www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

Drill alternatives?
Goto page Previous  1, 2, 3

Post new topic   Reply to topic
  Author    Thread
Mouldy



Joined: 10 Aug 2011
Posts: 107
Location: Birmingham, England


 Reply with quote  

I ran banebots P60 16:1'S with RS775's and 98mm wheels this year on 5s lipo and they lasted briliantly, didnt have to touch them through the entire competition.... people had alot of problems with the gimpsons this year. however those were the GR01's not the GR02's, but again the exsternal face of the bearing on the gr02 doesnt look good to me.

Anyone over there tried the speed 700's? They give real impressive results in a relatively light package with a single stage reduction.

Post Tue Aug 20, 2013 5:18 am 
 View user's profile Send private message
Ellis



Joined: 21 Jul 2012
Posts: 129
Location: Shopshire, England


 Reply with quote  

Started thinking about alternate methods of addressing the pin failure issue in drill gearboxes. I don't have the right tools or parts to do this quite as I'd like but the concept is there. For the pin to loosen it'd have to either strip all the threads, those in the carrier plate itself and on the nut behind, or somehow loosen despite the counter-tightening and loctite. I used regular ungraded m4 bolts for this, so on this particular prototype there's an added risk of the pins bending, but with some better materials I think this is viable. As viable as the ballpeen method mentioned earlier, anyway. And for the average Joe, probably easier, as the parts needed are less specific.

http://aug.imghost.us/Flul.jpg
http://aug.imghost.us/Flw6.jpg
http://aug.imghost.us/FlwM.jpg

edit: and yes of course, chances are those nuts will foul in a drill gearbox, but again, I was just trying to distract myself for a while!

Post Sun Sep 01, 2013 12:15 am 
 View user's profile Send private message
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

I believe there is more to it then just the pins. Dewalts use rather small diameter pins (<3mm), but they run 4 & 5 gears per stage.


_________________
https://www.halfdonethings.com/

Post Sun Sep 01, 2013 12:56 am 
 View user's profile Send private message
Ellis



Joined: 21 Jul 2012
Posts: 129
Location: Shopshire, England


 Reply with quote  

Possibly down to a combination of better carrier plate material, so they don't tend to let the pins squidge out of place, and a better bearing setup? I think much of the reason the pins in drills fail is because the whole gearbox flexes when you hang a load on the end. Add the speed, shocks and often overvolted motors giving very high torque and the result is the pins go byebyes.

Post Sun Sep 01, 2013 1:59 am 
 View user's profile Send private message
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

The thickness of the plates in the dewalt is also much greater stopping the pins from flexing.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Mon Sep 02, 2013 12:28 pm 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
tetraPark



Joined: 07 Oct 2013
Posts: 62
Location: Brisbane / Ipswich


 Reply with quote  

So hearing mixed reviews about drill planetary gearboxes. Some seem to last forever, others get chewed out fast...
Most failures seem to be in the second stage carrier pins attached to the output shaft. Just wondering how catastrophic this failure is
for the gearbox? Does it ruin all the planet gears in one or more stages, carriers, ring gear, etc. What I'm getting at; is this a case of replace some parts, or replace the whole gearbox...

quote:
Originally posted by Krustalien:
I think much of the reason the pins in drills fail is because the whole gearbox flexes when you hang a load on the end. Add the speed, shocks and often overvolted motors giving very high torque and the result is the pins go byebyes.


Sounds reasonable...
So apart from not hanging load off the gearbox (say, supporting axle with other bearing on other side of wheel) are there any other precautions against this type of failure using existing parts (plastic gears notwithstanding)?

Cheers

Post Wed Nov 13, 2013 3:34 pm 
 View user's profile Send private message
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

If a 2nd stage pin breaks, it usually messes up at least one of the planetary gears and very often the sun gear of the first stage. Its very hard to find any spares to buy and most people just replace the whole gearbox. At least you get some salvaged parts from the broken gearbox...

Post Wed Nov 13, 2013 3:45 pm 
 View user's profile Send private message
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 3 of 3

Goto page Previous  1, 2, 3

Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.