The metal rails per the table design are 114" (289.56cm). I left mine at 120" (304.8cm) for a little vertical milling area on the table when completed. As seen above.
I didn’t understand the instruction “lay some long strips beside the topmost MDF sheet ( to serve as riding plates for the LR3 to ride on).” This made itself apparent when I went to cut the full-length struts for the table and did not have the reach in the Y direction.
You’re going to need a set of LowRider 3 CNC - table extenders as listed in the revised build instructions. Post on X tube/gentry length revised instructions Also Doug’s build is flipped so don’t get too hung up on the file names, if you print a full set they’ll work. You can look at them in your slicer and see where each one gos.
And some of these
LowRider 3 CNC - Rail Blocks for Unistrut M5 x 8mm Machine Screws
To drill and tap the Unistrut for M5 screws, you’ll need an M5 tap and a 19gauge bit. The closest standard size bit is 5/32" and works fine.
Measure your cutting tool my 1/4" (6.35mm) bit was 6.31
Cut slot test pieces!
Cut some test slot pieces to test your strut to spar fit up. I adjusted mine so it was a tight press fit. Some needed tapping with a small mallet to slide together.
This step seemed a little daunting. I spent more time trying to get around this than it actually took to do it.
8) Adjusting the slot size in fusion 360.
Under Solid, Modify, change parameters, select Thickness Plywood_Material and change to your plywood’s thickness. With that changed I still needed a little more snugness. So I edited Slot Width. The expression for that is ( Allowance_Torsion_Slots * 2 ) + Thickness_Plywood_Material. So I just add -.02in to the end. ( Allowance_Torsion_Slots * 2 ) + Thickness_Plywood_Material - 0.02 in
Then per Doug’s instructions:
Then in each component, right-click on the sketch identified as “for DXF” in the name, and choose “Save as DXF” to export it. The only two components affected by this are the “X Ribs” and “Main Y Spars” (which together make the main body of the torsion box)
Use the new DXF files to make notch test pieces. When satisfied cut your struts and spars.
Wow, thank you for the great job in pulling together all these bits of helpful documentation! Sometimes when you’ve been around the block a few times, you forget little details that you ought to mention that folks new to this would not know!
Thanks for going through this. Was about to start cutting this past weekend, but realized I needed more Y-axis for the full sheet as well.
I’m curious about the vertical milling area you mentioned. Is that going to be like a drop table off the end? What are those screws and handles in your image at the end of the table?
EDIT:
I think I see, like a vertical milling machine, you keep the router stationary and move the piece using those screws there. Cool! I’m planning on a drop table off the end for more Z access
I was just on a video call with @steved in the V1E Discord, and he showed me that setup. My understanding is that it will work as a drop table, in that some taller item to be CNC engraved/pocketed or whatever, could be clamped into the end-vice he’s created, and then the LowRider could reach it because his metal struts are left longer on purpose.
I think the screws he used are these, either the 9" or the 12" — and I’m not sure which:
12"
9"
I think it was the 12", and the price on those has been fluctuating. He got them for somewhere around $20 or $21 I think, and according to “Honey app” price history, they were that cheap a couple of times in recent weeks. Who knows, they could drop the price again at any time. The Honey app price-drop watch feature can alert you if they do lower the price.
I installed the new gantry (1435mm) and its about 10mm to long on the non-rail side. The rail side lines up perfect. Doug was gracious enough to hop on Discord and we did a walk around the table. We concluded the the table cut files are correct. The documentation might need updating/clarification as to the default gantry width. I’m sure Doug will post the results when he finishes looking into it.
Ok we think we got this straightened out. I will edit the original post to reflect this.
The proposed change to the builds instructions is:
Note: The table cuts and build remain the same for all of the following X-gantry lengths.
TUBE LENGTH for X-gantry – FOR TABLES WITH METAL STRUT SIDES:
Note: Testing has not been performed for use with Optional Urethane Wheels.
If you already have an X-gantry size other than listed, cut your strut plates to your choice of size as listed below. You would then need to buy new EMT/tubing and cut to match your choice.
A. 1425mm (56.102362″) X-gantry length, based on using LR3: non-adjustable table extenders (wood or printed)
B. 1435mm (56.49606″) X-gantry length, based on using LR3: HIDE/PROTECT non-rail side Y AXIS BELTS inside metal strut. This option brings the non-rail side Y Bearing Wheel Bracket closer to the edge of the metal strut to aid in the installation of the mod.
C. 1400mm (55.11811″) X-gantry length, based on using LR3: table extenders (wood, printed, or adjustable).
This option works by not installing the two MDF 1/2" wide spacers along the metal strut as per plans. This allows builders who are building this table and already have a full standard LR3 full sheet build to quickly move to the new table. To use the full area of the design, installing option A or B and the two 1/2" spacers can be done at a later time.
To be clear. X-axis Gantry tube length of 1425 if NOT planning on using the “Hide Y-axis belts inside strut” is what works best for this table? (No belt bending outward as seen in your photo if 1425mm is used)
OK, so @steved mentioned above about the new remix of the “table extenders” that has 10mm worth of adjustability for dialing in the exact right location on the long belt on the non-rail side. That download is here: Printables
Note:
If you already downloaded it, please re-download, as just now a revised version was uploaded, to fix an issue that @steved caught, and I fixed. Change log updated:
Change log:
Tuesday, September 19, 2023 - re-uploaded corrected versions of the new “Front LEFT” and “Rear LEFT” extenders, as they were wrong. Kudos to Steve (@steved on V1E forum) for the heads-up and collaboration on fix. I confirmed the issue and fixed it.
The names of the files for the table extenders downloaded from printables may not be right (front back left right). If you print a full set you will be fine for a “standard LR3 build”. You can verify the files in a slicer and see where each one will fit. Like I said I just printed a set and they were good.
I’ve updated my first post with this info as well as here.
