Anybody have extra throttle motors in the Bay Area?

[grem110]

Hey everyone,
We're planning on teaching new students design skills by having them build laser-cut drivetrains. We're using Denso throttle motors for the drivetrain as we have a number of them and we'd probably never use them for a "real" robot. However, we probably need a few more. Does anyone in the CA Bay Area (specifically the peninsula) have any they're not using and don't want?

Thanks!
Matthew

[asid61]

115 definitely has them, I'll see if we can get rid of them.
How many motors are you planning for the chassis/how heavy are they chassis?

[frcguy]

How urgent do you need them? We have some, although we won't be back in our shop until mid-August, but we can probably sell them at cost when we're back. If that's ok PM me and we can work it out.

[grem110]

@asid61 great, let me know if you can and I'd be happy to drive over at a time that works for you. Thinking 4-6 motors per chassis, not sure how heavy they'll be yet (we're still in early-ish planning) but the drivetrains will be max 24" x 24" because that's the longest side of our laser bed. They'll also be made out of 1/4" plywood, and we'll be getting some lithium batteries. So not super heavy in other words. We're going to make some gearboxes out of plastic, probably acrylic, to gear them down. We don't know how many new students we're going to have yet, so that will dictate how many drivetrains will be built.

Thanks!
Matthew

[Sperkowsky]

Originally Posted by frcguy

How urgent do you need them? We have some, although we won't be back in our shop until mid-August, but we can probably sell them at what we paid for them when we're back. If that's ok PM me and we can work it out.

Hold up...

You PAID for throttle motors.

[frcguy]

Originally Posted by Sperkowsky

Hold up...



You PAID for throttle motors.

I agree the wording was a bit confusing and have edited my post to reflect that.

[asid61]

Originally Posted by grem110

@asid61 great, let me know if you can and I'd be happy to drive over at a time that works for you. Thinking 4-6 motors per chassis, not sure how heavy they'll be yet (we're still in early-ish planning) but the drivetrains will be max 24" x 24" because that's the longest side of our laser bed. They'll also be made out of 1/4" plywood, and we'll be getting some lithium batteries. So not super heavy in other words. We're going to make some gearboxes out of plastic, probably acrylic, to gear them down. We don't know how many new students we're going to have yet, so that will dictate how many drivetrains will be built.

Thanks!
Matthew

I sent a chat to the person in charge, I'll let you know when he replies.
24" x 24" seems way too big for a chassis made of throttle motors. IIRC they have a max output power of 20w, which is 1/15th the output of a CIM.

2 cims can make a 120lb chassis go at 8fps easily. If we follow that, then we need 30 throttle motors per 120lb, or 1 throttle motor per 4 lbs.
I'm disregarding a lot of factors here, but you may want to make a much smaller chassis on the order of <30lbs just to be safe. Will you be running FRC control systems or just RC?

[grem110]

We haven't decided whether we're doing RC or FRC control systems---the appeal of the former is that everyone can drive their robot at the same time, but we like the idea of the latter b/c we could have a swappable electronics box that teams would have to design to easily connect and remove from their drivetrain (we don't want to buy each team a full control system for the obvious reason of $$). But yeah, we're not thinking more than 30lbs, hence the lithium batteries, and we don't expect the robots to go very fast. JVN DesignCalc seems to tell me I can get 5-6 fps with 3 CIMs on each side, which is good enough for this. We're planning on building a test drivetrain and seeing exactly how much we can get, however.

[swootton]

We probably have 10+. I'd be willing to give them to you for the cost of shipping. Most likely $6-7 Priority mail shipping box.

[sanddrag]

There was one team that used one a few years back for some minor function on their robot. Can anyone recall who that was? That was the only instance I've ever seen or heard of one being used.

[bkahl]

Originally Posted by sanddrag

There was one team that used one a few years back for some minor function on their robot. Can anyone recall who that was? That was the only instance I've ever seen or heard of one being used.

4613?

They posted a Throttle Motor gearbox on here a little while back, I don't remember if it was actually used though.

EDIT: http://www.team4613.org/#!redbox/g8y3o

[saikiranra]

Originally Posted by sanddrag

There was one team that used one a few years back for some minor function on their robot. Can anyone recall who that was? That was the only instance I've ever seen or heard of one being used.

IIRC, 469 used it in 2013 to pivot their shooter.

[Knufire]

Originally Posted by saikiranra

IIRC, 469 used it in 2013 to pivot their shooter.

The 2013 shooter was pivoted by a CIM and two mini CIMs (I wonder what that was supposed to be for ).

The 2012 shooter, however, was pivoted by a throttle motor coupled to a lead screw.

[swootton]

In our rookie season we used two for our feed drives. They worked great to run timing belts to feed in the basketballs.

[pilleya]

Originally Posted by sanddrag

There was one team that used one a few years back for some minor function on their robot. Can anyone recall who that was? That was the only instance I've ever seen or heard of one being used.

Originally Posted by bkahl

4613?
They posted a Throttle Motor gearbox on here a little while back, I don't remember if it was actually used though.
EDIT: http://www.team4613.org/#!redbox/g8y3o

We designed a gearbox for the Denso Motor that gives it a 7.5:1 reduction and a 1/2 hex output shaft. We manufacture these gearboxes ourselves and have donated them to new and inexperienced teams in 14 different countries.

There were many teams at the Australian Regional who utilised Denso Throttle motors to power intakes through the gearbox. One team using the motor/gearbox on their robot ranked 13th in their Division at the 2016 CMP.

Although it is only a low power motor, it is actually very useful once you give it an adequate gear reduction and give it an output shaft that can interface with other FRC specific COTS parts.

Originally Posted by grem110

We're using Denso throttle motors for the drivetrain as we have a number of them and we'd probably never use them for a "real" robot.

This sounds like a great training exercise, PM me if you require any help finding gears to interface with the motor pinion or for the mounting hole spacing etc.