I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

John Lusignan /

I mushroomed the tip of my crankshaft where it inserts into the right crankcase cover journal. You can see my original post here

here

Ive printed an attachment for my dremel and lined it with 400 grit wet/dry sandpaper.

I'd like to take off about 0.10-0.15mm maximum on the end of the shaft where it mushroomed.

Does this seem like an acceptable solution?

Thanks in advance, John

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Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

Seems like it will work .

Maybe do the initial take down by hand and finish with your tool ?

Probably have to be real slow at first or the paper might stick and rotate in the cup .

Not sure how much heat that cup will stand , but , I'd give it a go .

Let us know how it turns out . ;)

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

Hopefully that cup can withstand 20,000 rpm’s without shattering. It should be ok, but wear goggles!

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

You could try cutting a slot and get a longer piece of sand paper... pulling both ends through the slot and taping it down on the outside so it stays put easier.

dremel-slot.png

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

I personally don't trust plastic in a Dremel but it could work.

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

Won't work in the way you think.. but will probably remove the diameter of material that is now protruding out.

Better off just grinding a taper to the end to remove the damage

Once you mushroom the end of a thread you also change the pitch and the pitch diameter of the thread from normal.. which means your nut still won't go on.

Can use a die nut if it is available to chase the threads.

EDIT: oh i see in the photo your not sanding the thread it is a journal that goes into a bearing. Should work. Go slow, measure lots. Carry on. (edited)

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

Probably better to spin the crank and hold a piece of sandpaper or a file on there.

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

Thread files have saved me many times. Another trick I like is once you get the nut to thread on but it's tight is to use valve grinding compound.

http://www.warrensvillefile.com/index.php/speciality-files/thread-restoring.html

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

from my experience: a handheld rotary tool with too close tolerance to the diameter of the workpiece will grab/chatter/orbit.

Personally, I would probably dress that deformation by hand with a diamond file slowly and avoiding the bearing surface as much as possible. aluminum bushing in the case, even as an outrigger, might not be too happy with the damage already done from smooshing it in, or reducing the diameter of that part of the crank enough to make it sloppy or unsupported.

Re: I 3D printed a crankshaft sander for my dremel. Any thoughts/advice?

> Daniel '' Wrote:

> -------------------------------------------------------

> Probably better to spin the crank and hold a piece of sandpaper or a

> file on there.

+1

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