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Bondtech BMG upgrade for the N series

Posted: Mon May 01, 2017 5:06 pm
by Jetguy
Martin of Bondtech just sent me the latest and greatest prototype BMG style dual extruder for the Raise 3D n series. This is cleverly made to drop onto all three models (N1, N2, N2Plus) and fits either cast or CNC style central crossing block.
This is insanely lighter than the stock dual extruder feeder system of 2 full sized NEMA17s and the massive aluminum extruder feeder assembly.

I'll post more details as I get on with this, but again, this is a really, really, really huge jump for those wanting dual direct drive, and you get the added bonus of 3:1 geared NEMA17 pancake motors for even more mass reduction.

This is the original BMG single just for reference so you can better understand the design. http://shop.bondtech.se/ec/extruders/bmg-extruder.html. Also, here is a video https://www.youtube.com/watch?v=gUzqtpTxMgY

Also, for reference, another user Eric Lien had done some side by side testing of the BMG design against other brands of extruders (Titan- cough, cough, for example). http://www.bondtech.se/en/products/extr ... -extruder/

The key here is this is a highly customized variant made just for the Raise 3D series.
Please note, I just bolted this up to my brand spanking new N2Plus and it was configured in single extruder trim. I have all the parts to make it dual extrusion and will 100% be testing that way, this was just a take it out of the FedEx box and bolt it on for test fit session and immediate feedback to Martin test. I will have results hopefully later today. Also a bonus, the latest shipping printers that come with the black motors have connectors that directly match the Bondtech supplied pancake motors. This is basically bolt and go, you simply add one line to your starting gcode to adjust steps per mm, and adjust the stepper driver current manually on the stepper driver (motors are 0.7A rated). In all, it should give a much better and stronger dual extrusion experience, also reducing moving mass and thus ringing and other print artifacts.

Re: Bondtech BMG upgrade for the N series

Posted: Mon May 01, 2017 6:04 pm
by Stratosphere
That's really awesome!

Re: Bondtech BMG upgrade for the N series

Posted: Tue May 02, 2017 4:28 pm
by walshlg
OK , NOW you have my attention. definitely interested, please continue to keep us updated.

what is the difference in weight??

How do you adjust Z with the dual extruders?

Re: Bondtech BMG upgrade for the N series

Posted: Tue May 02, 2017 7:47 pm
by Jetguy
Adjust z? Same as before, the hotend system is still all Raise 3D V2. Just in that picture, I still had it in single extruder trim with the single extruder style print cooler duct on the right hand side. I had the extra V2 hotend and just need to install that, level the nozzles, and print tonight.

Re: Bondtech BMG upgrade for the N series

Posted: Wed May 03, 2017 6:40 pm
by Jetguy
Sorry, just trying to get all this setup and tested and it took a day or to for me to get spare time to answer some of these questions.
The combined BMG dual extruder with 2 pancake style 25mm thick motors is 428 grams ready to bolt on. That's motors and everything.

So a stock single is 155+288= 443g
Stock dual extruder is 253+288+288 = 829g
Current previously shipped version of the N2 Bondtech upgrade using the stock NEMA17 motor as supplied with the printer=367 g

Broken down individual weights of components:
Stock single extruder aluminum block plus acrylic top plate and 2 thumbscrews without motor is 155 grams
Double aluminum bracket plus acrylic top plate and 3 thumbscrews is 253g.
The stock NEMA17 motor is 288g
Short pancake style 25mm thick NEMA17 153g


So basically, compared to a stock setup, right now today if you buy the current version of Bondtech based on the mini and reuse the existing stock NEMA17, you are at 367 grams VS the stock single extruder at 443g
If you swap in the new BMG style, you get dual extrusion direct drive feeders 428g so still lighter than the stock single.
If, you used the new BMG and only installed one motor or they come out with a single motor variant of the BMG bolt on upgrade, that's roughly 428-153=275 grams, and given the normal non configured for an N2 BMG is 220 grams, I have to think if they go that route, that's probably closer since my math still left more housing and stuff for a second motor and gears.

Also, pull force (and thus push force) on this is just outstanding. It's even stronger than the Bondtech mini and right up there with the QR. If you jam this extruder, something has gone horribly wrong.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 2:14 am
by firesped
I heard during a test, it actually pushed a hotend out that wasn't completely tightend down.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 10:28 am
by Brad
I have been thinking about getting into dual nozzle printing with some PVA so i can make my prints require less post processing work.
Now that martin has made a dual extruder, he is going to cost me more money buying another 4 extruders from him.
Jetguy, let me know how you are getting on, and Martin if you are lurking here somewhere, I will be getting a set from you real soon ;).

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 10:40 am
by lami3d
If it appears that dual extrusion is perfect or nearly perfect (+ maybe motors will be not so hot that actually), i will remove bontech hybrid on a printer and will install this set up.

About the pancake motors : is their step value the same than the stock motor one ? (i think it's not the cas but maybe...)

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 12:40 pm
by Jetguy
BMG is 415 steps per mm
Bondtech mini is 140 steps per mm
Bontech QR is 476.5 steps per mm
Stock Raise 3D extruder is 94 steps per mm.

The biggest thing here is the problem we had before with the older mini system. In and of itself, a single extruder was simple, just change the value in firmware or add the M92 E140 to your starting gcode of every print. This is as easy as editing the machine profile so it does this automatically in Ideamaker.
The problem was, originally, the second extruder would have been a remote Bowden tube feeder, and that means it would have been the suggested QR 5:1 geared extruder with 476.5 steps per mm, while your left extruder was 140 steps per mm. The issue was, Marlin firmware did not support 2 different steps per mm.
So, based on that limitation, there were 2 parallel paths being taken. One was editing the firmware source to attempt to add the functions to support 2 different steps per mm extrusion and the second was just at the hardware level, just use another Bondtech mini extruder on the remote Bowden drive so that both extruders were the same 140 steps per mm. The tradeoff with that is that Bowden adds friction to pushing the filament and the QR feeder is stronger than the mini. Not so much a problem, just a noted difference.

The point being, the BMG dual shatters all of this. If it sells in a singe extruder version, it's stronger than the current Bondtech upgrade version and lighter. So light, that in dual extruder, it's not much heavier than the single previous Bondtech but provides more pushing force, and solves the mismatch steps per mm problem. Again, the Bondtech BMG dual extruder is still lighter than the single extruder stock Raise 3D extruder.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 12:54 pm
by Jetguy
Also, sorry for lack of pictures and printing updates. I was just trying to work around my schedule and ran into my own snags with my printer that has nothing to do with the upgrade. I purchased my N2Plus in single extruder version because I had more than enough parts on hand to make it dual. The issue was, I needed to insulate my brand new hotends and also install brand spanking new upgraded plated hard MicroSwiss nozzles. Just saying, if you are doing it, go all the way kind of mentality. Well, I also dug out a fiberglass and silicone sleeve alternative insulation and realized I got the wrong size.

All that to say, I already printed with it a basic test cube and of course it was perfect to show I had the right steps per mm, I had adjusted the stepper driver current correctly, and luck of all luck, the existing stepper cables plug right into the upgrade Bondtech motors and were even correct polarity and direction of motor rotation. What I'm saying is, this is a very easy mod to install. Especially if you already were setup for dual extrusion. Me, I'm doing a double conversion. Upgrade to Bondtech dual BMG and convert mine from single to dual extrusion and, install some upgrades to the hotends (insulation and nozzles) all in one shot.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 2:28 pm
by Bondtech
Brad wrote:I have been thinking about getting into dual nozzle printing with some PVA so i can make my prints require less post processing work.
Now that martin has made a dual extruder, he is going to cost me more money buying another 4 extruders from him.
Jetguy, let me know how you are getting on, and Martin if you are lurking here somewhere, I will be getting a set from you real soon ;).


I am lurking around here Brad ;) and it is good to hear that you will be upgrading... this design was not the simplest to accomplish I can tell you but I finally got it together.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 3:13 pm
by woofy
When will they be available to purchase?

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 3:31 pm
by Jetguy
I think he was waiting on more feedback from me on this test, and I'm working very hard to ensure I'm testing it through the paces. So far, the tiniest of tiny mods was done to the electronics housing for the extruder breakout board. Just an adjustment of hole positions and standoffs. The main body of the extruder, the fit and finish is perfect. I just got my second nozzle and hotend leveled so getting ready to throw dual extrusion prints at this now.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 3:31 pm
by Bondtech
woofy wrote:When will they be available to purchase?

Once we have got the feedback we need to be sure to start the production of the parts. Hopefully very soon but it is hard to tell an exact date at the moment. ;)

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 4:10 pm
by walshlg
One thing to note: The current printed plastic cover over the thermocouple/ heater board that screws into the cold end, is too small for adding the 100nF ceramic capacitors to the thermocouples (rec mod from Raise3d) without pushing them perilously close to the bare wires. I just broke the top off.

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 7:56 pm
by IMDIMA
Congratulations Martin,
This promises to be an excellent upgrade!

A question:
In the configuration in simplify3D, for use in a choice of single or double extrusion, the modification of the e-step in the gode of the "starting script" (M92 E415) must be done in each of the three operating modes? (Left Extruder Only / Right Extruder Only / Both Extruders) ?
Thanks

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 8:37 pm
by Charles
Martin, will you make an adapter available for those of us with the original kickerstarter motors? I think Jetguy mentioned that the cables / plugs are not the same as the new pancake motors?

thanks!

Re: Bondtech BMG upgrade for the N series

Posted: Thu May 04, 2017 10:30 pm
by Brad
Charles wrote:Martin, will you make an adapter available for those of us with the original kickerstarter motors? I think Jetguy mentioned that the cables / plugs are not the same as the new pancake motors?

thanks!


Hi Charles,
To me, the motors are cheap enough, I would just buy replacements and modify the code as per necessary. This way your original system is still in its factory setup and should you require to put it back on (unlikely, but things happen), its ready to go.

Re: Bondtech BMG upgrade for the N series

Posted: Fri May 05, 2017 8:59 am
by Bondtech
As Jetguy says there is now two type of motors in the printers, all new ones will have the black motors, the older will have the silver motors.
These two models does not share the same type of connector.

Raise3D Motor connectors.JPG


On newer printers the the orginal cable from Raise3D will fit directly into the motor.
Our motors are supplied with a short cable that we can solder a connector to that will fit into cable directly on older printers. This would solve this issue in a simple way making the kit to fit both older and newer printers.

Re: Bondtech BMG upgrade for the N series

Posted: Fri May 05, 2017 12:20 pm
by walshlg
Bondtech wrote:
On newer printers the the orginal cable from Raise3D will fit directly into the motor.
Our motors are supplied with a short cable that we can solder a connector to that will fit into cable directly on older printers. This would solve this issue in a simple way making the kit to fit both older and newer printers.


THanks, that is a relief, I have the older motors.