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An engineering challenge - speeder related
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Le Chuck:
In an effort to keep my build thread focused what's actually been built I'm yet again posting harebrained related questions for group brainstorming.

I need to selectively connect two square axles.  This will allow me to use the left and right speeder handles independently or in unison.  My plan is to linearly actuate a collar bearing mounted square-holed sleeve across a gap a RCH wide between the two axles. 

I'm in love with this: but it costs a measly $1500 with controller for an inch of travel.  F that. 

Here's what I'm thinking:  DC motor connected to a rail similar to what's on TJC's CP slides with two limit switches.  Put the rail in the middle and two guide rails on either side then just mount my axle joining bracket to a base plate on all of that.  Whole shebang should take up 3 or 4 inches and only needs to actuate an inch either direction.  Motor wired to a DPDT. 

Crazy, ludicrous, just might work?  Is there a better way to skin this cat?  What parts would you all recommend I start loading into my shopping cart.  I am not opposed to spending money on this to work, I've looked at micro-slide tables and really like those but am not sure how to actuate them as is so building one of my own came to mind. I just don't want to break the bank over a trite feature. 

Thanks!
Nephasth:
First thing that came to my mind was how tractor brake pedals are set up...
yaksplat:
This made me think of the hi-low gear on my lathe.  When you want the lathe in high speed you manually push a pin that connects the  gear to the shaft.

To put it back in low you pull the pin out and reconnect the reversing gear.



With the limited amount of travel that you should have, you should be able to  automate a pin, or several pins on a collar that are spring loaded and actuated with a solenoid.
BadMouth:
I'm not coming up with anything better than the square collar and linear actuator.
(picturing it attached to one axle and extending a collar to the other axle when activated)
Surplus Center has some real cheap ones without limit switches, but built in ones would eliminate a lot of parts.
http://www.surpluscenter.com/item.asp?item=5-1783&catname=
Not sure if you'll already have a 24v source, but the draw is low enough it could be powered from a laptop brick.

EDIT:  probably need to ensure that the collar doesn't move until the axles are aligned. (handles in same position)
          I can see kids messing that up real fast. hmm.....

EDIT 2: maybe have the collar spring loaded in the linked direction and have it ride against a panel that is keyed in such a way that it will only slide through when the axles are aligned properly.  The actuator would keep the spring compressed when in "separate" mode.  Not real crazy about having surfaces riding against each other, but it would only do that until the operator moved the handles to the same position.
Le Chuck:

--- Quote from: BadMouth on September 06, 2012, 01:52:21 pm ---probably need to ensure that the collar doesn't move until the axles are aligned. (handles in same position)
          I can see kids messing that up real fast. hmm.....

--- End quote ---

Good call!  I have limit stops from the SWRA throttle bodies that I'll be using and there is plenty of room to mod a limit switch onto those.  I can put one on each and wire them together so that the handlebars both have to be all the way back before the switch will activate (just hack into the ground I imagine).  I have also toyed with getting a locking switch cover for that control since it's not something that I want folks messing with... plus those locking switch plates are teh kewlz. 

As for spring loaded... I'm gonna call that one out of my range of abilities, for now at least.  I need to sit down and evaluate doing a motor vs a linear actuator.  That LA you linked to can push 100+ lbs and is somewhat overkill since this is not really a load bearing or torqued application, but the size is right and the price isn't bad. 

Yak & Nep - I love this place because I get the coolest ideas of stuff that I get to go research and figure out how it works.  Chasing the rabbit is how I get most of my ideas anyway.   :cheers: :cheers:
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