Replaced my extruder completely

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jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Replaced my extruder completely

Post by jeeplvr » Wed Apr 30, 2014 6:10 am

I finally got so sick of the Mini extruder that I replaced it completely with a better and way cheaper unit. I got the new one off ebay for about 63.00 and free shipping. It was not an exact fit by any stretch of the imagination. The mag holder for the mini had to be redesigned to move the magnets and allow for the longer stepper. Also I am making a new mount for the PCB to allow the use of the factory PCB and plugs for the wires. For now it is just hokeyed in place until I can get the mag base printed then I will get the PCB mount made. The tensioner for the filament guide roller had to be shortened about 3/16". In its original length it held so much pressure on the filament that the stepper just stalled. I machined the spring bolt by about 3/16" and counter bored it for the adjuster screw. I will post as many pictures as I have for now and will get more up later. I will also post the mag base and PCB mount files on Thingiverse tomorrow.
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jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Wed Apr 30, 2014 6:16 am

Here's some more info. The thermocouple that comes with the hot end will not work with the mini (wrong type), you have to use the mini t-couple. There is enough romm for the mini t-couple and a small set screw accessable under the insulation on the new hot end.
Here's a link to the one I bought.

http://www.ebay.com/itm/121281423242
0.4mm Nozzle MK8 Extruder Print Head for 3D Printer
Extrusion nozzle : 0.4mm
Print Material: ABS 1.75MM, PLA 1.75MM
Nozzle flow rate: about 24cc / h
Sports shaft speed: 0-100mm/s
Heating nozzle voltage: 12V
Normal rking temperature: 190°-230°
100 k thermocouple
the cooling fan operating voltage 12V
Heating rods: 6mm, 12v 40w
Net weight:450g

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Wed Apr 30, 2014 6:18 am

All the wires on the new piece matched the wires on the mini exactly so you just have to splice the plugs from the mini extruder to the new one and use the thermocouple from the mini.

D3rax
Posts: 139
Joined: Thu Feb 07, 2013 7:54 pm
Location: Netherlands

Re: Replaced my extruder completely

Post by D3rax » Wed Apr 30, 2014 6:31 am

Drastic measuers ;), like to hear your experience with this new extruder. If they are positive this might also be a good modification for the plus!
Up! Plus

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wilsonj
Posts: 569
Joined: Tue Feb 28, 2012 10:26 pm
Location: Australia

Re: Replaced my extruder completely

Post by wilsonj » Thu May 01, 2014 12:53 am

Did you change the toothed pulley? as it is a different diameter to the original UP one. This will change the feed rates.
Regards
Jamie
3DPrinterGear.com.au

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Thu May 01, 2014 1:47 am

wilsonj wrote:Did you change the toothed pulley? as it is a different diameter to the original UP one. This will change the feed rates.
Everything works like the Mini extruder.I have printed a number of models and they all look great. Best part is NO JAMS!! :)
Here is the Thingiverse link. Some of the pictures uploaded sideways but you get the jist.
http://www.thingiverse.com/thing:316658

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Thu May 01, 2014 1:54 am

Only thing I had to change was the filament tensioner spring and bolt length. I basically took out the spring and bolt, put a piece of filament through the extruder and measured the space between the tensioner lever and the bottom of the housing where the tensioner spring sits. I turned down the spring bolt head until I got the right length. When I say spring bolt I do not mean the adjuster screw for the tensioner. The tensioner spring has a 5mm socket head screw on top of it so the adjuster screw has something to push against when setting tension. Without doing this the spring tension was so heavy that the stepper would stall and no amount of adjustment of the screw was enough. This is the only real mod to the new extruder other than drilling a couple of holes to mount the PCB holder.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Thu May 01, 2014 1:57 am

Also the stepper motor never gets above room temperature. Its probably due to the insulation on the hot end. There is a tiny setscrew in the hot end that is used to hold the thermocouple in place. You have to use the UP Mini thermocouple or the UP software freaks out.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Thu May 01, 2014 2:02 am

Getting filament in and out of the new extruder is slick. Just push down on the tensioner lever and either insert or pull out the filament. You can push in new filament all the way to the nozzle if you used the "withdraw" feature in the UP software.

caesar
Posts: 64
Joined: Sat Feb 22, 2014 1:32 am
Location: Romania

Re: Replaced my extruder completely

Post by caesar » Thu May 01, 2014 10:09 pm

Congrats, the new assembly looks slick. The stepper, being bigger, support a lot more current, hence the lower temperatures.
Having the same dimension on the toothed pulley is a big plus.

From pictures it looks like an Mbot/Flashforge extruder/nozzle assembly. Please take care of the temperature, from what I know these hotends use PTFE insulation inside so going to 260-270C with them would burn through the PTFE tubing pretty quick.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Fri May 02, 2014 5:34 am

Not sure if the gear is the same dimension or not but it seems to work good. The support seems a little harder to remove but that might something else. Can't wait to try it with some good filament.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Fri May 02, 2014 11:42 pm

Update:
I measured the Mini extruder gear against the new extruder gear and came up with a radius difference of 1mm. The new extruder gear measures 5.5mm radius and the old Mini gear is 4.5mm radius. I removed the new larger gear and shoved the Mini gear on and it is a good press fit. I aligned the Mini gear center with the filament roller guide center and it seems to work great so far. The center line of the filament through the extruder is off slightly but it doesn't seem to matter. On my first print I noticed the detail was better than the prints were with the 11mm gear that came with the new extruder.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Sat May 03, 2014 12:45 am

Ok, printed a couple of models with the Mini extruder gear and I'm getting missing layers and general mayhem. So the larger goes back into the new extruder and I'm done for now.

jeeplvr
Posts: 212
Joined: Sat Jun 08, 2013 5:26 am

Re: Replaced my extruder completely

Post by jeeplvr » Mon May 05, 2014 1:24 am

After some more experimenting I have found that the teeth on the smaller extruder gear from the mini are just to sharp to work properly. Whenever the filament resists the flow the Mini gear digs in to the filament and I get a jam. There is very little heat in the new extruder so I can't blame the jams on heat this time. With the larger smoother hear is causes the filament to flow a little too fast but it works fine on the "fine" setting. The finish on the models is a little rough but I can live with that for now. If I can figure out where to get the proper sized gear or reduce the effective OD of the larger gear I will do that.

Macflame
Posts: 29
Joined: Mon Feb 09, 2015 11:22 pm
Location: Sheffield, U.K.

Re: Replaced my extruder completely

Post by Macflame » Sat Feb 14, 2015 9:57 pm

I bought an Up! Mini that did not have an extruder, so I was delighted to find your mod.
Unfortunately I do not have the PCB board that the large ribbon cable plugs into. I have emailed TierTime but they have not responded apart from an automated message some time ago.
Do you happen to know the pin outs so that I may make my own board?

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