360 degree servos in analogue gauges

[No Longer Active]

Hello.

Would it be possible to use a 360 degree servo in an analogue gauge as an air speed instrument?

Normally you would use a normal servo with a 1:2 gear, but with the new 360 degree servos readilly available, this would appear a good idea.

However these servos appear to be continuous rotation, so maybe a stop would need to be in place?

Any thoughts on this?

Thank you.

[AK Mongo]

Alex,

Not sure the 360 servos sense a relative position, they just turn cw or ccw don't they? I think this is why stepper motors may be a better choice because they keep track of the position. Could be wrong, but that is my understanding.

Reid

[No Longer Active]

Hi,

To be honest I did read a little more on this and your right.

I need to build an RPM gauge for the right of my pit and was wondering if I can 'pull a fast one and cheat'

Cheers,

Alex

[Ronson2k9]

Either way you will need a controller for the gauge. I would suggest you take a look at Mike Powells site (http://www.mikesflightdeck.com/instruments/simulated_instruments.html) on building gauges. You can also check out FSCockpit.com (http://www.fscockpit.com/mechanicalgauges.html) article on mechanical gauges. If you are good with electronics you can build the items yourself or you can go to Phidgets (http://www.phidgets.com/)and get them ready built.

Both will require a controller (a sensing unit) to detect where the needle is. A pot is the best choice however a pot only turns so far about 300 degrees so you have to gear the receptor so that the amount of turns can be read by the pot.

[No Longer Active]

Was thinking of an opencockpits servo card, they are only £25!

Luckily, the RPM only turns under 270 degrees, so was thinking that there is an easy way to implement this.

I have a spare simkits housing and faceplate, just need a servo and if required some gears to get the movement required.

Alex

[fordgt40]

Alex

It is not difficult to make a gauge for use with an OC servo card. See here

http://www.737ng.co.uk/djb/brake_pressure_gauge.pdf

Regards

David

[No Longer Active]

Hi,

Yes I will be making a gauge using gears:

I am thinking that this gear set will be good (cheap and cheerful):

http://www.ebay.co.uk/itm/DIY-Gearbox-Pack-20-plastic-gears-plus-shafts-/260861217106?pt=UK_ToysGames_RadioControlled_JN&hash=item3cbc8a4952#ht_1044wt_825

Cheers,

Alex

[No Longer Active]

Gears and servo now ordered, Ive made a start atleast!

http://i434.photobucket.com/albums/qq62/alexpilot2008/gaugerpm.jpg

Thanks to David for the idea VERY simple idea using a mini servo and gears!

This gauge will be for the co pilot side of my Cessna where only 2 gauges are needed which is the tachometer and ASI.

If I can pull this off then I will have the confidence to make more!

[fordgt40]

Alex

One further bit of advice. Choose a gear combination that gives a little bit more movement than you need. The Hitec servo/OC Card combination does not work well at the servo limits of travel - it can get a tad erratic!

Regards

David

[No Longer Active]

Advice taken! :) When I get my gears through the post I will make a temp breadboard and experiment until I get the correct/desired rotation. The Cessna tacho requires just under 270 degrees of movement. However the RPM of a Cessna 172 never exceeds more than 2500-2700 which equals around 180-200 degree of movement. So I still have plenty of movement to play around with.

Thank you

Alex

[notgotaclue]

Your spending well lately, have you sold the misses or something? ;)

[No Longer Active]

Ive spent over £200 this weekend.

£50 on my CH yoke, £45 for a LCD monitor foy my gauges to be displayed, £25 on an old P4 pc to run my gauges on a network, £110 for my plasma telly. About £10 on nuts, bolts, servos and other hardware etc.....

I just needed to get a crack on with this sim, too much planning and not enough building!

Ive got a partition going up in my garage soon for the sim room! (Studded wall, plaster board, air vents, lighting, the works!) That will be cool!