! Thanks!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Big Swifty on April 27, 2018, 05:39:43 AM
Wowsers, that's impressive!

And having your "students" build you a new guitar...feindishly clever!

B.S.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on April 27, 2018, 08:10:41 AM
Quote
And having your "students" build you a new guitar...feindishly clever!
Haha!  ;) I’m very fortunate to be surrounded by lots of cool and talented engineers who are into this stuff!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 03, 2018, 03:34:08 PM
Update:

First pass of bridge complete--here are some progress shots!

(http://www.vjmanzo.com/clients/forums/parker/bridge_1st_pass_3.jpg)
(http://www.vjmanzo.com/clients/forums/parker/bridge_1st_pass_1.jpg)
(http://www.vjmanzo.com/clients/forums/parker/bridge_1st_pass_2.jpg)

More to come when the rough edges are smoothed out and the saddles come out.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: ParkerPlayer on May 03, 2018, 05:48:51 PM
Cool.  Are you planning to using it as a floating bridge or fixing it somehow? 
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 03, 2018, 07:21:36 PM
Thanks. Yes, I’m ultimately going to block the trem.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on May 04, 2018, 02:18:57 PM
Nothing cooler than watching CNC chips fly.  Especially for a fly.  lol

Really nice so far... looks like some fairly aggressive cuts but nice finish, just the way to do aluminum so it doesn't smear. 

Smart clamping move to do the underside first too!

Can't wait to see next steps
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 04, 2018, 02:33:17 PM
Thanks, Billy! Will keep you (and everyone posted).
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 13, 2018, 05:26:10 PM
Update: bridge and saddles fabricated!

(http://www.vjmanzo.com/clients/forums/parker/bridge_finished.jpg)

There are a variety of next steps, but I wanted to share the progress; primarily because of how cool I think this is :)
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Patzag on May 13, 2018, 07:01:07 PM
Wow!
Looks awesome!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 13, 2018, 07:16:12 PM
Thanks!!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: jb63 on May 13, 2018, 08:03:11 PM
That just LOOKS expensive!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 13, 2018, 08:25:51 PM
That just LOOKS expensive!

 :D thanks! The block of aluminum was about $30  ;D
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on May 14, 2018, 03:37:13 PM
Wow, that looks great!  I bet it didn't take any time at all to machine it.  lol

Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 14, 2018, 04:21:03 PM
I bet it didn't take any time at all to machine it.  lol

Haha! We pressed the "Go" button and out it came!!  :P
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: Big Swifty on May 15, 2018, 07:42:47 AM
!!!!!

Wow!

Looks fantastic, and that's gotta be the hardest part to make happen, there rest is just being careful..congrats, can't wait to see how it turns out!

B.S.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 15, 2018, 09:41:52 AM
Thanks man! Yeah, I do think of that as the hardest part.

After a few conversations I’ve had with Billy offline, he recommended performing some simulations of stress tests on basswood and mahogany guitar necks and truss rod anchors. So we’re effectively building cheap-o mock necks just to make sure that the truss rod anchors don’t cause wood compression. I’m thinking we’ll have to go with a Mojo to support the added tension, but maybe we can use a Deluxe. I’ll let everyone know how that turns out!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: jb63 on May 19, 2018, 11:37:29 AM
For some unknown reason (out of the blue) it occurred to me that you could do this to a Nitefly with no tension worries at all. That neck is a tank!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 19, 2018, 12:12:43 PM
Good thought! Thanks! I had the same one about a week ago; I don’t own a Nitefly, but I figured the bolt-on neck would be rock solid.

Long story short: after doing some tests, I think the main concern with the added tension is not the stability of the neck (Fly or Nitefly), but the notion of the truss rod anchor causing wood compression. I made a list of the Nitefly models with mahogany necks (harder wood than basswood) in case I couldn’t find a reasonably priced Fly Mojo, but I just recently found one to use for this project. Nice!

I’m working with a former student now to do some stress tests on mahogany to see at which tension the anchor causes wood compression.

The next steps after that are to work through making/modding some piezo sensors to put in our saddles. Graphtec wouldn’t sell me just the sensors, so we’ll either have to make our own sensors or try to unglue the Graphtec ones from the saddles they came with.

Once that’s done, I’ll string it up with six strings and make sure everything is cool and stable (block the bridge, etc.) before :: gulp :: we start practicing the headstock hole drilling! 

Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: mmmmgtr on May 19, 2018, 04:12:35 PM
It seems to me that six more holes in that skinny headstock might present the biggest risk for failure.  May need to reinforce....
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 19, 2018, 04:24:17 PM
Agreed. My initial thought is to put a steel plate between the tuners and the wood; Sperzel ships the D-Thing with an individual plate like this to help strengthen the wood. Other ideas?
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on May 24, 2018, 10:38:03 AM
Aluminum is probably strong enough for a little tuning machine support, easier to work and lighter weight.  You might even try a 90 deg extrusion for a little more stiffness.  You might have to route a small lip on the top of the headstock to allow the tuner nuts to engage but I doubt that's a problem.
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 24, 2018, 10:52:24 AM
Thanks, Billy. Good suggestion; I’ll keep that in mind. I’ve got a Mojo to work with now, so we’re trying to ensure that the new bridge works properly while simultaneously testing the truss. We’ll start doing some practice holes on a block of mahogany, and, I think we can make an aluminum plate.

So many opportunities for this to all go wrong!   ::) I suppose if you see me make a post about my new “Fly Mojo wall clock”, you’ll know that we goofed  :)

Thanks!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: billy on May 24, 2018, 11:25:00 AM
FWIW I think it's going to be pretty cool and you're taking good steps to check the potential issues.

I like the aluminum 90 deg extrusion since that bend makes it stronger without adding a lot of weight or material.  the local home store has it in various widths and lengths for about $10 or so. 

But I'm also interested to see what you guys come up with if you make your own.  ;)
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on May 24, 2018, 11:58:05 AM
Thanks, man.

Yes, I think the 90 degree aluminum extrusion concept is great! We'll probably pick one up locally and then drill holes. Thanks!
Title: Re: Tension Question for Parker Fly 12-String Hybrid Project
Post by: vjmanzo on November 16, 2018, 04:22:43 PM
Hi everyone,

Just a quick update on the 12-string Fly project before a really detailed update later on:

After our first bridge prototypes, our team modeled the Fly headstock and devised a number of potential solutions to 1) fitting additional tuning pegs and 2) avoiding string collisions. Our full report (forthcoming!) will show all sots of approaches, but this was the one we decided to implement (shown here on a wood mockup):
(http://vjmanzo.com/clients/forums/parker/12-string/string_collision_1.jpg)
(http://vjmanzo.com/clients/forums/parker/12-string/string_collision_back.jpg)

Here is a better view with an acrylic mock-up:
(http://vjmanzo.com/clients/forums/parker/12-string/acryllic_model_1.jpg)

Lots of holes in not a lot of space!  :o We were able to simulate the tension on the neck and found that we are well within the safe threshold for both mahogany and basswood, but went with a Mojo just to be safe. In order to add more rigidity to the headstock, we lasercut steel plates to cover the headstock, which helps to anchor the headstock and tuners together.

(http://vjmanzo.com/clients/forums/parker/12-string/headstock_plate.jpg)

After coming up with more than 20 mock-up test models of the headstock in both wood and acrylic, we put on our brave faces and drilled holes in the headstock using a guiding piece we fabricated:

(http://vjmanzo.com/clients/forums/parker/12-string/drilling_holes_1.jpg)
(http://vjmanzo.com/clients/forums/parker/12-string/drilling_holes_2.jpg)
(http://vjmanzo.com/clients/forums/parker/12-string/headstock_drilled.jpg)

Then we put the plates on the headstock:
(http://vjmanzo.com/clients/forums/parker/12-string/headstock_with_plate.jpg)

We opted to use these Sperzel tuning knobs with knurled buttons in both short-post and long-post varieties:
(http://vjmanzo.com/clients/forums/parker/12-string/sperzels_knurled_knobs.jpg)
(http://vjmanzo.com/clients/forums/parker/12-string/sperzel_knurled.jpg)


We have a few more things to do before it's playable, but I wanted to give a quick update because it's been a while.


We've also made a few observations that you may find interesting (or "obvious", or "dull as dirt"!  :D):

1. The string holes in the original Fly bridge don't really align 100% with the top point of contact of the saddles and it doesn't really seem to matter.

(http://vjmanzo.com/clients/forums/parker/12-string/IMG_1141.jpg)

Our original bridge prototype didn't align 100% either, so we modified our saddle pieces and our bridge holes to both accommodate larger strings and align the holes better wit the saddle notches only to discover that even the original Fly bridges (we examined 7 Fly bridges) don't do this.

(http://vjmanzo.com/clients/forums/parker/12-string/bridge_modified.jpg)
(http://vjmanzo.com/clients/forums/parker/12-string/saddles.jpg)


2. The Fly we're working with is a 2011 Fly Mojo...and after drilling new holes a few of my team members suspect that it actually has a basswood neck.

(http://vjmanzo.com/clients/forums/parker/12-string/basswood_mojo.jpg)

The existing tuning peg holes are lined with carbon fiber, but after cutting new holes, we see the color and woodgrain that doesn't really look like mahogany. Every woodworker I show this to says it's definitely not mahogany, and one said outright: "that looks like basswood or pine". This detail is somewhat irrelevant (I hope!) to this project because our tests suggested that a basswood neck could support the added tension, (and, personally, for a variety of reasons, I was hoping to do this mod to on a basswood neck Fly), but: wow! Isn't that interesting if this Fly Mojo with MM in the serial is actually a Fly Classic?!


More information soon! Thanks for reading!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: jb63 on November 16, 2018, 07:10:40 PM
"Isn't that interesting if this Fly Mojo with MM in the serial is actually a Fly Classic?!"

In 2011, I'm not surprised.

But I am really happy to read this giant post! I can't wait to read more!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on November 16, 2018, 07:23:31 PM
Thanks, man! It's been a long time coming, and I've learned a lot in the process, which I can happily share with the community!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: Patzag on November 17, 2018, 11:51:38 AM
Best Thread ever!  Bated breath and all!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on November 17, 2018, 12:02:05 PM
Hahaha! Thanks, Patzag! We definitely appreciate the encouragement from you and everyone else on the forum! One step forward for Fly-obsessives worldwide!

Here are a couple more photos to help with the waiting!  ;D

(http://vjmanzo.com/clients/forums/parker/12-string/headstock_12_front.jpg)

(http://vjmanzo.com/clients/forums/parker/12-string/headstock_12_back.jpg)

There's no backplate on the back of the headstock, and we're trying to determine if it actually needs one.
Title: Re: Parker Fly 12-String Hybrid Project
Post by: jb63 on November 17, 2018, 12:15:13 PM
I'm going with NO backplate needed! What gauge strings are you going to go with? I haven't played a 12 in so long I don't even remember what they usually were-- 11 on top?
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on November 17, 2018, 12:36:04 PM
We're going with D'Addario 10’s (EJ38 12-string set) as follows:

String Note Gauge       Tension
1   E 4   0.0100 in.   16.22 lbs                                                                             
2   E 4   0.0100 in.   16.22 lbs                                                                             
3   B 3   0.0140 in.   17.85 lbs                                                                             
4   B 3   0.0140 in.   17.85 lbs                                                                             
5   G 3   0.0230 in.   27.90 lbs                                                                             
6   G 4   0.0080 in.   14.68 lbs                                                                             
7   D 3   0.0300 in.   26.71 lbs                                                                             
8   D 4   0.0120 in.   18.54 lbs                                                                             
9   A 2   0.0390 in.   24.66 lbs                                                                             
10   A 3   0.0180 in.   23.41 lbs                                                                             
11   E 2   0.0470 in.   19.91 lbs                                                                             
12   E 3   0.0270 in.   26.91 lbs

I think we'll be okay without it too, but we'll do some tests just to make sure. The first month of playing this will probably be in "Drop D" until I feel confident that it's not going to snap in half :)
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on November 17, 2018, 12:42:30 PM
Also, fun fact: after lengthy discussions, we're going with the "Rickenbacker 12-string stringing" of low string/high string for each of the courses as opposed to a traditional 12-string which has the higher string one on the bottom of the course.

This stringing will, I'm sure, make a huge difference to the people sitting in the back of the noisy club who are already on their third beer by the time I play the middle section of Stairway  :P
Title: Re: Parker Fly 12-String Hybrid Project
Post by: jb63 on November 19, 2018, 02:03:05 PM
HHaha! Play one wrong note in that part and they will call you out!

Yet I am still pretty excited about this.
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on November 19, 2018, 02:20:51 PM
Thanks, man! Me too!! We’re cutting a new nut right now, but first were blocking off to the bridge...although: who wouldn’t love the tuning stability of a 12-string with a floating bridge!!

Will keep you posted!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 01, 2018, 08:12:18 AM
Ta da! I present: the 12-String Fly!

(http://vjmanzo.com/wpi/electricguitar/images/_projects/12-string/Fly_Mojo_12-string_01.jpg)

(http://vjmanzo.com/wpi/electricguitar/images/_projects/12-string/Fly_Mojo_12-string_02.jpg)

(http://vjmanzo.com/wpi/electricguitar/images/_projects/12-string/Fly_Mojo_12-string_03.jpg)

(http://vjmanzo.com/wpi/electricguitar/images/_projects/12-string/Fly_Mojo_12-string_04.jpg)

Thank you to everyone on this forum for the help along the way!

Full details of the process here (http://electricguitarinnovationlab.org/12stringfly)

I also suppose this is as good a time as any to officially announce a new research lab I put together at my institution (WPI (http://wpi.edul)) last spring: the Electric Guitar Innovation Lab (EGIL)(http://electricguitarinnovationlab.org (http://electricguitarinnovationlab.org)). All the work done to this Fly came through this lab with, of course, the help we received on this forum. I'm so thrilled to share this news with everyone, and I hope you find the detailed report interesting! Please let me know if you have any questions!!


And here's a quick demo of what it sounds like:
(http://vjmanzo.com/wpi/electricguitar/video/_projects/12stringfly.jpg) (https://www.youtube.com/embed/HepSKcm0VQQ)

There are still some slight tweaks we're going to address, but it's a terrific instrument! Thanks again, everyone, for all of the encouragement, advice, and insight throughout this project and in general; this forum is is a terrific resource, and if there's anything that I or my lab can do to give back to this community, just lemme know! 
Title: Re: Parker Fly 12-String Hybrid Project
Post by: jb63 on December 01, 2018, 08:54:25 AM
Yow!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 01, 2018, 09:01:17 AM
Yow!

Hahahahaha Thanks!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: jb63 on December 01, 2018, 09:46:11 AM
You definitely get points for actually getting these things out and playing them, but the is one pretty guitar. I was thinking you would use an old beat up deluxe but this makes it even better!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 01, 2018, 09:54:06 AM
Hahaha thanks, man! I looked for a beater, but, while I was on the lookout for a project Fly with a low-end budget in mind, Guitar Center had a great deal on that Mojo, so I picked it up! Very pleased that it’s as beautiful as it is! It’s a very thin neck Fly and feels just great!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: Patzag on December 01, 2018, 09:28:09 PM
Amazing!

Thanks for sharing the adventure with all of us.  And the result is stunning. 
I'd love to hear the strings ring out and in various contexts. 

Well done!!!!!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 01, 2018, 10:53:26 PM
Thanks, Patzag!!! I’m very happy with it! Thanks so much for all the useful suggestions you’ve made for this thread as well as many, many more threads!

I’ll try to record some additional audio clips soon; I’m also open to loaning it out, though I have no idea how that would work lol PM me if that’s of interest.
Title: Re: Parker Fly 12-String Hybrid Project
Post by: Mr303 on December 02, 2018, 07:06:09 AM
Wow!
That turned out really well.
Very good project, thanks for letting the forum in on this “little” project.....wonder if KP himself ever sees posts like this?  He should.
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 02, 2018, 07:14:36 AM
Thanks! And really my pleasure to share the good news of this!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: Big Swifty on December 03, 2018, 03:13:49 PM
Holy Crapballs, you did it!!

Man, that is incredible, well done.

I'll make one comment though...the headstock/tuner/string solution...looks pretty messy to me, especially within the context of such a well designed guitar.

If i were to make any suggestions.. i would consider redesigning the headstock to maintain the overall elegance of design, ie cut the old one off and graft a new one on. Don't know exactly how you'd do it, but i'm sure it could be done.

However, that's just a quibble, again, what an amazing project. That bridge/tailpiece, great piece of engineering!

Stairway on dude!

B.S.
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 03, 2018, 03:26:23 PM
Thanks, man! It was a long time coming!

Thanks for the suggestion about the headstock; we considered the “decaptiation approach” you suggested, and agreed that the best way to ensure stability was to use the existing headstock; I, personally, kind of like the string-crossing look  ;)

Lol Stairway felt appropriate for a first demo  :P
Title: Re: Parker Fly 12-String Hybrid Project
Post by: ParkerPlayer on December 03, 2018, 03:31:12 PM
I am truly amazed that you pulled this off !   And the biggest hurdle of all, fitting 12 tuners onto that tiny headstock, I thought would be insurmountable, a real showstopper.  But you have proved me wrong, sir.  Well done.

Can you describe the experience of winding up all of the strings (and truss rod too, I assume) for the first time?   I imagine a real butt clenching one?
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 03, 2018, 03:43:30 PM
Haha--thanks, man! It was a little unnerving when I tuned it up the first time! Originally, I was thinking that I'd leave the whole instrument dropped down a step or more, but, I have to say: I felt really comfortable with having worked through a bunch of test simulations, so we just decided to go for it and tuned it up to standard. No guts no glory!  :P

When we adjusted the truss and it turned just as easily as it ever has, then I knew we were safe. If there was any sort of friction going on, I would have been a bit more reserved about what we could do going forward, but it's solid; the tuning is stable, and I'm really happy with it!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: billy on December 03, 2018, 07:48:40 PM
No guts no glory indeed! 

I said it before and I’ll say it again-

Super stoked to see this and sounding so great too. Awesome job all the way around, and especially love the write up. Frosting on the cake!
Title: Re: Parker Fly 12-String Hybrid Project
Post by: vjmanzo on December 03, 2018, 08:01:41 PM
Thanks, Billy!