Bruce

All things small and scratchy.

Moderators: BeligerAnt, petec, administrator

Post Reply
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Bruce

Post by earthwormjim »

Thought I would start a topic on Bruce,as I am going to start again with him.
Hope no one minds. :)

I have stripped off all the bodywork,and had a look at the drive servos,as it has been possibly as much as 10 years sinc the last time they were looked at properly.
The label is long since gone,but they are fairly unique servos,due to the molding where the shaft exits.
I can't honestly remember the exact mod,but the lego output shart is epoxy'd onto one of the gears,and I think that at least 2 reduction gears have been removed,and there is a 3mm nut used as a washer to fill the space where the gears used to be...
Image
I am going to rebuild Bruce in a similar fashion,but with an eye on being a little more robust,(hopefully!) :D
Cheers,James
alasdair
Posts: 563
Joined: Sat Jan 03, 2009 3:52 pm
Location: Marlow, Bucks

Post by alasdair »

How did you get him to go so fast?! With servo drive I thought he would be super slow! :-?
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Post by earthwormjim »

alasdair wrote:How did you get him to go so fast?! With servo drive I thought he would be super slow! :-?
As far as I can recollect,the three final reduction gears have been removed,so the gearing has changed hugely from when the servo was made,but it has also reduced the torque as a result.
User avatar
joey_picus
Posts: 1137
Joined: Tue Jan 13, 2009 1:51 pm
Location: Lancaster, Lancashire
Contact:

Post by joey_picus »

It's still one of the best built fleaweights I've ever seen :) at the risk of sounding a bit noobish, how did you get the lego adaptor to sit centrally on the gear?
Joey McConnell-Farber - Team Picus Telerobotics - http://picus.org.uk/ - @joey_picus
"These dreams go on when I close my eyes...every second of the night, I live another life"
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Post by earthwormjim »

Joey wrote:It's still one of the best built fleaweights I've ever seen :) at the risk of sounding a bit noobish, how did you get the lego adaptor to sit centrally on the gear?
Pure coincidence! The shaft fits perfectly through the hole in the casing,and the shoulder on the shaft fits snuglt against the inside of the casing too.So I put a small dab of epoxy on the gear,attached the shaft,then put the casing on.When the epoxy had dried,I opened the casing,and added a load more epoxy to make the joint a bit more permanent!
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Post by earthwormjim »

I have been searching servo pics and stats this morning,and have found Bruces drive servo...
Image
It is available here...
http://www.robotshop.com/eu/gws-pico-st ... n=GoogleUK
For about ?8,(non UK site.)
Or here...
http://www.shop-uk.high-torque.com/inde ... s-GWS.html
For ?18.66,(UK site!)
They are also listed on Pololu's website...
http://www.pololu.com/catalog/product/501
Enjoy! :D
User avatar
peterwaller
Posts: 3213
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Post by peterwaller »

I remember them my first ever antweight reobot Combatant started with those for drive. I seem to remember the output shaft was a bit floppy so I put a bearing out side of the wheel to give more support.
http://i109.photobucket.com/albums/n66/ ... 160097.jpg
They were only held together with a piece of heatshrink and the label.
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Post by earthwormjim »

peterwaller wrote:I remember them my first ever antweight reobot Combatant started with those for drive. I seem to remember the output shaft was a bit floppy so I put a bearing out side of the wheel to give more support.
http://i109.photobucket.com/albums/n66/ ... 160097.jpg
They were only held together with a piece of heatshrink and the label.
Thats right,Mine are held together with masking tape! :)
User avatar
earthwormjim
Posts: 1190
Joined: Thu Sep 16, 2010 4:57 pm
Location: Secret Undisclosed Moonbase Location

Post by earthwormjim »

I dont suppose anyone has a spare servo arm for an SD 200 servo in their collection of old parts?
Bruces was ripped in half! :(
I would be very grateful.
:)
User avatar
peterwaller
Posts: 3213
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Post by peterwaller »

I have never used that servo but Galaxy Models sell the arms.
http://www.galaxymodels.co.uk/detail.as ... 9&rootid=2
Strangely they have the pico servo's on offer for ?4.99 at the moment
Post Reply