I’m midway through assembly and just put the gantry on. It took a whole lot of effort and now that it’s on it barely moves on the tube. It’s slghtly more loose in the center and makes a loud “clang” whenever it crosses roughly the center of the tube. It’s barely movable by hand toward either end. Is there a tutorial on adjusting the bearings correctly?
Hi @icantdrift,
With the gantry assembly slid onto the upper rail, loose the 8 bolts that hold the bearing blocks flanges to the welded carriage. Sometimes the welded carriage can drag on the upper rail tube, causing the drag you are experiencing. The picture below shows 1 of the 8 bolts being loosened.
Before retightening them, go ahead and complete the machine alignment step that is described in this video: *ARCHIVED - OUTDATED BAG NUMBERING SYSTEM* CrossFire Assembly Part 7: Machine Alignment - YouTube. It make sense to do it at this step since you have to loosen those 8 bolts anyway.
If that doesn’t resolve the issue, please send me a PM and we’ll go over some things by phone.
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Mine done the same thing and I followed these steps and it lossened up
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It freed up ok after redoing the alignment a few times. It still makes an odd click when it rolls over the center of the gantry tube that I can’t seem to pinpoint but it doesn’t seem to be hanging up.
I will add that the flanges on the carriage are 1/8” out of square so the bearings ride crooked. I’ll try to run something in the next couple days to see if it causes any problems but my more long term concern is it chewing up the bearings.
After initial construction why access would lock up on jog. After reading a few posts I do lubricated the lead screw and it seem to help somewhat. I could jog at slow speeds but not on fast speed. I loosened up the lead nut screws and that helped a lot more, about to the point where they could float. I checked the lead not bracket and it is dead on 90°. What I did notice was a lot of wobble in the lead screw. I took the entire drive apart and rolled the lead screw noticing that there was quite a bow in it. I carefully straightened it the best I could by hand, but it is far from perfect. All back together now and runs at all speeds but still has a wobble on the lead screw. How much wobble would be normal? My X axis runs perfectly straight and true.
I just received my unit today and got it put together. When running the break in test file, I also noticed my lead screws wobble quite a bit. I ended up loosening the lead screw collets on both ends and re-tightening right away. This seemed to help quite a bit with the wobble but still notice some when running the full length of the X or Y axis. I assume this is normal but also afraid what kind of wear this will have on the bearing or step motor in the long run.
Hope to hear some feedback from Langmuir on this thread.
Given the large length to diameter ratio, it is normal to have runout in the lead screws. Our lead screw manufacturer only guarantees the screws to have no more than 1/8” runout over a 36” distance.
If both of your axes jog normally, then there’s no issue with a little bit of runout. It wont influence performance/accuracy.
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Great! Thanks for the quick and detailed reply. Super excited about testing some cuts tomorrow. Awesome job guys!!
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I have the same issue with both X and Y lead screw bowed with a very visible wobble when running. The gantry will not consistently travel the X and Y axis enough to even complete the break in procedure. I’ll try to lube up the screws and to straighten the lead screw like you did. To me it seems they were possibly bent in the package.
Heres a few things to check:
- Are you able to pull back on the white compression collars of each lead nut to compress the spring? If not, that is the issue and those need to be pulled back.
- Loosen the mounting screws for each lead nut but don’t remove them. Loosen them to the point that the lead screw can float, but still transmit torque. Jog each axes and see if there is any binding.
If step 2 is successful, the check to see if the lead nuts are resting flat against their mounting surfaces. If they do, then jog each carriage until they are adjacent to the lead screw bearing couplers. Then tighten the lead nuts. Be very careful not to deflect the lead screw when tightening. Consider tightening one screw and then jogging to make sure that it still jogs without binding. Then tighten another and do the same, etc.
If one or both lead nuts are not making good contact with their mounting flanges, let me know and I will give you a call.
Looked into this more last night
Compression collars looked fine
I pulled the lead screws and checked them out on my welding table. They were much straighter than they appeared to be wobbling on the system. I decided to pull the adapters/couplers off. Found there were burs on the ends of the lead strews so I cleaned the edges up on belt grinder and reseated them. Then I carefully retightened the lead screws to the mounts 1 screw at a time while testing the system each time. All seems to be good now. I also discovered some of the issue was due to to my computer. The screen protector was coming on and when it did the system went crazy. I extended the screen protect to 20 min and haven’t had an issue.
Now just have to dial in the rest of the system. Made a first cut and torch doesn’t seem square and the water table is leaking from a bad weld…
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Do you have square that you can use to check the squareness of the torch mount. Here’s a thread showing what to look for and how to correct it:Torch square to table adjustments
Sending you a PM about the leaky weld.
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I have a square, just didn’t have time to look into it all last night. I’ll hopefully get it all aligned this weekend.
I am going to keep working on it but here are a few videos of what is happening. I’ve got it so it only stops in one spot at this time.The wide-angle shot is trying to run the break-in program. The others are more details of what is happening.
https://drive.google.com/open?id=1FwBXfxL8hly28cYBI_EmbBiYCUwVdHT9
https://drive.google.com/open?id=1GMXq-Ara8UaDk5vohQde40rRVmTorDsR
I loosened all the screws and got the Y axis to move freely. I jogged it to the spot where it bound up. I then flexed the lead screw, up and down and back and forth, making sure that the lead nut was centered on the gantry flange. Then tightened one screw at a time. It’s now moving good with minimal wobble. Thank you for the tips and tricks!
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