Which extruder to choose?

Hey guys,researching extruders has been fun, but I'm at a standstill on what extruder to use for my kossel mini(750/360)
Hopefully this thread will help other people when they are just starting out as well.
Here are the options I've found:
1.) Johann's extruder - comes with printed parts kit, requires geared stepper motor, slightly pricier, is compact.

2.) Airtripper BSP - takes a regular Nema17 motor, prone to slippage due to using underpowered motor, cheaper than johann's if buying a kit(tridprinting), no hobbed bolt.

3.) RichRap's Geared Bowden Extruder - design based off of Greg's Wade extruder, plastic kit is pretty expensive and less common than the other 2. Uses a standard nema17 with a herringbone, so less prone to slippage than airtripper. Uses standard Wade's hardware(8mm hobbed bolt). Purchasing a kit makes this option more expensive than 2.) But still less than 1.) Otherwise, this is quite a cheap option if you can print parts.

4.) Greg's accessible extruder - as seen on electronhack's YouTube, he uses the accessible extruder for his kossel mini. Making me confused on the difference between 3 and 4.

5.) PG35L microextruder - mounted a small, lightweight direct drive extruder under the kossel mini effector or above on the larger Rostock effector. Removes the need of the Bowden extruder.

Other questions:
1.) Is it better to have a Bowden extruder tube as vertical as possible? I.e. mounting it on top of the kossel?

2.) Is it much more difficult to utilize a larger effector instead of the smaller kossel mini's? Losing x/y?


Thanks for everything!

Consider an EzStruder from SeeMeCNC

[seemecnc.com]

E3D v5 the best hotend (with a mod to hold in thermistor

[e3d-online.com]

And another one to add to your list: [www.thingiverse.com]

I would choose whichever one which allows me to change the gear ratio (by printing new gear or pulley).

Lots of examples in this thread.

This one looks a bit good too. I'm planning to print it next week so I will post back with a review

[www.thingiverse.com]

Andy

A larger effector is a bit more stable I have found but you may lose some print size. The Kossel mini effector is about as small as I would consider.

I prefer my extruder mounted on top, pointing horizontal. I did my Rostock in the middle pointing up, so the bowden made a "U" shape and it always flopped all over. I also trid center mounting horizontal, that didn't work well either. Mounted at the top, horizontally, it seems to behave more, it's also shorter. In all cases, at the end of the day, put your effector down, this will keep your tube from taking a memory shape that lends itself to flopping.


My thoughts on the extruders I've used (Don't go cheap! Just like a cheap print head, extruders will cause you a lot of headaches!)

Ez Struder - LOVE IT! However, I don't recomend it for anything much smaller than a .5mm nozzle, as it lacks the torque for it, even with a Kysan. If you are using a large diameter nozzle though, this is the best extruder in my experience. It's simple, cheap and effective. Don't be fooled, nozzle size is far less important for quality than layer height.

Airtripper - It works well, but it's overcomplicated and again, lacks torque for smaller nozzles.

Berry Tripper- (Gregg's and Richrap's are all similar) One of my favorites. However, if your herringbone gears are not perfect, it can destroy itself (body and bearings). Use straight cut gears and it will be easier to print and last longer. This could push your finger through a bowden tube it has so much torque. In fact, due to some oversize fillament, I broke several pneumatic fittings with mine. Like the Air Tripper, it's a bit over complicated, bulky, and the gears, while handy for feeding filament manually, can nip your fingers if you aren't careful. I don't know how much damage it could do if it ever caught your finger fully into the hears, but it would certainly not be pleasant. This was always my go to extruder for my Rostock and if I didn't have the geared Nema, the Greg's or Richrap would probably be my choice today (it's more compact and has quick release compared to the Berry). If you use one of these, print the pinion from ABS and the spur from PLA. This quiets it due to dissimilar materials, but also ensures your pinion doesn't stretch and deform as easy. However, I would still do any of them with straight gears. If you want to use a standard Nema 17, use one of these, the Ultibots 1.75mm hobbed pulley, and use straight cut gears, it will work great. The YRUDS would be great if it had quick release.

Various PG35L extruders - I hated this setup. The motor really needs a heat sink for smaller nozzles. It also is gear reduced so much that it will not only slow your print speeds, but I couldn't eleiminate blobs due to the slow retraction. Basically, I just a bad experience with this. Warning, the gear box on this REQUIRES output shaft support. The output shaft only has a single bearing supporting it and many extruder designs don't do this. It will tear itself apart quickly. I also don't like the idea of an effector mounted extruder, bowdens are an inconvenience, but weight really slows a delta. My small Griffin usually runs at 200-350mm per second (depending on the job), and there's no way this could keep up, nor could the printer move that fast with it mounted on the effector. This goes double if I used magnetic joints.

Johann's Extruder and variants - A bit costly, and you need the 5:1 version, which is still a bit overgeared (retraction is a bit slow), but otherwise, this is the most elegant and best working sollution I've seen. If they made a 2:1 or 3:1 version, it would be perfect. I broke a fitting (and bowden tube) with this setup as well, and in a more spectacular fashion. The one big downside (besides price) is a lack of hobbed pulleys, no one makes a 1.75mm version and most 3mm hobbs don't work so well on ABS. With the torque of these setups, there is a fine line between slipping or ovalizing ABS, which jams in the bowden.

Personally, I'm using two Griffin Extruders, which are similar to the Kossel extruder, but works with a Nema 17 or Geared Nema. l use it geared.

Edited 1 time(s). Last edit at 03/25/2014 07:49PM by sheepdog43.

Wow thanks again sheepdog. I'll look into the berrytripper. So many derivatives to look at

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3DRapidClone
I'll look into the berrytripper.

If you want something like geared airtripper, then you may want to consider this one too: [forums.reprap.org]
It is the same as the rest except it is parametrized - a lot of small adjustements are easy to do.

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3DRapidClone
Wow thanks again sheepdog. I'll look into the berrytripper. So many derivatives to look at

You're welcome.
I would think the 3DR and Accessible Wades would probably be a bit better. The Berry really is an Airtripper with gears, as such, it's a bit over complicated and lacks a filament quick release. Something you will miss once you have had it. Even the creator of it has moved onto a geared Nema system.

Most designs, if they follow the same format, while slightly different, all work roughly the same and have the same pushing power, this was why I grouped them how I did. Take the Berry Tripper, 3DR and Wades, they all use a Nema 17 and a set of Wades gears, the only real difference is the shape. Yes, one may be easier to print, another easier to work on, but in terms of pushing filament, given the same hobb, they should all work the same. I only listed the Airtripper and Ez Struder separate because while identical in use, they are extremely different in terms of complexity.

The big thing is make sure you have enough power for your nozzle size (and a good hobb). How you get that pushing power, is up to you.

With accessible Wade's, is that directly usable with a Bowden? Its not designed for a pushfit right? Since its my first one, I'm really focusing on being able to get it from a kit since I can't print my own parts yet. But to decide between a standard nema with gears vs. A geared stepper seems to be quite daunting.

I figure that a .35 nozzle would be a bit too finicky for someone so new, wanting speed especially for infill, a .4 seems like a good compromise.

.35 is finicky and .4 is a great size actually.
I found the jump between .5 to .4 to be not bad, going down to .35 though, seemed like a big jump. I suspect that dust and things have a much easier time passing through .4 than compared to a .35. Knowing what I know now, I would probably just go with a .4, unfortunately, a good .4mm head isn't always easy to come by.

Most Wades are not made for Bowden, and worse, most are not made for 1.75mm filament either.

A geared stepper setup like the Kossel Mini is dead simple. There is no exposed gears, no printed gears to wear out, no shafts that your hobb wobbles on... I will take a geared stepper motor over a geared extruder any day. It's like using direct drive because the gear system is self contained.

I see! The 5:1 geared nema stepper is a bit over geared right? So it slows retraction a bit? Seen anyone try to gear it down to 3:1 if that's even necessary? Im hoping an astroyn damper will fit too but it probably won't due to it needing to be close together.

That is the reason I use printed gears. 5:1 (common for geared steppeers) is too much. Your retract speed will be low (probably below 50 mm/s). My opinion is one should have retract speed at least 100 mm/s for ABS with 0.5 head.

I'll most likely go with Johann's for simplicity and then once I get printing, I'll try out other extruders. Thanks!

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3DRapidClone
I see! The 5:1 geared nema stepper is a bit over geared right? So it slows retraction a bit? Seen anyone try to gear it down to 3:1 if that's even necessary? Im hoping an astroyn damper will fit too but it probably won't due to it needing to be close together.

You would be doing double duty and getting the worst of both systems, the complexity, ineficiency, and hassle of a geared extruder, and the added cost of a geared stepper all to accomplish what you could do with just a geared extruder.

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hercek
That is the reason I use printed gears. 5:1 (common for geared steppeers) is too much. Your retract speed will be low (probably below 50 mm/s). My opinion is one should have retract speed at least 100 mm/s for ABS with 0.5 head.

I agree 3:1 is closer to ideal, but from a simplicity standpoint, the geared stepper is just so much easier to live with on a day to day basis.

If we could get a 2:1 or 2.5:1 geared stepper, I would jump all over it.

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sheepdog43
Ez Struder - LOVE IT! However, I don't recomend it for anything much smaller than a .5mm nozzle, as it lacks the torque for it, even with a Kysan. If you are using a large diameter nozzle though, this is the best extruder in my experience. It's simple, cheap and effective. Don't be fooled, nozzle size is far less important for quality than layer height.

Are you seeing these problems with 3mm or 1.75mm filament? I'm currently building my first printer and I've ordered an EZStruder and a E3D V5 0.4mm hotend for 1.75mm filament. I've bought a 70oz-in stepper for the extruder.

Just wondering if I should order a larger nozzle straight away

1.75mm, almost no delta uses 3mm and many cartesians are moving to it these days.
With a .4, you will be pushing it pretty hard, but it will work. Just make sure you don't crank up the amps too high on the driver and I wouldn't go any smaller on your head size.

It can still get pretty warm on a long print. One thing I like to do on all of my extruders, is if you have an old motherboard, take the chipset heat sink and strap it to the extruder motor (with heat sink compound and zip ties). It's cheap, and quite effective.The ones from P4 and Core2Duo motehrboards are usually just about the perfect size.

Thanks for tips sheepdog43, I'll give it a go

Hmm, which extruder option would give the fastest possible prints?

Extruders don't usually limit your print speed, they can move plenty fast.
Remember, every mm of filament is 3.5mm to 5mm of extrusion out of the nozzle, at 200mm per second, your extruder only needs to push 57mm of filament (at most). Even heavily geared down, it's not likely to be much, if any, faster than your movement steppers are moving. I have had mine up to (an honest) 280-300mm per sec, and not had an issue with a 5:1 geared stepper, and if I didn't have a problem, you won't.

Your print head is more likely to be a limiting factor than your extruder (hint, add more heat!), however, you will be most likely bottlenecked elsewhere. The longer the belts (more stretch) and diagonals (more leverage), the slower you will be. The taller the printer, the slower you will be due to longer belts and frame flex. Magnetic ball joints mean a BIG speed reduction. There is simply too much weight, and flinging that around, the belts will either stretch and cause head crashes or the joints will separate. Not to mention what that weight does for frame flex. I lost over 50mm per sec. on my Rostock switching to them and even then they were trying to come apart.

My big printer (1000mm tall/500mm wide, which flexes a tad more than a kossel Mini) struggles to maintain 100mm per second with any resemblance of quality, my little carry on size printer, which is solid as a rock, I use about 200mm per sec. when I want quality. Same parts, same printer design. The difference is belt length, leverage, and frame flexibility. My Rostock which sat right in the middle in terms of size and stiffness, also fit right in the middle for speed. Keep in mind, it's been my experience that people over estimate their speeds by almost double. My mini at 180mm per sec., is estimated by other printer owners to be 300mm per sec. every time I show it. When they see 300, they are shocked.

If you really want speeds well into the 200's you need a very strong and stiff frame, short belts and short diagonals. A Kossel Mini may have a short diagonal, but the belts aren't that short and the frame is far from stiff. The belts on my mini sound like an unplugged electric guitar when plucked, until you get that, you won't get close to 300.

Wow, thanks for the insight, I'm hoping my cross-bracing and other modifications to the frame will help boost its rigidity enough. Now that I know extruders don't have as large of an effect as I thought, Airtripper and EZstruder are identical other than their difference in complexity. Is it a clear cut victory for the Ezstruder due to ease of use? I've seen people modify and used geared versions for the Ezstruder as well.

I have also tried most extruders on the list but am a huge fan of Johann's extruder. Yes, the geared stepper takes a big chunk out of your budget but it's a beast. All my direct driven extruders eventually fail. Bowden setups just have more drag. Speed is in my opinion not an issue. I drive mine pretty hard and fast and they do so 24/7 (for 4 months straight now!) and the extruder never fails (it's always the hotend that gives headaches). I sell both the geared steppers and the spur gears needed in my shop. The spur gears also really bite into the plastic and don't wear out. Other brass gears eventually got worn in. Ours are made in-house from stainless steel and on a computerized CNC machine. I agree, price is steep but you never need another setup again. Combine it with Johann's extruder head or Griffin's and you're done. Remember, if you pay peanuts you get peanuts.

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Builda3Dprinter.eu Your one-stop-shop for 3Dprinting and home of the Kossel Delta printers.

I'm testing on my delta Bulldog Lite E3d Hotend
excellent economic solution

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DELTA Printer - Duet -Touch5" - E3D_V6

I just wanted to post about my experiences with the Bulldog extruder.
I ordered it through their initial Indiegogo campaign, so I would have a good extruder for my new printer. Not sure if I got a lemon or what, but the extruder I received is a piece of junk. It doesn't have the strength to push ABS or PLA filament through even a basic .5mm hot end even at reduced speed, let alone the tighter nozzles that it included (Merlin and Magma). It fails to maintain a good enough grip on the filament to push it through, and when you tighten it enough that it ought to have enough power, it starts jumping gears in its gearbox.
I have a Wade's Accessible extruder on my old printer and I have never had a single problem with it. It works flawlessly. And so I am putting together another one and scrapping the Bulldog until I can get either a refund or replacement from ReprapDiscount.

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JBernal
I just wanted to post about my experiences with the Bulldog extruder.
I ordered it through their initial Indiegogo campaign, so I would have a good extruder for my new printer. Not sure if I got a lemon or what, but the extruder I received is a piece of junk. It doesn't have the strength to push ABS or PLA filament through even a basic .5mm hot end even at reduced speed, let alone the tighter nozzles that it included (Merlin and Magma). It fails to maintain a good enough grip on the filament to push it through, and when you tighten it enough that it ought to have enough power, it starts jumping gears in its gearbox.
I have a Wade's Accessible extruder on my old printer and I have never had a single problem with it. It works flawlessly. And so I am putting together another one and scrapping the Bulldog until I can get either a refund or replacement from ReprapDiscount.

my bulldog lite is working great with both hot E3D Abs that Pla
these are my images
look also the sharp curve in output
do not tighten the screws a lot of pressure otherwise the thread mill

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DELTA Printer - Duet -Touch5" - E3D_V6

Hi,

I read this thread several times as I am trying to find my way into the topic of choosing a proper extruder setup.

I am personally interested in a reliable, high-end, well performing solution that is a combination of a hot+cold end (extruder), rather then a cheap one.
Basically I need to buy everything that is between the filament (1.75mm most probably) and the deposition orifice. Pardon me for swinging a bit aside from the main topic (extruders only) and including hot ends here as well, but it looked like I can get an insightful response here from experienced guys.
Please also feel free to comment on bowden vs. direct setup. It's not that I am fully fixated on Bowden, it's just seemed better from what I saw so far.

From what I have seen so far, I was almost ready to order an EZstruder + Prometheus hot end (prolly need to get the beta V2 at this point) and configure them in a Bowden setup.

@Sheepdog43
That was until I saw your post about EZstruder lacking the torque.
So I guess what I am trying to find out is if EZstruder (was planning to buy also their own stepper motor) + Prometheus, 0.4 orifice in a 1.75mm bowden setup could possibly have problems performing.
Other high performance solution I can see at this moment is E3D v6 with a geared cold end, one of those mentioned earlier (Berry tripper following your classification).

Thanks for everyone's reviews so far, particularly Sheepdog43 being the most active one on this thread.
I would appreciate any other information or comments you might have, also from the fact that nobody has used this thread for 10 months now, so...there might be some news or experiences.

SL

Edited 1 time(s). Last edit at 03/12/2015 08:21AM by StickyLube.

I've always used a Greg's Wade Bowden extruder and never had an issue. The E3D V5 clones from China perform surprisingly well too.

@AndyCart

About the Gerg's Wade extruder..do you know if someone is selling an entire kit for assembling it?
Cos all I have found till now are thinginverse designs, and I am not even sure which one is the most reliable for 1.75mm filament.

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StickyLube
@AndyCart

About the Gerg's Wade extruder..do you know if someone is selling an entire kit for assembling it?
Cos all I have found till now are thinginverse designs, and I am not even sure which one is the most reliable for 1.75mm filament.

I have a V6 Clone and that also works well as for Extruders you could look at the RepRapPro complete Mendel Mini Extruder that they sell for around £30 this includes the Motor as well so is a not bad price.

I have fitted one to my machine

You get all the White printed parts you can see in the Picture (Plus a few others) this is the Same Extruder that Think3Dprint3D supply in there mini Kossel kit.

I drilled the body to 9mm diam (Very Carefully and in stages 6 then 7 then 8 then 9mm) and fitted a Norgren 4mm Airline fitting (RepRapWorld sell them if you can't find one at a industrial supplies type place) 1/8 BSPP thread.

And printed out the Red mounting arm to my own design.

HTH

Doug

Edited 2 time(s). Last edit at 03/12/2015 11:29AM by dougal1957.

I figured I would throw my design out there as well. Its a belt drive extruder. 2:1 ratio. It only works with bowden and 1.75mm out the box. Its designed around the premise of having the retraction speed of a direct drive, with no slack while being stable at pushing filament. At the present time I have got between 150-175mm/s with my .5mm nozzle. It shows no signs of issues at that speed. That is the top speed my delta will do without reducing quality too much. I am upgrading it currently with lighter parts to allow 200mm/s +.

My extruder needs 3.5mm of retraction via bowden and as of now I use 200mm/s retraction speed with no issues, I could probably push it faster.

If you want to try it be my quest.

Here is the BOM and STL files as well as the sketchup files included. [www.youmagine.com]

I am also selling a few of these on everybodys favorite auction house.

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