Hedgie Posted March 25, 2014 Posted March 25, 2014 My servo motor (part 99498) recently broke and TLC kindly shipped me a new one. Instead of just throwing the old one away, I thought it would be nice to show you all some pictures of what the inside looks like: As you can see, it took quite some aggression to open this thing. The dark gray part is fixed to the light gray part by only 4 plastic clamps, but they are so tight it's impossible to open it without damaging it. The plastic is also very soft, it's possible to scratch it even with just nails. Here's an overview of the main components: 1) housing, 2) motor and circuit board (bent 90 degrees), 3) gearing, and 4) more housing. Now it becomes clear why the circuit board is bent 90 degrees and how the system actually works. As the output shaft rotates, the two metal pieces slide over the contacts of the circuit board. Thereby the microcontroller knows what the current rotation of the output shaft is, and can stop the motor when it's reached the proper destination. The motor itself turns much faster than the output thanks to this planetary gearing system. Unfortunately, I don't know enough math to calculate the actual gear ratio. Obviously, this particular servo motor will never function again. It's a shame, because I've hardly ever used it and there is nothing that looks out of the ordinary. I suspect the problem was somewhere inside the wire, as I could sometimes make it function by wiggling it. Unless anyone here wants this motor for research purposes, I'm throwing it away Quote
Milan Posted March 25, 2014 Posted March 25, 2014 Why don't you take it to some electrician? If it is wire problem, he can repair it. Quote
vmln8r Posted March 25, 2014 Posted March 25, 2014 I think wires are the weak spot for PF; I've had loads of L motors and a few M motors become unreliable in a similar way. Quote
aol000xw Posted March 25, 2014 Posted March 25, 2014 It is a shame that TLG made the wires part of the motors and to add insult to injury instead of a couple screws they use those terrible latches that prevent a safe servicing. Quote
zux Posted March 25, 2014 Posted March 25, 2014 On 3/25/2014 at 2:45 PM, aol000xw said: It is a shame that TLG made the wires part of the motors External wire would make motor-wire assembly at least 1 stud longer, wider or higher. Quote
skppo Posted March 25, 2014 Posted March 25, 2014 Yeah I think around 5 of my 8 m-motors are broken. Most likely the wire. And it's not like I handle them roughly >:( External cord wouldn't neccesarily add any bulk if it wasn't stud based like the old system. The connector could be made really thin. Then again it would cost more. I'd pay for that though. Quote
DrJB Posted March 25, 2014 Posted March 25, 2014 At issue is the WIDE ribbon like cable. SUch cables do not take bending too well. Would have been easier to make a round cable ... but cost would have been higher as well. Those wide/flat cables make it very easy to assemble and produce those motors in mass quantities ... Quote
Zerobricks Posted March 25, 2014 Posted March 25, 2014 Is the electric motor same as in M motor? Quote
Hedgie Posted March 26, 2014 Author Posted March 26, 2014 On 3/25/2014 at 8:32 PM, Zblj said: Is the electric motor same as in M motor? They do look very much alike: Quote
Doc_Brown Posted March 26, 2014 Posted March 26, 2014 Very interesting! Looks like you used a bit of force to open it. XD Quote
gregorijs3kivi Posted March 26, 2014 Posted March 26, 2014 On 3/25/2014 at 12:50 PM, Milan said: Why don't you take it to some electrician? If it is wire problem, he can repair it. yes, i do it Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.