usage of denso window motor

[heathput]

Originally Posted by NyCityKId

reference rule <R47>

Rule <R47> talks about modifications to motors. If I understand the rule, I can remove the motor, leaving the gearbox. Then I can mount a different legal KOP motor to the gearbox. It would require an adapter, but would be legal. Does anyone think I am off base?

[NyCityKId]

Originally Posted by heathput

Rule <R47> talks about modifications to motors. If I understand the rule, I can remove the motor, leaving the gearbox. Then I can mount a different legal KOP motor to the gearbox. It would require an adapter, but would be legal. Does anyone think I am off base?

As long as the motors you plan to use are in accordance with rules <R45> and <R46>, it should be OK as far as I know, but I don't really see why you would want to. Furthermore, I wouldn't want to be the one to have to figure out how to securely attach a bane bots motor to a window motor gearbox.

[heathput]

Think about it. The window motor gearbox is small and has mounting holes so it is easy to mount. The motor is pretty wimpy though. A 775 banebot turns only slightly faster, but has a much higher stall torque. By my calculations the window motor on the gearbox can produce about 90 inch pounds of torque at stall. With the banebot on the gearbox the number is a little more than 300 at stall. I do not think the plastic gears will hold up to 300, but I can run the motor at less than half the stall and still lift a boat load.

[Vikesrock]

I believe in past years the Window Motor gearboxes have been ruled to be integral to the motor and covered by the equivalent of <R47>.

If you want to use the gearbox with a different motor I highly recommend posting to the Q&A for clarification. I think it would be legal to use the gearbox with a different motor, but not the motor with a different gearbox.

[NyCityKId]

Originally Posted by heathput

Think about it. The window motor gearbox is small and has mounting holes so it is easy to mount. The motor is pretty wimpy though. A 775 banebot turns only slightly faster, but has a much higher stall torque. By my calculations the window motor on the gearbox can produce about 90 inch pounds of torque at stall. With the banebot on the gearbox the number is a little more than 300 at stall. I do not think the plastic gears will hold up to 300, but I can run the motor at less than half the stall and still lift a boat load.

Well if your numbers are correct then I can see why you would want to switch. I personally feel that you might be taking the difficult route by trying to switch motors since there are other ways to increase torque other than switching motors. However since I don't know how you plan to use the motors I cant say whether your going overboard or not. In any case, like Vikesrock said, the best place to post a question like this the Official Q&A forum.

If you don't mind though I would love to see how the motor swap turns out though, assuming the GDC says its OK.

[heathput]

I am going to try the swap anyway and see what happens. I will let you know how it goes.

[ratdude747]

good luck. in the past two years i have been on two teams that tried it... the motor has the worm molded into the the motor's shaft. you would have to either fashion the shaft into a press-on for the motor or machine a new piece.

i would not mess with it, just me $0.02.

[yara92]

Can you plese send me the cad for this photo

[clayman]

The CAD for those custom sprockets would also help our team a lot (we currently have no CAD skill).

[artdutra04]

Attached is a STEP file of the sprocket I machined in the photos above. All I did was download a regular sprocket model from McMaster-Carr (they have CAD models for most of their hardware (screws, nuts, shoulder bolts, sprockets, etc) on their website), use calipers to measure the metric output "spline" of the Denso motor, draw it on the part, and extrude cut it.

To machine it was a four step process. The first thing I had to do was machine a fixture plate out of 6061 aluminum. Then I machined about 90% of the sprocket features onto the 1/2" 7075 aluminum raw material. Then I took that part out, bolted it to the fixture plate upside down, and machined the sprocket teeth into it. The last step is to use a lathe or hand file to bevel the teeth.

There is nothing in this CAD model to keep the sprocket on the shaft of the motor or to support it for cantilevered loads. In the second photo I previously posted, our solution was to machine a custom bushing out of Delrin to both support the shaft and to keep the sprocket laterally in place on the shaft.

[JRysenga]

Originally Posted by NyCityKId

reference rule <R47>

We have been debating the same question... Can we use the worm gear transmission only? If you remove everything related to the motor (armature, brushes, wires, etc.) you are left with a nice input shaft to drive the worm gears. Why couldn't we use another (un modified) motor to drive this transmissioin? R47 talks about "modifying" motors. We demolished the denso motor and threw it away! R47 also states, "The intent of this rule is to maintain the maximum power level for each ROBOT" We didn't change the maximum power level since we plan to use another (legal) motor from the kit to drive the worm gears. Think we would pass inspection?

[NyCityKId]

Originally Posted by JRysenga

We have been debating the same question... Can we use the worm gear transmission only? If you remove everything related to the motor (armature, brushes, wires, etc.) you are left with a nice input shaft to drive the worm gears. Why couldn't we use another (un modified) motor to drive this transmissioin? R47 talks about "modifying" motors. We demolished the denso motor and threw it away! R47 also states, "The intent of this rule is to maintain the maximum power level for each ROBOT" We didn't change the maximum power level since we plan to use another (legal) motor from the kit to drive the worm gears. Think we would pass inspection?

To the best of my knowledge and understanding of the rules taking apart a gear box or transmission should be perfectly OK as long as rules <R47> and the rules on COTS items are followed. They don't have any specific rules governing gearboxes and they're uses. And there is also this: This intent is clearly met when a team obtains a MECHANISM or COTS items that was designed for non-FIRST purposes, and then modifies or alters it to provide functionality for the ROBOT. For example, if a team obtains a gearbox from a power drill and modifies it to use on the ROBOT, they gain insight into the design of the original gearbox purpose, learn to characterize the performance of the original design, and implement the engineering design process to create their customized application for the gearbox. According to that excerpt, taking apart a gearbox and using it in an innovative way is perfectly acceptable. This, however, is only speculation. If you want a final answer you should post this question to the official Q&A and see what the GDC has to say.

[yara92]

My team 1946 thank you for your help

[cilginbilgin]

Hello can anyone suggest us to use window motors without using gears

[PAR_WIG1350]

Originally Posted by cilginbilgin

Hello can anyone suggest us to use window motors without using gears

I'm sure many people (myself included) would be more than happy to help, but the question seems a little unclear.

If you want to remove the stock gearbox from the window motor in order to use the motor, this would be illegal since it is integral to the motor <R47>.

If you want to use the window motors with the stock gearbox and nothing additional, this would be fine, all you would need to do is mount the mechanism to the adapters provided in the kit. The only thing you would need to worry about is stripping the teeth of the gears.

If neither of these two answers match the question, rewording the question might help.