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I'm running out of big chunks of aluminum.

I've used wood and aluminum so far for vacuum tooling plates.

I'm looking into various manufacturers of dense urethane tolling board...the type used at pattern houses...but I'm hoping to get a fuller list of potential substitutes.

What have ya'll used in the past?

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Stuart, I've used Richlite before, it makes nice spoil boards.
For proofing large mockups I've used Renshape (which cuts like a dream, no dust) and some stuff from General Plastics and from a small company Golden West that worked well also but doesn't cut as clean as Ren. I would rate them in the order listed.

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Jim Watts
http://jameswattsguitars.com

Thanks Jim, I've been quoting with Renshape and General Plastics but their minimum orders and shipping are killing me.

That Butterboard from Golden West looks intriguing. It won't bother me too much if it's less than ideal machining-wise. I'm sure it'll be fine for vacuum fixtures...as long as it's stress free and stable in the 1.65" thickness. Would you characterize this stuff as easier or harder than wood to machine? I've made fixtures out of maple easily enough.

My first fixture would be a 1.5" x 14" x 19" vacuum plate with a single registration pin in the middle. The pin will slip fit into a bushing which is press fit into the plate. The plate is secured to the table with custom edge clamps on four corners.

You think that Butterboard is stable and dense enough for this application?

Also...Golden West makes a number of formulations. Which one are you referring to if you think it'll work for me?

_________________
I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Stuart, It's been many years since I've done anything with any of these. They all machine pretty easily with the Renshape being the best in my opinion. Richlite can be hard on tools as it's a phenolic tooling board. If I recall I was looking at butterboard for a project but wasn't convinced of the stability of it, but things could of changed.

As a side, I believe a few folks are using or have tried a Richlite product as a substitute for ebony fingerboards.

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Jim Watts
http://jameswattsguitars.com

Stuart, look around for a local distributor for the General Plastics stuff - their price was less than half of what the direct from GP price was.

I have a distributor nearby so if you can't find one locally, let me know and I'm sure we can work something out.. a plate that size shouldn't cost too much to ship via USPS or UPS.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

I've been using the garolite xx paper based phenolic that sounds a lot like the Richlite. I'd like to find something better. I'd like to find something that will hold a threaded insert well over time. McMaster sells generic urethane foam and are listed a distributor for General Plastics at much lower prices than I got from General especially considering how much I need. http://www.mcmaster.com/#standard-ureth ... ts/=p5tcoz

Stuart: How does the cost of these alternatives compare to aluminum ?

I use Aluminum for fixtures that require it. For most vacuum fixtures I use Phenolic (Garolite). It's not as humidity stable as I'd like. Chips pretty easily but is relatively repairable if you F up a tool path. It holds pins and threads well if you're careful. I use 1" on most fixtures. I've brought in some 3/8" and 1/2" to try for pickguard fixtures. No need for 1" there.

It's less than half the cost of Mic6 IIRC. We get it from Synthane Taylor. They've got great pricing on 1/2 sheets and up.

How does foam compare to Garolite? I brought in some foam samples but it seemed like it wouldn't hold threads or pins very well.

Speaking of which, I've switched from doing a vacuum grid to a simple 1/8" deep pocket on neck fixtures. It sure cuts down on programming and machining time.

All told...I'm right about 1/5th the cost of aluminum plate.

I just quoted a 6061 plate at 1.25 x 19.5 x 14.5 at $198...or about 56 cents a cubic inch.

Foam prices depend on density so it's apples to oranges if your not looking carefully at that. Seems like the least density you'd want is 40 - 45 lbs. Renshape 460 is used at a lot of pattern companies...meaning it's amply suitable for vacuum holding fixtures. It's 48 lb. stuff. I was quoted $254 for a 1 x 20 x 60...or 21 cents a cubic inch.

I found a sign company in Spokane that uses a lot of material made by http://precisionboard.com/products/high ... hane-pblt/ . I ordered a 40 lb. board 2 x 20 x 60 for $268....about 11 cent a cubic inch. The shipping was killing me (almost doubling the cost in some cases) because this stuff can't be sent UPS...has to go through a freight company. The sign company gets free shipping on large wholesale orders. They bundled my order onto their next inventory order...so I'm not paying any shipping at all now.

It depends on what your doing with it, but I expect the 40 lb material will be fine. There are few homogeneous materials with the stress-free dimensional stability of these foams. Any time I need to pin anything I can press fit a drill bushing or even make a bunch of hardwood or aluminum bushings.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Btw....I got a nice visit from Saul Koll the other night. Saul was in town on personal business and took the time to drive out to the boonies for an evening. A gentleman.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Works better, too. The only material that should be left under the part is that required to stop it from deforming. I leave a little round island every 2-3 inches.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Thanks for the info on the foam tooling board. I'd like you hear how you like it. Sounds like Andy is already using it ?

I like using these little Carr-Lane pins and sleeves for sub-fixture locating and for my bodies which I bolt down. I've been using the knurled press in brass bushings made for plastics and those eventually ream out their holes in the garolite when they are used too many times. Maybe I should be using a helicoil type.
http://www.carrlane.com/catalog/index.c ... 285356415D

Yes, I'm using the General Plastics stuff and it's fantastic. I've got a few fixtures made from the 40lb stuff and it's absolutely wonderful. Cuts like buttah and apparently it's got some sort of anti static stuff in there to keep the chips from clinging to everything.

The 50lb stuff is a bit harder but I decided to go with the 40lb because it came in a 24" width, the 50 comes in a 20" width.

The thing is that GP will kill you on the shipping charges. Shipping doubled the price but luckily, I found a local distributor. I had to special order the block but they didn't charge any shipping. If there's interest, I could buy the stuff locally and cut it up into smaller pieces to ship to anyone that's interested at a small mark up + shipping. I have large flat boxes on hand.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

I'm outside making a bunch of pin bushings today....out of Ipe.

I'm making them 3/4 of an inch high and an inch in diameter...to hold a 1/4" steel dowel pin with a slip fit. They'll epoxy into the foam tooling plates and then I'll face them off flush to the tooling plate...that ought to hold the pin hole intact forever.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

For 1st generation tooling...which can last amazingly well...we use MDF with two or three applications of Smith & Co. Clear Penetrating Epoxy Sealer. I've done hundreds of parts on some of our vacuum fixtures. Yeah, MDF!

If we need to do many hundreds of a given part, I'll switch to something else, but this is good...and cheap...and it's cheap enough so you can test the whole concept of a fixture and not blow a couple of hundred bucks per fixture design.

I looked up that Smiths. Thanks Rick, I was wondering about a good product for that purpose.

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Ken

As a follow up...

I received two 20" x 60" x 2" 40lb. slabs of urethane tooling board from http://precisionboard.com/products/high ... hane-pblt/

After making several vacuum fixtures I'm very happy with the material. The next time I order, however, I'll probably go ahead and get the highest density they make, which is 75 lb.. The 40 lb. foam is perfectly adequate and stable for vacuum and tooling fixtures, but the higher density will definitely last longer through repeated clampings and use. The price is pretty much linear so, yes, it will be nearly twice the cost but I think it's worth it.

At the very least, I'd want 60 lb. foam.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Stuart,

Mind me asking approximately what this stuff costs? How do you think it compares to UHMW or Garolite?

Thanks,
Kevin

Kevin, refer up nine posts and you'll see I laid the costs out thoroughly.

The urethane foams machine very accurately....like chilled butter. The point of this material is its stability and ease of machining. It's made utterly stress free and can't dull a tool.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Ahh I missed that one. Thanks.

Dimensional stability is the big one. But there are other factors like durability (hardness). We deal in huge quantities over here to the point where sawdust being thrown by the cutter wears out our current fixtures which are engineered panels with MDF skins. When it becomes too great an issue I've tried phenolic and uhmw. They both have big stability issues.

So do you think this stuff can handle some abuse and last a respectable amount of time?

-Kevin

Most certainly.

Coincidentally, I received a sample of their 70lb and 75 lb. tooling board today. On a flat surface there is absolutely no chance of denting the surface with direct downward pressure with your fingernail...for instance. I can BARELY do it with the 40 lb. material. I expect the 40 lb. stuff will last long enough. I have no doubt about the 75 lb. stuff. If you are worried about durability (I am too) I can't imagine you wouldn't absolutely love the denser stuff. If you planned on using pin registration of any kind you'd want to maybe press fit or glue in a bushing. I just made about 60 pin bushings from some Ipe I had. That'll last a while.

Here's some tooling I just made with the 40 lb.

_________________
I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

I dug out my samples last week and ran a file across the edge of some 50 lb foam and compared it to filing the edge of some garolite XX. The garolite is way more resistant to that type of wear. It seems stiffer too but that's only flexing by hand, not a measured test. 70 lb may be the ticket.

Ok thanks guys. Sounds appealing and I will try some. We do pin registration on just about every fixture we have and we use bushings or press-fit bushings so no big deal.

-Kevin

For folks on the other coast, try the following link for Paper stone, a phenolic countertop material. They have 2nds that are really cheap this time of year, and it makes great vac jigs.
http://www.paperstoneproducts.com

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."