LumberJocks

Oversize CNC Bench Top Help!

  • Advertise with us

« back to Designing Woodworking Projects forum

Forum topic by parks88 posted 09-05-2018 12:30 PM 411 views 0 times favorited 7 replies Add to Favorites Watch
View parks88's profile

parks88

29 posts in 897 days


09-05-2018 12:30 PM

Topic tags/keywords: cnc shapeoko kreg universal bench table top oversize torsion box support design application workbench table top dead flat

I am in the process of assembling my kreg universal workbench for my shapeoko cnc machine and can’t come up with a table top to satisfy me. The reason I am puzzled on the best approach is because the table is a 64”x64” and obviously there are no sheet goods that fit the bill. So after days of being stubborn and trying to figure it out on my own, I give up and reaching out to LJ’s to hear what solution you feel is best? Is it 2 torsion boxes that have a brace down the middle for the sides that aren’t supported by the bench. Or is it best to bite the bullet and buy some aluminum stretchers and space them across the top to support 2 32”x64” sheets of BB? Help save me from going back and forth and just commit to something!


7 replies so far

View John Smith's profile (online now)

John Smith

1873 posts in 579 days


#1 posted 09-07-2018 12:31 PM

Can’t come up with a table top to satisfy me. ~ parks88

can you describe the issue in a little more detail ?
is it for aesthetics or structural reasons that you don’t want
to join two pieces together for the table.

.

.

-- I am a painter. That's what I do. I paint things --

View mahdee's profile

mahdee

4291 posts in 2184 days


#2 posted 09-07-2018 01:29 PM

Can you make a “railing” (like a bed support/box spring) out of 2×4’s and attach your 32”x64” to it?

-- earthartandfoods.com

View parks88's profile

parks88

29 posts in 897 days


#3 posted 09-07-2018 06:02 PM

Can t come up with a table top to satisfy me. ~ parks88

can you describe the issue in a little more detail ?
is it for aesthetics or structural reasons that you don t want
to join two pieces together for the table.

.

.

- John Smith

The top will be built best for structure. Being that I will be attaching the cnc I want to make sure it stays as structurally sound as possible. I have made a few torsion boxes in the past, but never one that is 64”x64” and takes so much material.

View parks88's profile

parks88

29 posts in 897 days


#4 posted 09-07-2018 06:11 PM



Can you make a “railing” (like a bed support/box spring) out of 2×4 s and attach your 32”x64” to it?

- mahdee

Trying to keep it dead flat, and without building a giant torsion box. I guess what I’m asking is what other LJ’s would do in this situation.

View John Smith's profile (online now)

John Smith

1873 posts in 579 days


#5 posted 09-07-2018 07:24 PM

yes, on a CNC bed of that size, dead flat, plumb and level is a must have.
I would not be opposed to building the torsion box of that size with maybe
a 2×6 base frame vs the KREG metal one. I would make the torsion bed 64” x 48”
on the front end and 64” x 16” on the back end. I would probably go the extra step
of two sheets of 1/2” MDF (vs plywood) for the top and alternating the joints accordingly.
after assembly, several coats of your favorite paint or clear coat to “minimize” movement
caused by moisture.

-- I am a painter. That's what I do. I paint things --

View Redoak49's profile

Redoak49

4036 posts in 2405 days


#6 posted 09-07-2018 10:30 PM

+1 on John Smith suggestion. I coat MDF jigs and stuff with shellac, let it soak in, sand and recoat.

View parks88's profile

parks88

29 posts in 897 days


#7 posted 09-10-2018 02:00 AM

Thanks a lot for the recommendations fellas. On Friday I was able to stumble across 4 sheets of 72”x24.x1.5” industrial grade particle board, and here is what I did.

1. Ripped each sheet of particle board to 16” and crosscut to 64”, then attached each board with multiple sets of pocket holes and biscuit joints on both edges of each section piece.
2. Laminated that giant panel with two sheets of 32”x64”x.75” baltic birch, glued and screwed across the PB joints.
3. I flipped the top so that the BB plywood was on bottom and attached .25” hardboard on the top for the final layer with contact cement and screws. I then screwed the frame to the top with 1” screws.

Honestly once I found particle board I was set on just moving forward with it. now that its complete I am very confident that it is super flat, and it’s not lacking in the weight department by any means.

I almost forgot to mention that I reinforced the legs of the table with 2×8’s on two of the sides to help reduce any racking stresses when the machine is running.

I will post some pictures tomorrow when I get a chance.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com