HobbyCNC Router - Holddown question

[buckey29]

I'm brand new to this, just got my CNC router from MikeBeck.org which is based on the HobbyCNC plans.

My question is regarding the top for this machine. Its a torsion box design with a vacuum hold down system. However, I'm afraid that the vacuum system won't hold well with my shop vac as the source for vacuum.

What I thought of doing was replacing the top with HDPE and using threaded inserts to create an array of threaded holes so I can have a flexible hold-down system.

I guess first, how well would you expect the vacuum system to hold? (cutting things like 1/8" birch plywood, 3/8" Acrylic, if that matters).

Second, if I replace the top, what designs would you suggest for a flexible holddown system?

Thanks!

[buckey29]

Thanks for all of your responses! LOL


I've decided to remake the top of the router with Phenolic Faced birch plywood. A 3/4" piece on the bottom with a 1/2" piece on top of that -- with 3 "T" slots going across the X axis.



It should provide a good, flat surface and the T slots will give me a flexible hold down system.

[Crx_dude]

Hello,

I have been searching too for a flexible system.
I came up with this:

It is a metal plate with some fast snappers on it. (don't know the name)
The metal plate is fixed on the machine with 2 bolts.
Slide a piece on the table, snap snap, your ready to go ;-)
Works fast and reliable.

Sorry for the crapy pictures ;-)

[dz1]

i tried both tslots and an array of those threaded inserts

still want a vac table but I have ended up using the simplest and most
flexible thing yet.

3/4" sacrificial board screwed down on top of the real table

then you just woodscrew your stock down to it.

biggest advantage is that literally nothing sticks up above the work piece
so you dont have to worry about running into anything, lets you work with
less stock sticking over the edge to make it to the clamps, and the screws can literally be anywhere , no need to worry about trying to find a long enough clamp or a hole close enough.