www.robowars.org

RoboWars Australia Forum Index -> Builders Reports

MBX - Team Knightrous - QLD
Goto page Previous  1, 2, 3, 4, 5, 6, 7  Next

Post new topic   Reply to topic
  Author    Thread
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8509
Location: NSW


 Reply with quote  

Changed my mind on the gearbox design. Last one ended up too long, so I went for a bit of an odd design.


Still gotta add some clearances here and there, fixture point and probably design a milled out plastic housing to cover the gears. Looking forward to trying my luck on milling a large portion of it on my new milling machine (when it gets here Sad )
_________________
Team Knightrous

Post Thu Jun 11, 2009 11:06 pm 
 View user's profile Send private message
Nick
Experienced Roboteer


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


 Reply with quote  

Why not go with two larger, wider gears? Much easier to make and more compact.

Post Thu Jun 11, 2009 11:16 pm 
 View user's profile Send private message
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4435
Location: Sydney


 Reply with quote  

I wonder if rather than trying to accelerate and decelerate a motor, it might be easier to apply a brake to the motor. (mechanical or electrical)
Just something to think about
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Thu Jun 11, 2009 11:27 pm 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8509
Location: NSW


 Reply with quote  

quote:
Originally posted by Nick:
Why not go with two larger, wider gears? Much easier to make and more compact.


MOD1 or MOD1.25 gears from SDPSI didn't come in the ratios I was looking for, and I need this gearbox to be an inline solution, no offset output. The box is 2 stages of 1:1.4. I was originally going to double the gears up on the second stage, but it ended up making the gearbox too long, so I came up with the above solution. Gearbox is 80mm long, 70mm tall and 50mm thick (shaft not included). I could reduce the thickness if I machine all the bosses off the gears and keyway them to the shafts, might be something I do in the future with the mill and some new tools.

Hopefully it should hold up, if not, I'll design something else Smile

quote:
Originally posted by Valen:
I wonder if rather than trying to accelerate and decelerate a motor, it might be easier to apply a brake to the motor. (mechanical or electrical)
Just something to think about

I've thought about that before, but never really gone much further into it because it's just 10x easier to pulse it. Anguz and I have a melty brain chat on msn and we discussed using a h-bridge for the braking and pulsing side of things. Big problem is I'm not aware of any small 25A h-bridges that handle 40v and are small enough to use (I don't want to have to put a Victor in there!).

I've had other crazy ideas with using 1 big brushless that drives two wheels and the opposite wheel is speed controlled via an electronic differential, similar to FireStorm's drive but it just complicates things damn fast Razz
_________________
Team Knightrous

Post Fri Jun 12, 2009 8:15 am 
 View user's profile Send private message
assassin



Joined: 27 Jun 2004
Posts: 1105
Location: SunshineCoast


 Reply with quote  

Which Mill did you decide on? I might look @ one with my tax return this year.
_________________
Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.
Albert Einstein.

Post Fri Jun 12, 2009 10:05 am 
 View user's profile Send private message Send e-mail
Nick
Experienced Roboteer


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


 Reply with quote  

I guess its more interesting and challenging to build your own gearbox, but it looks like one of the Banebots P80 single stage planetarys would do the job. After buying all those gears, shafts and bearings, the cost might not be that much different.

Post Fri Jun 12, 2009 11:02 am 
 View user's profile Send private message
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8509
Location: NSW


 Reply with quote  

@Nick:Never thought of the P80 boxes, ratios will probably be wrong for me though.. I need a 1:2 gear ratio, I'm gearing the scooter motor up, not down. Good suggestion though, I might consider those if I ever make up some small boxes for scooter motors in the future. Always like the prospect of a scooter motor with a compact 4:1 gearbox on it instead of the annoying belts Smile

This gearbox will cost me about $100 all up once I get all the parts, and building my own gearboxes is rather rewarding from a personal perspective. My Ionboxes for Schmackhed (as rough as they were) worked well, till I started breaking the drill internals. It was a fun experience making them too, had to think outside the box to machine square billet with a 3-jaw chuck Smile

@Trent: Ended up getting the M150, still waiting for hafco to deliver it though, paid for it two weeks ago Evil or Very Mad Think I'll spend my next tax check on a bunch of tools for it, or maybe an Ebay Tig welder.
_________________
Team Knightrous

Post Fri Jun 12, 2009 11:31 am 
 View user's profile Send private message
assassin



Joined: 27 Jun 2004
Posts: 1105
Location: SunshineCoast


 Reply with quote  

I'm liking this bad boy:

http://titanmachinery.com.au/index.php?option=com_content&task=view&id=14&Itemid=32
_________________
Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.
Albert Einstein.

Post Fri Jun 12, 2009 2:15 pm 
 View user's profile Send private message Send e-mail
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8509
Location: NSW


 Reply with quote  

That's a kick ass mill, just a shame about the price tag Sad
_________________
Team Knightrous

Post Fri Jun 12, 2009 7:23 pm 
 View user's profile Send private message
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

thats the mill i was looking at too, if you could get one with an MT3 taper. that or the 5 grand one at hafco with the DRO. just incase you needed something that big one day Laughing
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Fri Jun 12, 2009 8:00 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
assassin



Joined: 27 Jun 2004
Posts: 1105
Location: SunshineCoast


 Reply with quote  

Its the accessories that make it good value, and apparently the company is good to deal with.

Here's one with a CNC mod:
http://www.youtube.com/watch?v=8PQOQEJyO2w&eurl=http%3A%2F%2Fwww.cnczone.com%2Fforums%2Fshowthread.php%3Ft%3D68153&feature=player_embedded
_________________
Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.
Albert Einstein.

Post Fri Jun 12, 2009 8:13 pm 
 View user's profile Send private message Send e-mail
Nick
Experienced Roboteer


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


 Reply with quote  

Yeah, its a good option, looks very similar to the Hare & Forbes HM-45 with better paint. Square column mills are definitely the way to go if you have the cash.

Post Fri Jun 12, 2009 8:33 pm 
 View user's profile Send private message
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4435
Location: Sydney


 Reply with quote  

We have the HM-45.
ballscrews for CnC have arrived, got the .001mm linear scales and I'm going to try 500W motors from oatley for the servo drives.

got the controller card powered up, going to try hooking a linear scale up to it tomorrow when i can get the right IDC header for the control card.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Fri Jun 12, 2009 11:44 pm 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8509
Location: NSW


 Reply with quote  

I <3 SDPSI!
Ordered the gears on the 11th, they arrived today(16th). Moral of the story, don't order from SmallParts Razz

_________________
Team Knightrous

Post Tue Jun 16, 2009 3:40 pm 
 View user's profile Send private message
assassin



Joined: 27 Jun 2004
Posts: 1105
Location: SunshineCoast


 Reply with quote  

What was the postage like, price wise?
_________________
Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.
Albert Einstein.

Post Tue Jun 16, 2009 6:36 pm 
 View user's profile Send private message Send e-mail
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 5 of 7

Goto page Previous  1, 2, 3, 4, 5, 6, 7  Next

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.