2 drive gears 1 motor

Hey,

I'm just coming back from a 3d printing convention and was reminded of an idea I had earlier. I would like to try if I get more grip on the filament when I have it going by 2 drive gears instead of only one plus bearing.
I would install a second axis parallel to the motor shaft and have two same sized cogs drive two drive gears.

I saw that executed like this.
[4.bp.blogspot.com]

However i would like to translate that to a direct driven 5mm D shaft with 1,75mm the only issue I see is the difference between out and inside diameter in the MK 7 and 8 drive gears. This difference is listed as 2mm which I find weird because even the the smallest listed diameter is probably not really the average real diameter where the filament touches the gear, it would still mean that the filament almost completely sinks in giving the bearing nothing to push.
http://1.bp.blogspot.com/-if9Jm7gswD8/VBtDdOEIcdI/AAAAAAAACbE/BW3_pJFurfw/s1600/Screenshot%2B3.jpg

My question therefore is if its realistic that two drive gears side by side would be able to even grip the filament. If the space between the two inside diamters is effectivly wider than the filament itself the whole idea is useless.

I have a low-cost (1.50$USD Chinese part bought on eBay, seller accecity2008) MK7 drive gear made for 1.75mm filament and 1.75mm ColorFabb PLA filament right here.

The edge of the drive gear is not even close to being at the middle of the filament diameter so the idea should work if your drive gear is made for 1.75mm filament.

Great I'll check it out. E3D in the meantime also offers a drive gear which should fit my need.

[www.ebay.com]
this hear you mean right? great price for experiementation.

Edited 1 time(s). Last edit at 01/07/2015 03:53PM by sungod3k.

Quote
sungod3k
[www.ebay.com]
this hear you mean right? great price for experiementation.

Yes, in the description it says "Suitable for 1.75 Filament". Don't forget to order two of them!