Loches Z Axis Upgrade for MakerGear Prusa Mendel
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Published on May 11, 2012
Description
Update May 20, 2012:
Uploaded a new X-Carriage Endstop holder that is designed to attach and give clearance with the triangle frame at the very top.
Update May 13, 2012:
Added a new X-Carriage version that requires no support. It assumes you can bridge well and requires you to cut excess material at the end. Note: I have not actually printed it as of yet, so I can't be sure it all works properly.
Update May 12, 2012:
Here is a video of me printing the Pink Panther Woman thingiverse.com/thing:1216 at full size (147.535mm tall).
youtu.be/c93jLzPYmBQ
Goals:
- Increase the Z Axis Build Range.
- Modify Plastic Parts only and re-use the current Vitamins.
Comments:
- So many plastic parts have been modified, I'm not sure if I should consider this an upgrade or a full blown new printer version.
- It's possible that this change isn't limited to the MakerGear Prusa, but I will leave that to you.
- I had a few issues with the X and Z endstops and had to jury-rig my own solutions. Perhaps I will design some new mounts for these.
Summary:
My original build area was about 80mm, I came across a print that required more height so I decided to try and design my own modification that would give it to me. Looking at my printer, I noticed a few areas that could possibly be improved, so I went to work! My new and improved build height is now 150mm!
Problems and Solutions:
- Problem 01: The rear mounted X axis belt collided with the threaded rod on the triangle frame vertex assembly. This resulted in a clearance issue when raising the nozzle.
To fix this, I had to consider a new location to mount the belt. I chose to utilize the space just underneath the X track rods as that space is already used by the extruder nozzle.
- Problem 02: A good amount of rod space on the Z axis ends up being un-used. The motor mount blocks the Z axis from going beyond the two threaded rods on the top of the printer.
To fix this, I extended the upper frame vertex piece so that it raised the two top rods a good distance. This in turn also raised the Z axis rods so I also extended to lower Z bar clamps to compensate. This worked because the space taken up by the lower clamps was previously un-used rod space anyway.
- Problem 03: My current extruder mount caused a clearance issue because the side mounted motor would go underneath the upper frame vertex. Since my new vertex still blocks this, a new extruder mount was required.
To fix this, I designed a derivitive extruder mount that was essentially the same as the one I was using except the motor protrudes from the rear instead. Since I previously moved the X axis belt, there was no issue with the motor colliding with it. You can find this derivitive here: thingiverse.com/thing:22395.
- Problem 04: I found it difficult to tighten the X track rods in place without causing the X carriage to bind.
To fix this, I changed it from using the tension screws (on the bottom of each X-end) to just having some clamps on the rods themselves. The clamps prevent the rods from sliding out, but it's still ok if they slide a little bit, they don't need to be tightly locked. One of the rods is in a hole that does not give it room to 'wiggle', this gives it the stability it needs so the nozzle doesn't move around in the Y direction. The other rod is in a slightly elongated hole which provides the track with the 'play' needed to keep the carriage from binding. I've found that this modification works well and causes no noticable change in print quality.
Uploaded a new X-Carriage Endstop holder that is designed to attach and give clearance with the triangle frame at the very top.
Update May 13, 2012:
Added a new X-Carriage version that requires no support. It assumes you can bridge well and requires you to cut excess material at the end. Note: I have not actually printed it as of yet, so I can't be sure it all works properly.
Update May 12, 2012:
Here is a video of me printing the Pink Panther Woman thingiverse.com/thing:1216 at full size (147.535mm tall).
youtu.be/c93jLzPYmBQ
Goals:
- Increase the Z Axis Build Range.
- Modify Plastic Parts only and re-use the current Vitamins.
Comments:
- So many plastic parts have been modified, I'm not sure if I should consider this an upgrade or a full blown new printer version.
- It's possible that this change isn't limited to the MakerGear Prusa, but I will leave that to you.
- I had a few issues with the X and Z endstops and had to jury-rig my own solutions. Perhaps I will design some new mounts for these.
Summary:
My original build area was about 80mm, I came across a print that required more height so I decided to try and design my own modification that would give it to me. Looking at my printer, I noticed a few areas that could possibly be improved, so I went to work! My new and improved build height is now 150mm!
Problems and Solutions:
- Problem 01: The rear mounted X axis belt collided with the threaded rod on the triangle frame vertex assembly. This resulted in a clearance issue when raising the nozzle.
To fix this, I had to consider a new location to mount the belt. I chose to utilize the space just underneath the X track rods as that space is already used by the extruder nozzle.
- Problem 02: A good amount of rod space on the Z axis ends up being un-used. The motor mount blocks the Z axis from going beyond the two threaded rods on the top of the printer.
To fix this, I extended the upper frame vertex piece so that it raised the two top rods a good distance. This in turn also raised the Z axis rods so I also extended to lower Z bar clamps to compensate. This worked because the space taken up by the lower clamps was previously un-used rod space anyway.
- Problem 03: My current extruder mount caused a clearance issue because the side mounted motor would go underneath the upper frame vertex. Since my new vertex still blocks this, a new extruder mount was required.
To fix this, I designed a derivitive extruder mount that was essentially the same as the one I was using except the motor protrudes from the rear instead. Since I previously moved the X axis belt, there was no issue with the motor colliding with it. You can find this derivitive here: thingiverse.com/thing:22395.
- Problem 04: I found it difficult to tighten the X track rods in place without causing the X carriage to bind.
To fix this, I changed it from using the tension screws (on the bottom of each X-end) to just having some clamps on the rods themselves. The clamps prevent the rods from sliding out, but it's still ok if they slide a little bit, they don't need to be tightly locked. One of the rods is in a hole that does not give it room to 'wiggle', this gives it the stability it needs so the nozzle doesn't move around in the Y direction. The other rod is in a slightly elongated hole which provides the track with the 'play' needed to keep the carriage from binding. I've found that this modification works well and causes no noticable change in print quality.
Instructions
Build of Materials:
2x: Loches_Upper-Frame-Vertex.stl
1x: Loches_Lower-Z-Bar-Clamp-Left.stl
1x: Loches_Lower-Z-Bar-Clamp-Right.stl
1x: Loches_X-Carriage.stl or Loches_X-Carriage_NoSupport.stl
1x: Loches_X-End-Idler Bushing.stl
1x: Loches_X-End-Motor Bushing.stl
4x: Loches_X-Track-Bar-Clamp.stl
1x: Loches_X-Track-Endstop-Holder.stl
Various nuts and bolts, mostly re-used from the original setup.
Various vitamins re-used from the original setup.
Steps:
- Print out the above parts. 50% infil should be enough.
- Remove your current Z axis rods and assembly. This includes the Z smooth rods on either side, the threaded rods attached to the Z motors, the Z motor mounts on top, and the Z rod clamps on the bottom.
- Take out all the bearings, nuts, screws, brass bushings, motors, pullies, belt, rods, and etc from the the removed parts.
- Take off the two upper frame vertex pieces and replace them with the new versions.
- Re-mount the Z motor mount plates on top.
- Mount the new lower Z bar clamps on the bottom, don't forget to attach the bearings to them. Note that the new version has the lower rod hole in the center and is not offset from the Z axis bar clamps like the original part, so you will have to adjust accordingly.
- Assemble the brass bushings and Z axis nuts into their respective places on the new X-ends and X-carriage.
- Thread the Z axis threaded rods into the X-ends so they protrude about 1/3 of their length from the bottom of each end.
- Place the bottom of each Z axis threaded rod into their respective locations on the lower Z bar clamps (where the bearing goes) and attach the tops to the motor Z couplings. The motor mount should be on the left side of this assembly.
- Slide and clamp the Z axis smooth rods through the top motor mount, X-ends, Z endstop, and lower Z bar clamps. The smooth rods should be almost exactly the length to clamp in.
- Level both X-ends with eachother and slide both X smooth rods through their respective tracks on the X-ends and the X-carriage. The X-carriage belt mount should be in the back and facing down.
- Place 4 X-track bar clamps on the X-track smooth rods. They should be on either side of each rod in between the X-ends. You will need a M3 nut and bolt for these clamps. Alternatively, you could also just use some tape to clamp them. Note, these clamps should be snug, but not too tight, we want them to 'wiggle' a little to provide optimal track clearance for the X-carriage. It's possible that a modified X endstop mount is necessary, but so far I haven't had a problem with my mount rotating with the rod, since the rod is only snug and could essentially free-rotate.
- Attach the X axis belt motor and idler pullies on each side. These mounts are slightly adjustable, when you attach the belt you need to adjust them so you can freely slide the X-carriage from min to max without the belt rubbing against the Z axis rods.
- The new X carriage endstop is design to clamp onto a single track rod on the X axis while rest on the other rod. This is because the new method of clamping the X rods allows them to free rotate to some degree, so we don't rely on them to keep a single clamp stable. The second function for the new endstop is to allow clearance when the Z axis is at the very top while still triggering early enough that the X carriage doesn't bump into the triangle frame.
- The Z endstop is now mostly blocked by the belt now, so I had to aim it at the motor pully instead (image provided). This works and I haven't had any problems with it so far, but a possible new mount can be designed if you're not comfortable with this.
- Run your machine and make sure all axes move in the proper direction and without binding. I had to reverse my X axis motor since the belt goes in the other direction now. You shouldn't have to re-calibrate your steps per unit settings if you did not change the belt or pullies that you were using before, but it's always a good idea to double check your calibrations :)
Please provide any questions and comments you may have here, I will try and keep my eye on this thread so as not to miss anything. If you decide to build this upgrade, please share your thoughts! Any improvements on this will be much appreciated! Thank you!
2x: Loches_Upper-Frame-Vertex.stl
1x: Loches_Lower-Z-Bar-Clamp-Left.stl
1x: Loches_Lower-Z-Bar-Clamp-Right.stl
1x: Loches_X-Carriage.stl or Loches_X-Carriage_NoSupport.stl
1x: Loches_X-End-Idler Bushing.stl
1x: Loches_X-End-Motor Bushing.stl
4x: Loches_X-Track-Bar-Clamp.stl
1x: Loches_X-Track-Endstop-Holder.stl
Various nuts and bolts, mostly re-used from the original setup.
Various vitamins re-used from the original setup.
Steps:
- Print out the above parts. 50% infil should be enough.
- Remove your current Z axis rods and assembly. This includes the Z smooth rods on either side, the threaded rods attached to the Z motors, the Z motor mounts on top, and the Z rod clamps on the bottom.
- Take out all the bearings, nuts, screws, brass bushings, motors, pullies, belt, rods, and etc from the the removed parts.
- Take off the two upper frame vertex pieces and replace them with the new versions.
- Re-mount the Z motor mount plates on top.
- Mount the new lower Z bar clamps on the bottom, don't forget to attach the bearings to them. Note that the new version has the lower rod hole in the center and is not offset from the Z axis bar clamps like the original part, so you will have to adjust accordingly.
- Assemble the brass bushings and Z axis nuts into their respective places on the new X-ends and X-carriage.
- Thread the Z axis threaded rods into the X-ends so they protrude about 1/3 of their length from the bottom of each end.
- Place the bottom of each Z axis threaded rod into their respective locations on the lower Z bar clamps (where the bearing goes) and attach the tops to the motor Z couplings. The motor mount should be on the left side of this assembly.
- Slide and clamp the Z axis smooth rods through the top motor mount, X-ends, Z endstop, and lower Z bar clamps. The smooth rods should be almost exactly the length to clamp in.
- Level both X-ends with eachother and slide both X smooth rods through their respective tracks on the X-ends and the X-carriage. The X-carriage belt mount should be in the back and facing down.
- Place 4 X-track bar clamps on the X-track smooth rods. They should be on either side of each rod in between the X-ends. You will need a M3 nut and bolt for these clamps. Alternatively, you could also just use some tape to clamp them. Note, these clamps should be snug, but not too tight, we want them to 'wiggle' a little to provide optimal track clearance for the X-carriage. It's possible that a modified X endstop mount is necessary, but so far I haven't had a problem with my mount rotating with the rod, since the rod is only snug and could essentially free-rotate.
- Attach the X axis belt motor and idler pullies on each side. These mounts are slightly adjustable, when you attach the belt you need to adjust them so you can freely slide the X-carriage from min to max without the belt rubbing against the Z axis rods.
- The new X carriage endstop is design to clamp onto a single track rod on the X axis while rest on the other rod. This is because the new method of clamping the X rods allows them to free rotate to some degree, so we don't rely on them to keep a single clamp stable. The second function for the new endstop is to allow clearance when the Z axis is at the very top while still triggering early enough that the X carriage doesn't bump into the triangle frame.
- The Z endstop is now mostly blocked by the belt now, so I had to aim it at the motor pully instead (image provided). This works and I haven't had any problems with it so far, but a possible new mount can be designed if you're not comfortable with this.
- Run your machine and make sure all axes move in the proper direction and without binding. I had to reverse my X axis motor since the belt goes in the other direction now. You shouldn't have to re-calibrate your steps per unit settings if you did not change the belt or pullies that you were using before, but it's always a good idea to double check your calibrations :)
Please provide any questions and comments you may have here, I will try and keep my eye on this thread so as not to miss anything. If you decide to build this upgrade, please share your thoughts! Any improvements on this will be much appreciated! Thank you!
You must be logged in to post a comment.
hugh
on
October 20, 2012
said:
Built one months ago -- been printing lately at 200-300mm/sec quite happily with no stability issues or print quality problems. :)
I can't say that my printer looks anything short of a calico cat though with the different amalgamations of materials and colors though.
fehknt
on
October 6, 2012
said:
I can't bridge that well yet apparently - it looks like it'll be less work to just deal with a lengthy cleanup. Any awesome advice to bridge more effectively to print things like this without support?
Anonymous
on
September 17, 2012
said:
After chewing on this concept (that I really like) just thought you would like to know that I am throwing some plastic at it right now. I hope that it performs as well as it looks as I was looking for something to increase my build size. I will let you know how it turns out on this end and if I add a thing or two to enhance the design I will let you know. Any changes since your initial upload? Besides the no support version?
JerZ
on
May 12, 2012
said:
I almost tried this once, but I wasn't sure how stable the printer would be at say, 140mm high with the x-axis whipping back and forth. Figured I'd have to start from scratch with the frame. Is it prone to "racking"? Great work here.
Lochemage
on
May 12, 2012
said:
It's actually quite stable, I was worried about that too at first. I haven't noticed any change in print quality since the change (besides me overall just getting better with printing), only that I have more height now. I suppose, as an alternative, you could get longer Z rods and avoid using the extended lower Z bar clamp... if any part of my upgrade is to be unstable, it would be those. But, as long as it is bolted very tightly to both the base rod and the Z smooth rods, I think you will find it to be quite stable though.
License
Loches Z Axis Upgrade for MakerGear Prusa Mendel by Lochemage is licensed under the Attribution - Share Alike - Creative Commons license.
More from Lochemage
More from 3D Printer Parts
will your x carriage work with linear bearings?
I made a quick polygon modification for the dimensions of standard 15mm OD x 24mm Length LM8UU bearings.
https://www.dropbox.com/s/kiwd...
I've only designed it based on my current build. Unfortunately, If I were to update it for different builds, it would be guess work on my part. It's probably better if someone who actually has the set up make the modifications and then upload a derivative if possible.
yes this would be nice to get a version with lm8uu, i have no lucky hands with blender so if someone can make a version with lm8uu or a scad version of it it would be realy nice