I like the way you explain things so beginners can understand it. with a bit of experience under your belt a threaded wasteboard seems trivial, however it’s one of the first things you need to do when you buy the machine and for most people it’s their first experience with CNC. Props to you.
I’ve had a short corner fence and cam clamps modelled for months and not yet cut them, they’re not too dissimilar from the ones you’ve designed. I like the idea of the cutout in the fence for the probe, I may update mine to incorporate that before I make them
I may have found one of my next upgrades… I’m thinking a sheet of 10mm steel plate with two of these bolted to the top of it, and maybe maybe some HDPE or Bakelite bolted to it as a sacrificial component. Rigidity here I come…
Yeah, I keep looking at that, or a bed made up of extrusions (a neat design for that was just posted to the Unofficial Facebook group and recorded on the wiki at: https://wiki.shapeoko.com/index.php/Workholding#XXL_2 )
That is a nice setup - I’ve looked at extrusions too, but most seem quite lightweight, and if they are heavier grade they cost half of what the machine did! Those look to be pretty well priced though.
I’ll be going to my metal supplier in the next few weeks and will be getting quotes on a replacement base made from 10mm steel plate. I saw a guy on CNCzone forums had good results with bakelite/phenolic as a sacrificial wasteboard that can be milled and tapped. I ordered a small sample from Aliexpresss for testing, I just need to find some in Australia that isn’t crazy expensive.
I’m planning to drop the height of the steel plate a little, and give me the ability to mount a Vise similar to this one
PVC board is another option to consider, I know they have them at most Lowes and Home depot locations. That’s my plan anyway. don’t have to worry about moisture and they are eat to mill.
I’ve considered pvc several times, but cant get past how flexible it is. When I looked into it, this random chart told me to go with MDF again, or move to aluminum.
Maybe check out something like this signage board? It’s thin aluminum sheets with a solid plastic core. Ive used lots of it when in the signage industry, and it is fairly rigid, but you can cut it with normal tooling.
I have my XXL table on a metal frame cart with wheels so i can move it as necessary. My floor is not 100% level due so I am sure the table flexes a little. I have a sheet of plywood on top of the table and the XXL on top of that.
I just surfaced it recently and I already see different heights in different areas of the waste board. I am not sure if this is due to the table flexing or from sag in the XXL frame.
I was thinking about using two sheets of MDF laminated using contact cement (I have used this method for a table saw outfeed table and it seems super rigid) to make the top of my table rigid then remove the feet of of the XXL and place it directly on the laminated MDF surface.
Any thoughts on if this will solve my problem or would the unlevel floor still be an issue for me?
I think the problem with MDF is the absorption of humidity in the material over all of the exposed surface. I wonder if we would have better results if we coated the MDF with something like polyurethane after milling the wasteboard. Humidity would only be absorbed through the nicks and cuts thereby reducing the absorbing area significantly.
I can see how humidity and moisture absorption can be a problem in some environments however my garage is both heated and cooled and stays pretty regular. I have had the table in my shop for two years now and no signs of irregularity in thickness from that. It is more sagging which I believe to be from the weight of the large pieces and insuficient support under the frame.
Very happy with it! I can’t recall exactly what type it was but any 1" marine grade ply would do. It is far more rigid than the mdf was, I can stand on the bed and get less than 0.001"flex.
I’m still looking for steel options, but haven’t really needed to change it so it’s not something I’m pursuing heavily
Not interested in an aluminum bed? Not sure how much you have been on the forum, so I thought I’d let you know that you can get an aluminum bed for your XXL.
This is an awesome option, more rigid than ply and waterproof. it’s on my upgrade list, being in Australia the cost is significantly more so I’m running with ply until I get the funds together - the ply is working well so an HDZ got priority over the ALU board
Yes, the HDZ is absolutely higher on the upgrade list. I had the original SO3 flat plate, and when I upgraded to the smaller, curved plate it was AMAZING how much more rigid the Z-axis became.
When I upgraded to the HDZ it happened again!
To be clear - I really like the SO3 and I understand why design decisions were made, and the original design worked well for me for 3 years, but the HDZ is just something else. @Luke did a great job designing it.
That’s good to hear, mine just turned up. I also had the original Z on a small SO3, then when the XXL came out I bought that and the new Z was a huge improvement!
I have cut a fair bit of aluminium with my 1" ply base and have not had any flex or issues with it, so my drive to change it isn’t that high. I’m still actually looking at 8-10mm mild steel plate then sacrificial hdpe or mdf on top, the reduced thickness combined with the HDZ would allow me to work on taller material
The HDZ is - as of now - the ultimate Z-axis upgrade to the SO3. The Z-Plus is an upgrade to the stock Z-axis, and it is more than enough to handle everything but the most aggressive cutting feeds and speeds without issue.
I went with the HDZ for two reasons. First, the Z-Plus didn’t exist, but second, I saw the rigidity improvement from the original flat plate Z-axis assembly to the curved Z-axis assembly, and I wanted more rigidity, so I went with it.
Now, with the Z-Plus available, I would probably still go with the HDZ because there’s no kill like overkill.
