Trying this again, nothing posted when I clicked submit last time... some sort of cloudflare error.(if you are familiar with Adam Sandler - At a Medium Pace, seriously NSFW don't click this with kids around, I hope the song is stuck in your head now).
I previously built an MPCNC without any issues. However, I didn’t have any time then (still don’t really, I have to take vacation days to work on these things like today) and got cheap/lazy with my build. I used “2x4 basics” workbench table legs, 2x4s as straight and acclimated as they could be, and MDF. The end product has served me well over the last two and one half years. I mostly use the MPCNC for laser work (10w+ endurance laser) but just successfully dusted off the old 500w cheap Chinese spindle and easily made my Y- and 611-plates for the lowrider v2. I should mention that I did all that after I moved a few hundred miles and had to reassemble the entire frame for the MPCNC - it just picked right up where it left off.
I have mocked up the lowrider v2 torsion box and table build in Fusion360 (images to follow). It will be 56" in X and 120" in Y, I calculated the height so that is will also serve as an outfeed table for my table saw.
I am going to rip 0.25" from either side of seasoned 2x4’s to make a nice consistently flat 3" member for most of the frame and webs (a 2x6 cut down to 5" will serve as a back stop). I was thinking of using a planer on the dimensionally longer sides but the DWE7491RS has a DOC of 3-1/8" - any thoughts about facing 2x4s with a table saw?
I have a rather large level surface to assemble all of this on, but plan on using cabinet making corner clamps/T-clamps to help me keep my angles true (wolfcraft).
The legs for the table will be made from 4x4 posts (not treated), rabbets/shoulders to set the torsion box/rails onto the legs. Structural screws as fasteners all around.
Skins will be 1/2" MDO or MDF - I am having a debate about the price points for each (more than double for MDO) and the advantages MDO has over MDF - I pondered ultralight MDF but cannot seem to find a local source where I can physically go and pick my own pieces.
This is the completed table with the skins, pretty self explanatory. When I first went through and designed everything (not using the parametric functions of fusion360 like an idiot) I realized I did not make the table long enough to accommodate for the actual cutting area once the x-carriage is moved to the furthest rearward position. Rather than start over, I just made some adjustments and I am happy with the result - now I can have a desk when not using the lowrider to cut full sheets.
[attachment file=“completed table LAO.png”]
[attachment file=“completed table RPO.png”]
This is the completed table without the skins. There will probably be some sag/deflection without posts towards the center - I was thinking of spanning these from the bottom skin of the torsion box to the skin I will be laying across the slats on the base frame, although I could always cut that base skin/bottom shelf on the router to perfectly fit around center legs that will reach to the floor.
[attachment file=“completed table no skin LAO-1.png”]
[attachment file=“completed table no skin RPO.png”]
These are the table legs, see the rabbets I plan for the legs along with the dados for the slats. The table legs will fit with friction (and screws) between the torsion box and the outside rails that the lowrider will glide along.
I will edit this post once I take photos of the assembled plates. Here they are:
I wired and belted up the x-carriage and it moves like a dream! 1270mm of travel. Go figure, no issues with tension using zip ties, works perfectly just as it does on my MPCNC.
Any thoughts or comments are welcome!
[rant] I was scheduled to get my stainless tubing delivered yesterday by UPS. Check the tracking and it says it was delivered?! I was home at the time the drive attested it was left on the doorstep - not a single security camera picked him up. No notifications from the doorbell. So I call UPS last night and file a claim. As I am writing this up my neighbor rings the doorbell, two separate packages in hand (my tubing and something my wife ordered). Our house numbers are not close, our names are not close, the neighbor has lived there for 30 years and we just moved here 3 months ago. This is the third time the UPS driver has delivered something to the wrong house since I moved out here. I have rather large reflective numbers on both sides of the mailbox (MPCNC made?) that someone with 20-200 vision could easily see 20 feet away if driving the speed limit. [/rant] Very pleased I have these in hand for this weekend!