Cim-Sim gearbox for shooter questions

[Ether]

Originally Posted by Dan_Karol

it appears I hit the wrong button

Ah. In each post, there's an icon in the lower right corner that says "quote". Click on that and it will automatically provide context (which you can redact as desired) and link your response to that post.

[RRLedford]

Originally Posted by Ether

Yes.

2.7 speed reduction on a 19300 rpm motor driving 8" wheels => high torque on pinion.

How much engagement was left of the pinion into the first-stage gear in the CIM-U-LATOR with those spacers?

The gear overlap was still >80% since we pressed the pinion on less far down the shaft to anticipate this. I was kind of suspecting over-torque was the culprit. We have the option to do a 2:1 further reduction by going 15 to 30 with the belt pulley pair, but will even this be enough? We could also add a flywheel to reduce the level of braking torque that the squished ball effect applies to the motors. We can also add a 2nd gearbox driving the other side of the wheel shaft to divide the torque loading that the motors see a factor of two.

Any suggestions on what order woulf be best for trying these options?

-Dick Ledford

[Ether]

Originally Posted by RRLedford

The gear overlap was still >80% since we pressed the pinion on less far down the shaft to anticipate this.

The cantilevered pinion would contribute somewhat to the stresses on the motor bearing.

Did you consider milling cooling grooves in the CIM-U-LATOR instead of using spacers?

http://www.chiefdelphi.com/forums/sh....php?p=1120101

[Mr.Savagness]

Originally Posted by Chris Fultz

We have a similar set=up, except we are pulling the ball from the bottom and shooting over the top.

We are using 2 CIM-sim's on our shooter. 2 FP and 2 AM motors total.
We are direct driving the wheel, so there is no speed reduction from the gearbox output.

We are running 2 8" AM hard plastic wheels, spaced about 2" apart. All is assembled as a single unit so all motors, gearboxes and wheels are linked with a single shaft.

We have about 2" of squeeze on the balls.

For shooting from the top of the key, i think we are running about 55% speed. Using Victors.

Isn't that a bit of an overkill? We are using 1 cim-u-lator with 1 banesbot motor and with only using a little under 70% power we are shooting around 52 feet.

[RRLedford]

Originally Posted by Ether

The cantilevered pinion would contribute somewhat to the stresses on the motor bearing.

Did you consider milling cooling grooves in the CIM-U-LATOR instead of using spacers?

http://www.chiefdelphi.com/forums/sh....php?p=1120101

Yes, I just got the 9mm ball end mill to di this, but meanwhile we switched over to using the single motor version of the CIM-U-lator with the 18V 775 motor.
Distance is not quite as good, but it seems to bedoing better at handling force on the pinion bearing end of the motor. We can also boost RPM 7% by going from 30-to-30 with the belt pulleys to 30-to-28.

Thanks.

-Dick Ledford