Does anyone know the size of the ring needed to lock the drill motor transmissions into low gear? I know where/how to install it. But I am not sure on size. I posted some information on locking the transmissions into high gear in the Whitepapers section.
29 mm I.D.
33 mm O.D.
5 mm Thick
I made mine in Aluminum - Works great!
I’m not sure if I understand, but what are the o-rings used for and what are you trying to do with drill motor?
Are you trying to lock the the planetary gear transmission on the drill motor?
And lastly, is 1 or 2 on the drill motor casing the low geared reduction?
Thanks in advance
Can someone tell me about the aluminum rings, etc. that you use to lock the drill gear boxes in low or high? We have shifted them since '99, but before that, we always locked them in gear with a cable tie between the little shift fork and an appropriately located item nearby. It always worked fine. What am I missing?
Thanks
To lock the gearbox in high gear (faster output, lower torque) all you have to do is put the plastic ring in “upside down” (motor side shaft side?).
If you do this, the teeth on the outside of the ring cannot mate with the teeth in the housing and thus you cannot shift it into low gear.
Low gear requires a machined ring or an o-ring to lock.
As to Kit’s question about why anyone would want to put anything inside the transmission when you can hold something outside the transmission just as easy, for many of us, that whimpy shifting ring is not good enough or it is just in the way of our machanism or mounting system.
Joe J.
clever idea, but how does the ring do with all the extra space to move around?
also, the first plastic ring (the smaller off-white one) tends to melt/strip in a few of our trans. what might be the cause of this?
As to your first question, I don’t know because Chief Delphi has not used the drill transmissions in many years. When I did, I used machined rings to lock the transmissions. The “flip the ring over” idea comes to me from Bill Beatty (though he is by no means the only one who suggested it). Based on the source, I would say it must be a pretty solid method. Unless my brain is fried and I am mis-remembering the source.
As to your second question, I have NEVER had any problems with that first ring. I have never even HEARD of any problems like this.
Are you using it with the drill motor only or have you made a homebrew of motors to input into this transmission?
Anyone else have ideas?
Joe J.
I don’t see why you can’t just duct tape it down? hehe
Or screw it down, it seems a little too much work too machine a custom piece just to hold the gear assembly.
Just my insight 
As to the rings it only takes about 10 to 20 mins to make each one. Twenty mins out of 1000’s of man hours isn’t that much for a fail safe way to do it. As to Joe’s question: We only use the drill motors with the trans. The trans are from 2000 and were used in competition. We never had this problem then. Would that have anything to do with it? i.e. wear and tear?
While these various rings, etc. may be a ‘better’ way of holding the transmission in high or low gear, it will be hard to convince me that it is necessary to do anything other than use the fork that comes with the drill and “tie” it into the gear you want.
We did that from '96 to '98 and won nationals in '98 with such an arrangement. Also, while it is not considered the ultimate in technology, we had the drill motors and gear boxes in the drill cases those three years.
While I completely agree with Joe that drill gearboxes held in gear with tie wraps, and mounted in drill cases are not the ultimate setup, a rookie team with limited resources who wants a robot that will move reliably can do very well with a simple drive train using drill motors and transmission mounted in the drill cases.
Joe,
You are correct. We have used the filpped ring gear every year to lock in high. It is quick, easy and free. It actually appears to improove the mesh a bit. Never had a gearbox failure in six years. (Now I’ve done it)
Not last year, cause we shifted.
we’ve used the plastic ring off of a plastic coke bottle before to lock it into gear. it seemed to work like a charm. but you do have to file down the little plastic things inside it
David,
What line on the additional materials list has “plastic ring off of a plastic coke bottle” or is it a Small Parts item (P/N Pleeezzzz).
As for why make a locking ring, it’s one thing less to worry about and worth the manufacturing time. I’ll loose sleep about 100 other things, but not the transmission slipping into (god forbid) NEUTRAL. argggg!
*Originally posted by Ed Sparks *
**David,What line on the additional materials list has “plastic ring off of a plastic coke bottle” or is it a Small Parts item (P/N Pleeezzzz).
As for why make a locking ring, it’s one thing less to worry about and worth the manufacturing time. I’ll loose sleep about 100 other things, but not the transmission slipping into (god forbid) NEUTRAL. argggg!
**
ummmm… it’s not. we used that in '00. last year we held it with tie wraps and this year we’re planning on switching gears. sorry everyone for breaking the rules in '00. not like it would have mattered. we sucked really badly that year
Can someone explain where exactly to install O-rings or some other part to lock gear in LOW. I understand how to flip the gear so you are locked in high but where are you putting these rings to lock it in low.
The way the drill transmission shift gear is that the metal lever on the transmission slid a ring gear inside the gearbox to either:
Lock the second stage of planetary gear with the first stage so that the transmission skip one stage of planetary gears.
Or, it unlock the first and second planetary stages and engage the second stage to have extra reduction.
The O-ring act as a spacer to prevent that sliding ring gear from moving from one side to another, holding it to lock the first and second stage together, OR holding it to engage the second stage.
You will have to open up the gearbox to put the O-ring in. Just decide between high and low gear.
If you want to keep it in high gear, the lever is supposed to push the ring gear TOWARD the motor, so you can install the O-ring next to output shaft-pointing face of the ring gear.
If you want to keep it in low gear, the lever is supposed to push the ring gear AWAY from the motor, so you can install the O-ring next to motor-pointing face of the ring gear.