Dual gear extruder drive

jens55 · 27 Dec 2019, 05:13

I am thinking of changing my single gear extrder on my CR10 to a dual gear system.
I have the choice of Bondtech, Bondtech clone (both with 3:1 reduction) or going with a dual gear drive without gear reduction.

Questions:

backlash with a gear reduction drive - is it an issue and should I stay with an un-geared system?

Does a clone setup at about 1/4 of the price of the real thing produce a good result or will I get substantially more precision by going with the real Bondtech (the prices are just nuts)

What can I expect for a maximum retract speed with the 3:1 gear ?

Danal · 27 Dec 2019, 07:18

I tried a lot of clone extruders until I got my first Bondtech. Once I used it, I started replacing everything else I had as I could afford it. To your questions:

Backlash - non issue.
Clone - Can't answer that without knowing which clone. And even then, I couldn't answer, I've always purchased the real ones.
Max retract speed - don't know the math, because this has been a non-issue.

Me personally, I won't have anything else.

jens55 · 27 Dec 2019, 07:21

Great, thanks! Not what I wanted to hear but I suspected that would be likely the way it would go.
$179 CDN ... ouch ..... for a BMG-X2.

Danal · 27 Dec 2019, 07:26

Maybe someone will chime in with a good clone.

Danal · 27 Dec 2019, 07:29

All the ones I have are BMGs (no X2), Still $79.85 USD at Printed Solid.

Veti · 27 Dec 2019, 09:50

@jens55 said in Dual gear extruder drive:

BMG-X2

what about the new e3d Hemera? i am intrigued by it but waiting for the smaller motor version.

jens55 · 27 Dec 2019, 13:54

I am waiting for confirmation from my supplier but I think the BMG-X2 can only be used with the Chimera/Cyclops in a direct extruder configuration rather than a bowden setup. I am not yet prepared to go direct.
The extruder for a CR-10 is $115 CDN each with no motor (the BMG-X2 was a two extruder configuration with motors). Last night I decided to blow $17 CDN for a Chinese clone to see what I get. I fully expect it to be lower quality but by the time taxes are included the real thing is about ten times (!!!) the cost of a clone which is crazy.
My curiosity will be satisfied by the end of January.
Re the Hermera, I would like to stick with my Chimera setup for now.

Danal · 27 Dec 2019, 15:08

Keep us posted! It will be very interesting to see how that all works out.

cdl1701yahoo.com · 27 Dec 2019, 19:37

I have had a bondtech QR, Bondtech BMG and the BMG x2 as well as a few clones, I ended up designing and printing my own gear housings and just using the gears from them. The Clone gears wear out much faster than the genuine bondtech gears so now I just buy bontech gears and parts.

I have customized my housings to work with the printer design I am working with rather than conforming to the standard Bondtech designs. I highly recommend going dual gear over single gear, you will not regret it.

Just a side note on the BMG x2, I never did get it working to my satisfaction although that was not a reflection on the extruder but more on the E3D Chimera (genuine). I personally cannot recommend the Chimera/Cyclops as a hotend.

jens55 · 27 Dec 2019, 19:49

The only issue I have with the Chimera is it's tendency to string with a Volcano hot end but I always felt that was due to the large melt chamber in the Volcano.
I am looking forward to receiving the clone BMG. If the concept improves things to the extent everybody says it does then I don't mind spending money on the original but spending that kind of money without feeling confident on the result seems a bit foolish.
Can you confirm that the BMG-X2 can not be used in a bowden tube setup ?

antlestxp · 27 Dec 2019, 20:13

I'm not ashamed to say the TriangleLabs bmg clones work the same as the originals. I bought the clone to see how I would like them. Then bought the originals to support the company that actually put in the RnD. Sorry to say they print exactly the same. I will always say support genuine products but if cost is a limiting factor, majority of the stuff coming out of trianglelabs is top notch. Side note, the TL e3d titan clones are actually better than the original e3d products.

jens55 · 27 Dec 2019, 20:16

Good to know! Here is hoping ....

zapta · 27 Dec 2019, 23:58

@Veti said in Dual gear extruder drive:

what about the new e3d Hemera? i am intrigued by it but waiting for the smaller motor version.

I presume for a direct extruder configuration. Same here though in a recent video, Tom compared overall weights and if I recall correctly, it was not as bad as it looks.

The hemera has a very short path from the extruder to the nozzle. Same for some metal BMG clones that uses the extruder body as a heatsink.

cdl1701yahoo.com · 28 Dec 2019, 04:57

@jens55
The x2 is not designed to be used with a bowden set up but that does not mean that it cannot be modified to work. Here is an image of the bottom of the main body of mine.
I suppose you could drill out the plastic holes to fit a push-in fitting for the bowden tube.

jens55 · 28 Dec 2019, 05:06

Thanks ! That is exactly the view I was looking for and that isn't published anywhere.
Probably doesn't even need to be drilled out, just print a tight fitting press fit internally threaded adapter to fit into the recess, screw in a regular pneumatic fitting and Bob is your uncle. I use that method in a couple of other areas and it's working well.

Good to know that this is another option.

cdl1701yahoo.com · 28 Dec 2019, 19:14

@jens55
The dimensions of those larger diameter holes is 10mm diameter x 5mm deep.
the depth of the internal hole is about 17mm that fits the PTFE tube.