Go to Post I hope you realize that by starting this thread you have earned yourself a permanent place at the "WOEWITWISTFT" ("What On Earth Was I Thinking When I Started THAT FIRST Trend?") table. It's members are few, but the conversation is the most honest and amusing in the entire place. ;) - Jessica Boucher [more]
Home
Go Back   Chief Delphi > ChiefDelphi.com Website > Extra Discussion
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Reply
 
Thread Tools Rating: Thread Rating: 4 votes, 5.00 average. Display Modes
  #1   Spotlight this post!  
Unread 21-12-2014, 08:19
JesseK's Avatar
JesseK JesseK is offline
Expert Flybot Crasher
FRC #1885 (ILITE)
Team Role: Mentor
 
Join Date: Mar 2007
Rookie Year: 2005
Location: Reston, VA
Posts: 3,695
JesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by asid61 View Post
If you lose a CIM somehow, then having to take off the gearbox and reassemble it is a no-no.
Under what conditions would one "lose a CIM"? In 10 seasons I have yet to experience a bad CIM or see one in person.
Reply With Quote
  #2   Spotlight this post!  
Unread 21-12-2014, 09:33
Jared's Avatar
Jared Jared is offline
Registered User
no team
Team Role: Programmer
 
Join Date: Aug 2013
Rookie Year: 2012
Location: Connecticut
Posts: 602
Jared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond reputeJared has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

It's actually really difficult to just pull a CIM out of a gearbox without taking it apart. If you're using a 12 or 11 tooth pinion, the retaining ring on the CIM catches on the gear that the CIM pinion mates to. If you're using a 14 tooth gear, the pinion won't fit through the .755" hole for the CIM boss.

Also, if you did want to remove the CIM without disassembling the gearbox, I'd be willing to bet that the gearbox wouldn't just fall apart if one (or even all three) of the upper standoffs were removed.

If you wanted to disassemble a gearbox without removing a CIM, you'll have to remove one of the mounting bolts from each CIM. From experience, the CIMs don't fall out of the gearbox when this happens. They can't go anywhere because the one remaining bolt hold the CIM boss in a tightly fitting hole.

It looks like a solid design, and the gear ratios sound good too.
Reply With Quote
  #3   Spotlight this post!  
Unread 21-12-2014, 10:36
Chris is me's Avatar
Chris is me Chris is me is offline
no bag, vex only, final destination
AKA: Pinecone
FRC #0228 (GUS Robotics); FRC #2170 (Titanium Tomahawks)
Team Role: Mentor
 
Join Date: Dec 2008
Rookie Year: 2006
Location: Glastonbury, CT
Posts: 7,718
Chris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond repute
Send a message via AIM to Chris is me
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by Jared View Post
It's actually really difficult to just pull a CIM out of a gearbox without taking it apart. If you're using a 12 or 11 tooth pinion, the retaining ring on the CIM catches on the gear that the CIM pinion mates to. If you're using a 14 tooth gear, the pinion won't fit through the .755" hole for the CIM boss.
Are you using an odd size of retaining ring? I've never had this problem before with the ring catching on other gears, but maybe I've just been lucky.

Quote:
Also, if you did want to remove the CIM without disassembling the gearbox, I'd be willing to bet that the gearbox wouldn't just fall apart if one (or even all three) of the upper standoffs were removed.
Take one motor off at a time and add nuts where the motors used to be. Not that hard to do really, it just requires a little thought beforehand.
__________________
Mentor / Drive Coach: 228 (2016-?)
...2016 Waterbury SFs (with 3314, 3719), RIDE #2 Seed / Winners (with 1058, 6153), Carver QFs (with 503, 359, 4607)
Mentor / Consultant Person: 2170 (2017-?)
---
College Mentor: 2791 (2010-2015)
...2015 TVR Motorola Quality, FLR GM Industrial Design
...2014 FLR Motorola Quality / SFs (with 341, 4930)
...2013 BAE Motorola Quality, WPI Regional #1 Seed / Delphi Excellence in Engineering / Finalists (with 20, 3182)
...2012 BAE Imagery / Finalists (with 1519, 885), CT Xerox Creativity / SFs (with 2168, 118)
Student: 1714 (2009) - 2009 Minnesota 10,000 Lakes Regional Winners (with 2826, 2470)
2791 Build Season Photo Gallery - Look here for mechanism photos My Robotics Blog (Updated April 11 2014)
Reply With Quote
  #4   Spotlight this post!  
Unread 21-12-2014, 12:33
Lil' Lavery Lil' Lavery is offline
TSIMFD
AKA: Sean Lavery
FRC #1712 (DAWGMA)
Team Role: Mentor
 
Join Date: Nov 2003
Rookie Year: 2003
Location: Philadelphia, PA
Posts: 6,634
Lil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond reputeLil' Lavery has a reputation beyond repute
Send a message via AIM to Lil' Lavery
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by Chris is me View Post
Are you using an odd size of retaining ring? I've never had this problem before with the ring catching on other gears, but maybe I've just been lucky.
It always happens to us. We can usually get it far enough out to wiggle it around the other gear, though.
Reply With Quote
  #5   Spotlight this post!  
Unread 21-12-2014, 17:03
JorgeReyes JorgeReyes is offline
Team Captain
FRC #2002 (Tualatin Robotics)
 
Join Date: Jun 2014
Rookie Year: 2006
Location: United States
Posts: 94
JorgeReyes is an unknown quantity at this point
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by Lil' Lavery View Post
It always happens to us. We can usually get it far enough out to wiggle it around the other gear, though.
Even though it is a lot harder to switch out cims, I'm still think I'm going to keep the cims where they are because chances are we won't burn a motor. As far as the cim pinions go, its doesn't require the gearbox take apart because I could just take it out and change it.

One thing that does concern me though is the ease of changing belts if they snap.
Reply With Quote
  #6   Spotlight this post!  
Unread 21-12-2014, 19:03
asid61's Avatar
asid61 asid61 is offline
Registered User
AKA: Anand Rajamani
FRC #0115 (MVRT)
Team Role: Mechanical
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Cupertino, CA
Posts: 2,224
asid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by JorgeReyes View Post
Even though it is a lot harder to switch out cims, I'm still think I'm going to keep the cims where they are because chances are we won't burn a motor.
You have essentially guaranteed that you will now lose all of your cims during elims due to Murphy's Law.
But seriously, is it that hard to just add one more non-cim standoff? Two standoffs can hold your box together when swapping cims. In that situation, having through bolts to your cims is wise because it becomes easy to remove and add cims.

Last edited by asid61 : 22-12-2014 at 00:38.
Reply With Quote
  #7   Spotlight this post!  
Unread 21-12-2014, 19:48
Andrew Lawrence
 
Posts: n/a
Re: pic: Low Profile Gearbox Front View

What precautions are you going to take to ensure that your 6 CIM drive doesn't completely die when it goes under 7 volts of battery during a pushing match or high acceleration and the PWMs cut out due to the new control system?
Reply With Quote
  #8   Spotlight this post!  
Unread 22-12-2014, 00:35
Arpan Arpan is offline
Olin class of 2019
FRC #3061 (Huskie Robotics)
Team Role: Alumni
 
Join Date: Feb 2012
Rookie Year: 2011
Location: Naperville
Posts: 169
Arpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud ofArpan has much to be proud of
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by Andrew Lawrence View Post
What precautions are you going to take to ensure that your 6 CIM drive doesn't completely die when it goes under 7 volts of battery during a pushing match or high acceleration and the PWMs cut out due to the new control system?
I'd guess that implementing low-voltage protection in code by either auto-downshifting at low speeds or decreasing pwm power as voltage approaches 7 would keep this from happening.

Still waiting on 234's full report to make a call on it.
Reply With Quote
  #9   Spotlight this post!  
Unread 22-12-2014, 02:13
JorgeReyes JorgeReyes is offline
Team Captain
FRC #2002 (Tualatin Robotics)
 
Join Date: Jun 2014
Rookie Year: 2006
Location: United States
Posts: 94
JorgeReyes is an unknown quantity at this point
Re: pic: Low Profile Gearbox Front View

Yeah I think we are going to make an automatic downshifting program but we will do more testing to see what works and what doesn't. Possibly a shift light on the driver station to know when to shift.
Reply With Quote
  #10   Spotlight this post!  
Unread 22-12-2014, 09:21
JesseK's Avatar
JesseK JesseK is offline
Expert Flybot Crasher
FRC #1885 (ILITE)
Team Role: Mentor
 
Join Date: Mar 2007
Rookie Year: 2005
Location: Reston, VA
Posts: 3,695
JesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by asid61 View Post
You have essentially guaranteed that you will now lose all of your cims during elims due to Murphy's Law.
But seriously, is it that hard to just add one more non-cim standoff? Two standoffs can hold your box together when swapping cims. In that situation, having through bolts to your cims is wise because it becomes easy to remove and add cims.
Sure, it isn't "hard". But why add any extra complexity to deal with a very rare case? Sure, you have a box of dead CIMs - but would the average 6-CIM team also have as many? Why not deal with it by ensuring less stress on the CIMs to begin with, which reduces complexity and increases reliability?
Reply With Quote
  #11   Spotlight this post!  
Unread 22-12-2014, 16:52
JorgeReyes JorgeReyes is offline
Team Captain
FRC #2002 (Tualatin Robotics)
 
Join Date: Jun 2014
Rookie Year: 2006
Location: United States
Posts: 94
JorgeReyes is an unknown quantity at this point
Re: pic: Low Profile Gearbox Front View

Does anyone know if its possible to use this with the WCP gearbox bearing block ( which is currently shown on this gearbox) and using Versablocks on the sides. In the versa blocks, the 1/8" drop is created by flipping the block around.

http://content.vexrobotics.com/vexpr...40122-Rev2.PDF

Based of the drawing, I am thinking I could make the center of the gearbox bearing block .940" from the bottom of the 2in tube and then use versablocks on the sides. Would this work?
Reply With Quote
  #12   Spotlight this post!  
Unread 22-12-2014, 16:56
Thad House Thad House is offline
Volunteer, WPILib Contributor
no team (Waiting for 2021)
Team Role: Mentor
 
Join Date: Feb 2011
Rookie Year: 2010
Location: Thousand Oaks, California
Posts: 1,105
Thad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond reputeThad House has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by JorgeReyes View Post
Does anyone know if its possible to use this with the WCP gearbox bearing block ( which is currently shown on this gearbox) and using Versablocks on the sides. In the versa blocks, the 1/8" drop is created by flipping the block around.

http://content.vexrobotics.com/vexpr...40122-Rev2.PDF

Based of the drawing, I am thinking I could make the center of the gearbox bearing block .940" from the bottom of the 2in tube and then use versablocks on the sides. Would this work?
Yeah that would work I'm sure.
__________________
All statements made are my own and not the feelings of any of my affiliated teams.
Teams 1510 and 2898 - Student 2010-2012
Team 4488 - Mentor 2013-2016
Co-developer of RobotDotNet, a .NET port of the WPILib.
Reply With Quote
  #13   Spotlight this post!  
Unread 22-12-2014, 22:58
asid61's Avatar
asid61 asid61 is offline
Registered User
AKA: Anand Rajamani
FRC #0115 (MVRT)
Team Role: Mechanical
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Cupertino, CA
Posts: 2,224
asid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by JesseK View Post
Sure, it isn't "hard". But why add any extra complexity to deal with a very rare case? Sure, you have a box of dead CIMs - but would the average 6-CIM team also have as many? Why not deal with it by ensuring less stress on the CIMs to begin with, which reduces complexity and increases reliability?
Well, it isn't hard to add another standoff. You only need one more. It's a total of 0.05lbs on the robot extra. "Why not" is the question here.
It's good to ensure the safety of the cims OC, I'm just saying that's it's good to plan for the worst case. You can still plan for reliability and add a standoff to the gearbox too. Do both.
Reply With Quote
  #14   Spotlight this post!  
Unread 22-12-2014, 17:46
Oblarg Oblarg is offline
Registered User
AKA: Eli Barnett
FRC #0449 (The Blair Robot Project)
Team Role: Mentor
 
Join Date: Mar 2009
Rookie Year: 2008
Location: Philadelphia, PA
Posts: 1,109
Oblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond reputeOblarg has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by Lil' Lavery View Post
It always happens to us. We can usually get it far enough out to wiggle it around the other gear, though.
Same here. It always catches, but I've never not been able to remove a CIM because of it.
__________________
"Mmmmm, chain grease and aluminum shavings..."
"The breakfast of champions!"

Member, FRC Team 449: 2007-2010
Drive Mechanics Lead, FRC Team 449: 2009-2010
Alumnus/Technical Mentor, FRC Team 449: 2010-Present
Lead Technical Mentor, FRC Team 4464: 2012-2015
Technical Mentor, FRC Team 5830: 2015-2016
Reply With Quote
  #15   Spotlight this post!  
Unread 21-12-2014, 11:14
Gregor's Avatar
Gregor Gregor is offline
#StickToTheStratisQuo
AKA: Gregor Browning
no team
Team Role: College Student
 
Join Date: Jan 2012
Rookie Year: 2012
Location: Kingston, Ontario, Canada
Posts: 2,447
Gregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond reputeGregor has a reputation beyond repute
Re: pic: Low Profile Gearbox Front View

Quote:
Originally Posted by JesseK View Post
Under what conditions would one "lose a CIM"? In 10 seasons I have yet to experience a bad CIM or see one in person.
I have, just once. It was a brand new CIM in 2012. We weren't able to climb the bridge straight one match, so right after the match we felt all four CIMs, three were the standard moderately warm to touch, one was cold as if it hadn't been running (which it hadn't, we checked after removal).

While rare, it can happen so it's not a bad idea to design for CIM removal.
__________________
What are nationals? Sounds like a fun American party, can we Canadians come?
“For me, insanity is super sanity. The normal is psychotic. Normal means lack of imagination, lack of creativity.” -Jean Dubuffet
"Insanity is doing the same thing over and over again and expecting different results." -Albert Einstein
FLL 2011-2015 Glen Ames Robotics-Student, Mentor
FRC 2012-2013 Team 907-Scouting Lead, Strategy Lead, Human Player, Driver
FRC 2014-2015 Team 1310-Mechanical, Electrical, Drive Captain
FRC 2011-xxxx Volunteer
How I came to be a FIRSTer
<Since 2011
Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 06:06.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi