My extruder design totally reliable

This is the second one that I've made and it is rocksolid reliable I have never had it fail extruding extremely cold or very fast. In my opinion the main problem with extruders that are available is the size of the drive wheel everything out there is too small of the diameter. The ones I use are serrated drive wheels for a mig welder they are over 1 inch in diameter with normal pinch wheel tension on centerline I have indentations above and below on the filament obviously more teeth engaged because of the larger radius. Because of the large diameter I use 100 to 1 year motor. I cannot get this extruder to fail it has an incredible amount of pull or push depending on which way you look at it. Coupled with a housing that has no room for it to buckle this is bulletproof I've been trying to get this across for a year now nobody's listening

When you say you can print very fast could we get some numbers? Including acceleration numbers since they are what actually determine the true speed. Also layer heights and extrusion widths.

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I'm listening. I know nothing, of course, so I listen to just about anybody at this point.
Makes sense to me. I haven't really thought too much about the extruder part of printing. I did know one thing, though, smaller drive gears seem to have a problem gripping. I would also think that it would tear up the filament more, since it's pressure in a smaller area. More area and slipping is more than compensated by other teeth keeping it along, preventing it from happening in the first place.
I like it. Honestly, why is no one listening? First idea is that everyone wants compact and lightweight.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

I'm not a fan of the Bowden type extruders but in that case it would not matter again everybody wants light I understand why but in my mind the extruder and the hot end are the most important part of 3-D printing and besides the ones that I have built I hear everybody has a lot of problems. I haven't put a lot of PLA through just ABS but I'm assuming it's just as good. On the first larger one I made for my large printer I built the hot end first and then the extruder tested and tested until I was happy with it and then built the machine around it. On that one I even use a nema 23 motor and 100 to 1 gearbox with pinch at normal tension I could hold onto the filament and throw the heavy extruder towards the ground quite a bit of force and it didn't even slip

Edited 1 time(s). Last edit at 05/28/2014 01:09PM by cnc dick.

I've been looking at all of the problems everyone has and in planning my printer build I have been trying to remove all of them. My first and foremost rule was that absolutely no functional part will be 3D printed. In my personal experience. 3D printed parts are extremely unreliable. I'd love to poke your brain and figure out what you have done and why, so I can ditch this old Solidoodle for a reliable set of printers.
But I'm also interested in what speeds you can reach with your setups.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

One thing you need is high acceleration rates to get good square corners a lot of people slow down the acceleration rates to get higher millimeters per second travel but it's terrible for printing machine needs to be extremely sturdy if you're going to print anywhere near 80 mm a second. Print quality seems to suffer the faster you go not that the printer can't do it it's the molten plastic not having enough time to bond correctly to what's below it I usually print with ABS but with PLA you could probably go faster and still get a good print. Depending on what it is with ABS I usually print anywhere from 50 to 80 mm a second can go much faster print quality suffers not because of machine wobbles because a plastic laying down. In your configuration H file I would not go below 2000 for the acceleration settings for the X and Y somewhere between 2000 to 8000 seem to be good for the acceleration settings depending on the mass you are throwing around. I would definitely use Nema 23 motors with the standard electronics if you get them somewhere around 4v to 5 V and 1.5 to 1.7 amp they will run perfectly with much more torque for amperage that is because of their diameter think of it is a lever for the same voltage and amperage you end up with more torque because it's further out from the center point. One of the other things on this last little printer which is approximately 12 x 12 x 12" I wanted it to be easy to work on literally on the latest one I built you can remove the whole y-axis in one piece by removing four bolts and unplugging motor plus switch and heat bed which is an electric griddle under a quarter inch aluminum jig plate plate access belt drive everything this rate out of the printer. You also to remove the whole x-axis in one piece by removing 12 bolts and unplugging the motor and the switch. I wouldn't go much larger than what I've built here with belts any larger I would use ballscrews with high lead for the X and Y which I thought about doing this one I have two nice 40 mm per turn ones laying around

Edited 7 time(s). Last edit at 05/28/2014 02:18PM by cnc dick.

I've already got my NEMA 23's purchased, typically go with a 3-5000 accel, so I've got that down. I don't print anything beyond 60mm/s, mostly because I suffer from Solidoodle syndrome. Was hoping to acheive faster with my new printer, but I guess I'll have to see, that won't change my build at all. Solid and sturdy are my biggest hopes with my printer. I plan to bolt it to something, likely a heavy table with a wall to bolt two sides.
4-5V? That's a far cry from the standard 12V, you'll have to explain there.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

Hopefully the stepper motors you bought are rated around 4 to 5 V and not any higher if you're going to run 12 V or even 24v when you size stepper motors try to go way below the voltage of the power supply voltage should be up to 8 times greater if you match the voltage with the motor it's going to run terrible. Stepper motors are kind of a black art I designed and built plenty of machines in my life using them. And as far as printing fast goes it all depends on the quality you like me I am kind of fussy with quality my worst prints at high rates of speed at 80 to 100 mm a second are better than most I see so you may be able to go way faster it's just up to your personal preference. On the motors the ones you bought are 12v or anywhere near I would buy other ones

Edited 5 time(s). Last edit at 05/28/2014 02:44PM by cnc dick.

This is my motor. Standard ATX PSU, running from 12V line, hooked up to my Minitronics board, ATM. Megatronics in the final build.
I'm not following you with the voltages. I should run a 4ishV rated motor on a 12V PSU? Doesn't make sense to me, so I'm quickly assuming I'm not reading it the way you're saying it.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

Let me see if I can clarify this when you buy the stepper motors the rated voltage of the stepper motor has to be way lower than the voltage of the power supply you're going to run

Edited 3 time(s). Last edit at 05/28/2014 04:40PM by cnc dick.

So the rated voltage is a minumum voltage? What's required to get it to move?

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

This one looks to be optimal here is a link[www.automationtechnologiesinc.com] look at the PDF manual and you'll see the voltage and and inductance. I don't think the motors you got are a very good choice. Try to find something closer to the resistance and inductance of this one I pointed out to you and you should be good

Edited 3 time(s). Last edit at 05/28/2014 05:21PM by cnc dick.

Alright, yeah, I never researched that far. I only looked for bipolar, four lead, and high torque for reasonable price.

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Realizer- One who realizes dreams by making them a reality either by possibility or by completion. Also creating or renewing hopes of dreams.
"keep in mind, even the best printer can not print with the best filament if the user is the problem." -Ohmarinus

Its funny, I got my hands on a mig welder driver myself. Its design is very interesting, however the one I have is meant for .5mm wire, so too small for my use. However I can say that the teeth are farily spaced apart compared to direct drive or hobbled bolt. This design has a lower chance of shredding the filament or wire. Something to be learned from this path. Good luck with yours.

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jaguarking11
Its funny, I got my hands on a mig welder driver myself. Its design is very interesting, however the one I have is meant for .5mm wire, so too small for my use. However I can say that the teeth are farily spaced apart compared to direct drive or hobbled bolt. This design has a lower chance of shredding the filament or wire. Something to be learned from this path. Good luck with yours.

being made for a little smaller wire seems to be no problem the corners dig into the filament nicely obviously .5 for you is little too small if I remember right my wheel was for I.2 mm and I run 1.75mm

Edited 1 time(s). Last edit at 05/31/2014 08:20AM by cnc dick.

Dick, how many of those teeth are engaged at one time? I'm really starting to dislike the machined bolt thing. It's really becoming a problem for what I am doing now and this looks like a good solution. You are running a 100:1 planetary on a nema 23 or 17?

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Bill Clark
Dick, how many of those teeth are engaged at one time? I'm really starting to dislike the machined bolt thing. It's really becoming a problem for what I am doing now and this looks like a good solution. You are running a 100:1 planetary on a nema 23 or 17?

in this post it's a NEMA 17 but I have built one with Nema 23 for my large machine. But the 17 would have worked just fine you can see by just pushing it in I get one tooth above center one and one below with pretty good indentation three good indents on filament without moving the filament. Would be more if I increased the diameter of the pinch roller but I haven't had any problems the way it is

I'm trying to understand exactly how it works. does the filament go all the way in between the rollers and does the filament side opposite of the rollers ride on the housing keeping it engaged? with only a few teeth engaged the results are impressive. seems you could engage many more teeth if needed

No bill it's very simple is the same as normal the groove further in towards the gear motor is for a smaller diameter wire most of these mig welder drives have two different sizes so you can turn it around for the wire size you use. The one that's in board is not being used besides the design which is very good because the points are offset one point on one side is the gullet on the other obviously they are meant to feed wire. But the real advantage is the diameter and this is what I think reprap and even Pro machines are missing. Don't worry about matching your size filament that accurately I think the ones I use are for 1.2 wire and obviously I use 1.75 filament it is a fairly good picture try to zoom in on it and you'll see what I mean. Because of the radius of the filament you could be undersized on the drive the corners of the drive wheel dig in superbly in fact it's probably better to go a little bit undersized like I say I use a 1.2 mig wire wheel on a 1.75 filament. I know you understand what I'm talking about I been trying to get this across for over a year now in the reprap community and nobody's listening. The radius of the drive wheel is a big problem when it's small you dig into what we will say on the centerline and the other teeth the other teeth aren't even touching the filament that's where a large radius drive wheel comes into play

Edited 12 time(s). Last edit at 06/02/2014 09:41PM by cnc dick.

I like it and plan to start working on a design utilizing this approach. I think the reason everyone isn't biting on this is because the "standard" performs ok in normal use. Besides not everyone has mills and lathes to go bang this stuff out. I'm way outside the box on my current project and this is exactly what I need. Thanks

Quote
Bill Clark
I like it and plan to start working on a design utilizing this approach. I think the reason everyone isn't biting on this is because the "standard" performs ok in normal use. Besides not everyone has mills and lathes to go bang this stuff out. I'm way outside the box on my current project and this is exactly what I need. Thanks

Bill I knew you would understand what I'm talking about keep us up to date on your project

This Is something I printed yesterday just to put some time on the little machine it's a Dragon I got off thingaverse. In sprayed some clear lacquer on it made of ABS so the clear lacquer tends to melt the surface little bit and smooth it out but it was a good print to start with very little sanding probably about five minutes it was a six-hour print but I have no doubts that the machine would run flawlessly for days

Seriously considering designing an extruder using this technique for my current CoreXY build. Think there would be any problem using printed parts instead of milled parts?

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Plastic should be fine but you do have to use a gear motor and one with that high gear ratio I use 100 to 1 I think the minimum would be somewhere around 50 to 1

Edited 1 time(s). Last edit at 06/06/2014 07:34AM by cnc dick.

Cooool. Yea I found some Chinese 100:1 Nema 17s for $40 so it seems pretty reasonable assuming they will work properly.

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As far as mounting the mig drive wheel goes you are probably going have to drill and tap the end of the shaft of the gear motor plus make some kind of a little adapter for the shaft the mig drive wheels are extremely hard

Could you please post a diagram of your cold end? I'm unclear whether the contact area is at a pinch roller (if so, what size?) or the drive wheel presses the filament against the housing, or what. If you're interested in more widespread adoption of your drive, diagrams with measurements and part numbers would help people reuse your idea without having to redevelop it. Thanks.