pic: Team 954 Preview: Heavy duty Master Link

[CD47-Bot]

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[David66]

WARNING!!! I can absolutely, and without a doubt garuntee that if you use the drill motor in that manner without supporting that shaft BEHIND the gear the transmission will snap off the motor in the middle of the match. it WILL happen, no questions about it. I speak from person experience of doing the EXACT same thing. Also, bracing the shaft from in front of the gear will not work. It needs to be supported between the transmissiona dn the gear. Please please please contcat me with ANY questions

[NoRemorse]

I can see yu reason for concern, but when i look at the picture, i see ply wood, and tape, i think this bot is FAR from done!

[dhoffman]

Thanks for the warning! This was just a mock up for a picture/non driving prototype - on our "final robot" we have pillow blocks supporting the shaft on both sides of the sprocket (the dirlls are moved back). Thanks for the suggestion though, my team is new to Chief Delphi and we appreciate the caring attitude of the members. Thanks again.

[Greg Needel]

i personally disagree with the coments of supporting the shat infront of the tranny and after the gear. the rule of thumb is that you put 2 bearings on a shaft which is true but in the case of the drills the transmission acts as the bearing on the motor side and putting another pillow block there unless all three (2 pillow blocks, and the tranny) are exactly lined up will work against you and make your drive more effiecnt. about the issue of breaking the tranny in half i only saw that last year when the end beyond the sprocket wasn;t supported. other then that they shouldn;t have broken unless there was something unrelated as the cause

[WakeZero]

I am deeply concerned about the sprockets you are using... LOTS OF WEIGHT!!!!

If you can get the same gear reduction with smaller gears... use the smaller ones.... and from the looks of it, it looks like a one to one so you don't need such bulky sprockets anyway

[Cory]

That is definitely not 1:1. Looks way closer to 2:1. There is a lot of unnecessary weight on there though. You could drill out quite a bit of it, very easily.

Cory

[dhoffman]

Thanks again for all of your concern - as you can all probably tell our team is still very rookie in nature. As far as the sprockets go, we are using smaller one's on the "real robot" - and just for your general info the picture shown does have reduction, it's something like 45 to 30 or around that area. Now, since our motors have not been totally mounted on the finalized design and we could gain more space by not having the second pillow block, since we have two differning opinions on the neccessity of an additional pillow block, could an additional person (or a few?) please clear up if we need an additional pillow block or not?

[David66]

To clarify my earlier post: Last yearwe used almost the exact same type of drive system (concerning the drill motor/trans) and supported the shaft only after the sprocket. This leaves only the plastic bracketry holding your trans in place-plastic flexes. When we put a high torque load on any of these motors the plastic would flex allowing the gears inside the trans to bind and fling the whole thing to pieces . If you watch some videos from nationals you will often see judges walking around with magnets after one of our mateches...thats our drill trans being picked up. However, for the absolute best information there is a team on here that proudly defends the 2003 drill motor and gearbox (294?). Look for one of them for the best answer.

[WakeZero]

Originally Posted by dhoffman

Thanks again for all of your concern - as you can all probably tell our team is still very rookie in nature. As far as the sprockets go, we are using smaller one's on the "real robot" - and just for your general info the picture shown does have reduction, it's something like 45 to 30 or around that area. Now, since our motors have not been totally mounted on the finalized design and we could gain more space by not having the second pillow block, since we have two differning opinions on the neccessity of an additional pillow block, could an additional person (or a few?) please clear up if we need an additional pillow block or not?

It is always a good engineering habit to take the side load off of your motors. Without the second pillow block, what happens is that your motor is now being pulled from side to side. This is often the number one reason for the magic smoke

One pillow block on each side of your sprocket will save your motors a lot of stress

Here is what we did last year to show you what I mean:

[matt111]

do u no what heavy duty actually means?

[Matt Adams]

Originally Posted by WakeZero

It is always a good engineering habit to take the side load off of your motors.

One pillow block on each side of your sprocket will save your motors a lot of stress

I'll completely second that opinion.

The bearings inside the drill motor (and almost all motors) are probably awarded to the lowest bidder... do you want that supporting your drive train? I know I wouldn't!

Also, make sure you double check your gear ratios.. from past experience, I know that if you're using just the drills and want to make sure you don't blow your 40 amp circuit breakers, the proper ratio from low speed is (roughly):

Wheel diameter in inches * .375 = total gear ratio speed reduction

Go with two pillow blocks!

Matt

[Joel Glidden]

Definitely go with two pillow blocks.

Pillow Block - Sprocket - Pillow Block - Drill Motor Transmission