New Mendel 3 RepRapPro Kit building experience 
Posted by buggy
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New Mendel 3 RepRapPro Kit building experience May 05, 2015 11:44AM |
I have always been wanting and needing a 3D Printer 
My inspiration was an article and interview with Adrian Bowyer in the Elektronikpraxis Magazin from March 2015.
On March 11.2015 I ordered a Mendel 3 Full Kit from RepRap Professional Ltd. Three weeks later the package arrived. According to the packing list everything was complete.
I realized that the Mendel 3 was new and expected problems.
During the construction, I noticed a few minor mistakes, failing components or small corrections that would possibly be of interest to make this kit even better.
Here my building, commissioning, calibration and printing experience:
A few minor documentation errors and misspelling have been corrected by RepRap support after my email correspondence.
Frame Assembly
Fasteners set #956 11bags
Mendel Fasteners bag #3
# Component Qty
241 M3x20mm cap head screw 7 (only 7 were packaged)
Here the required Qty should be 10 pieces (as mentioned in the mounting assembly description)
Support reply: Yes, you need 10 x 241 - M3x20mm cap head screw. The first few kits we sent out only had 7 packed, due to a mistake in the Bill of Materials. This has now been corrected
Mendel Hardware bag #3
# 199 Ingus clip bearing 8mm is called in the axis rails Component list:
# 199 „Ingus 8mm clip bushing“ (to be totally clear, one and the same description would be nice)
The same goes for the following:
# 242 M3x16 A2 ST/ST SOCKET CAP is called „M3x16mm cap head screw“ in the X axis rails Component list.
Support reply: Updated to "Igus clip bearing - 8mm" in component list. The "M3x16 A2 ST/ST SOCKET CAP" is wrong in our parts database, where the names for the labels on the bags come from. I think this has been updated, and will change the next time the labels are printed.
X axis assembly
X axis rails (documentation)
# Component
279 623 bearing
The bearing was packaged but was missing in the parts list
Support reply: Added to component list.
extruder drive assembly
Extruder block assembly
In order to mount the motor using the two M3x20mm cap head screws #241, the combination of 4mm thick-spacer and block will not flush mount because the screws are about 1,5mm too long. The screws that hold the motor together from the opposite side protrude into the 3mm holes for the cap head crews and must be shortened 2-3mm,
or the 4mm spacer should be 6 or 7mm thick to compensate for the long screws.
I simply replaced the screws with new ones with a length of 16mm.
Support reply: I think you're right, these should be M3x16mm screws, not M3x20mm. Not sure how this has got through all the checks we did! I'll check when I'm back in the office, tomorrow. Our old Mendel instructions use M3x16mm (the extruder drive is much the same)
Fitting the drive
To attach the Extruder drive mount the mentioned M3x35mm screw #520 is also too long.
An M3x30mm was packaged but was missing in the parts list. It fits here perfectly.
Support reply: I checked the extruder drives, and it seems you may have received a slightly older version, where the screws are recessed further into the extruder drive body. This shouldn't matter much, but does mean that you need to use the M3x16mm screws. It also means you need to use the shorter M3x30mm screw for mounting. But otherwise the extruder block is the same.
Wiring
Y-endstop loom
The end of the loom for the microswitch will not fit into the small notch of the Duet enclosure. The wire plus insulation, shield and silver tape will only fit when the notch is enlarged. The pin connection to the microswitch is also not very dependable.
I preferred to solder the crimp to the contacts of the switch.
Support reply: We haven't had a problem with fitting the Y endstop loom in the perimeter, as far as I'm aware. Soldering the wires to the microswitch is fine, just more permanent!
Motor wiring looms
The Z1 (#589) and Z2 (#789) looms have the same length. In this case Z1 was far too long and the silver tape should be attached about 2cm from the plug in order to engage in the notch. In the description it says that Z1 and Y are the same length.
Support reply: It sounds like you received one wiring loom that was too long. The Y axis and Z1 should be the same length, as they both only have a short distance to go.
Proximity Sensor loom: The pins from the connector were not correct. According to the picture and in wiring diagram the blue and red wires are correct, but the connector was not correctly mounted on the loom. The notches should face to the outside in order to engage between the outer pins. I just removed the pins and turned the connector around 180 deg.
Support reply: I think the connector fits on those pins either way around, but so long as the wiring is in the correct place, no problem.
Cooling fan: In the wiring diagram the red wire is on top then the yellow underneath on the connector also corresponding correctly to loom with it’s plug.
In the picture of the wiring (3948) the yellow is on top. (presumably false-will see if the motor turns in the right direction)
Support reply: You're quite correct; the picture is wrong! Generally, we use yellow for ground (it should be black, but the shrouded cable we use does not have that colour combination), and red for +ve. I've also updated the wiring diagram colour reference, so you can check the wiring against the loom
Duet Commissioning Docs
8 Testing Machine control
8.1 Test the heaters
8.1.2 Heated bed
The command to heat the bed to 45 degrees did not function because one crimped end of the wiring loom copper core did not have contact with the female crimps and only the isolation was crimped.
The LED on the heated bed also was not lit. 12V came out of the duet but was not present measured at the heated bed. After properly renewing the female crimps on the end of the loom, the heated bed functioned.
Support reply: Sorry you received one loom that was poorly crimped. I'm glad you were able to diagnose this and fix it easily.
Test axis homing
The X axis homing is was not correct for the Mendel 3 because the reference is for the Ormerod including picture No. 67
Utilizing the ”X” homing caused the X carriage to bump into the end and clatter against the X motor on the right. The proximity sensor is actually at the other end of the Mendel 3.
Here the yellow and green wires of the X axis loom were reversed on the Duet side.
Since „Home All“ was utilized the Head crashed onto the lower left corner of the heat bed.
Before I could stop it, one of the three # 914 Y bearing holders broke on the upper right side because of the pressure exerted on the lower left. I was lucky since the glass plate could have broken. After contacting support again I was told that a revision has been made to repair this defekt.
In order to repair this very unstable heat bed to print a new bearing holder, I stabilized this with a piece of wire.
Support reply:
Look at the homing macros (homex.g, homey.g, homez.g and homeall.g) which have all been updated. The X axis moves out 65mm to put the nozzle on the edge of the bed, then when you home Z, it move to X30, to put the proximity probe over the target. They are fully commented, so you can work out what is going on, and adjust them as necessary.
Regarding the SD Image, we have been testing a new firmware update all week. It should be released to 'master' this evening (May 1). This includes an updated SD Image for all machines, and corrects a number of mistakes, including homing on the Mendel 3.
The commissioning, calibration etc documentation is being heavily revised over the coming weeks. We realise it is heavily biased towards the Ormerod at the moment, but the Mendel is very similar functionally to the Ormerod. This will be addressed. However, we now have three machines (Ormerod, Mendel 3 and Huxley Duo) that effectively use the same electronics and firmware; keeping three separate sets of documentation (actually, four, including the older Ormerod 1) up to date is far too time consuming, and there will be more mistakes due to repetition. Sorry it is not entirely clear at the moment, but it will be steadily improved!
In the mean time, I printed a new bearing holder for the heat bed and am satisfied with the result.
First I would like to express my compliments for an otherwise very good top quality kit.
I hope to have been of assistance getting the kinks and quirks out of a well planned system. Since it was presented in March, like every new machine, it takes time and feedback to ripen.
As soon as I have the printer running to my satisfaction I intend to implement the Duo print function with a second Hot End and possibly later a Tricolor version.
Have fun building and printing.
buggy
Edited 1 time(s). Last edit at 05/05/2015 01:51PM by buggy.
My inspiration was an article and interview with Adrian Bowyer in the Elektronikpraxis Magazin from March 2015.
On March 11.2015 I ordered a Mendel 3 Full Kit from RepRap Professional Ltd. Three weeks later the package arrived. According to the packing list everything was complete.
I realized that the Mendel 3 was new and expected problems.
During the construction, I noticed a few minor mistakes, failing components or small corrections that would possibly be of interest to make this kit even better.
Here my building, commissioning, calibration and printing experience:
A few minor documentation errors and misspelling have been corrected by RepRap support after my email correspondence.
Frame Assembly
Fasteners set #956 11bags
Mendel Fasteners bag #3
# Component Qty
241 M3x20mm cap head screw 7 (only 7 were packaged)
Here the required Qty should be 10 pieces (as mentioned in the mounting assembly description)
Support reply: Yes, you need 10 x 241 - M3x20mm cap head screw. The first few kits we sent out only had 7 packed, due to a mistake in the Bill of Materials. This has now been corrected
Mendel Hardware bag #3
# 199 Ingus clip bearing 8mm is called in the axis rails Component list:
# 199 „Ingus 8mm clip bushing“ (to be totally clear, one and the same description would be nice)
The same goes for the following:
# 242 M3x16 A2 ST/ST SOCKET CAP is called „M3x16mm cap head screw“ in the X axis rails Component list.
Support reply: Updated to "Igus clip bearing - 8mm" in component list. The "M3x16 A2 ST/ST SOCKET CAP" is wrong in our parts database, where the names for the labels on the bags come from. I think this has been updated, and will change the next time the labels are printed.
X axis assembly
X axis rails (documentation)
# Component
279 623 bearing
The bearing was packaged but was missing in the parts list
Support reply: Added to component list.
extruder drive assembly
Extruder block assembly
In order to mount the motor using the two M3x20mm cap head screws #241, the combination of 4mm thick-spacer and block will not flush mount because the screws are about 1,5mm too long. The screws that hold the motor together from the opposite side protrude into the 3mm holes for the cap head crews and must be shortened 2-3mm,
or the 4mm spacer should be 6 or 7mm thick to compensate for the long screws.
I simply replaced the screws with new ones with a length of 16mm.
Support reply: I think you're right, these should be M3x16mm screws, not M3x20mm. Not sure how this has got through all the checks we did! I'll check when I'm back in the office, tomorrow. Our old Mendel instructions use M3x16mm (the extruder drive is much the same)
Fitting the drive
To attach the Extruder drive mount the mentioned M3x35mm screw #520 is also too long.
An M3x30mm was packaged but was missing in the parts list. It fits here perfectly.
Support reply: I checked the extruder drives, and it seems you may have received a slightly older version, where the screws are recessed further into the extruder drive body. This shouldn't matter much, but does mean that you need to use the M3x16mm screws. It also means you need to use the shorter M3x30mm screw for mounting. But otherwise the extruder block is the same.
Wiring
Y-endstop loom
The end of the loom for the microswitch will not fit into the small notch of the Duet enclosure. The wire plus insulation, shield and silver tape will only fit when the notch is enlarged. The pin connection to the microswitch is also not very dependable.
I preferred to solder the crimp to the contacts of the switch.
Support reply: We haven't had a problem with fitting the Y endstop loom in the perimeter, as far as I'm aware. Soldering the wires to the microswitch is fine, just more permanent!
Motor wiring looms
The Z1 (#589) and Z2 (#789) looms have the same length. In this case Z1 was far too long and the silver tape should be attached about 2cm from the plug in order to engage in the notch. In the description it says that Z1 and Y are the same length.
Support reply: It sounds like you received one wiring loom that was too long. The Y axis and Z1 should be the same length, as they both only have a short distance to go.
Proximity Sensor loom: The pins from the connector were not correct. According to the picture and in wiring diagram the blue and red wires are correct, but the connector was not correctly mounted on the loom. The notches should face to the outside in order to engage between the outer pins. I just removed the pins and turned the connector around 180 deg.
Support reply: I think the connector fits on those pins either way around, but so long as the wiring is in the correct place, no problem.
Cooling fan: In the wiring diagram the red wire is on top then the yellow underneath on the connector also corresponding correctly to loom with it’s plug.
In the picture of the wiring (3948) the yellow is on top. (presumably false-will see if the motor turns in the right direction)
Support reply: You're quite correct; the picture is wrong! Generally, we use yellow for ground (it should be black, but the shrouded cable we use does not have that colour combination), and red for +ve. I've also updated the wiring diagram colour reference, so you can check the wiring against the loom
Duet Commissioning Docs
8 Testing Machine control
8.1 Test the heaters
8.1.2 Heated bed
The command to heat the bed to 45 degrees did not function because one crimped end of the wiring loom copper core did not have contact with the female crimps and only the isolation was crimped.
The LED on the heated bed also was not lit. 12V came out of the duet but was not present measured at the heated bed. After properly renewing the female crimps on the end of the loom, the heated bed functioned.
Support reply: Sorry you received one loom that was poorly crimped. I'm glad you were able to diagnose this and fix it easily.
Test axis homing
The X axis homing is was not correct for the Mendel 3 because the reference is for the Ormerod including picture No. 67
Utilizing the ”X” homing caused the X carriage to bump into the end and clatter against the X motor on the right. The proximity sensor is actually at the other end of the Mendel 3.
Here the yellow and green wires of the X axis loom were reversed on the Duet side.
Since „Home All“ was utilized the Head crashed onto the lower left corner of the heat bed.
Before I could stop it, one of the three # 914 Y bearing holders broke on the upper right side because of the pressure exerted on the lower left. I was lucky since the glass plate could have broken. After contacting support again I was told that a revision has been made to repair this defekt.
In order to repair this very unstable heat bed to print a new bearing holder, I stabilized this with a piece of wire.
Support reply:
Look at the homing macros (homex.g, homey.g, homez.g and homeall.g) which have all been updated. The X axis moves out 65mm to put the nozzle on the edge of the bed, then when you home Z, it move to X30, to put the proximity probe over the target. They are fully commented, so you can work out what is going on, and adjust them as necessary.
Regarding the SD Image, we have been testing a new firmware update all week. It should be released to 'master' this evening (May 1). This includes an updated SD Image for all machines, and corrects a number of mistakes, including homing on the Mendel 3.
The commissioning, calibration etc documentation is being heavily revised over the coming weeks. We realise it is heavily biased towards the Ormerod at the moment, but the Mendel is very similar functionally to the Ormerod. This will be addressed. However, we now have three machines (Ormerod, Mendel 3 and Huxley Duo) that effectively use the same electronics and firmware; keeping three separate sets of documentation (actually, four, including the older Ormerod 1) up to date is far too time consuming, and there will be more mistakes due to repetition. Sorry it is not entirely clear at the moment, but it will be steadily improved!
In the mean time, I printed a new bearing holder for the heat bed and am satisfied with the result.
First I would like to express my compliments for an otherwise very good top quality kit.
I hope to have been of assistance getting the kinks and quirks out of a well planned system. Since it was presented in March, like every new machine, it takes time and feedback to ripen.
As soon as I have the printer running to my satisfaction I intend to implement the Duo print function with a second Hot End and possibly later a Tricolor version.
Have fun building and printing.
buggy
Edited 1 time(s). Last edit at 05/05/2015 01:51PM by buggy.
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Re: New Mendel 3 RepRapPro Kit building experience June 30, 2015 06:20AM |
Having just built a Mendel 3 tri-colour myself I just found and read your article with interest.
Disappointingly many of the screw length problems you reported back in may are still current nearly 2 moths later.... however, one of my extruder packs did include an extra set of screws with a note advising they are replacements for screws that are two long.
the problems I encountered with the build were
-a missing belt retainer for the Y axis
-one of the Z axis motor cables was wired backwards
-the short Z axis Jumper cable was mis-crimped
I found the build instructions and pictures for the power supply and duet assembly hard to follow
On the one hand many of these issues are a little disappointing, but then again if I wanted something that worked right out the box I wouldn't have bought a kit, but this kit is definitely not for a novice machine builder... fortunately I have over 20 years experience with building multi axis industrial CNC machines, so was able to work through these issues fairly easilly.
I read your problems with the X axis homing with interest, because I had and still have a lot of problems with the X axis homing, and yes had crashed the nozzle into the bed a few times (but not broken the bearing brackets yet..... maybe I need to print some spares before I do
The problem I still have with X axis homing is it homes in a different position for Home X and Home ALL... and yes I have checked the code files
Still not commissioned the second and third extrudes yet, will continue working with just the one until I get the hang of 3d printing
Disappointingly many of the screw length problems you reported back in may are still current nearly 2 moths later.... however, one of my extruder packs did include an extra set of screws with a note advising they are replacements for screws that are two long.
the problems I encountered with the build were
-a missing belt retainer for the Y axis
-one of the Z axis motor cables was wired backwards
-the short Z axis Jumper cable was mis-crimped
I found the build instructions and pictures for the power supply and duet assembly hard to follow
On the one hand many of these issues are a little disappointing, but then again if I wanted something that worked right out the box I wouldn't have bought a kit, but this kit is definitely not for a novice machine builder... fortunately I have over 20 years experience with building multi axis industrial CNC machines, so was able to work through these issues fairly easilly.
I read your problems with the X axis homing with interest, because I had and still have a lot of problems with the X axis homing, and yes had crashed the nozzle into the bed a few times (but not broken the bearing brackets yet..... maybe I need to print some spares before I do
The problem I still have with X axis homing is it homes in a different position for Home X and Home ALL... and yes I have checked the code files
Still not commissioned the second and third extrudes yet, will continue working with just the one until I get the hang of 3d printing
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Re: New Mendel 3 RepRapPro Kit building experience August 07, 2015 01:44AM |
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