648 looks thinner than 638
1 Like
High viscosity == honey
Low viscosity == water
Higher viscosity is useful for filling big gaps, hence why 638 is meant for ~0.25mm loose running fits and 648 is meant for 0.15mm max gap aka locational/sliding/snug fit.
Either can be used with a gear on a shaft - it depends on the tightness of the fit. But typically new off-the-shelf gears have a very tight fit.
1 Like
Eh what is 10mm, but I get what your saying in your early comment. Itâs the same use just different size gaps and since I had some gears already done with 648, I figured they would have about the same gap as me which was under 15 mm.
Right, yeah I know what viscosity is haha
Weâre just running in circles here, I guess the point is either works
3 Likes
I 
you
2 Likes
Thanks guys 
Iâll just coat the components with loctite before I put it all together then. No flowing needed
1 Like
Did I do something wrong? One side spins well while the other seems stuck. Itâs more noticable in the second video. One tires spins while the other doesnât. One thing to note I havenât applied loctite or grease anywhere. I will reassemble when that gets here. This was just to see how it goes together - I wonât actually be using it like this.
1 Like
Too little backlash on the second drive? Thatâs what it sounds like.
3 Likes
I didnât precisely set the backlash yet. Backlash can make that much of a difference in a simple hand spin?
2 Likes
Definitely. You can nearly lock them up with the gears too close. If you didnât loctite the gear yet then it wouldnât be as bad however. This could be many things
The 5 screws through the hubs. Are any of them scraping against the vase?
Are all the spacers in? Wheel nut tightened?
3 Likes
Wow thatâs wild. No screws are scratching, all spacers are in. Wheel nut not tightened on either. I will keep that and proper backlash in mind when assembling again with loctite. Hopefully it will go away then. Thank you.
1 Like
Didnât realize you had the key in. In that case it probably is the mesh. I thought it wasnât spinning the motor too. The cogging force would be exaggerated by a bad mesh. It sounds too tight to me.
Spin them without the motor gears on at all. That is much more useful for troubleshooting
3 Likes
Make sure none of your motor phase wires are touching each other when you spin the wheel. This will cause lots of drag
6 Likes
So some people have filed the truck to attain a press fit with the truck adapter. I got bn220 and it slides easily, so is not a tight fit (there is a little âbackslashâ) Is that going to be a problem? Should I glue it?
1 Like
No need. Once you tighten the wheel nut, the adapter gets pushed into the hanger so it wont rattle during operation.
5 Likes
These are for sale now
10 Likes
you need some backlash or itâll cause excessive heat and premature wear 
having it have complete contact also adds more rolling resistance
i should read lol
1 Like
I got mine already 
Theyâre awesome too 
4 Likes
Dual diagonal setup? Or single?
1 Like