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Post by travistrue on Feb 5, 2016 2:05:46 GMT
I've just built the entire gantry, but the X and Y sliders don't slide very well on their own. It does take some force to move it. Putting the bushings on were pretty tough, and required a rubber hammer to do the job after running my drill through the holes beforehand using a 7/16" drill bit. Would it be better to have used a 1/2" drill bit?
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Post by all3dprinting on Feb 5, 2016 7:21:54 GMT
I've just built the entire gantry, but the X and Y sliders don't slide very well on their own. It does take some force to move it. Putting the bushings on were pretty tough, and required a rubber hammer to do the job after running my drill through the holes beforehand using a 7/16" drill bit. Would it be better to have used a 1/2" drill bit? Hmm.. a mallet.. when you install the bushings it is important to put the rod through first and then add the bushings while the rod is in position. By doing this you center the rod and bushings. I have found that if you install the bushings one at a time without the rod in place you can actually seat the bushing off center to the next bushing so when you go and install the rod it fits nice in one, then the other bushing needs the rod to flex to get through, this is what causes the additional friction on the rod. The bushings should be a tight fit but need more of a push against a flat surface rather than forcing it in with a mallet. I get both bushings started before pushing the first one in.. all with the rod in while doing it. |
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Post by travistrue on Feb 5, 2016 8:23:44 GMT
Putting the rod in first, then using it as a guide makes way more sense. I was wondering about how to get them in straight, but tried to leave the rods out of it initially as I was afraid of scratching them up. I'll try to cut the bushings out of the printed parts (carefully, as not to damage the bushings!), then reprint the new parts. Thanks for the advice!
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Post by all3dprinting on Feb 6, 2016 1:13:11 GMT
Putting the rod in first, then using it as a guide makes way more sense. I was wondering about how to get them in straight, but tried to leave the rods out of it initially as I was afraid of scratching them up. I'll try to cut the bushings out of the printed parts (carefully, as not to damage the bushings!), then reprint the new parts. Thanks for the advice! I did that at first also, because the x gantry holes were extremely tight. I opened the holes (maybe another .2mm) up in inventor and re-printed it and even then they were still pretty tight, which is was ok since you don't want them to come out when the gantry is moving. I then put the bushings in as described above, it was still pretty snug, and with the x gantry installed it still required me to exert a lot of force to move the gantry... I was unsure if the motors would be able to move the gantry because in comparison to the Y axis, it was significantly more difficult to move. but the motors do move it without issues... |
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Post by pyroviking on Feb 6, 2016 4:24:55 GMT
I am mid-build and experienced the same issues in two different stages. First, I had to dremel out the bearing sleeves on the printed pieces slightly so that the bearing didn't compress on the rod when they were pressed in. Once I had that completed and the X & Y both moved *shockingly* smoothly, I installed them and both gantries required a fair amount of force to slide. I finally determined that my frame was -ever-so-slightly- out of square, and had to spend a considerable amount of time fixing that. Problem solved.
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Post by travistrue on Feb 9, 2016 7:11:51 GMT
I am mid-build and experienced the same issues in two different stages. First, I had to dremel out the bearing sleeves on the printed pieces slightly so that the bearing didn't compress on the rod when they were pressed in. Once I had that completed and the X & Y both moved *shockingly* smoothly, I installed them and both gantries required a fair amount of force to slide. I finally determined that my frame was -ever-so-slightly- out of square, and had to spend a considerable amount of time fixing that. Problem solved. I found this to be a problem for my y-movement. Everything would move fine when towards the front, but it'd be increasingly more difficult to move the gantry the further I pushed it towards the back of the printer. I found that tightening and loosening the side brackets helped as well as checking to see if my frame was as perfectly square as possible. It's still not perfect, but it's better. |
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Post by animoose on Mar 20, 2016 17:28:17 GMT
How have your experiences been now you've had more time to use the printer?
I am just starting to assemble the parts, as far as I can (I have everything except the Robotdigg delivery). I inserted the bushings in the A1 X Gantry piece using the technique suggested above, that is putting bushing on the rod as a guide. I slightly opened the holes for the bushings, mainly to get rid of some elephants foot. One set seems very smooth, the other moves but it slightly stiff. A test I apppied is to hold up the X gantry with the rods vertical and see if they will run under their own weight. One does, the other needs a slight push to get it started.
I'm looking for opinions here: will this be OK, or do I need to try to get the bushings out, ream out the hole, and then try again?
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Post by rock75 on Mar 20, 2016 22:19:28 GMT
How have your experiences been now you've had more time to use the printer? I am just starting to assemble the parts, as far as I can (I have everything except the Robotdigg delivery). I inserted the bushings in the A1 X Gantry piece using the technique suggested above, that is putting bushing on the rod as a guide. I slightly opened the holes for the bushings, mainly to get rid of some elephants foot. One set seems very smooth, the other moves but it slightly stiff. A test I apppied is to hold up the X gantry with the rods vertical and see if they will run under their own weight. One does, the other needs a slight push to get it started. I'm looking for opinions here: will this be OK, or do I need to try to get the bushings out, ream out the hole, and then try again? animoose - Mine were about the same as you are describing (once was probably a bit stiffer even). once everything was together and power applied to the steppers everything worked great! been printing solid for a couple months now and all is good. I recently had to tear things down and replace my A1 X Gantry piece and was surprised when I disconnected the belt at how smooth everything had gotten over time. Robert |
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Post by animoose on Mar 20, 2016 22:35:40 GMT
Thanks for the reply, and that reassures me. I thought it would probably be OK, based on the experiences I had with my Folger 2020 where the Y axes seemed really graunchy when run by hand, but has worked fine.
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Rick
Junior Member
Posts: 75 
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Post by Rick on Mar 21, 2016 7:55:43 GMT
A trick that I used was to take a Craftsmen 8mm socket which had an OD of about 11.3mm. Wrap a single layer of sandpaper around it which made it pretty close to 12mm and use it to dress the holes. After I cleaned up the holes I could press the bearings in quite easily. I put the rod through the A1 and then slid the bearings on from either side. I could press them in about half way with just my fingers on each side. With the rod still in I would press the whole assembly against the table to drive the bearing the rest of the way home.
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Rick
Junior Member
Posts: 75
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Post by Rick on Mar 24, 2016 2:31:39 GMT
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Post by travistrue on Mar 26, 2016 7:13:46 GMT
Btw, I just wanted to point out that my friend used a flat head screwdriver to further insert the bushings so that they were completely pushed into the gantry. This appeared to reduce friction. Haven't been able to test it out myself yet.
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Post by 3DprintedLife on Mar 30, 2016 22:31:31 GMT
Btw, I just wanted to point out that my friend used a flat head screwdriver to further insert the bushings so that they were completely pushed into the gantry. This appeared to reduce friction. Haven't been able to test it out myself yet. This is likely because the openings of the holes for the bearings are usually a bit smaller just due to the solid layers printed here, where the rest of the blocks are printed with infill. You could get a similar effect by adding a chamfer to the opening of each bearing hole by hand with a small knife. |
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