Official Luthiers Forum!

I have had a William's jig for some time now and love it. But recently I learned that I have not been using it correctly - thanks Barry!!!

I thought that you jig up the guitar so that everything is level when instead you want to jig up the guitar so that the neck and tail blocks are at 90 degrees to the bench top.

My William's jig was always very stiff and unable to smoothly move up and down. So I took it all apart and filed and reamed until it all moves very smoothly now.

My question is with the 4 bolts that hold the parallelogram together how snug should these be? Right now the router will always fall to the lowest position on it's own and because of it's weight. This seems a little heavy to me and I am concerned that this much downward pressure might leave marks on a soft top where the donut contacts the top.

Should I snug the bolts more so that say the router when extended outward can stay in position or do I want the thing to naturally fall to the lowest position very easily?

Many thanks!

I make them so they a not snug. The rig has to float.

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John Hall
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Thanks John - meaning that under it's own weight, the weight of the Lam trimmer, it will fall to the lowest position on it's own?

I have been using the jig that John from Blues Creek Guitars graciously donated to the lutherie program at the school. This past semester we put approx. 30 guitars through it and it is asking for more! I give it two thumbs up!

That is exactly what I was doing too Filippo. But Barry weighed-in in another thread and indicated that the blocks need to be square to the bench surface and that the parallelogram that the Lam trimmer is attached to will permit the router to move up and down with the irregularities in the height of the guitar top or back.

My slides move like butter but my problem is, perhaps - not sure here, that the parallelogram was too snug and would not let the router go up and down. So now that I have it loosened up I am wondering how loose it should be and concerned about the full weight of the router on a soft top if mine is too loose.

Maybe I should not be concerned - anyway that is my question.

I think the answer to your question would be not to worry. Just don't put any excess downward pressure on the router and make sure the base is clean.

I just cut the first tracks with the Williams jig I made yesterday. It worked great but I did learn something. You must breath. I had to keep telling myself that. Kinda' a scary step. I did notice that you don't want to push too hard into the sides as the bearing tended to leave a bit of a mark.

Cheers,
Danny

I can relate - the first time I used mine I probably did not breath either........

This is exactly what I was looking for Danny - Thank you kindly!!!

I have seen the crease that you speak of when I used to free hand route the channels. Something that helped eliminate about half of the severity of the crease was to place one layer of masking tape around the bearing. Of course the depth of cut will change by the thickness of the tape but that is easy to factor in. I learned the masking tape trick from Uncle Bob, aka Uncle Woody....., aka Zootman....

Thanks again!!!

Yes, the blocks need to be square with the bench. But the body still needs to be as level as possible, side to side. I really think the OP meant that... just wanted to clarify.

Mike

When I built mine, I couldnt find phenolic resin stuff to make the parallelogram, so I used MDF. But knowing that it was soft enough to get the holes all distorted, I used nylon bushings in the holes. It seems to be a good combination, as I can snug up the bolts and yet still get the motion I want.

I would agree that you don't want its motion stiff, you'd like it to float so that you're not forcing it and risking damage to your soft top wood. I also wouldn't worry about leaving any marks on a soft top as you're going to be cleaning up and leveling your binding anyway, and your donut is pretty close to the binding channels.

My concern with my jig is that I don't like the idea of it just hanging there when I'm not using it. So I think I'm going to use a piece of conduit and some conduit clamp things to make a door-bolt like slide to hold the parallelogram portion up. Maybe this is complete overkill.

I also read initially that you need to get the sides of the body completely perpendicular to the table. I had a difficult time getting things perfect, so I just shot for as good as I could get, and it seemed to work out pretty well. The jig certainly took a lot of the learning curve out of the equation.

Darrin

I do the blocks square with the table. After I make sure the neck and end blocks are square with table with machinist square in carriage, I tighten them up. I then check the bouts and waist. I find most time fairly square, but I have done enough I can kind of see it. I make sure it doesn't rock on the supports of the carriage. Once as square just go for it so far, so good.

I have had to make some adjustments on the rig itself making sure it moves without restrictions but not so loose the moves to free. KInd of a feel thing.

I REALLY do not like my body holding jig. Its the same design as the Williams. It never seems adequate or flexible (configuration wise) enough for me. I can make do, but I would like to find a better design.

Maybe we can bounce some ideas around in here to come up with a better design. For me, a better design would include F-style clamping to more securely hold the body. Next, index wheels on threaded rods to raise and lower the clamps. Next, no feet on the clamps to avoid conflict on the base of the jig. Finally, some freeform method of clamp placement (ala peg board for example?)
Perhaps T-slots?


Mike

Hey Hesh

I have one made by Don himself and had the same experience with the stiff parallelogram. Don told me the parallelogram should be stiff enough to where it moves freely, but only under the weight of the router. I'm sure the Man Himself will see the thread soon enough to chime in

James bro - me too - mine is a D.E. Williams original too! He signed mine........

That helps because mine was too stiff to even move under the weight of the router but since I gave it a ream job it has freed up and moves easily now. Before the bolts, tightening and loosening them, would not change a thing. Now they can adjust the ease of movement completely including stopping it from moving.

I think that Stan nailed it with the feel thing. I need to snug these up just enough that the router will still fall under it's own weight but not plummet out of control.

That answers my question - many thanks everyone!

Hesh, thanks for the thanks.

I don't think you should use the tightness of the parallelogram to make up for a heavy router. Tighten the parallelogram just to the point where it starts to bind then back off the nuts a little bit. This way, it will move freely but there will not be a lot of slop. Now if your router is heavy, the only thing to do is to add a counterweight. At one time, I attached a string to my router, that went straight up to the ceiling, over a pulley, and down to a plastic bottle filled with enough water to make the router just the right weight. But you may not need this if your doughnut is large enough not to dent your soundboard.

Barry my friend thanks for the thanks for the thanks.....

The counter weight idea has crossed my mind only I was thinking of mounting it from a pole on top of the top of the jig hood. Problem is, as you already know, the weight also has to make up for the outward travel of the slides if not attached to the ceiling as you did it. I didn't think of the ceiling - excellent idea if I have a problem with it leaving any marks on the surface.

Thanks again!!!!

Could you run a spring from the bottom of the parallelogram at the router end to the top at the other end? This way you could loosen up the joints in the parallelogram and dial in exactly how much pressure the router is exerting on the top by adjusting spring tension or the height of the mounting points.

I recall a lot of old school drafting lamps and such that had some kind of arrangement to allow you to move the lamp around without re-aiming it. e.g. : http://salestores.com/alvincl1.html note the spring going from the top arm to the lower one.

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Great idea Andy bro!!!!

OK, have a question (anyone). Do the feet of your clamps point to the center of the body holder, or do they point out?

Mike

Hesh,
I don't have a Williams jig, I have the Ribbeke type but the body alignment is the same. What I usually do is crouch down and sight the edge of the router bit as it contacts the body around the whole guitar. They should be parallel all the way around. Adjust the holding jig to achieve this.
This usually translates into having the sides and ends at 90 degees to the table top if the router is set up properly.
Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

To the center Mike.

With an articulated fixture like this where the router shaft centerline is constrained to a specific plane, you want both the router shaft centerline and the sides of the guitar body perpendicular to a common base surface. (IE a bench top) to insure that the channel it cuts is square to the sides If the base of the fixture sets on one surface and the guitar body sets on an other then you must make sure that either both surfaces are coplanar or that the router shaft centerline is perpendicular to the surface that the body is squared to.

Filippo my question was concerning the full out weight of the router, PC-310 and the pivoting parts of the William's jig when there was nothing to dampen their downward movement. I don't want to damage a top and some tops, like WRC dent when you look at them.

For Barry to be concerned enough about this to consider a counter weight was exactly what I was asking about.

But I am good-to-go now the bolts are adjusted as Stan suggested. BTW here is a picture of my donut if this helps you any.

Your donut looks great Hesh.
I made the contact lip on mine only 1/8" & it's pretty scary... If you drop off an edge, the router bit can touch the sides. Also it is small enough to do compression damage to a soft top. I'll copy yours before I use the rig again!
Thanks for posting the pic.

Arrrgh!

Daniel my friend my donut was made by Don Williams one of the creators of this jig so I can't take any credit - or blame...... Seriously my jig is beautifully made and I had Don sign mine. I have a bit of a collection of tools and jigs that came from OLFers and I always ask folks to sign stuff for me. These are some of my very most prized things.