Chief Delphi

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)
-   Extra Discussion (http://www.chiefdelphi.com/forums/forumdisplay.php?f=68)
-   -   pic: WCD off season chassis from 2471 (http://www.chiefdelphi.com/forums/showthread.php?t=139926)

pribusin 02-12-2015 08:52

Re: pic: WCD off season chassis from 2471
 
Got it - thanks.

Are those 3" x 0.875" wheels? How are they kept from slipping off the hex shaft?

Nate Laverdure 02-12-2015 10:23

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by RobotsThatWork (Post 1509206)
Two 16 tooth vexpro sprockets do not sit next to each other inside the 2x1x1/8 (so width). This is true for both when bearings are press-fitted, and when I use a versa bearing block. The Sprocket with Chain attached to it has a total diameter of 0.491 inches. When I put 2 back to back it would be too wide to fit inside the boxtubing. Any solutions?

We chose to avoid this problem by using 2 x 1.5 x 1/8 tube.

The 17t sprocket works in the 2 x 1 x 1/8 because it has a large enough pitch diameter that the chain clears the 1.125 bearing OD.

jman4747 02-12-2015 12:37

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by pribusin (Post 1509254)
Got it - thanks.

Are those 3" x 0.875" wheels? How are they kept from slipping off the hex shaft?

External retaining rings: http://www.mcmaster.com/#97633a200/=102dny4

Nebster 02-12-2015 12:48

Re: pic: WCD off season chassis from 2471
 
What are you using to hold the corners of the frame together? It's not clear to me

notmattlythgoe 02-12-2015 12:52

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by Nebster (Post 1509306)
What are you using to hold the corners of the frame together? It's not clear to me

There are blocks in the ladders with through bolts going through the rails.

Ty Tremblay 02-12-2015 13:00

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by Nebster (Post 1509306)
What are you using to hold the corners of the frame together? It's not clear to me

http://www.team221.com/order.php?cat=15

See "Chassis Tube Connector"

Bryce2471 02-12-2015 14:46

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by Nebster (Post 1509306)
What are you using to hold the corners of the frame together? It's not clear to me

This was a point of much discussion while in the design phase. We thought gussets would be stronger, but using blocks would fit with the chain in tube solution better.
Quote:

Originally Posted by notmattlythgoe (Post 1509308)
There are blocks in the ladders with through bolts going through the rails.

This is what we ended up going with, partly because the belly pan is adding a lot of corner to corner strength already.
Quote:

Originally Posted by Ty Tremblay (Post 1509309)
http://www.team221.com/order.php?cat=15

See "Chassis Tube Connector"

We did not use these, but they look to be functionally equivalent. The plastic blocks ended up being a good project for younger students to get some training and experience in.

cxcad 02-12-2015 16:01

Re: pic: WCD off season chassis from 2471
 
It would be interesting to see the FEA for the block vs gusset design. On my team the thought was that blocks were stronger because the blocks were pulling the frame members toward each other.

zinthorne 02-12-2015 21:48

Re: pic: WCD off season chassis from 2471
 
Does anyone know where to find a cad file for this?
The half inch hex

asid61 02-12-2015 23:24

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by zinthorne (Post 1509427)
Does anyone know where to find a cad file for this?
The half inch hex

Because I couldn't find it, I just downloaded the round version, put a hex bore in it, re-saved it as a STEP file, and reopened it. That gave me the 1/2" hex 17t double sprocket.

zinthorne 03-12-2015 19:20

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by asid61 (Post 1509452)
Because I couldn't find it, I just downloaded the round version, put a hex bore in it, re-saved it as a STEP file, and reopened it. That gave me the 1/2" hex 17t double sprocket.

I can not find the round version. Am I missing something on the website?

Greg Woelki 03-12-2015 19:42

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by zinthorne (Post 1509585)
I can not find the round version. Am I missing something on the website?

I emailed them about it last year. The file can be found here.

Jacob Bendicksen 03-12-2015 22:42

Re: pic: WCD off season chassis from 2471
 
Wait, Mean Machine's not doing swerve? :D

Glad to see you're having fun and building robustly for BunnyBots -- should be a fun event.

Nebster 04-12-2015 17:43

Re: pic: WCD off season chassis from 2471
 
What are you doing for center drop? Do the sprockets you're using inside the tube have enough clearance with the walls of the tubing for a center drop? I haven't seen that done before but since you're using 1/16" tubing it could be possible.

Do you feel 1/16" walled tubing is strong enough for a traditional drive train?

Bryce2471 04-12-2015 18:06

Re: pic: WCD off season chassis from 2471
 
Quote:

Originally Posted by Jacob Bendicksen (Post 1509661)
Wait, Mean Machine's not doing swerve? :D

Glad to see you're having fun and building robustly for BunnyBots -- should be a fun event.

Yep, I'm looking forward to it! ;)
Quote:

Originally Posted by Nebster (Post 1509771)
What are you doing for center drop? Do the sprockets you're using inside the tube have enough clearance with the walls of the tubing for a center drop? I haven't seen that done before but since you're using 1/16" tubing it could be possible.

The bearing blocks we are using have their bearing holes drilled 1/16" off center. The center wheel has its block upside down compared to the outer wheels, so that gives us 0.125" drop. If it tips around too much or is too squirrely, we will flip one of the outside wheels for effectivly a 0.0625" drop. We are using 16t #25 chain sprockets.
Quote:

Do you feel 1/16" walled tubing is strong enough for a traditional drive train?
I think so, but we'll know for sure by the end of the month.
Anything that survives this BunnBot game will certainly be "strong enough for a traditional drive train"


All times are GMT -5. The time now is 04:22.

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