Far away from precision

Re: Far away from precision

Treito — Mon, 04 May 2015 14:40:58 -0400

Thanks Dave. But in my case it was indeed the connection from the belt to the heated bed. I was astonished that the belt could get loose in that way.
As soon as my printer works again and I have enough time I will print the Y belt clamp either in ABS or HIPS.

Re: Far away from precision

dmould — Mon, 04 May 2015 14:29:46 -0400

Also make sure the grub screws on the pulleys are tight and correctly aligned with the flats on the shaft. Loose pulleys are also a very common cause of your symptoms.

Dave

Re: Far away from precision

Treito — Sat, 02 May 2015 12:17:57 -0400

Many thanks.

That was indeed the problem. I fixed it now for the moment. I will try to print the Y belt fasteners later. I think I should print them in ABS or HIPS. Lickily there were some photos how to mount them.

Re: Far away from precision

dc42 — Sat, 02 May 2015 07:04:00 -0400

I use v7 which is the flat one. The shims go between the belt fastener pieces and the plywood rib that they are attached to. The belt has a 2mm tooth spacing AFAIR, and this isn't fine enough to adjust the belt tension precisely, because you can only adjust the belt length by a whole number of teeth. By choosing which shims to put under the belt fasteners, you can get a finer adjustment.

There are also designs out there for modified Y idler pulley supports with belt tension adjustment built in.

Re: Far away from precision

Treito — Sat, 02 May 2015 06:55:04 -0400

Many thanks for your help.
That was my first thought, too that the Y belt could have been slipped. I only used cable ties and I was sure that this would be enough. Maybe it was too late, but I checked the Y belt and I assumed that the belt was weak, but strong enough that slipping was no risk. Maybe I should teach my mechanical knowledge more. I totally can understand how your approved Z probe is working.
Which one of the Ybelt fasteners do you use? The round one or the flat one? And I have no idea what to do with the shims. I have been seeing them often, but I thought that these pieces belong to the Ormerod 2.
Okay I will disassemble my Ormerod and report later, but I am afraid, that there is a second fault. Maybe the X belt?

Re: Far away from precision

dc42 — Fri, 01 May 2015 16:48:05 -0400

Looks like a classic Ormerod 1 slipping Y belt to me. Have you done anything to secure the Y belt more effectively to the carriage? I use these Y belt fasteners [www.thingiverse.com], and these shims [www.thingiverse.com] under them to adjust the belt tension.

Far away from precision

Treito — Fri, 01 May 2015 16:05:19 -0400

Hello,

my Ormerod 1 lost its precision. I do not have any clue where I can look for the fault. Can anybody give me a hint?
Circles look like ellipses. The x-dimension is to big. the 2nd layer does not fit the first layer in y-direction.
I am using the firmware from dc42 Version 1.04f.

X=0 is at the top of the picture.

Part of my config.g

; RepRapPro Ormerod
; Standard configuration G Codes
M111 S0; Debug off
M550 P****; Set the machine's name
M551 P****; Set the password
M540 P0xBE:0xEF:0xDE:0xAD:0xFE:0xED ; Set the MAC address
M552 P192.168.***.***; Set the IP address
M553 P255.255.255.0; Set netmask
M554 P192.168.***.***; Set the gateway
M555 P2; Emulate Marlin USB output
M563 P0 D0 H1                       ; Define tool 1
G10 P0 S0 R0                        ; Set tool 1 operating and standby temperatures
M92 E420; Set extruder steps/mm
G21 ; Work in mm
G90 ; Absolute positioning
M83 ; Extrusions relative
M574 X0 Y2 Z0 S1					; set endstop configuration (Y endstop only, at high end, active high)
M558 P1 ; Turn Z Probe on
M305 P0 H14 L-11					; set ADC correction
M305 P1 H14 L-11					; set ADC correction
G31 Z1.8 P600 ; Set Z probe height and threshold
M906 X800 Y800 Z800 E800 ; Motor currents (mA)
M201 X800 Y800 Z15 E1000; acceleration tweaks for improved finish
M203 X15000 Y15000 Z250 E3600; speed tweaks for improved finish
M569 P0 S0                          ; Reverse the X axis
M556 S78 X-0.63 Y1 Z-0.3
M566 X600 Y600 Z30 E20              ; Minimum speeds mm/minute
M208 X214 Y210						; set axis travel
M208 X-15 Y0 S1							; set axis minimum
T 0
;End of config