[attachment file=118498]
For somereason the forum wouldn’t publish my post before, I hope this won’t end up as a duplicate.
Anyways, I took apart my cheap 500W spindle to see if I could improve it.
The first thing I wanted to do was changing the bearings.
[attachment file=“IMG_20191019_144732.jpg”]
[attachment file=“IMG_20191019_144740.jpg”]
The bearing in the back was easy to just slide off the shaft and replace with one I had left over from my MPCNC build. The one in the front I couldn’t change because it’s impossible for me to get the ER11 chuck off the shaft. I tried hitting it, I heated it up with a heat gun, it’s just stuck on there.
The next thing I wanted to improve were the rubber bearing sleeves.
[attachment file=“IMG_20191019_144725.jpg”]
I 3d printed a couple of new sleeves out of PLA until I got the tolerances just right.
[attachment file=“118504”]
I will do some test cuts tomorrow to see if this improves anything.
2 Likes
That pla is going to melt in the motor. If you’ve ever run it for more than an hour or so you’ll notice the collet gets pretty hot. That’s not from cutting, it’s from the motor.
1 Like
It’s a nice effort but there’s no way it will work, unfortunately.
The PLA will get soft and won’t last, plus there is no way it will be very concentric because printers are not very accurate in doing that kind of stuff (there are always some defects in each layer beginning/end). The only way I could think of would be to do these sleeves on a lathe, or enlarge the casing to fit a slightly bigger bearing.
Also, you apparently hammered on the chuck to try getting it out, which is really bad for the shaft. Changing the bearing was probably useless too if you put similar ball bearings back into place, only tapered bearings could make a bit of difference here.
Again, it is nice to try, but don’t expect much, unfortunately those spindles are total crap 
So I did some test cuts, only for about 10 minutes and it worked well. I know that PLA is not the right material for the sleeves and I will try to make them out of aluminium when I go to the local makerspace the next time. Regarding the concentricity, I printed it in vase mode, the walls turned out great without any lumps or bumps on them.
Dui, I didn’t hammer too hard on the shaft, more like gently tapped it. The bearing I changed was so loose it moved around by about 0.5mm, the new bearing definitely improved that. I know that angular contact bearings would be the thing to use here, but I just want to get some more use out of this spindle before I buy a better one.