I. Like. It!!!
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Iâve been a bit reluctant to pursue the âfloating railsâ thing because it adds a bit of complexity to levelling since there are three surfaces to get parallel not just one.
However Iâve just realised that it may serve well in keeping the dust away from the wheels.
Is that a reasonable thought?
I think, in this case, because of the CNC method of cutting this for assembly, having the surfaces parallel should not be an issue. I do also think there could be some benefit regarding keeping some dust/chips away from wheels.
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Just two, the middle in this case will always be surfaced since you can cut off the edge.
It could keep stuff away from the bearings, there is a gap, or a step. I have never had an issue with that though. This last round of HDPE was the most messy thing I have cut, a few chips get near the bearings but for the most part my Z was not critical to that degree, if it was I would either put a brush there or a longer tape skirt on the dust shoe. I know this seems to bother a lot of people, I just donât see it as a common issue. Worst case is cutting right next to the bearings. At that point what is the biggest chip your machine throws and how far off could it possibly move the Z? Big stuff gets pushed out of the way. At the other end there is some trig involved but basically zero effect of a chip under the wheels.
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I made that design that way for different thickness materials, and hopefully slide the vac hose on the rails side gap.
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I would think the twist of the table (making rails not parallel) would be the only degree of freedom, and there would need to be a procedure to true the table in any case.
Parhaps shim the feet until the rails are parallel. Use the cnc to surface the top of the ribs. Attach top and bottom skins to make the table super stiff.
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That table is beautiful! I love how you used the slot fittings, kinda figured you would, being a CNC cut CNC table, but wow, thatâs impressive! Iâd get on board funding that research & development! haha
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Hopefully when I get back from Rmrrf and the dust settles a bit, that is on my short list.
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Good luck with that, and stay safe out there!
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Might complicate things but the middle board if you cut the web structure platform into the wood 1/3. Would make it really grab and tie it all together.
As for the sides serrated joints that mounted to the box would be decent.
Or Pell able shims is a thing to level stuff after.
I really like the idea of this and i donât have the knowledge yet to pull off something similar lol
Also have fun at the convention
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Could also pocket out the places where everything fits, and make it a truly idiot proof build. Plus it would act as a channel for glue to really stiffen things up. I was kinda thinking this a while back when I was thinking of how I wanted to redesign my table once I started the LR2-LR3 upgrade, and my arcade machines came to mind, how the blocking had pockets for lining things up perfectly, could utilize that somehow here I think. Or⌠Just tabs in the top and bottom sheets. shrugs Or maybe all of that would complicate things for people whoâs cutting with less than perfectly levelled tables. Not sure. Now all plans to redesign my table are dead, because what Ryan showed here was exactly what Iâm wanting! haha
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I will throw my 2c in here.
I know that I am building a super over complicated, multi use table, due to my circumstances and shop space.
But before I decided on that i was going to just buy two internal doors glue them together and then add an MDF spoil board. So the X would be around 2300 and Y would only be about 800mm wide. I saw the suggestion here and loved the simplicity of the idea. Internal doors here in AUS are about $74 for a 2340x820 door which for a new CNC is plenty big enough to start using your CNC.
Sure we can argue, like me, that I am going to build it 1400 wide so I can can a 1200mm wide sheet etc, but at the same time the door still makes a great base to build from.
I would be interested to see the stats on what is the average size the user base is building for the LR3.
So after reading this, could you do both? Use a door to get it cutting, cut the plates and then the parts for you table of choice and use the door as the base of the table taking advantage of the existing torsion box structure, say just gluing the the new parts directly to the door and then a thin bit of something to the top of the structure to create that second torsion box and finally a spoil board?
This would give you the best of both worlds.
(ok, we can argue over your chosen size of table for your needs, but really this whole journey is about building up slowly to what you want to do, so wouldnât this be a good way to introduce the concepts of tables, flatness and size? )
I will say with how complicated I have made my build, I could have it much smaller and built a second one later to cut down those 2440x1220 sheets, in the mean time I would have a much more useable unit.
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Iâm building my LR3 to the same specs as my LR2. I made sure when I did the calculator, I made the cutable area 49"x97" (1244.6 x 2463.8) capable of cutting a full sheet of MDF (here in the US MDF is an inch longer in both directions than traditional ply) and itâs worked out well. I think I have built the most common size from what Iâve read other people post in the past. Hmm⌠The door idea, thatâs actually not a horrible idea. Gives a universal starting point for everyone else. Kinda how we put the temp struts on, so we can cut the actual struts. You might have a good idea here to ponder on!
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Yeah, I bought the LR3 last night and have been staying up trying to figure out the best way to make a table for it. I need to go over the documentation some more but it would be nice for a first timer like me to just be told what to build and how to do it
Hey have you done a search here for: âParametric-tableâ
There are both cuttable DXFâs plans available as well as fusion 360 models that are parametric driven and which can be edited to customize the size.
Also in the search results, I have a full length video showing how to cut and build a torsion box table for full-size Lowrider v3.
And Ryanâs fusion 360 file shows a suggested way to use 2x4âs to do legs, and bracing of the legs, and including a shelf underneath the LowRider, which can hold, for example, shop vac for dust control, etc.
I have now 
but it has taken a little bit of digging. I am a little overwhelmed at this step as I have very little wood working under my belt so seeing these plans for the tables, Iâm like yâall already have a table to begin with to start using the cnc to build this other table so where do I even start? This could just be a me problem though.
Not a you problem at all, I think CNC routers get a lot more people into woodwork than people who consider themselves woodworkers get into CNC.
Here are my conclusions from discussing this with my Dad who is in the process of building one.
Fundamentally, the key thing Iâd say is donât overthink it too much, or try to make it perfect first off. If youâre worried about things, try to consider the forces involved and take it back to a âreal worldâ scenario. A couple of weekends ago I tried to make some cuts using my router that I would have made using the MPCNC. It took a decent amount of force to do them by hand, but nothing superhuman. Ultimately, the table needs to support the work and be sturdy enough to have probably 5-10kg (10-20lbs) of force hauled on it by the Y belts.
Plenty of people get started with a cheap door, from the looks. If youâre ok with making a smaller machine than the full 1220mm/4â wide then you could start with just a single full sized sheet of something on the floor or an existing table and probably be completely fine.
The flatness that you need is relative to what kind of work youâre doing. If youâre doing through-cuts then every mm out of flat is a mm you need to âovercutâ to be sure youâve cut through. Even 2-3mm out of flat probably isnât that bad. This router is also intended for sheet goods, which usually means that the workpiece will conform to the table, to a degree, so surfacing the table with the router should yield pretty good results, even if the final surface isnât actually âflatâ as such. (Edit: Forgot to mention that the other side of it is if youâre engraving, especially across large surfaces then the Z height variation will need to be minimal if you want consistent line widths, so potentially well below 0.5mm of flatness over the area youâll be working on. On the other hand, if youâre only working over a smaller surface, then youâre setting the Z height for each job, so as long as itâs flat enough over the area youâre using then no issues there).
Making a âtorsion boxâ table really isnât that bad, as long as you can make long, straight cuts with âokâ accuracy. I built mine with a track-saw, but you could just as easily build it with a circular saw and a straight edge. Check out the Ron Paulk Smart Bench (he has a bunch of videos on Youtube) for some inspiration. Heâs using a track-saw and router with a pattern bit, but you can equally get away with a circular saw, straight edge or another sheet with a manufacturerâs edge still left on it and a jig saw.
If you have a local supplier that will cut to size then even better. The critical thing with a torsion box is getting the âwallsâ the same constant height, which means cutting the long lengths straight and parallel. Getting a sheet cut into âstripsâ that are the same width would be quick and easy on a big cabinet saw and then everything else is almost impossible to screw up, even if done with a hand saw. Thatâs where Iâd be investing in.
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The concept of bootstrapping a CNC cut table without having a table was mentioned in the video (part 2) and discussed in one or more of the threads. You can lay sheets of material on a floor, hopefully flat, and create a temporary cutting area. Even if not perfectly flat, you can still use it to cut the parts!
Here is an example of a simple floor based âsledâ, as @azab2c calls it, to cut the strut plates (and in your case, the table): Huge DIY CNC $900, V1E LowRider3, FREE design, normally $10,000+ - YouTube.
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That sled can certainly work, but it is far more involved that what has worked in the threads related to bootstrapping a CNC-cut table, which was laying one or more full sheets on the floor, with strips of sheets along side, and cutting. I did not personally do the bootstrapping of this type, but I saw report of success. I assume âtabsâ or pocket screws (or glue or maybe pipe clamps or such) were used to temporarily tie side strip stacks to main sheet stack. The details could certainly be worked out. I cannot remember the name of the member who reported doing it.