🔩 1:7 belt drive for mountainboard with badass torque

Esk8 Dev
#54

If you find a good recipe to thread stainless let me know, after I tried it and broke a lot of taps, from multiple brands, I gave up. It makes for a really clean design, but I’m back using nuts

#55

good cutting oil, a square, hss thread cutter.
break off the chips after 1-2 turns with a half backturn.

2 Likes
#56

Would be a dream if I could even manage to to one turn, on the 304 I was maybe doing 1/8 of turn before having to turn back to break the chip

#57

Which tools do you have?

#58

I have to check, isn’t anything special, I guess I will buy the expensive ones to give another try

2 Likes
#59

look for hss cutter(Gühring i. e.), where you can cut a thread in one take. A square for the squareness as said.
Don’t forget to countersink the hole.

1 Like
#60

Thanks for the tip, and countersink before starting right?

#61

Makes it alot easier to get it right.(10% bigger than the hole diameter.)
Do you cut them by hand?

1 Like
#62

Yeah, by hand, but I’m looking at some powered options that would be nice if they worked, don’t know if my powered screwdriver would have enough torque for a M4 tap

1 Like
#63

just a video

1 Like
#64

don’t have a access to a drill press?(slow speed)
throughholes with straight taps. spiral for the opposite

#65

Yeah, I have one, but it’s not that slow even at the slowest pulley

1 Like
#66

and you need a left turn mode. 90 turns/min would be good.

#67

No good, slowest I can do is 620 rpm

1 Like
#68

I finally managed to do all the holes. Countersinking really helps, as well as good tools. My biggest problem is to get it in straight. I had to use electric screwdriver to get it in, then switch to hand. Still broke some.
@Pedrodemio I would recommend to use a drill press and turn it by hand. This way you can get it in straight. Unfortunately I do not have one…

1 Like
#69

I know a method. Pull it to you during the turn. Don’t do it excessively. It’s hardened steel. Check again, if it’s straight with a square.
image

#70

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for a drill press. :joy:

1 Like
#71

Any progress on these?

3 Likes
#72

Maybe its smart when tapping holes you lasercut to pre drill them with the right size bit, dont know if you guys did that, but in this case 3.2 or (3.5 bit too big but easier tap) would do the trick i think.

1 Like
#73

So, one year has passed and many things happend. I finished my masters degree, got job and so on. Unfortunately there wasn‘t much time for the mountainboard project or esk8 in general. Or at least not that much effort. But now i started to build again. I‘m confident that I can finish the board in the next weeks and finally test the belt drive system in spring. Basically just the making of the battery and the assembly of the belt drive is left.
I guess a v2 of the belt drive is necessary to make it perfect as i messed up with the belt lenghts. We will see what will happen :slight_smile:

In the mean time I designed the battery box for my haero bro deck. I will add some pics of the box. This thread will also be the build log for the mountainboard :blush:

5 Likes