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extruder recommendation?

Posted: Thu Sep 07, 2017 11:47 am
by tenaja
I would like to add an extruder to my CNC mill. I want one that can take advantage of the speed I have available. My current printer can only go 30mm/sec, in large part because the extruder cannot keep up with thicker layers. I want something that can really MOVE the plastic--perhaps enough to do 250+ mm per second on .5mm layers with a .5mm nozzle. It needs to have the heating capability and the motor power to handle this.

I want something ready to make a bracket so I can bolt on and go. Any recommendations?

Thanks.

Re: extruder recommendation?

Posted: Wed Oct 04, 2017 6:50 pm
by tenaja
Nobody has an extruder they like?
Has anybody tried E3d Volcano or the i3D Inno?

Re: extruder recommendation?

Posted: Thu Oct 05, 2017 8:59 am
by jfkansas
tenaja wrote:I would like to add an extruder to my CNC mill. I want one that can take advantage of the speed I have available. My current printer can only go 30mm/sec, in large part because the extruder cannot keep up with thicker layers. I want something that can really MOVE the plastic--perhaps enough to do 250+ mm per second on .5mm layers with a .5mm nozzle. It needs to have the heating capability and the motor power to handle this.

I want something ready to make a bracket so I can bolt on and go. Any recommendations?

Thanks.
First off you can't do .5 layers with a .5 nozzle. Running those speeds would be better with a .8 or 1mm nozzle and .5 layers. A volcano type nozzle with a long melt zone will be better. You are going to be limited on plastics to print with because of no heated bed. I suppose you could clamp down a plate with a heater under it. Next you will be limited in Z height. Are all of your parts low height?

I think by the time to get everything you need to do this you would be better off getting a $700-$800 printer. You are still going to need a mainboard with heater controls. Not sure how you would interface your current steppers to the board and power them properly.

The next issue is Z height consistency and step movement. 3d printers are very sensitive to this movement being precise. A cnc router can be off a little and the next pass will take care of it.

Re: extruder recommendation?

Posted: Thu Oct 05, 2017 3:34 pm
by tenaja
Thanks for the "reality check" on the nozzle/height, but I just threw out a few numbers trying to get the point across that I'm not interested in a hand-sized part taking several hours to print, the way most hobby-speed extruders do.

This is not my first rodeo, and I'm not using a router; my mill can handle g-code just like any other mill, and I can add a few axes for the extruders. I'm just trying to find high speed extruders that will do a good job of pumping out plastic but can still be set up to put down a .15mm outer perimeter looking decent.

Re: extruder recommendation?

Posted: Fri Oct 06, 2017 3:19 am
by OwenSparks
Sounds like fun.

Just out of interest what material are you intending to print with? ABS will be strong but heated bed and enclosure of that size could be a challenge.

Please post some pics when you're up and running.

Cheers,

Owen S.

Re: extruder recommendation?

Posted: Fri Oct 06, 2017 10:16 am
by tenaja
I mostly print pla due to simplicity, but i have about a half dozen different materials I use.

The mill I have in mind is benchtop, but fully enclosed, so it can be heated without too much trouble. I'm just looking to reduce my machine footprints. too many toys...not enough space.

Re: extruder recommendation?

Posted: Fri Oct 06, 2017 11:02 am
by jfkansas
tenaja wrote:Thanks for the "reality check" on the nozzle/height, but I just threw out a few numbers trying to get the point across that I'm not interested in a hand-sized part taking several hours to print, the way most hobby-speed extruders do.

This is not my first rodeo, and I'm not using a router; my mill can handle g-code just like any other mill, and I can add a few axes for the extruders. I'm just trying to find high speed extruders that will do a good job of pumping out plastic but can still be set up to put down a .15mm outer perimeter looking decent.
It obviously is your first rodeo. Will your mill control extruder temps? 3d print Gcode isn't very much like any other mill gcode.

Good luck, be sure to take some pics of it when you get done in a few months. The proof is also in the part quality, be sure to take pics of those too. Try not to burn your shop down in the process as mills typically don't deal with 500 degree F heating elements.

Meanwhile me and my "hobby-speed" printers will be plugging away printing near injection mold quality parts.

Re: extruder recommendation?

Posted: Fri Oct 06, 2017 12:56 pm
by tenaja
jfkansas wrote: It obviously is your first rodeo. Will your mill control extruder temps? 3d print Gcode isn't very much like any other mill gcode.
You are funny. I usually use industrial temperature controllers for these applications. I have made hot air blowers, retrofitted multiple injection molding machines, and designed balloon blowers from scratch. That is just a partial list of temperature controlled projects, and all of those had to be calibrated. Fitting an extruder and heatbed to an existing mill is nothing.

Re: extruder recommendation?

Posted: Fri Oct 06, 2017 1:53 pm
by jfkansas
Like I said, proof is in the final part, quality and strength. I think you will find that a big mill doesn't like to move at the speeds that a 3d printer requires. Sure it can move fast, "Hobby" 3d printers can also, but there is a reason they typically move slower. Plastic takes time to cool, and the thicker the layers the longer it takes for the plastic to solidify before the next layer is put down. The faster you move means less time for the thicker plastic layers to cool.

Re: extruder recommendation?

Posted: Wed Nov 29, 2017 11:28 pm
by percar
for an extruder that doesn't slip on higher speeds I recommend http://www.bondtech.se their extruder drives are rock solid. I have been using their extruder drive for over 2 yrs no problems with slippage anymore.