1.75mm Filament in the Mendel90?

Hi. I have quite a lot of 1.75mm filament in various different colors and materials (ABS, PLA, Nylon, etc.) and I'm wondering what I need to do to be able to use it with my Mendel90? Obviously I need a different hot end (and was thinking of the E3D all metal hotend) but do I need a whole new extruder or maybe just a different hobbed bolt? Or, can I simply put the 1.75mm filament into the stock Mendel90 extruder and tighten the screws more than for 3mm filament?

I've tried to read up on this but haven't seen a conclusive/definative answer. I would appreciate any comment. Thanks!

We run 1.75mm through our Nophead supplied Mendel90s.

You need a new hotend - I'm obviously biased when I say that the E3Dv5 works well for this purpose. It fits without problem in the extruder using the same method as the supplied 3mm J-Head.

You can use the stock extruder too - the only thing that needs tweaking is that the idler bearing axle (the piece of 8mm steel round bar that was probably already pressed into the bearing when you got your kit) prevents the idler bearing from closing enough to apply pressure to the thinner 1.75mm filament.

To solve this we just use a printed idler axle that has a flat on one side, so the idler can get a little closer. That or you can file the axle a little bit.

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I Design/Sell all-metal hotends. My company is called e3d-online - you can buy at [www.e3d-online.com]

Very welcome news Sanjay - thank you. I am so glad my filament collection can be used. I was thinking the bearing axel was the problem. You had the solution. Thank you!

I've never done it before, but I've read about people converting 3mm jheads to 1.75mm by replacing the PTFE tubing with a smaller size, so you don't necessarily need a different hotend.

You should really also reduce the size of the filament path through the Wade's block because people have reported 1.75mm filament buckling in Wade's extruders designed for 3mm.

I don't think you will be able to file the axle through the idler bearing because it is the same precision hardened steel rod that the axes use. That is why it is such a tight fit that I have to hammer it in. It would need to be ground I think.

You can get a bit more travel if you cut away the plastic in front of the bearings so the axle can meet them but I don't know if it will be enough.

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[www.hydraraptor.blogspot.com]

BrianC Wrote:
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> I've never done it before, but I've read about
> people converting 3mm jheads to 1.75mm by
> replacing the PTFE tubing with a smaller size, so
> you don't necessarily need a different hotend.

Thanks Brian, would this this be the right stuff?:
[www.tridprinting.com]
I still want to eventually use the E3D nozzle but this would be a quick way to get started with 1.75mm printing.


nophead Wrote:
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> You should really also reduce the size of the
> filament path through the Wade's block because
> people have reported 1.75mm filament buckling in
> Wade's extruders designed for 3mm.

Thanks Chris, so to achieve this I have three options.

1. Print a new Wades block with a smaller filament path.
2. Print a sleeve and glue it into the existing Wades block.
3. Obtain some type of properly sized tubing and glue it in.

1. I can't print ABS (and PLA apparently can get warm enough to deform) right now so 1 will not work. Also I don't know how to operate OpenSCAD at present to make the filament path smaller in an altered Wades block so this is out for the time being.

2. I could easily print a new tube from PLA and glue it in. I don't think using PLA for this small part would be a problem. I suspect the only place it is needed is between the hobbed bolt and the bottom of the Wades block. A tube would not be needed above because the hobbed bolt would be pulling up when retracting filament so no chance of buckling.

3. Finding the right size tubing might be tricky so printing something would be easier.

So maybe I must try 2.

I usually just order it here: [www.hotends.com], since it's tapered and I don't have the tools to do it myself.

BrianC Wrote:
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> I usually just order it here:
> [www.hotends.com]
> oduct&path=60&product_id=86, since it's tapered
> and I don't have the tools to do it myself.

Thank you, this looks perfect.