Gimson Robotics

[ewan]

Re: Gimson Robotics

Here's an eBay supplier for the type used in the GR01's: http://www.ebay.co.uk/itm/M3-M4-M5-M6-M ... _500wt_922
You'll need an Arbor press to get them into the material.
Nylon is pretty ideal for them, you'd need a different kind for softer plastics like HDPE though- something with bigger 'splines' or an external larger pitch thread.

[PJ-27]

Re: Gimson Robotics

Perfect! Cheers Ewan.

[plargen]

Re: Gimson Robotics

they look like the threaded inserts i got off ebay

[harry hills]

Re: Gimson Robotics

first trial of gimson motors in combat (for me at least)
for me: very good, had exelent power and felt very tough compared to the drills. no problems and a good motor.
Jonny: due to the larger wheel size, 170mm, the gearbox had to be retightened a couple of times. he can probably comment more

[Anttazz]

Re: Gimson Robotics

Looking to get a set of the 14.4v motors when they come back in stock (looks like that'll be today/tomorrow) so was really hoping for some reviews after Barnsley, cheers Harry

[RogueTwoRobots]

Re: Gimson Robotics

That reminds me; had one of the bearings pop out of the front plate of one of the gearboxes yesterday. I put this down to the violent behaviour of the robot as I spun up a horribly imbalanced drum.

Easy enough to pop back in, and not a problem that's likely to occur if you use the front plate as the mounting point. I mount mine using the bottom fixings but will probably put a thin cover on the front plate to keep it secured. Didn't seem to impair the drive though.

[maddox10]

Re: Gimson Robotics

That is good information k_c_r. Adding a thin plate in front of the bearing won't harm anything.

Even a small strip just edging the bearing will do.

[Mouldy]

Re: Gimson Robotics

That's what put me of buying these in the first place as I mentioned on page 1;

What's stopping that front bearing poping out? Circlip on the output shaft?

Ewans response;


Re Dave: The bearings are press-fits (there's two, another on the hidden side of the Nylon front section), which is a more permanent solution in Nylon (as opposed to aluminium say) given its ability to deflect and maintain a compressive force on the outer bearing ring. They're not going anywhere basically, especially considering the lack of axial loads on them


I'd suggest aluminium to be a better bearing housing IMO, and as Jamie has proven... They are going anywhere.... Might suggest a circlip on the output to help retain it, and/or machine some thin front plates.

[maddox10]

Re: Gimson Robotics

Self made ali front bearing retaining plate £0.0

Turned and milled Gimson GR01 mkII guestimated £45

[Mouldy]

Re: Gimson Robotics

Yet again you fail to see the point mario...

If you purchased a new car with m6 wheel nuts and the wheels kept falling of you wouldn't change them for bigger ones... You'd expect the manufacturer to get it right.

[ewan]

Re: Gimson Robotics

Good to hear Harry, they ought to be providing more torque than many cheap drills (the motors come from a factory making drills for the American market at RRP ~$45) as they're a different build of 'speed 550' than you'll normally find.

I first heard of the bearing popping issue last week, it seems either vibration and/or temperature changes (creating expansion/contraction of the plastic) are causing the problem rather than axial loads. I will now be recommending that all users put a small cover on the front of the motor of some form if they're not mounting via the front surface. I imagine that for those of you that it's happened to so far the second bearing took up the load? Not ideal but hopefully not a damaging problem- please contact me (or PM) if either pressing a bearing back is too difficult or you've had other issues and I'll make sure it's sorted.

Dave, Mario's hit the nail on the head in that it might not be the best motor/gearbox that money can buy but it's absolutely the best that £24 can- Nylon was used for the ease of machining and ease of threading (inserts) over aluminium which would cost significantly more to produce for the same function. Furthermore all parts, including front plates were cut on a 3-axis mill and so features are only cut into one side of each part hence the front bearing not being on the other side of the Nylon front piece.

[Anttazz]

Re: Gimson Robotics

Are they back in stock now Ewan? WIll be looking for a pair when the website allows it again.

[ewan]

Re: Gimson Robotics

Not yet but will be tomorrow, on the current website for now as the new one's still being finished

[maddox10]

Re: Gimson Robotics

Double, sorry

[maddox10]

Re: Gimson Robotics

Yet again you fail to see the point Mario...

You think so. I feel so stupid compared to you now.

If you purchased a new car with m6 wheel nuts and the wheels kept falling of you wouldn't change them for bigger ones... You'd expect the manufacturer to get it right.

If you pay for a citycar, don't expect a sportscar.

You can , if you're willing to fork out the money, get the specs way up compared to the original, but then the question is, why didn't you buy the sportscar to start with?

Mario's hit the nail on the head in that it might not be the best motor/gearbox that money can buy but it's absolutely the best that £24 can

Thanks Ewan.