I am struggling to complete the last step to calibrate my K8200: the home position (0, 0, 0) is successfully set and the printer “finds its home” without issues. There are no issues with moving the X or Z AXIS as expected. When I am using the manual controls, however, to move the Y AXIS by 20 cm forward it overruns and the carriage bumps against the frame.
The Printer Shape in Repetier Host V0.84 is definitely set correctly and Y Max and Print Area are limited to 200 mm. The problem rather seems to be that the Y AXIS moves 11 mm when it should move only 10 mm, i.e. when I use manual controls to bring the HEATED BED forward by 10 cm it would move by 11 cm. As indicated above the other AXIS seem to operate relatively precisely.
I already switched wiring and used the X motor driver and controls to move the Y MOTOR, but the issue remained the same (so I think it can’t be a configuration topic?).
Any ideas how to solve this would be highly appreciated.
In Repetier check if the EEPROM settings are correct for the Y axis. Number of steps is 64.5 for both X and Y axis (if I remember well as I don’t have the printer at hand)
My EEProm configuration showed nil / zero for all settings. Trying to set them to default values in accordance with the following post had no effect on my issue - the Y AXIS would still overrun.
In addition, the Z AXIS MOTOR did not spin properly anymore. After restarting Repetier-Host all values were back to zero anyway and after restoring the factory settings the Z AXIS MOTOR operates properly again.
Unfortunately, throughout all steps and settings my initial problem remained. Any other ideas?
My EEProm configuration showed nil / zero for all settings. Trying to set them to default values in accordance with the following post had no effect on my issue - the Y AXIS would still overrun.
In addition, the Z AXIS MOTOR did not spin properly anymore. After restarting Repetier-Host all values were back to zero anyway and after restoring the factory settings the Z AXIS MOTOR operates properly again.
Unfortunately, throughout all steps and settings my initial problem remained. Any other ideas?
Regards,
Peter[/quote]
Make sure the following lines are uncommented in configuration_h:
#define EEPROM_SETTINGS
#define EEPROM_CHITCHAT
Otherwise the eeprom settings in repetier don’t work.
Good news: Thanks to ichbinsnur’s advice my EEPROM settings show in Retepier now.
Bad news: All settings seem to be set to correct default values (i.e. 64.25 steps/mm for Y AXIS).
Is the solution to tweak the numbers until 200mm in Repetier really reflect 200mm in movement of the HEATED BED? Seems rather dodgy to me and difficult to get precise results…
[quote=“peter23”]Is the solution to tweak the numbers until 200mm in Repetier really reflect 200mm in movement of the HEATED BED? Seems rather dodgy to me and difficult to get precise results…[/quote]Certainly not. The values are correct for the pulleys and belts provided with the printer. Post pictures of your Y axis. It hopefully could give us an idea…
I uploaded some pictures and videos (both showing X AXIS working correctly and Y AXIS not) to my dropbox (just ignore the request to create an account). For the videos I used the manual controls to move by 100mm.
[quote=“peter23”]Maybe this can shed some light…[/quote]Well it doesn’t. Everything looks fine.
One last thing : check the reference voltage of the stepper drivers (should be around 0.5V - better then the 0.425 recommended in the build manual).
Hi, mark up the electrical connectors that go to the control board.
Power off.
Swap X & Y motor connectors on the control board.
Swap X & Y end stop connectors on the control board.
Power up & test again.
If the Y axis is now correct & the X axis movers to far: the problem is electrical or in the settings.
If the Y axis still moves to far: the problem is mechanical (as ichbinsnur posted) it is most likley that the Y axis pulley has 10% more teeth than the X axis.
If the pulley has more teeth (otherwise don’t change the settings).
Reverse all the changes above.
Contact Velleman Support for a replacement.
In the meantime, you can change the settings to compensate.
(64.25 / number of teeth on Y axis pulley) * number of teeth on X axis pulley
[quote=“Barnabybear”]
If the Y axis still moves to far: the problem is mechanical (as ichbinsnur posted) it is most likley that the Y axis pully has 10% more teeth than the X axis.[/quote]
We already know that the pulleys aren’t quite right because of that 64.25 steps/mm figure.
5mm belt pitch and a 10 tooth pulley = 50mm per motor revolution.
1 revolution = 200 (whole steps) * 16 (microsteps) = 3200 steps per 50mm belt movement.
3200 / 50 = 64 steps/mm.
A pulley would have to be quite a bit oversize to generate a 10% error, but poorly formed teeth could cause the belt to ride up to a larger effective diameter.
[quote=“Paul Compton”][quote=“Barnabybear”]
If the Y axis still moves to far: the problem is mechanical (as ichbinsnur posted) it is most likley that the Y axis pully has 10% more teeth than the X axis.[/quote]
We already know that the pulleys aren’t quite right because of that 64.25 steps/mm figure.
5mm belt pitch and a 10 tooth pulley = 50mm per motor revolution.
1 revolution = 200 (whole steps) * 16 (microsteps) = 3200 steps per 50mm belt movement.
3200 / 50 = 64 steps/mm.
A pulley would have to be quite a bit oversize to generate a 10% error, but poorly formed teeth could cause the belt to ride up to a larger effective diameter.[/quote]
Hi, I have just counted the teeth on one of my old pulleys, it only has 10 teeth. Looking at the photos that is a GT2 pulley & a T5 belt.
The GT2 belt and pulley are used on the K8400, the T5 belt and pulley are used on the K8200.
Contact Velleman support and tell them “you have been supplied with a GT2 pulley by mistake and require a T5 pulley”.
Keep the GT2 pulley as it is a good modification for the printer at some time in the future.
[quote=“Barnabybear”]Hi, I have just counted the teeth on one of my old pulleys, it only has 10 teeth. Looking at the photos that is a GT2 pulley & a T5 belt.
The GT2 belt and pulley are used on the K8400, the T5 belt and pulley are used on the K8200.
Contact Velleman support and tell them “you have been supplied with a GT2 pulley by mistake and require a T5 pulley”.
Keep the GT2 pulley as it is a good modification for the printer at some time in the future.[/quote]
I just had a look at the last video.
Seems like Barabybear is abolutely right. Strange though.
Can you compare (and count teeth) then report back?
Guys, you are brilliant! Now that you mention it I can clearly see the difference between the X MOTOR and Y MOTOR pulley. But I would have never figured that out by myself (was actually counting teeth of the belts until going mad…).
Do you have a hopefully last hint for me how to best get in in touch with Velleman support? Searched their website, where they suggest to get in touch with my distributor, which is unfortunately not a convenient option as the printer was shipped to the UK as a present.
