Independent Vacuum Hold-down tables/devices

[Rusty]

Howdy to all:
Just wondering if anyone out there has built or bought an independent vacuum hold-down/device?
Any comments or suggestions would be greatly appreciated.
I am finding myself wanting to try out the lithopane cutting but don't really have a good way to hold down the thin pieces.
Thanks.
Rusty

[CRFultz]

Hey rusty,
litho's don't have much of a hold down requirement...the cutting force's from the little ball cutter isn't that much.
If you have already roughed it out you can hold it down with double stick tape.
Just make sure you have a good clean surface on both sides.
After i get done cutting I use a heat gun to warm it up then use a putty knife to gently lift it up...it will crack if you apply to much force on lifting.
I would think vaccum is the prefered method but the tape is cheap and works pretty good.
My scrap board is mdf so i lightly sand it with 220 and clean with a tack cloth before I stick it down.

Chuck

[Rusty]

Thanks Chuck:
What thickness & size of tape do you use?
Is there a chart/info available for speeds & feeds for lithos using several different materials, just to use as a starting point?
Do you have a web page.
Talk to you later.
Rusty

[CRFultz]

Thanks Chuck:
What thickness & size of tape do you use?
Is there a chart/info available for speeds & feeds for lithos using several different materials, just to use as a starting point?
Do you have a web page.
Talk to you later.
Rusty

Rusty the tape i started out using and worked very well for me, was just regular 2"
carpet tape....any hardware will have it.
I have also made little corner brackets that are 1/8th thick and used regular wood screws to secure two oppisite corners...just to help the tape stay put...It was more for peace of mind....you don't want to be cutting a litho for 7 and a half hours with 10 mins to go and the tape come loose.

i don't know of a chart for the info you refering to....
i cut my lithos at 25 to 30 ipm with a dewault VS router running apx 18k
I surface the white glacier corian down to about 1/8th and then cut the litho at .08 deep with a .04 ball cutter at 10 percent stepover.
I do alot of prep work on the photo's before I import into PVC...I usually black out the background....
if there are shadows on the subject then I will try and lighten them up.
As with anything you will get out what you put in so careful editing will give better results.
Lithos are a pain in the butt because of the time envolved but they do sell well.
hope this helps ya out...

Chuck

[js11110]

I cut my lithos with a .062 ball mill 10% stepover running 50IPM and 24000 rpm. I've tried using a .040 ball mill with 10% stepover and could not tell any difference in quality from the .062 ball except it took longer to do. As chuck says, spend some time tweaking the image in photoshop or equivilent. The better and clearer you can make the starting image, the better you litho will be.

Jason

[Edelwoodworks]

I us a vacuum hold down table that I purchased on ebay. I clamp it down to by bed and turn on the vacuum. Works well for smaller stuff. Not cheap but it works well. I have added a link.

http://cgi.ebay.com/Vacuum-Table-16-x-2 ... dZViewItem

[Phil]

The Shopbot forum http://www.talkshopbot.com/forum/discus.cgi under Shopbot accessories has several good discussions on vaccuum hold downs.

[Rcnewcomb]

I have a brief write-up on vacuum hold downs we use here:
http://222artisans.blogspot.com/2006/03 ... ns_16.html

[mcurtis]

And another http://www.baycraftdesigns.com/Shopbot.html Scroll down a little.

Maynard