3/4" ply strength for mobile base

[Justin Jones RDH]

I looked all through the DIY mobile base thread and got some good ideas. I will be building several bases with heavy duty 4-bolt casters (most likely the ones from woodcraft or something similar)

I want to keep it simple and cut the plywood about 1/2" larger than the respective machine footprint with the caster installed directly under each corner of the machine. I would use metal but I have no welding experience.

Will one sheet of 3/4 be strong enough?
The bases in the works are for the G0690 @507lbs
G0634Z @672lbs

Thanks for your input

[Neil Brooks]

Boy. I'd have to think TWO would be much better (2 @ 3/4" thick).

That's a lot of weight....

[Jonathan Spool]

Ditto on two layers of 3/4 IMHO. I sat my 22/44 OSC sander on one sheet and didn't like the feel, so I went with two sheets and its much more stable. That being said, my Vega and HTC bases are much better yet, but weren't available for some machines.

[Keith Westfall]

I want to keep it simple and cut the plywood about 1/2" larger than the respective machine footprint with the caster installed directly under each corner of the machine.

I would think that if the wheels are 'under' the corners of the machine, then all the weight would be directly transferred straight down to the wheels, and then the thickness of the material would be almost a non issue. If the wheels end up being 'outside' the machine, then yes, material thickness could (would) be an issue, depending on how far 'outside' you end up with the wheels...

[Rod Sheridan]

I made a temporary mobile base for a Hammer B3 out of 3/4" ply with a caster at each corner.

The B3 is heavier than your machines and the temporary base worked fine.

Be sure to use casters that have a mounting plate as opposed to stem type casters.

4 X 1/4" UNC bolts, nuts and washers will help spread the attachment stresses at the plywood.

Regards, Rod.

[Greg Portland]

I would build a torsion box, it will use less plywood and be MUCH stronger than a double stack of 3/4" ply. Screw & glue the box "skin" to the lattice and use solid wood where the castors are going to go (2x4s or some other junk wood). Lag bolt the castors into the solid wood through the lower box skin.

Keep in mind that with DIY solutions you need to keep stability in mind. Adding an extra few inches of height may make a tool more prone to tipping (a larger base will resolve the issue).

[Justin Jones RDH]

Thanks for the tip- I found a few good videos/plans for a torsion box- I will check it out.
Best Regards,
Justin

[Curt Harms]

The other thing you could do would be to bolt an angle iron perimeter to 3/4" plywood. That would avoid the welding issue, just put carriage bolts every few inches.

[Larry Frank]

I have built the bases for my tools using the locking casters from Woodcraft and they have worked well for the heavy tools. I would think that you would want a double layer of plywood and be careful how close to the edge the bolts are for the casters. All of the bases that I have built have been out of 2x4 stock to raise the height of the tools. I am taller than average with a bad back and raising the tools have made a huge difference.

Also, be carefull getting the tool up on a new rolling base. There are a lot of things that could go wrong and you do not want to either hurt yourself or a bright shiny new tool. I waited until HF had a sale on the shop cranes and bought one with nylon straps just for moving tools onto bases or moving them in the shop. It made it a lot easier to get the base under it just right. Maybe you know someone who has one that you could borrow.

[Chris Fournier]

I would think that if the wheels are 'under' the corners of the machine, then all the weight would be directly transferred straight down to the wheels, and then the thickness of the material would be almost a non issue. If the wheels end up being 'outside' the machine, then yes, material thickness could (would) be an issue, depending on how far 'outside' you end up with the wheels...

I would agree with Keith! The problem with your base design and machine weights is this: to have the base move nicely you'll need at least a 4" caster (about 5" overall height plus the plywood thickness) and honestly that's a minimum for smooth rolling. Because your casters have to fit under the machine you'll have significant change in the work surface height. This isn't always bad but...

I know it sounds crazy but learning to weld is a real treat if you're a woodworker. It's not that expensive to get into and a welded HD base for your machines lets you get the casters out from under the machine footprint for a minimal height change and superior stability. The Shop Fox product is pretty scrawny to boot. Once you can weld you won't believe the benefits that you can reap - custom racking for lumber, mobile bases for machines, assembly tables with tons of space for storage, storage shelves and wall fixtures for hanging jigs, fixtures to name a few. Once you can weld, you'll discover how many "friends" you have and that they will part with cash and/or beer for a quick 10 minute job! My welding set up was not cheap but I consider that it has paid for itself in three years use.