GearHeads Forum

More than...
..just curious.  

Thanks,
John

Okay! Now that I look harder, I see wires circling one leg of the platform. I guess those might be the electrical connections to the heated platform.   Yah, I meant the platform and not the actual xy table.
Thanks for that pdf of the traces on the platform.

I will look into obtaining just the extruder/heater unit.

One more queation...
What keeps the molten "plastic" (ABS?) from oozing out of the top instead of only at the nozzle?  Is there some sort of "O"-ring in there that seals the wire/filament as it enters the heat chamber?  Or is it just the presssure of the leading unmelted wire against the nozzle.
I'm sure there must be cut-away diagrams depicting this.  I'll look around the web more closely.  

Well, either way I will find out when I settle on what heater/nozzle to use.

Thanks Dan again for your continued support

John

Thanks Dan,
 Wow! that gear is a lot smaller than I initially thought!
There are quite a few flavors of the extruder available out there.
all of those(that I have seen) also use a stepper motor as the force to move the wire.
I've got a few very small 48V servo motors from a ebay buy.  I was thinking the stepper could be replaced with a 4th axis servo.  The others would be used to cobble together a fairly tight three axis PCB table upon which to create the gears.....for fun of course!  

Or am I making it harder than it is?  :)

Also, From the pictures you posted, I can't tell if you are heating the table, or if you heated it from the start for sticktion. Maybe the table material you use allows for adhesion with the ABS?


Thanks for the info.
John

I just finished writing an article for a magazine called digital machinist. They said it would probably be published in the summer edition. In that article I included several pictures of my retrofitted machine. I'll post the one about the machine and the extruder.  I would think almost any half way decent 3 axis  machine using mach3, the slic3r program ,stepper plastruder extruder and the Gnexlab temperature controller could be used . The only issue is how practical is it? Most prints are about 50Kb and some files could take several hours ruuning at 900mm a minute. So you also need a machine with no or very low backlash.
One thing I discovered is that while I can create a gear in GM and save it as a stl file that slicing program need then it could be difficult to modify the gear for let say adding a boss so you could use a set screw with it. I found that I could save the GM stl file and then open it in Bobcad 24. Then in BC24 modify the gear for what I wanted to add. Then save the file as a stl file and run in in the Slic3r program and then onto Mach3 and the printer.


Dan Mauch
Camtronics Inc