Looking good!
Hey Dan, you did a version that is 50mm higher, right? Did that work out without issues? 
3 Likes
No problems, but I actually don’t use the extra height most of the time. I have used it for some thicker projects, but mostly it was because I don’t like the idea of cutting the 200mm.rails that I bought.
2 Likes
Did you upload the files here? I remember someone uploaded something somewhere… I’d love to have 2.2cm more working height, so I’d need 4.4cm more Z-travel, right (assuming my workpiece is a 6cm cutting board)? I could also design a table where I can remove some boards, but I think that might be a lot more hassle in the long run. 
1 Like
I am pretty sure that I did upload the files, and I know other people have remixed them. I don’t remember where exactly…
@jamiek has an adjustable version on Printables
I know mine are around somewhere too.
2 Likes
3 Likes
Thanks guys.
1 Like
So… how square is “square enough”?
I had done the squaring on my LR3 to the point where a 2’ square cut had diagonals closer than the 24x24 piece of plywood from ye olde agent orange Home Despot. Figured that when I was cutting on the table saw, that was always square enough, so I didn’t worry about it.
Putting together a retro arcade machine, and stuff wouldn’t fit. One panel kept popping out pn me.
I guess I had two pieces that were at the wrong angles on the machine, and that was enough.
So I squared it again. Measured diagonals on a 3’ by 5’ rectangle (about as large as I can cut) and adjust… now they are as close as I can measure with a tape. I used several foam boards from the Dollar store, cutting grooves into it, probably doing a number on the bit going through that paper (taped 4 pieces down to the table in the corners of the table.)
Bummer I wasted about 3/4 of a sheet of 5/8" plywood.
I think though that I need to make a better torsion box. If Im going to be this picky about square, maybe it’s time to make sure things are also flat.
3 Likes
I never cared about that too much until I built the vacuum table, since the MDF has to be planed from two sides and it is near impossible if the table isn’t completely flat. This time I am going to plane the base-board first.
1 Like
I noticed you are using 2 separate pieces, 1 for the spoilboard and 1 for the wheels to roll on.
Wouldn’t it be better to use an oversized MDF board to use 1 area so it is actually easier to make things flat?
Most of the time you are planing your spoilboard anyway. If you only have one board you will have a hole, so to speak, and can’t overlap stuff. If you just add a board that is exactly your workarea, you can plane it without having the hole.
Also the pieces for the wheels make the CNC higher, so you could exchange the “normal” spoilboard for a very thin one if you need more height for a project.
1 Like
Yes, because this is a conversion from an LR2, and I was increasing the span to use the previous spoilboard. The LR2 also had 2X4 rails which are longer than the table which let me do some edge milling, and the surface that the LR3 rides on keeps that.
I am going with a somewhat modular spoilboard, that can be rearranged. I find that most projects use the are near the machine origin, so that sees the most wear. On the Primo, the spoilboard is 4 quarter sections all the same size, and I can rearrange them to get the most wear from them before replacement. The LR has strips 12" wide that I can rearrange or flip end for end. Once they have been “used up” I’ll plane them, but probably by running them all through a planer so they continue to follow the base table. I’m thinking though probably not, as it will be easier to just replace them, and since each piece is small, it’s also not one big expense.
1 Like
An interesting thought, however for me, a full sheet of MDF is about the same price as a half sheet, and a half sheet plus the cost of getting to the hardware store would logically knock that argument on the head.
On the other hand, end for end, then flip, then end for end again will give a fairly useful service life I would have thought? (Mine’s been there for more than a year and there’s not a mark on it!! 
)
2 Likes
Not too different for me, but I cut the pieces of spoilboard on the tablesaw, so it still saves me a lot of time and trouble. It makes a partial replacement possible, and then I still have several pieces. For the Primo, all I did was swap a mostly unused piece into the position nearest the origin, which sees the most use, then I did it again later. The Primo spoilboard pieces have a gridwork of 1/4" Tee nuts in them, which are cut into the piece by the Primo itself. This is also much easier to do in sections.
1 Like
Speaking as one with zero (0) CNC experience - I got all excited at the prospect of machining in a tee track or tee-nut grid or even at the present considering a grid of hold-down holes, but a bag of tee nuts is a bit more than a sheet of MDF, so just screwing stuff down and securing it with some scrap makes more sense to me. (It’s OK one day the machine will end up being used!)
This I think is the danger of the internet - what looks like a great idea in someone else’s work flow may not make sense at all in one’s own. I may well go with the most interesting thing to build rather than the most sensible thing to use, because of the combination of ignorance and the joy I get out of building it.
2 Likes
Yeah, because you have to actually use the machine for marks to appear… 
1 Like
I hear you on the T-nuts as I was thinking of doing that on a 24x48" machine that I have (my plans for an MPCNC have now drifted to the new LR3 - maybe this summer??), and then I realized how many of those I would need, and how long it would take to screw them all in (and then undo and redo when I replaced the spoil board (1/2’ MDF). So I too a page out of the internet (thank you BROINWOOD on the YT) and used 1/2" PVC. I cut a grid of holes that fit the PVC very snuggly, then will use scrap wood to wedge in (or maybe some camlock type of hold downs). I cut the PVC into 1.25 in pieces to have them tall enough to stick out, but not too tall if I have thinner material. Plus it is plastic, so if a bit does hit one, NBD!! Just another thought for you. I will probably do the same for the LR3.
1 Like
Oh, and I finally got around to insralling those acrylic YZ plates. I’ve been playing with a different router, and just never got to actually installing these. I can’t see any reason why they ought to make a difference though. I decided to keep the skate wheels instead of the bearing ones though. I’d intended to change them, but figure that fewer changes are easier to troubleshoot than mote changes.
6 Likes
What is it you connected to Z? The bracket?
Wow, that is just WOW! I like acrylic!
1 Like