Hi again folks!
I thought a thread on adhesive workholding would be useful.
I start the ball rolling with this video. Please post your thoughts and experiences on adhesive workholding in this thread.
Cheers Cliff
Hi again folks!
I thought a thread on adhesive workholding would be useful.
I start the ball rolling with this video. Please post your thoughts and experiences on adhesive workholding in this thread.
Cheers Cliff
Another good video Cliff. I've never used tape, just superglued stock to a faced-off baseplate.
That worked for the job and was easy to clean up. Re-run the facing pass on the baseplate to clean off superglue remnants after removing the part. To remove the part, either heat it up (its vital coolant stays on the entire cutting time when using superglue) or give it a tap with a plastic hammer. Superglue is strong but brittle. The tape may soften the blow but you might try giving one of your parts a sideways whack with a wooden or plastic punch. That is very fast but does tend to scatter parts around the chip tray. Wood chisels also work quite well for thin part removal and scraping up adhesive, similar to your wedge.
I've used a lot of different double sided tapes for workholding in the past. I find the Scotch 410M is my favorite tape for workholding. It's thin and adheres well. The residue can be removed either with acetone or Goo Gone/Goof Off. I really like using superglue for metal parts, but I find sometimes it's more convenient to use double-sided tape - especially if I'm machining plastic.
A couple of interesting ideas I've never used include heat-deforming wax such as Mitee-Grip, and UV cured, water soluble adhesive. I'm always on the lookout for workholding ideas, so I'm curious if anyone has experience with these sorts of things.
Thanks for posting this video Cliff. I experimented briefly with cyanoacrylate glue recently and it did not go well. Your video is of great help it will save me some experimenting. I was surprised from the video that the coolant was not a factor. I blamed that on the time I tried it and it failed. Now I'm thinking it was because of old glue.
A method I used in the past was double sided 3M carpet tape. I used it many times to make tapered shims for flap carriages. I had to use 2 thicknesses of tape as the blank was secured to a template so it was not exactly rigid. I was planing aluminum to thickness with a fly cutter. It mostly worked but some times there were failures. I can't remember the part number of the tape it was what we used to hold down carpets in airplanes. Pressing down firmly was the key.
For holding plastic (mostly thin acetal) I've had good results with Nitto (Permacel) P-02/WI07536 P-02 Double Coated Kraft Paper Tape. The Scotch 410m appears to be slightly cheaper. I can't immediately find the website but I've had some success using a moldable thermoplastic to bed parts that are essentially flat rectangles but with a 3d contour on both sides.
as kstraus mentions double side tape. I have used nitto pattern makers taper for 20 years I bet. key to double side tape is to set the tape using clamped pressure for a minute or so. I use c clamps or large bench vise to set the tape adhesive to sub plate's then take to mill or router to machine parts.
masking tape on both subplate and material then super glued together also works good and cleans up easy. no need to clamp and set adhesive. I have parts come lose if I try production speeds when milling parts. So I tend to slow down and adjust woc to 10%
straight epoxy of clean surfaces to a sub plate also works good and parts are released by heating in oven to 200 deg then cleanup.
easy to keep things flat across a larger area.
The model engine builders forum has some crafty, talented people making things like running scale 12 cylinder merlin engines with blowers.
they also show by far some of the best methods and setups for holding material and making parts I have ever seen anywhere, period.
If you want to see a wide variety of work holding those are some people to learn from.
side note:
up cut high speed router bits can pull just about anything lose that is double sided taped down. cutting deep pockets is even worse. From experience I now use only compression cut router bits for all roughing and most finishing. just have to deal with pockets and chip regrind by blowing or sucking them out. Its no joke having a simple material like red oak explode at 16k rpm when it pulls lose under the cutter.
I’ve had very good results using 3M painters masking tape & superglue from Walmart. This works especially well using my high speed spindle on smaller parts although I’ve had good luck using the standard spindle and on larger parts too.
Kapton tape is thinner, less spongey and holds up well to coolant (so far) haven't had any issues with residue being left behind. I have had very good luck with loctite superglue professional 20 gr also found at most hardware / home improvement stores and have kept open bottles for 6 months no problem. I have found tape strips wider than 1" (25 3/8mm) are more difficult to keep smooth when setting in place. YMMV
-Jon