Gator foam hold down

[ccwerks]

I need some help holding down smaller parts. Im cutting Gator foam, the bigger parts on the sheet hold just fine but the letters are moving. I have tried to cut the smaller parts first too maximize my hold down but that is not working either
I have a 15 HP Vac. hold down on a freshly surfaced table. I'm using a .250 cutter. I have good edge quality. any thoughts would be great

[Rob Gunn]

I would adjust the cut depth, leave a small amount (don't cut all the way through). This will leave the part in place, part wont move and will save your table surface. Then just break the part out by hand.

[joe]

Mark,

My good friend Gary Beckwith informed me yesterday he has come across a new product to solve one of his hold down problems. It's a 4'X8' panel made by, I think, Luster Board. That's a foam board and that comes with a surface adhesive made to do just what you're after.

He's cutting hundreds of small aluminum parts and this board holds everything right in place.

Joe Crumley

[ccwerks]

@ Joe, I am being provided the material.
@ Rob The finish product has too have good edge quality and I dont have a good way of releasing the part once I've cut it.

[bobmoore]

I would try a 1/8 straight bit at least for the small letters. Upcut bits are the enemy for vacuum hold down and their benifits are sometimes exaggerated IMHO.
Bob

[garyb]

Mark
Since the material is supplied get yourself some transfer tape
Gary

[knight_toolworks]

I would try a 1/8 straight bit at least for the small letters. Upcut bits are the enemy for vacuum hold down and their benifits are sometimes exaggerated IMHO.
Bob

up or downcut would be better they cut foam better. the 1/8" upcut may be ok if the parts are not too small if they are a downcut. Turn off your dc as it will suck parts up. 18k 2ips is about the max.

[jimgray]

Have you tried using tabs they are a life saver for me

[tuck]

Mark,

My good friend Gary Beckwith informed me yesterday he has come across a new product to solve one of his hold down problems. It's a 4'X8' panel made by, I think, Luster Board. That's a foam board and that comes with a surface adhesive made to do just what you're after.

He's cutting hundreds of small aluminum parts and this board holds everything right in place.

Joe Crumley

I would like to know more about this, please. Gary? Joe? Anybody?

[knight_toolworks]

yes it would beat rolls of double sided tape.

[joe]

I believe Gary told me it was common luster board that comes with a tacky side. It's used for a poster backdrop. I bet all sign supply houses have it. As I remember it comes in several thicknesses. That's the stuff with white foam inside.

Joe Crumley
www.normansign.com

[garyb]

Mark & Steve
it's really nothing new, its just single sided high tac ultraboard 4x8x.125 you can also use PSA sintra
Works great to cut small alum parts without movement and especially without bridges/tabs.
Could you imagine having to clean 4 tabs off 1200 2" parts!
The catch is you may need a release agent such as mineral spirits or acetone to ease release if left on too long, but they come up clean.
For a small size job I use high tac transfer tape (12") a few shots of 3m 90 adhesive to smooth sided 3/16 temp masonite backer. Works just as well.
Gary

[tuck]

Gary - I'm still unclear. I can't find any google results for PSA Sintra. As far as Ultraboard, are you talking about this?: http://www.ultraboard.com/ultramount/

Here's my problem: I have a gig cutting out numerous college athletic logos (pre-printed on 1/2" Ultraboard) and some of them are quite small and with the smaller ones there may be 90 of them on a 4' x 8' sheet. To get a clean cut on these, I often find myself following the router around on the table and holding the parts down with my hand as it finishes the cuts. I don't have a vacuum table and I ain't gonna get one. Tabs are out of the question also as I ain't gonna spend the time to knife cut them suckers out, no sir, as a large order may involve hundreds and hundreds of 'em.

This sticky Ultraboard, is it reusable many times over? Meaning, would I be able to cut at least 2 dozen sheets with the sticky as the suicide board? It seems to me that the chips would stick to the sticky board, causing a lot of clean-up time. No? Tell me, please.

[garyb]

Mark in your case as you are already cutting Ultraboard you would probably want to test the low or med tac. This method is a one use deal as you figured out and a part of the job cost. I'm cutting Aluminum 1200 parts on a 4x8 so is very cost effective. For me its about holding the part and speeding up the application time plus no tabs to clean.

For a more cost effective application you might try a low or med tac transfer tape, such as TransferRite available in widths up to 48", 560U is the low tac number I believe
google sintra psa board and you should locate it, I had my sales rep look up what was available, then physically test to see what worked
Gary

[bleeth]

I haven't tried this with heavier stock like 1/2" ultraboard but when I want to cut fine patterns in laminates or veneer and light metal like nu-metal laminates or Chem-Metal I use a light spray coat of contact cement and bond it to a piece of quarter inch mdf. After cutting the parts peel easily.
The secret is enough to hold but not nearly as much as you would use for permanent bonding. For a full sheet you can flip the mdf and get two sheets of main material out of one sheet of mdf. 1/4" is pretty cheap.

[tuck]

Thanks, Gary. I don't think a sticky board would work for me regardless of tac since it would be a "one use" deal. Some of these orders require dozens of sheets to cut and I have to be cost effective to keep my client happy.

This will be the 2nd year I've had this gig and it really ramps up in football season. Last year I made about $7,000.00 and this coming season looks to be busier, or so they tell me: http://www.stukups.com/ I like the work, everything is light weight and easy to cut, but eventually I'm gonna have to look at a vacuum table system it seems, or continue to babysit the smaller parts as they cut. Another solution may be a different 1/8" bit. I'm currently using an up-spiral as it was the only one I could find that was long enough to punch through the 1/2" Ultraboard with a little room to spare. I'm sure the up-spiral is causing some of my problems with these small light weight parts wanting to lift up off the table (climbing the bit), before the cut is finished. After extensive searching, I finally found 1/8" straight-cut bits that are plenty long enough: http://www.ebay.com/itm/10-CNC-router-wood-double-straight-cutting-bit-1-8-32mm-/170865576063?pt=LH_DefaultDomain_0&hash=item27c861c87f

They are in China. Nobody in the states sells anything like them that I could find. I'm gonna order some soon and hopefully my little problem will be solved. I really, REALLY, don't want to build a vacuum table!

[bill.young]

hey Mark...Centurion Tools in Virginia sells 1/8" two flute straight bits in both 5/8" and 3/4" cut length...we use them often for cutting 1/2" ply.

www.centuriontools.com

[Brady Watson]

Cheap 4mm coroplast + 2 sided 6" wide mounting tape + 4" masking tape + vacuum = Vacuum Film Technique (http://talkshopbot.com/forum/showthread.php?t=11481)

A cheap vacuum motor from Lighthouse + a sheet of Trupan or Ultralight MDF with a grid machined into it 1/4" deep + 2.25" hole in the center of the table for a vacuum port will get you into the vacuum hold down game for less than $175. You OWE it to yourself to kick it up a notch with vacuum hold down as an option in your arsenal. This config is a BradyVac I. Vacuum alone will NOT hold down small parts...so don't be fooled. When parts are held down properly you can cut Gator as fast as your machine will allow. I cut about 1,000 'G' logos for Gitano years back @ 9 IPS in 1/2" Gator using a 4-flute end mill and a BradyVac II. Edge quality was absolutely perfect.

Layup masking tape (tan stuff from 3M works great) on the back of the Gator. Layup the 2-sided mounting tape onto the coroplast (roll each with J-roller to get good adhesion and no bubbles). Laminate them together and J-roll it. Put the layup on the BradyVac Trupan/Ultralight bleeder and turn on the vac. You can cut through the parts and slightly into the coroplast nearly as fast as your tool will let you go. You may have some issues with letter 'i' dots, but other than this, it should AMAZE you with how well it works. I've cut over 500,000 (yes a HALF A MILLION) 2" letters using this technique...It works reliably. If you get tired of messing with narrow width tapes, then you can invest in a laminator...or at least a tape holder to make it easier.

If you are focused on costs, you need to sit down and really think about the bottom line & how much it costs you to sit there biting your fingernails while you babysit small parts. I set my machine working and walk away, knowing that parts are held down and in 4hrs, I'll swap out another sheet. You could probably make more money by doing something else while the machine is cutting unattended...which is really the whole idea behind a ShopBot.

-B

[tuck]

Hey thanks, Bill. But Centurion wants $28.20 for one 1/8" bit (3/4" cutting length), plus shipping and the Chinese want $29.99 for 10 bits plus $5.99 to ship. I think I'll try the Chinese. I always try to buy American but for all we know, the Centurion bits are made in China too.

Edit to say that I do try to buy American, but I can't afford a Harley! Them Japanese make some fine motorcycles!

[tuck]

You OWE it to yourself to kick it up a notch with vacuum hold down as an option in your arsenal.
-B

Well, Brady, since you put it THAT way, lol! If the straight-cut bits don't alleviate my problem, I will give your system and technique every consideration, good sir!

[joe]

This forum hasn't changed a bit. If I came back in ten years, it'd probably be the same.

Nickels and dimes with a vacuum.

[jerry_stanek]

Mark I buy a lot of bits from that seller He ships pretty fast and they are good quality. He will combine shipping also.

[tuck]

This forum hasn't changed a bit. If I came back in ten years, it'd probably be the same.

Nickels and dimes with a vacuum.

Well..., each to his own, Joe. I have managed for over 10 years without a vacuum hold down and I hope to continue to do so. This gig I've been talking about is the first one I've had to give me problems with the smaller parts, but I'm pretty sure the right bit will solve that problem. I've also managed all this time without a zero plate, but that's not to say that they are of no use. Rather, it's to say that I have personally found no use for one with the kind of work I do.

I love your technique of cutting really small parts (letters, whatever), into HDU to a certain depth and then running the piece through a band saw. Absolutely brilliant and soooo simple! But then, you are "the professor"!:)

@ Jerry: That's good to know, brother. I have purchased various products from China before and never had a problem. Takes a little time to get here but if you plan ahead, it's ok. By the way, it's "Mark" and not "Hark". Herald angels don't sing to me, lol!

[jerry_stanek]

Sorry fat fingers on the keyboard.