Collective Build

Some pictures of my collective mechanism.

 

The collective is mainly made from aluminum and brass. The sensor is a hall-effect sensor (i.e. magnetic non-contact) with a 90 degree pickup range. The two wheels on the side has a ratio of 2.5 which means a 30 degree movement of the handle correlates to a 75 degree movement of the sensor. The belt is made from about 5 layers of common electricians tape.

 

The sensor outputs 0 to 5 V based on the position and is connected to a Plasma MM2 card from Beta Innovation (which unfortunately seems to have closed down, sorry to hear that Leo).

 

The red cylinder is a dampener made for mini-motos and is used to give the collective a mechanical feel + prevent gravity pulling (from the internal friction in the dampener) the handle down. There is also the possibility to add counterweights for this purpose (notice the slotted alu-bar attached to the main axle).

 

 

 

A quick demo of the mechanism.

 

 

Now off to learn russian :book:

 

/Oakes

great work Oakes.

good to see you're as crazy as everyone else.

gotta love the sensors, sure beats pots :thumbup:

 

will it be chair mount or are you making a pit.

very nice job

good to see you're as crazy as everyone else.

Right back at you:thumbup:

 

 

will it be chair mount or are you making a pit.

It will be mounted on some kind of side platform to get the correct height, the platform will be freestanding (easy to remove, relocate etc). Similar to my joystick (picture below) which sits on the right side of the chair. The joystick uses hall effect sensors as well btw.

 

 

 

Very nice mechanics. What controller and what kind of angle sensor did you use? Potentiometer? Hall sensor? Magnetoresistive sensor?

I used the Plasma MM2 controller from Beta Innovation's, the collective shows up as a normal DirectX controller in Win XP. Simple as pie:music_whistling:

 

The sensor is a hall-effect sensor, bought from conrad.se (or conrad.de), the senor was chosen based on availability (i.e the only one I could find with 90 deg travel available in small quantities) -> see http://www2.produktinfo.conrad.com/datenblaetter/175000-199999/182865-da-01-en-HALLEFF_WINKELS_91680_1KAN_45GR.pdf

for more info.

 

And maybe it will be better to use toothed drive belt (like in ink jet printers)?

Yes, from a purely technical standpoint I agree, a toothed belt would have been better and that was my starting idea as well.

 

However, quality belts and toothed wheels are rather expensive if you just want to buy one or two pcs, and I needed to have the correct gear ratio for the sensor to work (i.e. hard to find in an inkjet printer), so after some searching I decided to use a design where I could manufacture all the parts myself + it is very easy to change the the travel of the collective handle if need to (just make two new wheels and its done, notice that the senor box and lower wheel can move up or down in the slots in the vertical bar for this very purpose).

 

And it works, there is absolutely no backlash in this design.

 

/Oakes

 

 

The collective is nice!

 

Care to post a blueprint and where did you get the hall fx and how much? No worries if you don't want to divulge the info.

 

Never mind, did not read your post.

 

Care to post a blueprint and where did you get the hall fx and how much? No worries if you don't want to divulge the info.

 

Sorry leafer, all I got is a design sketch I made in 3dStudio (the only 3D program I've manged to learn:cry:) i.e. no real measured drawing is available.

 

I can, if you like, post a bunch of measurements for the parts you see in the pictures to help you along. Just let me know.

 

/Oakes