Which extruder setup ?

Hi
Which extruder setup is most people going for lately if you have a metal hotend ? I was thinking of changing my Mendel90 extruder setup or is this the best that this setup can do ?
I know that the type of printer plays a big part, however I would appreciate your comments.

Your comments & recommendations would be great.

Thanks

Edited 1 time(s). Last edit at 06/23/2015 02:13AM by scubi.

The "classic" extruder design for the various Prusa Mendel and Prusa i3 variants is the Greg's Wade's Geared Extruder. Its qualities can be summarized in three words: it just works.

There are two new classes of extruders that attempt to improve in one way or another on Greg's Wade's Geared Extruder:

- Direct drive designs (no more gears).

- Bowden designs (the extruder is attached to the frame and connected to the hotend using a Bowden arrangement). These can be geared or direct drive.

You'll find a large variety of different designs along those two lines on Thingiverse. You can choose one or another and experiment until you find one that fits your requirements and works well for you, on your setup.

Do you guys know if direct drive designs have issues with slippage or resolution? I'm curious is a direct drive design with a NEMA 17 will have enough torque (Ebay Example)

I need to customize the mount for my extruder and a direct drive would simplify the design considerably or I could find an off the shelf option.

My instincts are to avoid 3D printed gears in this area for reliabilty and accuracy, but if the Greg Wade's Geared extruder has a good reputation, I should take that into consideration.

The challenge in getting a reliable direct drive extruder is very exactly that of torque. You have to rely on a proper drive gear (the MK7 and the MK8 gears are popular choices) and a good stepper motor driven at or near its maximum rated current, meaning it will also get quite hot.

Greg's Wade's Geared Extruder has a sterling reputation because it avoids these issues. The 3D printed fishbone gears have very little or no play/backslash and at least in my case, have proven to be extremely reliable.

You have to experiment and try various extruder types and check the pros and cons of each type and how they suit your particular setup, there is no universal solution.

Quote
TFinleyosu
Do you guys know if direct drive designs have issues with slippage or resolution? I'm curious is a direct drive design with a NEMA 17 will have enough torque (Ebay Example)

I need to customize the mount for my extruder and a direct drive would simplify the design considerably or I could find an off the shelf option.

My instincts are to avoid 3D printed gears in this area for reliabilty and accuracy, but if the Greg Wade's Geared extruder has a good reputation, I should take that into consideration.

As long as the feed in clean and the setting are ok, the bulldog and hexagon are a good combo.
(just go a bulldog lite+Hexagon AO+0.3 nozzle to work well.)

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GRAYWOLF

Quote
TFinleyosu
Do you guys know if direct drive designs have issues with slippage or resolution? I'm curious is a direct drive design with a NEMA 17 will have enough torque (Ebay Example)

I need to customize the mount for my extruder and a direct drive would simplify the design considerably or I could find an off the shelf option.

My instincts are to avoid 3D printed gears in this area for reliabilty and accuracy, but if the Greg Wade's Geared extruder has a good reputation, I should take that into consideration.

As long as the feed in clean and the setting are ok, the bulldog and hexagon are a good combo.
(just go a bulldog lite+Hexagon AO+0.3 nozzle to work well.)

Hadn't considered the Hexagon... Thanks.

Do you know what the overall length of the Hexagon is from end to end with nozzle?

Edited 1 time(s). Last edit at 06/25/2015 03:55PM by TFinleyosu.

Quote
AndrewBCN
The challenge in getting a reliable direct drive extruder is very exactly that of torque. You have to rely on a proper drive gear (the MK7 and the MK8 gears are popular choices) and a good stepper motor driven at or near its maximum rated current, meaning it will also get quite hot.

Greg's Wade's Geared Extruder has a sterling reputation because it avoids these issues. The 3D printed fishbone gears have very little or no play/backslash and at least in my case, have proven to be extremely reliable.

You have to experiment and try various extruder types and check the pros and cons of each type and how they suit your particular setup, there is no universal solution.

Thank you for the advice. The printer that I'm repurposing has mounts for a DC motor that will actually fit nicely with a stepper motor with planetary gearbox. I think I'm going down that path right now. It will take a custom bracket to hold the hot end, but I think its going to be a nice setup. Now I need to figure out if the hot end is going to be too long.

Direct drive does not have enough torque IMHO. I was using the airtripper design and it is a good extruder. But not exactly high speed. I wanted a geared extruder and designed one. I was not happy with the lash on it. Even though I was using premade gears and not printed ones. Now I run my 2:1 extruder that is belt drive, its much more compact than my previous geared extruder and uses some nice parts. However all my extruders are built for bowden drive. If your interested search for modicum extruder. I have one last unit for sale on ebay. if your interested search e-bay and you will find it. If you have the patience here is a youmagine link with the STL files and BOM. [www.youmagine.com]

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

Modicum V1 sold on e-bay user jaguarking11

During the past year I have developed a new dual drive extruded that now are in production, it has a very high feeding force and do not have problems with grinding and slipping. It uses a geared Nema17 stepper which gives huge torque and high resolution.
I have happy users all over the globe.

Please visit www.bondtech.se for more information.
It is an open source project with downloadable stl files if you want to print your own housing parts.

@ bond

I checked your website and honestly, I cannot see any outstanding feature with your extruder that would grant its $180 price. Compared to a $10 (overall cost of components) Greg's Wade's Geared Extruder that provides the same torque, it is certainly more compact, but is also less maintainable and not as practical when it comes to filament access.

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GRAYWOLF

Quote
TFinleyosu
Do you guys know if direct drive designs have issues with slippage or resolution? I'm curious is a direct drive design with a NEMA 17 will have enough torque (Ebay Example)

I need to customize the mount for my extruder and a direct drive would simplify the design considerably or I could find an off the shelf option.

My instincts are to avoid 3D printed gears in this area for reliabilty and accuracy, but if the Greg Wade's Geared extruder has a good reputation, I should take that into consideration.

As long as the feed in clean and the setting are ok, the bulldog and hexagon are a good combo.
(just go a bulldog lite+Hexagon AO+0.3 nozzle to work well.)

My previous comment is bull, the xcarriage overheated and deformed using this setup, avoid the AO and 0.3 nozzle, stick to 0.4 and use the pla fan as a backup for the abs cooling fan!

I've been using a BullDog XL with an E3Dv6 hot-end to print 1.75mm ABS daily for more than 6 months and have not had a single jam.

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the_digital_dentist
I've been using a BullDog XL with an E3Dv6 hot-end to print 1.75mm ABS daily for more than 6 months and have not had a single jam.

I'm running the lite not the XL and I think the 0.3 is to blame!

Well I guess it is not comparable with regards to cost. The drive gears of my extruder is precision cnc machined in hardened tool steel at a Swedish producer of gear components for the automotive industry. Since the volume is still low it is very hard to get lower production costs. It is for sure a big difference from the China mass produced parts. The price is Usd 145 if you are outside EU because of the VAT.
I have users that have replaced their Bulldog extruders with the Bondtech that are super happy.
The key is to use two drive gears to grip the filament from booth sides and at the same time give huge force without filament deformation. very important in Bowden applications.

I would say it is very easy to maintain, two m3 screws and you have full access to the components.

To change filament a small Goode is used to load and unload the filament. The current design is not openable.