Parts for a belt driven extruder in the UK?

Hi,

I am interested in building a belt driven extruder for my Delta printer, mainly to quieten the printer as much as possible, but I am struggling to find the parts.

There are a few designs floating around and most of them seem to use something like the following...

• GT2 pulley - 5mm bore (17T standard, 36T bowden)
• GT2 pulley - 8mm bore (65T standard, 60T bowden)
• GT2 belt (88T standard, 94T bowden)

Terawatt Industries seems to be the suggested place for the parts, but apart from being in the USA, the store seems to be down.

I suppose the pulleys could be printed, but I am still struggling to find a suitable closed loop belt.

Any other suggestions?

Regards,

Les

---

Pointy's Things
Pointy's Blog

I had the same questions. The pulleys I found were somewhere in the ~60dollar + range for the 65T gt2 belt. Not only that but using a hobbled bolt is not exactly to my taste. I designed my own extruder using some of the thoughts but using a MK7 gear for drive. This gives me better control and better tolerances. I run 2:1 ratio on my extruder and have no issues with power up to 150mm/s with a .5mm nozzle. With that said my design has a maximum of 2.5:1 ratio. I am doing a small production run before I release the STL's and BOM for it. Expecting the last of my parts get here before the end of next week.

Here is an overview.

[engineerd3d.ddns.net]

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Thanks jk11, I had already read your blog and watched your videos. Your extruder looks great.

Regards,

Les

---

Pointy's Things
Pointy's Blog

I have searched high and low for these in the UK and not been able to find any. I had to resort to ordering from China through AliExpress.

---

[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

Quote
3dkarma
I have searched high and low for these in the UK and not been able to find any. I had to resort to ordering from China through AliExpress.

Thanks for the reply, I did manage to find some parts on AliExpress.

Can I ask which one you built? There seems to be a few designs floating around, other than the 00str00der I am not sure if any are suitable for a bowden setup.

Regards,

Les

---

Pointy's Things
Pointy's Blog

My belts only just arrived. I'm planning on modifying the Wade's. Pulleys are also difficult to source, so I'll be printing the larger pully. I'll use a standard 16 tooth pulley and marry it with an 80 tooth printed pulley, to give me a 5:1 drive ratio.

---

[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

Quote
3dkarma
My belts only just arrived. I'm planning on modifying the Wade's. Pulleys are also difficult to source, so I'll be printing the larger pully. I'll use a standard 16 tooth pulley and marry it with an 80 tooth printed pulley, to give me a 5:1 drive ratio.

I have given up looking for a moment, after fitting a damper the noise is better, just a bit on retract.

There seems to be lots of opinions about the ratio, my current geared extruder has 11 teeth on small cog and 45 on large which makes it about 4:1 (Wade's bowden). If I changed it to belt drive, should the ratio change, if so why?

Regards,

Les

---

Pointy's Things
Pointy's Blog

The whole point of a belt drive is to increase the retraction speed and possibly the precision. If your running a 5:1 or 4:1 ratio there will still be some problems. Do you really need so much torque? I find my belt driven extruder with a 2:1 ratio works very well in the 150mm/s range with 1.75mm filament. I have retraction set at 200mm/s in the 3.5mm range and this is for a bowden setup. Artifacting due to blobs etc has been minimal at best. I would suggest you guys try a 2:1 setup or even a 2.5:1 given you already have a 16T pulley. If you find your lacking torque its not the gear reduction fault but something else like lack of precision or tuning.

My .02c on the matter. One more thing I would suggest is to get rid of the hobbled bolts and use a precision ground 5mm shaft coupled to a mk7 gear to increase precision. Most of these hobbled bolts were not machined well, nor are bolts designed to be very true or round to begin with. At least not the ones I have seen......

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
The whole point of a belt drive is to increase the retraction speed and possibly the precision. If your running a 5:1 or 4:1 ratio there will still be some problems. Do you really need so much torque? I find my belt driven extruder with a 2:1 ratio works very well in the 150mm/s range with 1.75mm filament. I have retraction set at 200mm/s in the 3.5mm range and this is for a bowden setup. Artifacting due to blobs etc has been minimal at best. I would suggest you guys try a 2:1 setup or even a 2.5:1 given you already have a 16T pulley. If you find your lacking torque its not the gear reduction fault but something else like lack of precision or tuning.

My .02c on the matter. One more thing I would suggest is to get rid of the hobbled bolts and use a precision ground 5mm shaft coupled to a mk7 gear to increase precision. Most of these hobbled bolts were not machined well, nor are bolts designed to be very true or round to begin with. At least not the ones I have seen......

What size filament / nozzle combination are you using?

---

[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

I am using 1.75mm filament. As of now I am using a .5mm nozzle. It should do over 100mm/s with a .4mm nozzle though.... 150mm/s on the .5mm nozzle is not pushing the extruder, its pushing my printer.....

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Thanks for the replies jk11.

I have a spare stainless steel prop shaft from my model boat that is 5mm dia, 120mm long and has a M4 thread on one end.

Stupid questions time...

Would a MK8 drive be better than a MK7?

Do you file a flat on the shaft for the drive gear grub screw?

Is the no of teeth on the belt critical? Surely it would just make the spacing between gears smaller/larger.

What size bearings do you use?

Regards,

Les

Edited 1 time(s). Last edit at 02/17/2015 11:50AM by Pointy.

---

Pointy's Things
Pointy's Blog

Spacing is not critical. I prefer the MK7 gear as its better suited for 1.75mm filament. Number of teeth does not make a difference, you can have a long belt. However tension does matter. I have my extruder under allot of load as far as the belt goes. I can barely feel any give between the two pulleys. You can get a 40T GT2 pulley with 5mm bore just about anywhere in the world through e-bay etc etc. They are a bit pricy for a simple alu pulley but they are worth it.

As for grinding a flat spot? I have not needed to do so on my own setup. I dip the screw in ABS slurry and crank it down hard. I may do this if this becomes a problem but as of now it has not as the pulleys I use both have two set screws in them. The MK7 gears I use are stainless and therefore I can crank down on them very hard. The main thing is that the shaft has to be steel. Alu shaft is not adapt. Hardened drill rod steel is what I use.

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
Spacing is not critical. I prefer the MK7 gear as its better suited for 1.75mm filament. Number of teeth does not make a difference, you can have a long belt. However tension does matter. I have my extruder under allot of load as far as the belt goes. I can barely feel any give between the two pulleys. You can get a 40T GT2 pulley with 5mm bore just about anywhere in the world through e-bay etc etc. They are a bit pricy for a simple alu pulley but they are worth it.

As for grinding a flat spot? I have not needed to do so on my own setup. I dip the screw in ABS slurry and crank it down hard. I may do this if this becomes a problem but as of now it has not as the pulleys I use both have two set screws in them. The MK7 gears I use are stainless and therefore I can crank down on them very hard. The main thing is that the shaft has to be steel. Alu shaft is not adapt. Hardened drill rod steel is what I use.

Thanks for the reply, I think I edited my post to add the question about bearings as you were replying.

Regards,

Les

---

Pointy's Things
Pointy's Blog

Did you build your extruder? How did it come out if you built it.

I am anxius to find out how you like the setup. You are one of the first guys to adopt my extruder, therefore I am all ears on your experience with it.

Also for the people looking at this thread. Here is a video I made on the extruder assembly - [www.youtube.com]

Here are the source files for the extruder. - [www.youmagine.com]

And if anyone is interesed in purchasing one in the US. - [www.ebay.com]

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
Did you build your extruder? How did it come out if you built it.

I have it part assembled, but I am waiting for the 40T pulley and belt which have finally left China. Had to print some parts again after tweaking the files as the holes came out quite a bit under size. ( I think it's a problem with Slic3r when you do infill before perimeters) It went together pretty easy, I just had a little trouble with the push fitting but managed to find a tap of the right size.(maybe because PLA is harder than ABS?) I did find it a little fiddly to feed the filament, but it certainly seems to grip it nicely when I turn the knob by hand.

I post some pics when I get a chance.

Regards,

Les

---

Pointy's Things
Pointy's Blog

Quote
Pointy

Quote
jaguarking11
Did you build your extruder? How did it come out if you built it.

I have it part assembled, but I am waiting for the 40T pulley and belt which have finally left China. Had to print some parts again after tweaking the files as the holes came out quite a bit under size. ( I think it's a problem with Slic3r when you do infill before perimeters) It went together pretty easy, I just had a little trouble with the push fitting but managed to find a tap of the right size.(maybe because PLA is harder than ABS?) I did find it a little fiddly to feed the filament, but it certainly seems to grip it nicely when I turn the knob by hand.

I post some pics when I get a chance.

Regards,

Les

Awesome! I cant wait to hear your thoughts for good or bad. As for fiddly, thats a compromise I made on having the feed hole slightly offset from the gear. This allows for a mild wrap that gives it a bit more grip. As for holes under size, internal holes almost always come undersize when 3d printing. I usually clean them up with a drill bit. Hoping your as happy with it as I am. Its my baby afterall.

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11

Quote
Pointy

Quote
jaguarking11
Did you build your extruder? How did it come out if you built it.

I have it part assembled, but I am waiting for the 40T pulley and belt which have finally left China. Had to print some parts again after tweaking the files as the holes came out quite a bit under size. ( I think it's a problem with Slic3r when you do infill before perimeters) It went together pretty easy, I just had a little trouble with the push fitting but managed to find a tap of the right size.(maybe because PLA is harder than ABS?) I did find it a little fiddly to feed the filament, but it certainly seems to grip it nicely when I turn the knob by hand.

I post some pics when I get a chance.

Regards,

Les

Awesome! I cant wait to hear your thoughts for good or bad. As for fiddly, thats a compromise I made on having the feed hole slightly offset from the gear. This allows for a mild wrap that gives it a bit more grip. As for holes under size, internal holes almost always come undersize when 3d printing. I usually clean them up with a drill bit. Hoping your as happy with it as I am. Its my baby afterall.

Well over a year later and I finally put it together.

If you are still around jk11, I have a couple of questions...

I have done a very quick calibration and it has come out at 204 steps per mm. Does this sound about right?

I am using a Smoothieboard and am unsure what to set the following settings to, any suggestions?

extruder.hotend.default_feed_rate               600              	# Default rate ( mm/minute ) for moves where only the extruder moves
extruder.hotend.acceleration                    500              	# Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder.hotend.max_speed                       200              	# mm/s

Regards,

Les

---

Pointy's Things
Pointy's Blog

Quote
Pointy

Quote
jaguarking11

Quote
Pointy

Quote
jaguarking11
Did you build your extruder? How did it come out if you built it.

I have it part assembled, but I am waiting for the 40T pulley and belt which have finally left China. Had to print some parts again after tweaking the files as the holes came out quite a bit under size. ( I think it's a problem with Slic3r when you do infill before perimeters) It went together pretty easy, I just had a little trouble with the push fitting but managed to find a tap of the right size.(maybe because PLA is harder than ABS?) I did find it a little fiddly to feed the filament, but it certainly seems to grip it nicely when I turn the knob by hand.

I post some pics when I get a chance.

Regards,

Les

Awesome! I cant wait to hear your thoughts for good or bad. As for fiddly, thats a compromise I made on having the feed hole slightly offset from the gear. This allows for a mild wrap that gives it a bit more grip. As for holes under size, internal holes almost always come undersize when 3d printing. I usually clean them up with a drill bit. Hoping your as happy with it as I am. Its my baby afterall.

Well over a year later and I finally put it together.

If you are still around jk11, I have a couple of questions...

I have done a very quick calibration and it has come out at 204 steps per mm. Does this sound about right?

I am using a Smoothieboard and am unsure what to set the following settings to, any suggestions?

extruder.hotend.default_feed_rate               600              	# Default rate ( mm/minute ) for moves where only the extruder moves
extruder.hotend.acceleration                    500              	# Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder.hotend.max_speed                       200              	# mm/s

Regards,

Les

Hey. im glad you got yours going. The steps per/mm sound about right. I would do this if I were you. Unplug your hot end and trim the filament flush with the bowden. Then command the extruder to extrude 100mm of plastic. Then measure from the edge of the tube to the tip of the filament. Then simply take your knowsn steps in this case 208 then multiply it by desired distance which is 100 then divide by measured distance which lets for arguments sake say its 93, so your new steps per mm would be 223 or so. Hopefully this makes sense to you.

-Bruno

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
Hey. im glad you got yours going. The steps per/mm sound about right. I would do this if I were you. Unplug your hot end and trim the filament flush with the bowden. Then command the extruder to extrude 100mm of plastic. Then measure from the edge of the tube to the tip of the filament. Then simply take your knowsn steps in this case 208 then multiply it by desired distance which is 100 then divide by measured distance which lets for arguments sake say its 93, so your new steps per mm would be 223 or so. Hopefully this makes sense to you.

-Bruno

Well, it's not technically going yet, but pretty close. I am just in the middle of adding a heated bed and tidying up a few bits, but hopefully I will get to print something soon!

I am ok with calibrating the steps thanks, I wasn't sure about the other settings posted, I am not even sure if they are applicable to a delta.

On a side note, how are you finding the hall effect sensors? I saw your article and I have ordered some to play with.

Regards,

Les

---

Pointy's Things
Pointy's Blog

Quote
Pointy

Quote
jaguarking11
Hey. im glad you got yours going. The steps per/mm sound about right. I would do this if I were you. Unplug your hot end and trim the filament flush with the bowden. Then command the extruder to extrude 100mm of plastic. Then measure from the edge of the tube to the tip of the filament. Then simply take your knowsn steps in this case 208 then multiply it by desired distance which is 100 then divide by measured distance which lets for arguments sake say its 93, so your new steps per mm would be 223 or so. Hopefully this makes sense to you.

-Bruno

Well, it's not technically going yet, but pretty close. I am just in the middle of adding a heated bed and tidying up a few bits, but hopefully I will get to print something soon!

I am ok with calibrating the steps thanks, I wasn't sure about the other settings posted, I am not even sure if they are applicable to a delta.

On a side note, how are you finding the hall effect sensors? I saw your article and I have ordered some to play with.

Regards,

Les

The sensors have been flawless. No issues to report honestly. I plan on using them on my CNC mill build as well. They seem very accurate and more importantly they are repeatable.

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
The sensors have been flawless. No issues to report honestly. I plan on using them on my CNC mill build as well. They seem very accurate and more importantly they are repeatable.

What size magnets are you using,? I have some about 5x3mm but I am thinking something even smaller might be better. I am also thinking of how I can set up some sort of test rig with my digital calipers to measure the accuracy.

RE: The Extruder...

I still haven't printed with the Modicum extruder yet, but I am hoping to have the heated bed set up tomorrow now I have all the required parts. I did however have a problem with my Ormerod extruder, where the clip that holds the bowden extruder in place broke 6 hours into a large print. This made me wonder if I could adapt your extruder to work on the Ormerod. This is what i came up with...





It's designed to clip over the X-Plate the same as the original extruder, and also have the filament feed in the back and out the top so it should be a drop in replacement., It's probably going to be a bit heavier, but as I am using an aluminium X-Plate, I don't anticipate any problems.

I have it printed and assembled and I am just waiting on the MK7 drive before I can test it.

Regards,

Les

---

Pointy's Things
Pointy's Blog

I would not put that curve on the output. I think a straight shot is a much better way out the extruder as it reduces friction. PTFE tubing is used to get the radious curves you may or may not need. My .02c, this is a truely open design so you can do whatever you like.


As for the magnets. Mine are in the 3x5mm cylinder size. My advice is to mount the sensors on the body of the printer and have the magnets on the moving parts of the printer with some form of adjustment. The adjustment can be as simple as a M3 Bolt on an L bracket with the magnet super glued to the tip. This way you turn your bolt and adjust the printer, I would even go as far as putting a a nut on the bolt so you can lock it in place. ABS slurey makes a great thread locker for these printers, its impervious to vibrations but breaks free easily and cleanly from the threads when forced. Consider it a very mild thread locker.

Edited 1 time(s). Last edit at 08/02/2016 10:06AM by jaguarking11.

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
I would not put that curve on the output. I think a straight shot is a much better way out the extruder as it reduces friction. PTFE tubing is used to get the radious curves you may or may not need. My .02c, this is a truely open design so you can do whatever you like.
.

Thanks for the input.

I couldn't see another way of mounting the extruder and the filament really needs to come in the back and out the top when mounted on the X Arm. The 4mm PTFE goes into the block almost up to the drive, which I think helps a little...



I have done a few test prints, so far so good and it has definitely made the printer quieter.

Quote
jaguarking11
As for the magnets. Mine are in the 3x5mm cylinder size. My advice is to mount the sensors on the body of the printer and have the magnets on the moving parts of the printer with some form of adjustment. The adjustment can be as simple as a M3 Bolt on an L bracket with the magnet super glued to the tip. This way you turn your bolt and adjust the printer, I would even go as far as putting a a nut on the bolt so you can lock it in place. ABS slurey makes a great thread locker for these printers, its impervious to vibrations but breaks free easily and cleanly from the threads when forced. Consider it a very mild thread locker.

I am still playing with these, but I think I might use some analogue hall sensors with my own PCB, which will allow me to add some trimming to the circuit.

Regards,

Les

PS. Loved your 3D Printed Power Hacksaw.

Edited 1 time(s). Last edit at 08/08/2016 04:52AM by Pointy.

---

Pointy's Things
Pointy's Blog

What better way to test it than with a 6 1/2 hour print...



Really pleased with the results. This is what it looks like in the flesh...



Once it has been tested a bit more, I will put up the files for download, in case anyone else wants to give it a go.

Regards,

Les

---

Pointy's Things
Pointy's Blog

I have been on vacation for some time. Love the look of the extruder in your setup. I see you kept the faucet handle

I would love to test out your version of the extruder. I have been thinking of making a direct drive version as well for those who dont mind adding 200G to their carriage.

Let me know when you upload it.

-Bruno

EDIT: on the hall sensor front, I made the sensor holders adjustable so I can adjust distance.

Edited 1 time(s). Last edit at 08/25/2016 04:37PM by jaguarking11.

---

My Personal Blog. Build blog.
[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

Quote
jaguarking11
I have been on vacation for some time. Love the look of the extruder in your setup. I see you kept the faucet handle

I would love to test out your version of the extruder. I have been thinking of making a direct drive version as well for those who dont mind adding 200G to their carriage.

Let me know when you upload it.

Yes I kept the handle, it makes it look retro.

The version pictured above is specific to the Ormerod due to the mounting bracket, but it is the same basic design as your original. Apart from the feed and mounting, the only other thing I changed is the idler bolt. I made it longer, and added a spring and wingnut.

It has performed flawlessly since I fitted it, so kudos to the original design.

I have tweaked the bracket design to add a fixing on the X arm, but I have yet to print the new version. Once I have verified it I will upload teh files.

I have also modified your original version for my new delta, I'll try to get some pics and post them.

Re. Endstops.

I got some linear hall sensors and made a PCB with sensitivity adjustments. I also got some optical endstops to play with, but for the time being i have just fitted microswitches on the new delta. (I have fed 5v up to the top, just in case though)

Regards,

Les

---

Pointy's Things
Pointy's Blog