Gimson Robotics

[ewan]

Looking like it'll be £30 for the 12V version and £33 for the 18V.
Two reduction options will be available, 36:1 (as before) and 24:1, which would provide performance similar to the drive in Cobalt. All gears will also be available separately.
The exposed section of shaft is indeed longer (43mm) while the body itself is more compact owing to a smaller bearing and lack of plastic inserts which took up considerable space in the GR01.
The overall size is 40x40mm down from 45x45mm previously.

At the moment the shafts are out getting flats milled on them (which should expand the range of mounting options), once they're back then more pictures and specifications will follow.

[typhoon_driver]

Well Ewan they sound the business but my engineering input would be to reduce the length of the shaft. Easier said than done i'm sure but such a long unsupported shaft with a bored out center could have bending issues from large impacts.

[ewan]

The shaft length is completely intentional given that some people will want the added flexibility of increased mounting space and those that don't can simply take a hacksaw to it. If you were using the full length you'd of course be well advised to support the end of the shaft (which the internal bore can help with) or if intending to use the 3/8 UNF threaded section for direct wheel mounting then the first portion of the shaft could be fed through a bulkhead with its own supporting bearing. The internal left-hand 5mm bore is 21.5mm deep, stopping half-way along.

[harry hills]

well I'm going to order a couple of the 12v ones asap

[Gabe01]

Very exciting! I'm going to buy an 18v 36:1 for testing. I have three robots on the go now, so I will be ordering more stuff soon Ewan

[Ellis]

They really look fab. And for the price they'll be brilliant. But, as Gary sort of said, I fear the shaft being unsupported like that may cause problems. Not sure if it's now just one bearing in the front or two smaller ones or something, but a less supportive bearing setup and the leverage aspect of having a longer unsupported shaft could become an issue?

I realise you can support on the other side of the shaft to help with this, but if these are still mostly aimed at beginners then that sort of thing is beyond many. If it can't simply be screwed in with a wheel bashed on then I can see people being put off.

But, time will tell. Might well be fine. The two reduction options is very interesting.

[shakesc]

Ewan - rather than flats (which with a bench grinder / angle grinder you can do) did you consider keyways?

[ewan]

It's a single bearing this time just behind the front aluminium face. The dual bearings previously did indeed provide good support but there wasn't any real flexibility for mounting, I don't know anyone who didn't mount on the end of the threaded portion (which was the design intention), whereas with the GR02 the idea is that multiple mounting positions are now possible. This arrangement is similar to the Banebots gearboxes in the US, and just as they do I will be putting in the product documentation disclaimers against users placing large loads on the end of an unsupported shaft, as well as guides for good mounting practices. If you mounted close to the front face you'd be very unlikely to need additional support at the end, and if you did mount at the end, as I've said before, incorporating support at the beginning of the shaft can be as simple as adding a bulkhead-supported bearing to the first few millimetres of the shaft (rather than having to implement outer support).

The target for these motors isn't really beginner roboteers - that would narrow the market scope far too much especially as so many of them go down the 'must get the cheapest option' route these days and some even considered the GR01 expensive. The addition of a shaft flat follows this thinking by targeting users of other hobby and industrial planetary gearmotors where this is a standard option, certainly fitting sprockets/gears/pulleys will be more straightforward.

A keyway was considered but found to be both more expensive to implement and potentially too weakening to the 12mm shaft section whose final few millimetres coincides with the left-hand centre-bore.

[Eventorizon]

Are the mounting points in the same place as in the GR01's? So the same depth and width apart and M5 Bolts?

[ewan]

The distance between the hole-centres is slightly narrower at 18mm (from 19mm previously) and the distance between the front and rear holes is now 29.5mm (from 41.5mm)