C-Beam Opinions

[Devastator]

First though it seems you replaced some of the dimensional lumber with birch ply. Some questions, What thickness did you start with? Did you take thinner ply and laminate?

I used three layers of 1/2" ply. Which made the gantry really easy because I didn't have to cut the middle channel for lead screw clearance with a router, I just laminated two narrower pieces.

If so, just normal wood glue? What did you use to seal it, ie shellac, poly..? Any sourcing options besides big box stores?

Titebond II then waterbased poly sealer, then textured black spray paint. All from Home Depot.

I have adjustments to make in all axis. My thoughts were to start with the Z, by replacing most of the dimensional wood and rebuilding it. Is that the wrong place to start?

As long as the machine is useable enough to cut new parts for your Z. The best upgrade for the effort comes from replacing the bent aluminum flat bar on the Y bearings with solid aluminum bar stock, or at the very least some steel flat bar. Also, upgrading the aluminum angle bearing mounts to steel angle, and cutting tight fitting dadoes wherever they mount to so that they can't slide around.

I'll use your build thread as much as I can, but as long as you don't mind, I'll be throwing questions like this your way.

Feel free.

[kmartin57]

As long as the machine is useable enough to cut new parts for your Z. The best upgrade for the effort comes from replacing the bent aluminum flat bar on the Y bearings with solid aluminum bar stock, or at the very least some steel flat bar. Also, upgrading the aluminum angle bearing mounts to steel angle, and cutting tight fitting dadoes wherever they mount to so that they can't slide around.

Feel free.

After this question I will move future questions to your build thread.

Yes the machine is usable enough. What are your thoughts on using 3/4" MDF for the Z sides, top and back plate? I only ask because I have it laying around.

I didn't understand what you were trying to say about the outriggers. I did understand about using the aluminum bar stock, but not the parts about steel flat bar or steel angle. I think you meant steel cut at angle would be best, if so thickness? No worries, I'll be tackling the Z issues first. The reason I'm so hung up about the Z is that the top plate is already starting to crack and split, need to get what use out of it while I can.

Can you remember how many times you've had to tear your machine down as you upgraded?

[Devastator]

Can you remember how many times you've had to tear your machine down as you upgraded?

No, and it is still ongoing. I have to upgrade my Z housing in metal or G-10 composite depending on which I get scraps of first. Or possibly laminated aircraft ply since I do have plenty of that.

The bearing carriages is what I was referring to. The plans call for aluminum angle. Steel is better.

[Devastator]

What are your thoughts on using 3/4" MDF for the Z sides, top and back plate?

I don't recommend it. To snug up the bearings takes some tension on the rods and the MDF will flex more than ply. With the flex comes chatter when cutting. The Solsylva design relies on a lot of springy parts. Springy parts make a machine that is prone to chatter. Because the spring tensioned wood parts will eventually relieve, it is prone to needing frequent adjustments. Most of the modifications I've made to my machine involve engineering out the springy parts, but that entails that new parts are made more precisely because they are more rigid and can't be adjusted much (if at all).