Let's Make Robots!

Trouble with the bass drum

The first Solarbotics GM10 motor I mounted or LDM for the "bass drum" quickly started getting stuck, as if the gears were faulty. I cursed, cut the hot glue to get the motor off of the robot, and soldered up wires for another motor. With the new motor glued onto the robot, I tested it and, just like the first motor, it worked great for about a minute or two, and then started getting stuck as well. So now I suspect that the gears are just getting damaged when the stick hits the ground repeatedly. It's almost as if these tiny pager motors hadn't been designed to drive metal sticks onto hard surfaces...

So I don't know what I'm going to do for a bass drum. Maybe I'll just have to go without one. But I think it really adds a lot, so that'd be a shame.


Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Metal screw, adapted length, down tube, tape wrapped.

4AA's. erh..hang on.. oops - i'm used to thinking "motor-driver" before motors, and it has a 1,5 voltage drop.. But hey - there is actually none here - apart from the head - so I guess I am feeding erh.. there must be a voltage-drop, no? 4*1,2V (rechargeables) 4,8V then.. there is a darlington after the Picaxe.. But one of the motors (due to bad planing/no planing) feeds straight from Picaxe / a reverted input-port.

Good morning! (and where is your screw?)

/ Fritsl

Ah, OK, I see. Well mine seems to be working perfectly since I stepped down to 4 AA's, so I'm happy. I just posted an update -- I've got my sampling board wired up, so he can record himself now. That tiny speaker doesn't make much noise, so I'll have to find something bigger. But now comes the fun part -- coding the drumming.

My SRF05 showed up today too, so I can also figure out how to monut that and then I can add the second drumstick up front (I've been holding off on attaching the second one until I know exactly how much space the SRF and its motor are going to take). Exciting!

As for my screw, that's personal and I'll thank you to mind your own damn business. :)


I recomend second stick over head - dunno why really, but if you make sure - as I think you are already on - that the head can just turn, it sort of look cool when the top-stick is tamping, and the head is wikkeling, and it is close to touch each other, but is not :D

/ Fritsl

I am behiiind answering everything ;) Sorry, I will answer on the component as well! How much voltage are you feeding? I only feed <3.5V

/ Fritsl

Hmm, that might be the issue. I'm using 6 rechargeable AA's, so 7.2V, because I wanted a nice firm hit. The sticks seemed to be a little weak when I tested them on 5V. But I didn't test them at that voltage on the robot itself. Yours sounds good, so maybe I'll try switching to a 3 or 4-cell battery pack for the motors instead of 6-cell. It's too bad I already ruined two $12 motors though :)


in my BD there is a screw to keep weight.

in general i tried to balance so that spring would pull back, but more power on hitting-motion.

(If aliens read this out of context, they will not have a clue :D)

/ Fritsl

Where is your screw? At the end of the stick?

I tried switching to a 4-AA pack (so 4.8v) and it seemed to work better. The hits are softer, but still audible, so I think I'm going to leave it that way and see if the motor survives. Hopefully that'll keep it from putting such big dents in my walls and furniture too :)

I'm curious, how are you giving your motors only 3.5v? I saw you have a 4-cell pack too. Are you using a voltage regulator or something?

Second; You are not mounting it extremely firm, so it get's twisted?

/ Fritsl