FP power change?

[Al Skierkiewicz]

Alex,
The FP motors changed design and output power at least three times when supplied to FRC KOP. Check under the motors sub forum for discussions and part numbers. They all look very similar so you need to check the part number. I know one year they went from 90+ amps stall current to something like 63.

[Tristan Lall]

I know of many different Fisher-Price RS-550-sized motors—at least 6 were used in various years, and they've rarely been legally interchangeable. (12 V power output varies by a factor of about 2.5 between the least- and most-powerful ones.) Also, there are many BaneBots motors that look similar. Plus there are other manufacturers' products on the market.

In terms of identification, you can look at:

• Fisher-Price model number
• OEM model number (Johnson or Mabuchi, maybe others in the future)
• Label or printing style
• Manufacturer's logo
• Style and number of vent holes
• Style of end cap
• Plating colour and finish
• Quality of deep-drawn metal case
• Shaft style and length
• Fan blades
• Armature style
• Terminals
• Flux yoke (presence/absence/style)

It's difficult to explain exactly what the individual differences are without pictures or samples. But if you can compare motors based on those points of reference, it's pretty straightforward to identify legal motors when you've got them in hand (versus other models or kitbashed motors).