Sourcing my mendel90 a few questions..

I am sourcing my parts from a couple different places and asking someone who has a 3d printer to print the printed parts but I have a few questions.

First off, is a 40mm NEMA17 sufficient because 47 mm seems to be a lot harder to find and I can get a 40mm for dirt cheap. How thick should my MDF be? I live in America and I generated my BOM and I set it to 12 mm but I read somewhere some parts of the mendel90 need to be thicker than others. Also where is the best place to source the required spring and PTFE tubing from? They both have really specific parameters? Last question, I want to use the extruder/hotend from robotdigg (mk7 stepextruder) because its 1.75 mm and I am trying to source all my parts from them and they don't sell 3mm parts. Can I mount this extruder/hotend on it? if not can I mount the 1.75 mm hotend on the wades extruder?

Thanks.

For the motors, I don't think 47 vs 40 mm will matter. If you are buying wood, instead of a prefab base, then you can drill the holes where ever you want. The only variance for the motors will be the two z motors. The slots on the printed parts are pretty long and gives you lots of variance for motor height.

The X motor bracket is for a 47mm motor and both the E and X motors have 45mm screws through the back. The length of those would need to change and might not be a standard screw size.

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[www.hydraraptor.blogspot.com]

So would you say a 45mm would be the bare minimum because I thought I saw madmaxx use them in his tutorial when he assembled his. Also what about using hotends that are not Jhead mk5?

40mm may well have enough torque, but you would have to change the OpenScad configuration to move the screw holes for the Z brackets, change the length of the leadscrews and make the X motor bracket narrower. You then might need to cut down the screws that go through the back.

You can fit other hot ends that have the same groove mount as the J-Head, such as the E3D all metal one but the fan duct will not then fit and the Z height will be reduced. If you model it in OpenScad then it will adjust the frame and rods to give back the Z height but you need some other arrangement for cooling PLA.

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[www.hydraraptor.blogspot.com]

I built a Sturdy M 90 a little over a year ago. I picked up almost all my hardware from mcmaster.com. They carry just about everything you need (minus the MDF, electronics, and motors). My stepper motors I grabbed from ultimachine.com (also where I buy my PLA).

The one item I would suggest getting from Nophead is the dibond Y carriage board. It's so much more rigid than what I originally build.

My MDF is I believe a half inch sheet (I can double check if you like) that I cut by hand. I also painted it in the hope of avoiding any future moisture issues.