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New Side Bender design

Posted: Wed Nov 28, 2012 2:37 am
by rienk
As a new member of this forum (and a new guitar builder... I forget the fancy word for it), I hope to be able to offer back at least a portion of the help that I expect I will receive.
One thing I might be able to offer is access to some of the tooling we will be designing.

I intend to design a new side bender similar to the new LMI system, but with the added functionality of being able to do cutaways. Our Fox style works fine, but I like the capability of being able to side load the material, and not having to take everything apart for cutaways.
Once it's done (and de-bugged), I will let everyone know, and make the cut files available to anyone who might have an interest - and access to a CNC router or waterjet.

There is one design issue that I would appreciate some feedback on. LMI's unit uses some fancy roller tensioners, instead of the simple spring tensioned rollers that the Fox or BCG units use. Though I have the capability to have these parts made, it might be beyond the average Luthier's capability. Do any of you have any experience using both systems, and if so, is there any compelling advantages to using one system over the other?

I can design it either way - or both - though I'd prefer to do it with one or the other.
I don't expect that there will be a lot of feedback based upon actual experience, but I thought I'd throw it out there anyway.

Regards,
Rienk

Re: New Side Bender design

Posted: Wed Nov 28, 2012 11:59 pm
by  
I own a Fox style bender and had a comparison opportunity when an acquaintance brought his LMI over to my shop.
I didn't see any advantage to the rollers on the LMI since the Fox bender, without rollers gave equally good results.
One issue I have with the LMI is the amount of MDF it contains. At the LMI's price point I'd expect no MDF at all.

-tommy

Re: New Side Bender design

Posted: Thu Nov 29, 2012 8:37 am
by tippie53
I have used one of the new LMI units and to be honest , while it is a pretty looking device , it isn't any better. I may be a little biased here but Paul Reed Smith , Wayne Henderson , Fender all bought my units over the LMI . They are dependable and most important , they hold up.
I found the roller an issue . Rolling or spring hold down , the wood doesn't know the difference . Loading is not that hard and the sides of the bender help hold the sides square to the waist.

Re: New Side Bender design

Posted: Thu Nov 29, 2012 10:35 am
by Ben-Had
I can't even begin to tell you the trouble I had with side bending before I got John's machine. Since - NOT ONE SINGLE MISTAKE (and by that I mean cracked side). Every bend has been perfect and EASY.

Re: New Side Bender design

Posted: Thu Nov 29, 2012 11:17 am
by tippie53
As a side note
The LMI bender design I believe is patent protected so you may want to be sure there is enough of a difference so you don't end up in trouble should you try and sell.
MDF will swell like a balloon if it gets wet.

Re: New Side Bender design

Posted: Thu Nov 29, 2012 7:34 pm
by rienk
Thanks for the feedback.
I helped Gene Baker out with issues he had using the LMI side bender for his new archtops (D'angelico replicas). It worked great, but again, it can't do cutaways, which he will eventually want to do.
And for the record, the new LMI units are not made out of MDF, they are all baltic birch, which is what I'll make mine out of. And just like John shows on his videos, you have to take the sides out carefully - especially with the cutaway. Frankly, I'd rather not take my machine apart. Is it that difficult? No... but it's one more thing to do, and one more potential for forgetting and making a mistake.
Frankly, I like making tooling, jigs and fixtures - that is one of the most satisfying things about what I do for work, so designing my own guitar tools, or modifying others for my particular needs or preferences is fun. I enjoy the process of building, and this is one of those processes... appreciating the journey and not just the destination.
I have no interest in going commercial with these or any other tools we might design. I will make the plans freely available to anyone who wants them. Anyone can copy LMI or BCG stuff if they want (with virtually no patent issues for personal use), but most don't have the means or won't take the time. And if John's team likes my design and wants to build it for sale, they're more than welcome to. The same goes for KMG or anyone else.

Back to the point at hand, I think I'm going to design it with the cantilevered clamps like LMI's. but with the regular spring tensioners like BCG or Fox style. It will definitely be easier to make, and thus quicker to get guitars out of it (and we'll keep on using our Fox in the meantime).

For those with nothing better to do, here is a link to one of my favorite projects - which is a virtually self jigging airplane!

http://www.sreyaaviation.com/ts1/header.html

Re: New Side Bender design

Posted: Thu Nov 29, 2012 7:42 pm
by rienk
BTW, I'm well aware of the vagaries of MDF... we buy it literally by the pallet (full units)... same with Baltic Birch.

That brings up the question of radius dishes. I notice that some people use MDF, and some use plywood. MDF is obviously more dimensionally stable, but plywood is more rugged and structurally sound. Does anyone use both to make their dishes?
I'm thinking about machining some of mine out of UHMW, especially to use in our vacuum presses.

Feedback on this topic would also be appreciated.

(maybe it belongs in a different thread?)

Re: New Side Bender design

Posted: Thu Nov 29, 2012 8:16 pm
by B. Howard
rienk wrote:BTW, I'm well aware of the vagaries of MDF... we buy it literally by the pallet (full units)... same with Baltic Birch.

That brings up the question of radius dishes. I notice that some people use MDF, and some use plywood. MDF is obviously more dimensionally stable, but plywood is more rugged and structurally sound. Does anyone use both to make their dishes?
I'm thinking about machining some of mine out of UHMW, especially to use in our vacuum presses.

Feedback on this topic would also be appreciated.

(maybe it belongs in a different thread?)

MDF only exhibits superior dimensional stability until it gets wet, then it turns to cardboard and cornflakes. The factory surfaces are fairly impervious to RH but any cut edges or opened faces will become hygroscopic and slowly start to swell unless sealed with a solvent based coating or foiled. UHMW on the other hand sounds very interesting for radius dishes and router templates.

Re: New Side Bender design

Posted: Fri Nov 30, 2012 2:28 am
by rienk
B. Howard wrote:
rienk wrote: ... UHMW on the other hand sounds very interesting for radius dishes and router templates.
The only problem is that UHMW is pretty expensive; a 1" x 4' x 8' sheet runs about $800, which puts just the material cost at what you can buy a completed radius disk for. Of course, you may not need that thick for most dishes, and a 1/2" sheet is not much more than half the price. For someone doing production work, it may well be worth it.

I remember seeing Taylor's molds and tools - they look like they are all cast aluminum! Wow - beautiful stuff.

Re: New Side Bender design

Posted: Fri Nov 30, 2012 7:43 am
by JRHall
rienk wrote:
For those with nothing better to do, here is a link to one of my favorite projects - which is a virtually self jigging airplane!

http://www.sreyaaviation.com/ts1/header.html

Being a pilot, this got my attention. Do you have any flying yet?