I am building a MPCNC with 1" SS tubing with V1 supplied printed parts.
The gantry angle needed some tweaking, but it now okay until I insert the Z-axis tubes. Each tube opens up the angle by a couple degrees so the combination opens it up by a completely unacceptable amount.
I’m unsure of what to do about this. I put the tubing in calipers and it is right at an inch, so I don’t have a case of mis-sized pipes spreading it.
Help appreciated.
Have a second look through the instructions.
All tension bolts should be extremely loose until all 4 tubes are in place at which time it should open up to a pretty solid 90 degrees.
I started out with everything extremely loose and before inserting anything the angle was wide.
It should be able to be adjusted to very close to 90 degrees. There are a few adjustments as laid out in the instructions. It is supposed to spread a bit, that part should not worry you. If you can’t get it run it as is for a bit to break it in and rebuild the center. This is not all that common of an issue these days the 525 easy to adjust, the Burly is easier.
Make sure you have 25.4mm OD not the other one sometimes sold as 1" that is actually bigger. Make sure your Z axis is assembled correctly. I am sorry there is no simple instructions I can give to fix it. Pictures might help to see if you did something wrong but in general it should work.
I checked youtube and the guy just measured it at 90 degrees – which wasn’t that helpful. LOL.
I re-checked the assembly, but I’ll redo it from scratch.
Thanks for the help.
I separated the center piece into its component parts and re-assembled it. I’m unsure where I could have misassembled anything.
The piece is 90 degrees without any tubing added to it, as pictured.
Okay at this point the best thing to do is put it together use it for a few hours and recheck it. I have this in the FAQ’s.
Hi Jim,
Just wonderd if you had any luck with this? I have a very similar issue with a 25mm OD (F) Burly build - everything is square until the Z-axis assembly is pushed in to the middle assembly. The EMT conduit tube I have is 24.9mm measured according to calipers. The parts were printed at home so there’s a possibility of an issue there, but everything seems good from the measurements I have made. I seem to have tried every combination of tension bolt adjustment to resolve, but no luck
Its not out by much - approx 3mm skew on a 600mm x 500mm work area machine. I can trim that out by manually getting everything square before powering up the steppers and using something similar to this https://www.thingiverse.com/thing:1755510) , but would be great if I could find a solution
Just wanted to add that this is an amazing piece of engineering - me and my 14 year-old son have been totally absorbed putting this together and we are now very close to having it all completed. So a massive thanks to Ryan (and the MPCNC community) for making this all possible! Will post some pics of the completed build shortly
Cheers
Alan
Hi Alan,
Thanks for the suggestion!
No, so far the gantry has remained a bit out of square.
We made up a washboard leveling path and ran that a number of times but things are where they were.
I bought some plugs/sockets so I can take things apart without having to re-solder to facilitate the rebuild of the middle assembly, but haven’t done it again.
We put on the end stops that came with the logic board as a way around the problem for the moment. Warning – the pins on the Rambo1.4 board don’t fit that well – the pins are too long and get REALLY close to the bearings. It looks like the switches in the V1 shop are better. I have those on order.
We’re having fun with this, too. Have high hopes for what we can do when I get around to finishing it.
All the best,
Jim
Just bend them out. Super simple, no money required.
Ok jim - good luck and enjoy. Will let you know if we have any breakthroughs here (and that don’t involve the persuasive powers of a heat gun!)
All the best
Alan
This should not be the case, as mentioned in the instructions, nothing should even be attempted to be squared until all 4 tubes are in place. So before the Z is on place it should not be square. In the other thread I have said to keep the XY tension bolts extremely loose. Only slightly snug the Z tension bolts. Use it a bit I have a feeling your parts are just a bit off, they should break in.
Thanks, Ryan.
We used tape to separate. If that hadn’t worked would have bent them. Never really sure how much force to apply to tiny parts – and we were working on it across the holiday and didn’t want to be held up by a broken part so we played it safe.
I was perusing your shop looking for spares of things which would stop me dead in my tracks if they broke and saw that the contact switches with shorter posts (at least that is how it appeared) were there so added them to the basket. Worth the couple bucks. Want a spare motor, too, but you’re out of those at the moment. Happy to buy from your store with all of the support and help you supply.
Thanks Ryan - good information - will take another look
We took the middle assembly, x and y rails off the rollers to check for squareness. With the z rails inserted we noticed on the upper XYZ piece that one of the inner bearings didnt have much pressure on it, regardless of how the tension bolts were adjusted. The bearings on the lower XYZ piece were all fine
So we reprinted that upper part, just a tiny bit bigger (100.6%) - scaled uniformly, which made it just under 0.5 mm wider than the first print between centres of the 2 z-axis holes.
Seems to have done the trick - reassambled and both x and y axes can now be aligned to the stops without having to power up the steppers
Thought I should share, just in case it helps anyone else. Thanks again for the guidance
Happy Days - Onwards!
Alan & Fraser
How does your printer do on calibration prints? 100mm on each axis and a square diagonal check (skew)?
Hi Ryan
Just printed a 50 x 50 x 10mm square and the x and y are both 49.8. I also measured it just as it finished and it was bang-on 50mm - it was still hot (warm) off the press at that point so maybe lost 0.2mm on cooling?
Diagonals are both the same @70.2mm - so its good and square. A bit of trigonometry should have it at 70.43, but I guess the sharp callipers and slightly rounded corners on the print would explain that
A separate tall piece (the clip-over tubes for the rails that I printed to check gantry squareness) come in @99.8 to 99.9 vs 100mm per design, so Z is good too
So looks pretty reasonable - unless those .1/.2mm differences are critical? Amazing really considering we found the printer in a skip!
I quizzed my 14 year old assistant who did most of the original printing and there were ‘some problems’ with getting a couple of the parts out along the way, but short of taking it all to pieces again and measuring everything against the design dimensions in Fusion I think we will claim it as a win with the new XYZ piece and move on to fill the room with sawdust
Thanks again - it really is a fantastic machine
All the best - Alan
Well, that has to be one of the best calibrated printers I have ever heard of. That isn’t the problem.
I am going to adjust my printers now and see if I can get them any where near yours.
Haha - well good to know that those sort of accuracies are well within tolerance for the build. One rainy day we will check over all the other parts to see if there were any misfires along the way
But not today - will stick with what we have for now and get our hands dirty…
