Remote Extruder using Speedometer Cable?

blt3dp

Remote Extruder using Speedometer Cable?
August 03, 2016 06:47PM

Registered: 10 years ago
Posts: 651

I was wondering if anyone's tried making something similar to a Flex3drive or Nimble using a Speedometer Cable. Looks like they can be had fairly cheaply. Couple it to a motor, and the other end to some type of worm gear attached to a filament gear and might work?

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o_lampe

Re: Remote Extruder using Speedometer Cable?
August 04, 2016 02:53AM

Registered: 8 years ago
Posts: 5,232

Speedometer cable is pretty thick and stiff.
Why not try dremel style or other more flexible cables.
The issue usually is, these cables are wound to work good in one direction but can't transmit the same torque in the other direction. The wires start to unwind eventually and get stuck in the tube.

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blt3dp

Re: Remote Extruder using Speedometer Cable?
August 04, 2016 12:05PM

Registered: 10 years ago
Posts: 651

I've never laid hands on one, but all the pictures I see are the cables wrapped in a loop, I would have thought they'd be rather flexible. I did see that they way the cables were wrapped inside would probably be best for turning one way. My thought was that as long as the forward direction for the extruder turns it that way, that it could handle a little retraction the opposite way, and then once it turns forward again, any unraveling would undo.

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o_lampe

Re: Remote Extruder using Speedometer Cable?
August 05, 2016 04:52AM

Registered: 8 years ago
Posts: 5,232

The cables are rather flexible, but the tube often isn't.

A short but quick retraction will fail eventually, then the whole print is messed up.

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MechaBits

Re: Remote Extruder using Speedometer Cable?
August 06, 2016 12:05PM

Registered: 8 years ago
Posts: 1,671

square pin in square hole will probably round that hole eventually, especially if its a printed square hole.

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Dust

Re: Remote Extruder using Speedometer Cable?
August 07, 2016 02:34AM

Admin
Registered: 13 years ago
Posts: 7,001

see [mutley3d.com] same sort of system, but already works.

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o_lampe

Re: Remote Extruder using Speedometer Cable?
August 07, 2016 02:48AM

Registered: 8 years ago
Posts: 5,232

Quote
MechaBits
square pin in square hole will probably round that hole eventually, especially if its a printed square hole.

You are right, just use grubscrews too, to protect the hole from getting round.

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MechaBits

Re: Remote Extruder using Speedometer Cable?
August 07, 2016 07:57PM

Registered: 8 years ago
Posts: 1,671

I was thinking about the crank on my bike, the point of failure the square hole in the aluminium crank arm rounds over time, sure the forces are higher, but ever since I worry about square pegs in square holes, a couple of grub screws may well do the trick, I just started a longish print and forgot to add 2 3mm holes where i need them, part will work without but would have been better to have them.

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o_lampe

Re: Remote Extruder using Speedometer Cable?
August 08, 2016 03:03AM

Registered: 8 years ago
Posts: 5,232

Since small holes tend to print in wrong size or even mess up the first layer, I use to drill them if possible.

Sorry for OT
-Olaf

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MechaBits

Re: Remote Extruder using Speedometer Cable?
August 08, 2016 12:44PM

Registered: 8 years ago
Posts: 1,671

I see some people dropping the holes a little so they get a nice top layer, I might try doing same on base layer, as I have noticed the 3mm holes do mess up quite often, eventually sorting themselves out, but has to be introducing some distortions through the layers.

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o_lampe

Re: Remote Extruder using Speedometer Cable?
August 09, 2016 01:48AM

Registered: 8 years ago
Posts: 5,232

I've made a template in openScad to clean the bottom layer from holes. Especially useful for low adhesion filaments like HIPS.

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