Hi Kids,

MEA seems to be down, so I thought I'd post here....haven't done so in a while.

So I'm doing a boot isntall at the moment, and want to look further into actuators, servos, motors and general mechatronics sort of stuff. Linear actuators are way too expensive for my liking, so I'm trying to steer clear of those at the moment. More interested in 12V medium-high torque motors, worm gears n stuff like that. RS coomponents and Jaycar are good places to get equipment I need, however the prices are just stupidly high. Any suggestions as to where to source such things from?

Also, I've been thinking of salvaging motorised antenna masts, as they have an electric motor with spline. How much axial loading can these splines take? Most of the splines I know are probably nylon, and straining it too much will pretty much result in stripped teeth. I presume an antenna mast would be a hell of a lot lighter than an amplifier, glass panel, mdf and cabling.

I coulc consider the use of pneumatic rams and pumps, and tie it to my existing vacuum pump. Mercedes use a vacuum pump for door locking, fuel flap and boot lid releases. I can easily add the vacuum hoses into a terminal block at the vacuum pump, with a few vallves. The cost of pneumatic pumps and linear actuators are significantly higher than if I could use motors out of antenna masts and stuff.

In addition to getting the mechanical parts working, I will also need to design a logic controller, or some sort of limit switching and possibly a speed controller (if that can be done). Perhaps use an op-amp and H-bridge kind of setup? I haven't looked into it that much yet.

Anyways, I'm wanting to make panels rotate, on a hidden hinge, and rams to push things up and down. Hit me with knowledge people!:ninja:

(ohh, new emoticons I see)

How much weight are you trying to move?

How much force will be required?

The electric antenna's might be able to move something with 3kg of force, before the gear or spline snaps.....

In all honesty, for moving things with a good degree of force (like amp racks) you need linear actuators. However, they arnt AS expensive as you may think.

http://www.firgelliauto.com.au/

It what I'll be using in May for my next install to move some 15kg+ of amp rack.....

Yeah, I looked at the same website. They are probably the cheapsest suppliers I have found yet. They have a section called 'projects' where they are willing to refund 100% of your order if you submit photos of your project for them to post on the website. My only concern is, what sort of criteria are they looking for? What if they don't like your project, and decide not to post it? No refund....noooo.

I guess with enough worm gears, you can take a wimpy motor to turn pretty much anything, but it will most likely be a chunky setup. I have a hard-on for worm gears. I think hiding hinges will also be difficult when you want to rotate a panel. I was thinking some sort of a gear/cam setup on the hinge's pivot point, to act as a fulcrum, so you can push it with say....an actuator? :P

I'm probably going to be lifting close to 15kgs. My amps aren't light, and I'm putting glass panels over them to show the PCB and internal components. Probably looking at 150-200mm throw.

Electric window motors are also very very strong, though I'm not so fond of the hard-fast movement they provide. Also, will need to make custom rails for them....the motor is very strong though...might be worth visiting a few wreckers this weekend. Also, how much are electric antenna assemblies and electric window motors fetching at wreckers these days?

You're probably looking at around $100 for 2 motors from the wreckers, depending on the car...

Guide rails arnt much of an issue, contact a cabinet maker for some ball bearing slide draw rails, hiding these is another issue though....

I guess power window motors/regs might be the best bet for some cheaper motive power, though, im still a fan of actuators - they are purpose built to move big heavy things without breaking down, and smooth....

I guess with worm gears some power window motors would do the trick, in order to move an amp rack on a couple axis, some micro switches (like those used in the linear site) could be used perhaps, to stop one axis movement, while opening the circuit for another axis....

Let me know how you go with this - im still sticking with actuators, as for $160AUD each, they arnt *that* badly priced.

Possibly of no use to your project, but the electric boot release cable in 3rd Gens seems to be a little motor, probably with worm drive because it is MEGA strong. Using my "hands of steel" on the motor hub, there is no way I can hold it when release is triggered.

Also can be reversed, as I'm pretty sure that's how Verada Xi does the powered fuel-flap - the boot release motor travels one way for bott release, and is put in reverse for fuel flap release.

If you find one or two of these cheaply from a wreck you might be able to play around, try a larger hub to increase "throw" etc. Either that, or you could just make your amps "wiggle" when this is activated. :nuts:

So I've decided to cheap-out and try and build the thing from scratch.

Need to find lead bars, suitable threaded nuts and matching gears. Does anybody know where the hell to get things like gears, driveshafts and stuff like from? Any machine shops made them up? Only need a few small parts. Should all be powered by a power window regulator. As I will be using a leadbar, it will be similar principal as using a worm gear, so not THAT much torque is needed. I think I could use plastic gears, but they'd need to suit the leadbar so they can mesh properly. Also worried about the teeth stripping off.

Seeing as though it's a power window regulator, should be able to salvage the existing switching circuitry....if not, it should just be a DC motor I can reverse if and when needed. Not sure how they limit switching works on power windows either. Guess I'lll find out when I get one.

at a rough guess, its probably a microswitch that is the limiter.....

Its that or an inbuilt limit switch.

If I was to make one myself, it would probably be a bunch of limit switches and relays for switching. There's no real need to have it stop half way through moving I guess.

I need to find a place that will sell pinion, spur gears and shafts for me to mesh with the lead screw bar.


Argh, this is so distracting at work.....can't concentrate :P