Official Luthiers Forum!
http://www.luthiersforum.com/forum/

My Clamping System for the Williams Jig (prototype)
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=23312		 Page 1 of 1
Author:  Mike OMelia [ Tue Aug 04, 2009 9:09 pm ]
Post subject:  My Clamping System for the Williams Jig (prototype)
I have not been a big fan of the clamping system in the current set of plans for the Williams Jig. They are OK, but I have found them difficult to achieve a snug and secure fit. Also, I have never liked the inward pointing sliding bases, though that is not the key part of my clamps (one could go either way).

Like I said, these are prototypes that I will use for a while before I make more with lessons learned. I did try adapting my originals, but I found there was not enough material at the top to make them useful.

Once everything is postioned and leveled, just tighten the top knobs until the guitar is secure. In my prototype with the harp guitar, nothing moves. It holds tight.

I have already found things I want to change. Comments & criticisms welcome.

Mike
Author:  Rene [ Tue Aug 04, 2009 10:58 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Mike,
That's a great idea and I'm already looking at my support blocks to modify them. I think it will work, just need some threaded inserts and more knobs. Thanks!

Rene
Author:  Mike OMelia [ Wed Aug 05, 2009 10:49 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Hmmm... lots of lookers, few responses. Has someone got something better?

Mike
Author:  LanceK [ Wed Aug 05, 2009 11:55 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Mike that is a terrific mod for those side holders!
I'm going to use this for sure!

Thanks!
Author:  Wes McMillian [ Wed Aug 05, 2009 12:15 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Actually, I had the very same concerns and built mine with much the same idea with being able to crank the upper part of the legs in to better grip the body. You can put you hand under the body and pick up the cradle by them. Very snug. But your version is much nicer. Good job!

In fact, Lillian are you watching? I apologize I failed to ever get the measurements you asked for once my crazy overtime was finished but this is a much better solution.

Here was my quickie solution. Not pretty but functional. It works, so it was never important enough to rebuild it. I really like yours, though.

Image

Image
Author:  Mike OMelia [ Wed Aug 05, 2009 12:40 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
A number of things to note

1.) My reversal of the bottom slider was due to 2 issues... a) its hard to reach under the body and adjust them, and b) the sliders could intefere with each other (even if I tapered the ends, though that did help). Also, moment arms and all of that, it seems having the sliders on the outside makes more sense when using the pressure clamps.

2.) I had to make the vertical holders taller since you don't want the ledges to change the "pivot" pont on the pressure clamp. Plus, more height means more grip.

3.) I am going to take the cork off the lower part of the vertical bar... that was a dumb idea.

4.) You need to saw a good width out (1/8"?), biased toward the pressure side or the wrong part will deflect (obviously)

5.) McMaster was where I found 1/2" insert nuts (1/4"-20) for the pressure clamp. BORGS do not carry them

6.) I would love to find a way to insert a metal plate where the pressure screw contacts the wood... my current design may eventualy dig through the wood.
Author:  Dean [ Wed Aug 05, 2009 1:12 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Very nice setup. Slip in a penny and set with super glue for your pressure plate.
Author:  meddlingfool [ Wed Aug 05, 2009 1:27 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Awesome! Great timing too, as I was presently pondering how to make mine better. I'll just copy yours!
Thanks!
Author:  Mike OMelia [ Wed Aug 05, 2009 1:54 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Dean wrote:
Very nice setup. Slip in a penny and set with super glue for your pressure plate.


Thats a good idea! Thanks!

Mike
Author:  Wes McMillian [ Wed Aug 05, 2009 1:59 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
In discussing the merits of these designs (and I do like yours! I'll incorporate some of your ideas when/if I ever rebuild mine) I don't know if I would like the oversized board. I thought about that for the same reasons as you - to flip the lower arms around and keep from having to reach up under the body to tighten the nuts (which is a little more of a pain, but not much. And how often do you have to do it?) I finally decided the trade-off of having the smaller carriage was worth it. Now, for your big harp-guitar carriage it probably doesn't matter, as you won't be moving it around a lot. But I tend to drag mine around both during the routing process and other processes, and I like the smaller and lighter footprint.

Just something else to think about.
Author:  bluescreek [ Thu Aug 06, 2009 6:42 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
I had the same thought 8 years ago . The one thing about the carriage is that it isn't actually a clamp. Think more of a support for the body just to keep it from rocking. Another thing is you can crack a side . Be careful , that is why I don't use the design anymore.
Author:  Chris Paulick [ Thu Aug 06, 2009 7:13 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
I don't use the williams jig so the L brackets would get in the way if reversed. Looks nice Mike. But with the Williams jig couldn't you also use or adapt your building mold to work by just putting some block lifters in it? You all know that you can tap hardwood and get away without brass bushings in certain situations right?
Nice clean design to the clamping system and I also like how you dovetailed the L together.
Author:  Wes McMillian [ Thu Aug 06, 2009 7:48 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
John Hall is actually right here. There's nothing necessarily "wrong" with the cradle as is. It holds the body level during the routing process, which is all it was designed to do. I mean, it's not like the body is likely to jump up and out of the cradle during the routing process and land on the floor. And, yes, there is a risk of cracking a side with too much pressure. It's just more secure feeling and, hey, I like it. Until the first time I crack a side then it'll probably go in the dumpster, too. laughing6-hehe :shock:

I don't actually use a Williams jig, either, Chris. Mine is an articulating arm that swings off the wall. You know the one, seems like you built one like it. And I routed the bindings on my first while in the mold by adding leveling feet like you describe. Worked fine. My mold was actually designed where all I had to do was drill some holes in the rim and drop some bolts down through them head down to level off of.
Author:  Dave Stewart [ Thu Aug 06, 2009 8:11 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
bluescreek wrote:
Another thing is you can crack a side . Be careful , that is why I don't use the design anymore.

I agree....why induce a risk unnecessarily?
If the L-brackets are properly made, pushing them in by their base & then tightening the wing-nut will "torque" them into the sides enough that you can't remove the body ....plenty of clamping effect.
Author:  Mike OMelia [ Thu Aug 06, 2009 8:29 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
I am well aware of the danger of applying too much pressure. Most of my clamping positions are at the curvature points which are much stronger. The harp guitar is a special case and requires more grip. This is one of those ideas that some will like and others will not. I do not apply enough pressure so that I could lift the whole thing by the guitar body. Just enough to secure it. Wes, your design is pretty neat also.

John, what system do you use?

Mike
Author:  bluescreek [ Thu Aug 06, 2009 11:22 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
I use the carriage that I have listed on my site. It just uses the L brackets. The L brackets will clear any routing system you use. Just be sure to adjust the levelers to the correct height.
I use the same set up for both the Williams and the Tom Ribbeke designs. In fact other than the hardware the design is pretty much the same as what was first drawn on the universal binding machine.
Author:  Chris Paulick [ Thu Aug 06, 2009 7:05 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Wes, I know what you're talking about but I ended up building a Doolin style Ribbeke as space was a concern for me.
I don't think the extra clamping is a problem as long as like you watch it. I find that I use my carriage as a work holder too and can see the little bit of tweeking the clamp could be useful. I leave it in the carriage when I bind it and all sort of things. If I don't want it moving around I'll quick clamp it down to the bench. I pretty much leave it sit in there once the box is closed up.
I like the fact of just having the rectangular leveling foot as opposed to Mike's L foot. I will turn my foot from the horizontal to the vertical when I need more heigth when routing the back binding channel. I just like that option. But Mike might not need that with the Harp guitars. I don't think they have a back taper, do they?
Author:  Mike OMelia [ Thu Aug 06, 2009 11:51 pm ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
The whole thing is tapered if I understand your question. Each pair of feet is at a different height. Especially the harp arm. That arm can cause unfortunate torquing moments at the most inoportune times. You'd think balance was enough, but sometimes it is not.

This is what drove me to this clamping design. BTW, one can achieve similar (but not as strong) clamping pressures without the scew clamp by simply wedging the outward sliding foot with a couple of washers. Loose fit everything, then tighten the that foot. I am not talking about the ledge, I am talking about the bottom sliding bar. With inward bars, this is not possible.

Mike
Author:  Wes McMillian [ Fri Aug 07, 2009 6:53 am ]
Post subject:  Re: My Clamping System for the Williams Jig (prototype)
Well, actually it is possible, and without the use of wedges. When you push the sliders in, go just past the point where they contact the edge of the box, then tighten them down. Has the exact same effect as it draws them into the sides of the box. Only difference between the designs is whether you reach under the box to tighten them or not.
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/