pic: Window sprocket adaptor
 

Re: pic: Window sprocket adaptor
 

Out of curiosity, how was this made? I'm guessing the splines were broached?

Re: pic: Window sprocket adaptor
 

Wire EDM / Lathe? First one to guess correctly gets one for free, right? :p

Re: pic: Window sprocket adaptor
 

You could make them with a 4mm keyway broach, but I'm guessing they were made via wire EDM, since it's a lot easier than lining up six broaches accurately. If I guessed right, Travis can have the free one since literally ten minutes ago I finished machining nine 18t 25-pitch Denso motor hubs for GUS. ;)



// Still laughing over the timing of our photos...

Re: pic: Window sprocket adaptor
 

Travis hoffman is correct. They were lathed first, then wire edm. They took about 1hr 1/2 to make. The adapter is made out of 7075 aluminum and weight less then the plastic adapter they give in the kit. We also created an AM sprocket adapter. We are looking at producing more for teams only if there is a demand for them. Well art you can stop by our pit on Saturday at suffield shakedown and check one out. Travis pm me and Ill send one out you can test with and give me feed back.



That is funny we posted about the same time

Re: pic: Window sprocket adaptor
 

How do you plan on keeping the sprocket retained on the motor?

Re: pic: Window sprocket adaptor
 

How much do you want for a set of four?

Re: pic: Window sprocket adaptor
 

Art,

NINE? You know that you're only allowed 2 windows on a robot... :eek:

JK... Nice Job...

Mike

Re: pic: Window sprocket adaptor
 

ummm - how do I get some? I wish we had the ability to do stuff like this.

Re: pic: Window sprocket adaptor
 

Pretty sure you are allowed 4 window motors on the robot, seeing as we received 4 in the kit.

Re: pic: Window sprocket adaptor
 

You better make sure those motors are always turning at the same speed...

...otherwise its bye-bye Mr. Denso :cool:

Re: pic: Window sprocket adaptor
 

Eric,

Thank you for pointing that out to me. We only received 2 last year and I missed the increase.

Regards,

mike

Re: pic: Window sprocket adaptor
 

http://www.facebook.com/home.php?#!/...8&id=530290273
the motors hold the adapter from moving. We already have taken care of the motors at moving different speeds.

Re: pic: Window sprocket adaptor
 

We would be interested to know if you have any trouble with your Denso motors overheating and cutting out. We had two Densos mated exactly this way for our swerve steering, but had to switch to steering with a CIM because the Densos would overheat and stop. Perhaps on a kicker they do not run enough to be problem. They are window motors so for safety they are designed to cut out when they stall on something and heat up. Not really the ideal motor to build robots with.

Re: pic: Window sprocket adaptor
 

We did, but that's because the theoretical load I calculated was between 1/2 and 1/3 of the observed necessary torque*. Using this figure, I found we were loading the Denso motors to 20 amps... and their stall current is about 24 amps. :o So using the observed torque, I back tracked and redid the gear ratio to maximize the power output and lower the current draw to a reasonable amount.

* I've pinned the reason for the discrepancy down to a few SWAGs at coefficients of friction between different materials not listed in the commonly available engineering tables like Machinery's Handbook. In the future I'll probably perform tests to experimentally ascertain these values instead of guestimating values at 2am...

Re: pic: Window sprocket adaptor
 

If you power them with the same pwm value it's really not an issue based on the testing we've done. Been working fine all week for us.

I even took a pair driven together in my hands and tried to get them to rotate as differently as possible, they definitely handle a good deal of force difference while running together (at least at full speed).

Re: pic: Window sprocket adaptor
 

We were having a similar problem last weekend. If you want, shoot me a PM with some pictures of your set up and I can try to offer some advice. We were able to make ours work with two windows powering four wheels (one on front set, one on back set). It sounds to me like you've got some friction somewhere in your system, just as we did.