Remotely mounting the X-motor?

What kind of pulley system would you use?  Have you designed it yet?

It sounds like a Core X/Y system, I can't quite envision anything else that would have stationary X & Y motors.

Yes, that is basically how it is set up.  The main difference is that the motor is in the middle of the back 2 pulleys & there are a couple of other pulleys to reroute the cable, but that doesn't really matter.

So, I've been thinking about how to use the same type of setup to remotely mount the extruder motor as well.  Here is a crude mockup (not to scale, etc.) to show a system of cables/pulleys that I think might work.  I didn't include any kind of carriages so it would be easier to see cable paths.  Of course, the motors would need brackets designed to attach them to the frame as well. 

The attached .zip file contains an .stl so you can see it in 3D, if you want.

For this to work, we would have to use a post processing script to adjust the extruder motor stepping to compensate for the rotation of the filament extruder drive pulley due to x & y movement.  I have no idea if such a system would be feasible or not, but maybe someone out there wants to do some experimenting.

Yes, the top motor/system is that way on purpose so it can power the extruder drive pulley/shaft continuously.  While the print head is stationary, the motor would turn as usual to extrude filament. 

However, normal x/y movement will also rotate that drive shaft.  That's where the post processing script would be needed to counteract that rotation of the shaft to allow proper extruding.  The motors would be working in tandem similar to how the 3 motors on a delta machine do.

I know it's hard to tell from the picture, but "that shaft" doesn't roll on the cross bar.  It would be mounted on the print head carriage, basically taking place of the motor.  Here is a view from a different angle.  I also added the 123D file which is a much smaller file size than the .stl. 

And yes, it would add more places for slippage/slack, as you said.  But I know that kind of system for x movement works on our embroidery machines.  I only have to tighten the cable maybe once a year, and it pulls around a lot more weight than a simple print head.

I thought that adapting that system for the extruder as well, might be beneficial.  I have no idea if the benefit of mounting the motors remotely would outweigh any new issues that may arise by implementing it.  I was just throwing the idea out there as a possible alternative.

also what about a flex shaft just from motor shaft on rear pointed up, to the belt shaft on 'X'? it could just be curved like an arch above and still have room for bowden tubes and even filament spools in same area with inclosure over all but motors so over heating would be eliminated too.

That system would be the perfect candidate for fish line.

I kind of thought the same thing.  Just out of curiosity, what type of fishing line do you use.  A picture I saw you post in another thread didn't look like the typical stuff that comes to mind when I think of fishing line. 

That's how this system works as well.  It doesn't turn both motors to move horizontally or vertically like Core-X/Y & H-Bot.

You can try this line although its a little pricier than others http://estore.twinline-usa.com/collecti … ools-black.  I was planning on getting a spool for use in a heated build chamber.  I heard other fishing lines (spectra/Dyneema) have issues at high temperature with creep.  Vectran is almost creep free and can handle high and low temperatures very well.  They also have kevlar line if you want to use that.