Not really that I care to share at this point. (Normally, I’m very open to sharing along the way.)
A little over a year ago I made bevel gear drive for a special industrial machine application and decided to make a smaller version to somewhat fit Eska8. While I have ran the gearbox with a 6374 motor, I still have yet to mount one to trucks and actually ride though. (Making machines puts food on my table, not Eska8)
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2:1 ratio, correct? How are you liking that?
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This shouldnt be too horrendous to reproduce right? I have made bevel gearboxes for 30lb battlebots and its pretty straightforward. Just need strong bearings for axial and radial loads like tapered roller bearings
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First, great job making bevel gearboxes! That is awesome bro. It is very straightforward, and very easy.
Second, I’m not looking to reproduce this design.
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You had me at battlebots!
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I thought it wasnt enough, but 190kv 6374s was more than plenty for me.
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Love mine as well!
BTW I’ve scanned and reverse-engineered the components. I don’t know how he produced them for so cheap, (I think it was 160 USD per 1 assembly) it looks like a lot of machining.
BTW 2 - the front hub is Bergs hub 3D printed and being tested.
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Three years one rebuild, still the smoothest drives I have ridden.
Stormcore is maxed out to get decent torque on 2:1 (173kv)
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Your pic shows well of how small the gearbox is with the 107s.
@moav That looks awesome! Wth is your top speed with the bergs?!
I never dared to hook up my bergs with the drivetrain, how is the torque with that also?
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Does anyone have pics of the insides of their drives?
I wonder how much efficiency loss there is compared to other gear drive systems.
Gear Efficiency Comparison Table
| Type | Normal Ratio Range | Efficiency Range |
|---|---|---|
| Spur | 1:1 to 6:1 | 94-98% |
| Straight Bevel | 3:2 to 5:1 | 93-97% |
| Spiral Bevel | 3:2 to 4:1 | 95-99% |
| Worm | 5:1 to 75:1 | 50-90% |
| Hypoid | 10:1 to 200:1 | 80-95% |
| Helical | 3:2 to 10:1 | 94-98% |
| Cycloid | 10:1 to 100:1 | 75% to 85% |
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Does it make any note as to directionality on spiral bevel?
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i didn’t see any info regarding that, but technically they are the same if not very similar efficiency?
since its just like helical, but two axles are at 90 degree
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I’ve heard somewhere that spiral bevel gears are significantly worse in one direction than the other
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Well good thing you aren’t riding in reverse all the time then right
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I’ve never tried to go past 45kh because I don’t have protection. It should go over 60. Without a rider, battery full, app claims 72kh.
Overall torque-speed ratio is pro speed. Gear is 1:2 and I’m on 170kv motors with 6" rubber. Tourqe is just fine but I could have better efficiency if I go lower kv cause I don’t come near top speed.
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Bingo!
Usually, they are set up in the direction so that the concave part of the pinion interfaces with the convex part of the other gear. If you do it backwards, you reduce room for backlash.
Depending on drive design, that may or may not be desirable. Zero backlash is never desirable.
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I’m getting the impression there may be some potential in a spiral gear drive.
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