I ran my first print today, or at least started it. But quickly saw that I have an issue with the tension on the drive belts. I have them fairly slack and as a result the head and bed move, in one direction OK, but in the reverse direction they judder. After about 90 mins it seemed they had jumped on the pulleys as it was laying plastic in the same shape but shifted sideways!!!
But how tight should the belts be? Originally I had them tighter and it seemed to make the head and bed stiff to move. Any ideas please?
Also after about half an hour the paper tape on the bed started lifting up!!!
I first thought this was a temporary cover, as it has been put on with wrinkles and bubbles in it!
Then when I realised that this was the base the plastic was to go on I tried to smooth it out, but obviously without much success. I assume it was the bed heating made the tape lift up.
So what should I use there instead of what they supplied?
Any help or suggestions would be welcome
Nigel
The belts should be tightened enough so they make a low strum sound when plucked.
The carriage will be stiff to move if you haven’t disabled the stepper motors.
For the bed, I’d buy some build plates. These are self adhesive thin plastic, textured sheets.
Once you use these, you’ll never go back to tape.
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I appreciate that advice.
I found the bed stiff to move when I assembled it and first installed it’s belt. So I then slackened it off.
Clearly as the head drive belt jumped it was too slack, but I appreciate your guidance on how tight it should be.
I notice there is some noticeable stepping even in the other directions, but I guess as they are stepper motors there is bound to be some. In the build when both x and y were not jerking it did lay a pretty straight line.
I will look on Amazon for ‘build plates’ and see what I can find.
Other than the two problems the build was looking pretty good.
Thanks again
Nigel
You can find on thingiverse some models to help you with the belts
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Thanks for that.
It’s not so much difficulty in tensioning the belts as to know how much to tension them.
But I will keep these designs in mind.
Nigel
One thing I have noticed is that one side of the head belt drags by the wire bundle coming from the extruder.
The wire bundle is in a smooth sheath OK, but it still looks odd the belt dragging by it and even bending around it somewhat.
I don’t think it is making much if any difference. Maybe put it down to a design issue.
Nigel
I’ve ordered a set of BuildTak 3D Printing Build Surface, 8" x 8" (BT08X08WT-3PK).
Seemed to be little choice of makes on Amazon and so I chose based on size and price.
Nigel
I’ve now sorted (I think) the belt tension problem and the X and Y move smoothly.
Tho’ I am puzzled when initializing in the X axis, the nozzle carrier hammers the end stop repeatedly for about 3-4 seconds!
I would have thought the micro-switch would detect the first contact and stop the repeated movement.
I have used the BuildTak 3D Printing Build Surface, but the small test piece I have tried is now stuck so firmly I don’t think it will come off!! I read (on BuildTak) that it is due to the nozzle distance too small. But how can that effect the adhesion?
gikam
June 20, 2017, 9:59am
9
I removed the original tape from the beginning. U can use hair spray, paper glue stick, ABS ‘juice’ (dissolved in acetone), or special adhesion spray “DIMAFIX”
That’s interesting and a cheaper option than the BuildTak sheets.
I did find with a set of oil painters spatulas the thin blades were effective at releasing the builds from the print surface.
I am pursuing the suggestion that the X axis movement shouldn’t repeatedly hammer the end stop when initialising.
I believe the micro switch is contacting the end stop so maybe it is faulty or the wiring is.
gikam
June 20, 2017, 10:53am
11
push the switch with your finger while homing.
replace the switch
Thanks, but I do think the switch is physically operating as it contacts the end stop and I do hear the switch ‘click’ when I press it. So I think either it is faulty or the wiring is not correct.
Nigel
Sorted.
The switch was hitting the right piece of the frame but it wasn’t being pushed enough to ‘click’. I think the switch is faulty.
But I have placed a piece of card there which is enough make the switch click and the intialising doesn’t hammer against the end stop anymore.
Thanks for your help and suggestions.
