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Y-axis single bearing holders
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Once the Y-axis single bearing holders are tighten down it causes a tight Y-axis. I tried various ways to screw it down to no avail.

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kforrest created this task.Dec 3 2018, 12:18 PM
west added a comment.Dec 3 2018, 12:20 PM

Did you assemble the Y axis on the jig

west added a comment.Dec 3 2018, 12:44 PM

I checked out the Y axis mentioned above. It is very tight despite adjustments. The y bearing holder that were printed for the prototypes all seemed to work fine. @kforrest do you know the hole dia on those bearing holder?
If this becomes an issue, we can change the position of the slot to be downward facing instead of against the bed and that should allow variability. The current design has the hole slightly undersized so the bushing opens the slot more and when fastened, the screws should compress the bushing as to not make it vibrate, but no more than that.

west added a comment.Dec 3 2018, 2:42 PM

There is a branch with the slot in in a different location if we cant figure out that is happening

Okay, I will try my best to solve the issue before replacing the part. Would you like to stage 8 or 16 pieces so they are on stand by for a quick swap?

Steven reassigned this task from Steven to west.Dec 4 2018, 9:45 AM
Steven added a subscriber: Steven.
west added a comment.Dec 4 2018, 10:07 AM

This gcode is the same as I've been using for prototypes except the infill is 10% more

Quick update, I have built 10 Y-beds, so far. I believe I have a cause and solution to the issue. I will confirm this theory during the next 10 builds.

@west I am confirming that it's the shape of the bearing holders causing the Y-axis to resist movement. 3 out of the 12 (25% fail rate) I have built are stiff. I have tried the best I could to try many different ways to allow movement. May I ask the purpose of the slot in the bearing? In my opinion, we do not want give the part a chance to compress at all. Can we try no slot or is this to allow the bushing to be pressed easily?

tutley added a subscriber: tutley.EditedDec 4 2018, 12:35 PM

@kforrest the slot is similar to the taz5. the purpose is to not have to ream bearing holders or have them print the cylinder perfectly. In the past we have seen ~50% fallout on non reamed, tube style bearing holders.

west added a comment.Dec 4 2018, 12:36 PM

If we dont allow compression then there could be vibration introduced. The new slotted part allows more variance in the printed part so they dont have to be exactly the same every time. The old slot was designed to only compress the bushing when fastened down to prevent vibrating, but there is a tighter tolerance with the old version. We will try out the new ones to see how they work

This comment was removed by kforrest.

Okay, understood, I will update the ticket with the results of the new part. Thanks y'all.

kforrest added a comment.EditedDec 5 2018, 11:05 AM

@west Both parts you gave me worked very well, the re-sliced part and the reversed slot.

west added a comment.Dec 6 2018, 4:40 PM

@kent can we get some run in cluster with the g code above to see if they are any better?

kent added a comment.Dec 10 2018, 10:40 AM

Yeah we can do that. To determine which version we ship on the Alphas, we need to decide if the tight axis due to the deformation of the y-bearing is a critical design failure. If it is, we have to change it to the new version for the alpha builds. If it is not, we ship it with the alpha version of that part.

west added a comment.Dec 10 2018, 4:24 PM

The new version doesnt have a way to tension. We could make them tension-able but that would be adding more hardware and I would only want the front or the back to be tension-able (another printed part ). I dont think it would be necessary to have all 4 be tension-able, that seems like overkill to me

@EricNugent can you run the above gcode through cluster

west added a comment.Dec 11 2018, 12:10 PM

This comment was removed by EricNugent.
kent added a comment.EditedJan 9 2019, 10:48 AM

When I checkout the T4807 branch I don't see any differences to master I only see the V1.1 and it has the slot on the bed side but I think the one that ended up working most consistently had the slot on the bottom side. We need to make the changes to the branch that address the issue and then test them before we can close this one. Or if what is in master is working then we just close the ticket.

west added a comment.Jan 9 2019, 10:52 AM

@kent when i checkout T4807 the slot is on the bottom, maybe mater was merged in and overwrote the Y bearing holder

kent added a comment.Jan 9 2019, 12:52 PM

ok looks good, merged into master.

kent closed this task as Resolved.Jan 9 2019, 12:52 PM