Hi, I’ve seen a few discussions on ease of insertion for the adapters vs. the inserts and was planning on using the adapters as they ship with all the newer gears and wheels. I’m finding though these seems to have a lot more slop / play. E.g. twp gears mounted on the same 1/8" drive shaft using inserts can be rotated 8-9deg or so relative to each other. That pretty much doubles using the adapters. Wondering if anyone had any opinions on this. I’m guessing most applications it doesn’t matter, particularly if using sensors for auton driving for example.
Related to this we’ve been doing prototyping with the older green gears using inserts as that’s what we had previously and then buying the newer red gears for competition and using 1/4’" to 1/8" adapters as that’s what is provided with the new gears.
We’re seeing a lot more gear skipping in higher torque applications (e.g. 12T pinion to 84T HS gear) on relatively short spans. We always try to place our gears closer to bearings but that doesn’t seem to be enough anymore (e.g. 3/4-1" from bearing). We’re now using zip ties to hold drive shafts together for high torque applications as a placeholder. Or where there’s space to have opposing non-driven pinions on the other side of the larger gear.
Can post some CAD and pics of before and after if that’s helpful, but was wondering if there’s some general build guidelines using the newer red HS gears on 1/8" drive shafts. Our teams won’t be able to do the 1/4" drive shafts, so that’s a non starter.
This is a two stage 9:1 reduction. Separation of c-channels faces is ~3.4". Bearing flats are mounted on the insides of the c-channels. Replacing the green 36T gears (+insertr) with the newer red ones (+adapter) already feels less sturdy and skips at that mesh point.
One solution I’m guessing is to contain the gearing in a gearbox which would involve additional structure (although maybe 1x1 angles would work here).
On the first picture can you put a small washer/bearing on the metal side of the green gear, that increases the contact with the metal pinion. There are some on the other side, can you swap one over?
Do you have the Channel inserts? Can you get 2 to stand up in the space “north” of the 12 tooth pinion and use a pillow block to push it “south” to help the engagement?
Thanks @Foster - the washer idea got me thinking - I would need 3 I’m guessing to balance out (one on the shaft and one for each screw). But … a bar lock I’m guessing would actually solve the issue here. That would theoretically reduce any additional slop between the drive shaft and the new gear adapter.
By channel inserts - do you mean the c-channel (connector) gussets? The ziptie trick pretty much does the same (I believe).
I like to use them as braces then use the zip tie or some kind of push to move the axles together. I’ve found that zipping the two shafts puts a lot of stress on them, YMMV.
The metal bar lock would be perfect. It’s about the right thickness to move the green gear to mesh with the pinion. I’m not a fan of the plastic ones, a big torque level moves them around.
In the 6:1 picture it looks like there isn’t a gap between the red and green gears (may be a camera angle. But this also may be a case of a washer on the south side of the green gear pushing it off the red and giving some more “bite” to the pinion.
I do want to say that the 6:1 picture is a textbook example of how to stack gears to get to the ratio you are looking for. Nice work.
Yeah, the 9:1 is not robust as is, but this mech only moves a few times a match so I’m not going to have them change anything for now. This has been really helpful for the next time we need to do something similar.
On the 6:1 there is one of the small white spacers, I believe 1/16”, between the 24t and 32t. It’s close, but none of the gears rub that I can tell.
