Table Design

LowRider CNC Advice
1

Hi,

Any suggestions on advise for a table design - I’m looking to build 2mx1m (ish)
Also, how does the gantry stay parallel and square to the table

Thanks

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Lots of threads on different peoples designs with pics and write-ups. Basically, build it as square and flat as you possibly can. The better you build the table, the better the LR2 will work. It stays parallel and square based on your table build - that’s why getting it as close to perfect as possible is super important. I built mine to be able to cut a full 4’ x8’ sheet. Use the calculator tool located on the main page of the LowRider section to determine your table size. My table is 2900mm x 1420mm and is square to within 0.4mm (measured on the diagonals). I haven’t had a problem with it loosing parallel or square. I have been able to cut out circles over 1000mm in diameter and have them be perfect.

Build it square, build it flat and build it strong. I put cross braces every 16" on the length of the table and 1 long brace down the center.

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3

Hi Jeff,

Thanks for the reply.

I’ve looked around here a bit but there’s nothing glaringly obvious. My problem is I cannot find a design here which shows how all the parts work or fit together. I once found a superb post about a guy who used strut for some op his table I want to copy it in part - I just can’t find it agian!! (which is not unusuall on this site). Not only that, of all the pictures I have found here they just seem to show wheels top and bottom 'squeezing" the table and nothing holding the gantry stable along it’s longitudinal movement. I posted a question here and a guy called Ryan (basilcally) just said it just doesn’t wander off line so there’s no problem.

What I’m unsure about is:-

1)Is the gantry supported by SS tubes along the ‘major’ axis? If yes where are these located.

  1. Are there ‘hidden’ wheels inside the gantry mount to table brackets which are not visible in the pictures

3)Does the table bed need to over hang the frame? If so for what reason or is it beneficial.

 

Further to my original question about design pointers

  1. I have an issue with space, I need a table suitable for a finished size of 6ft x 2ft from a 8 x 2+ sheet - how much wider & longer do I have to allow around the table in practice.

  2. After constructing the table and having the system in use are there any pointers which you guys would’ve done differently position of wooden legs, supports, cable supports, allowances for whatever blah blah etc etc

 

Thanks again (sorry to be a PITA)

 

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A few of us have used unistrut/superstrut for the bearing surface. The lowrider v2 just has wheels on top. Gravity holds it down. If you’re doing anything that picks it up while cutting, you’re doing it wrong. Friction keeps it from sliding sideways. I’ve cut a few large 30-ish inch diameter circles in MDF and they came out perfect. As far as I know, no one has really made plans for a table design. The only real constraint is it needs to be at the max 4 inch thick. Otherwise parts will rub on the bottom. That’s why I used unistrut. My table is a foot thick, I think. Forget really.

[45 new photos · Album by Barry Woods (barry99705)] MPCNC Lowrider Table
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  1. Unclear to what you are referring, the tubes/ rails are only held at the ends.

  2. Nope.

3)Unclear. The wheels need more surface that you need for cutting, see the cut calculator.

3)Cut calculator gives you this info.

4)Make is as small as possible, probably a little taller than you think, as all the action happens at the surface, make the rail axis the shorter one.

There are several and I think most of them are starting to realize doing it that way makes it much harder to level and get right. Trying to make 3 pieces parallel is no easy feat. Just build a flat table to the size the calc gives you.

No squeeze, it literally just sits on top, Contrary to everything you read, there are very little lateral and horizontal forces. Aluminum takes about 1.5kg of force to cut, that can not move the machine. I know it seems nuts but remember this is Version 2, this is the better design. A few guys have wheel guides for peace of mind, I have not needed them.

 

 

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Ah thanks you both I think I’m overthinking things.

 

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Jeb is the guy who really started the unistrut builds (I did one myself for my full sheet LR2). As Ryan said, it’s kinda a pain in the butt to get the struts parallel to the top of the table (although it can be done). If your table is in the 6x2 range, I would use a 3/4” (or thicker) sheet of MDF as the top of the table since it is very flat and strong. Some people have made the entire frame and top of the table out of MDF (and just used 2x4’s for the legs).

My table is built out of 2x4’s with an MDF top. I built the 2x4 frame upside down on a flat concrete pad to get the top of it as flat as possible. I then flipped it over and put the legs on and then the MDF (after I routed out the 4’x8’ space for the MDF to fix a measuring error I had made). Even doing all this, my unistrut rails aren’t completely parallel to the table top, I’m off by about 1.5mm over the 4’ width. I know this because my Z is slightly off when I’m doing cuts and I need to compensate for it in my gcode. One of these days I’m going to remove the unistrut and rehang it using a better jig then I did the first time.

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