NEO GEO Evolution (EVS-1) - Experimenting with DIY trackball

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BadMouth:

--- Quote from: TopJimmyCooks on May 07, 2012, 09:11:22 am ---Are you sure with that geometry and the stroke of the linac that you're going to be able to get 90 degrees? It looks close but it's probably just the angle of the pics I'm seeing.

--- End quote ---

The stuff is just laying there in the pic. Nothing is drilled out or bolted together yet.
It's not too far off from where it needs to be though.
The actuator has a 6" stroke. Imagine a 6"x6" square centered on the back of the monitor mounting plate.
I just need to take one corner and push it to the positon of the next corner to get 90° rotation.
If it comes up short, I shorten the length of the crank, making the square smaller.

It will be together and working tomorrow, so I guess we'll find out then. :lol

I'm swiping ideas from the Switchade for the CP btw. ;)
Nothing as elaborate, but I'm using the same t-channel as guides.

TopJimmyCooks:
Cool can't wait to see what you did with it.

BadMouth:

--- Quote from: DaOld Man on May 07, 2012, 06:44:31 am ---Good build man! I like your attention to detail, I could use some of that, got any to spare?

--- End quote ---

I have attention to detail in the planning stages. When I actually go to build it and just want to get it working is another story.
Never enough time to do it right. Always enough time to do it twice :P
(and it's all your fault I'm playing with linear actuators)

I learned a lot this evening. The rotation mech works, but the final stopping points are very slightly off and I didn't build in any adjustments this round. I just wanted to get the thing together and see it work. I will end up redoing most of it, but taking more time to make sure it is correct.

If building off of a bracket, it may be useful to square the monitor bolts with the bracket and lock the bearing down to keep it from rotating.
This can help you set the position of the actuator so that fully closed (or fully extended) is square.
(but I didn't have anything handy to lock the position with, so my final result was slightly off)

Drawing lines between the bearing bolt holes on the monitor mounting plate will give you some good points of reference for mounting the crank if using one of these lazy susan bearings with a lot of open space in the middle. It would make drilling accurate bolt holes for the crank easier.
I will do that when I rebuild this thing.

Anyways, here's what it looks like thrown together for now.
(had to add nuts to get some extra height to clear the bolts holding the bearing on)

The stops are slightly off. I've got no excuse for the first direction being off, as I should have squared everything better before drilling the hole for the rear mount of the actuator. If you get that one right, the crank length should determine the other one.
If they were off by the same amount, I'd blame the actuator mounting point, but it seems both that and the crank arm length are slightly off.

This is a case for just making it over-rotate and using external limit switches to stop it. It would be a lot easier to get dialed in that way.

This design works fine...... :)
I just need to measure like a machinist.

Santoro:
:applaud: :applaud:

TopJimmyCooks:
At least you've got a machinist grade stamped steel framing square to work with! [Kidding- i use a little speed square all the time for metalworking, so I can't say anything]

Building in adjustable limit switches is the way to go.

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