Rango - Build diary

[overkill]

What's the size restriction for motors to fit into the robot and what RPM range do they need to be in?
I might be able to help you out

Look for the dimensions of 885 motors - they are the absolutely largest things that will fit.

[Revsmin]

The 885s originally in the robot were 48mm diameter, 83mm length.

[Ellis]

What's the size restriction for motors to fit into the robot and what RPM range do they need to be in?
I might be able to help you out

Yes please yes please yes please yes ple-

7-10,000rpm on 5s.

The largest cylinder that could fit where the motors go would be 74mm long, 49.9mm diameter. Smaller diameter can be longer, for example a 48mm can could be 78mm long.

The 885s originally in the robot were 48mm diameter, 83mm length.

This is true, but 83mm is full length minus shaft, the main body is only 68mm long.

[knightrous]

This was the best I could find on a quick break

http://www.ebay.com/itm/New-R775-Ult...item4acd3dbc98

Peak of 240W seems reasonable, so they should have some punch.

[Ellis]

Cheers for the link. I've researched far eastern sources in detail. The problem is misinformation. Direct from factory they can give you raw data (I can't afford to buy and ship in bulk), but any level of reseller (aliexpress/hongkong ebay) gives useless or patchy info, often contradicting their own figures or visibly copy-pasting from somewhere else. Western resellers are no better. :P

The ebay link says 240w, but idk what they're calling "max power". If that's max efficiency then it's pretty good.

[mrsam]

I found these on ebay, not sure if they're much use to you but they seem to have the specs you're after. ebay item 181451896371

[Ellis]

I found these on ebay, not sure if they're much use to you but they seem to have the specs you're after. ebay item 181451896371

Looks like that seller suffered the same fate I did with the 885s. Pollin sell that motor too: http://www.pollin.de/shop/dt/Mzk0OTg...C785LP_ES.html

Note the RPM/general stats.

Then the datasheet reveals that those stats are in fact at max efficiency: http://www.pollin.de/shop/downloads/D310506D.PDF

Pollin must have indirectly caused so many problems over the years...

[Niels - Team K.a.L.M.]

I think I have 2 or 3 of those lying about as well