Detents for rotary encoders?

[matta757]

Hey guys,

There is probably an easy answer to this, but when using a simple rotary encoder (not a rotary switch) and a spring plunger to create a rotary switch, how does one set the amount of distance the encoder needs to turn to register as one movement of the switch in flight sim? I am using the BUO836X board, but I have never tried to make my own switch using the plungers and encoders. I hope my question makes sense as I have phrased it...

Regards,
Matt

[autocadplease]

Ian's pdf might help:
http://www.737ng.co.uk/EFIS_BU0836_HOWTO.pdf

[Boeing Skunk Works]

You can buy rotary encoders with detents that are 360° motion. Unless I have misunderstood the question, why would you use the ball plungers for detents on an encoder when you can buy them?

I've read this several times since yesterday and I'm still not quite sure if this is what you are asking or not.

[matta757]

Mike,

I am using plain rotary encoders because they are smaller than the rotary switches and I have got VERY limited space on the MIP, simply because of the setup on the 757/767 with the monitors behind the MIP (for functions such as the autobrake, which is a 7 position switch). There is not a lot of room for the base of the switch but luckily the rotary encoders just barely fit, so I need to make them into a rotary switch.

The more I think about it, the more I think this won't work. I have encoders with 24 detents in 360 degrees. What I need is a rotary switch with 30 degrees in between each detent in order to replicate the autobrake switch. So my question restated: is it possible to turn a basic rotary encoder into a rotary switch?

Sorry for the confusion, I am not sure how else to describe this...

Matt

[makoy]

First am not master of these things and I dont know your systems.
I think you can use those, but system cant detect  position when you start your sim.
You need remember to put autobrake to off position every time you off computer.
Also need some codings, sioc or-and fsuipc depending what you use.
Someone correct me if am wrong.
I think in market there is very small rotary switches also?

Marco

[Boeing Skunk Works]

It might be difficult to almost impossible to find an encoder with that sort of spacing between positions. I get it now though, and wish you luck.

I had a heck of a time trying to fit monitors behind my MIP without loosing anything. I lost space for the flap indicator gauges, flap load relief indicator, and one low oil pressure indicator. Because of the way the main MIP monitor had to fit, I lost about an inch in height for the ADI instrument. It's essentially a three inch instrument now in a four inch hole. I was able to retain all of the indicators on that side of the panel though.

[jackpilot]

I am using plain rotary encoders because they are smaller than the rotary switches and I have got VERY limited space on the MIP, ....the rotary encoders just barely fit, so I need to make them into a rotary switch.

Matt

Matt.
What you are trying to do may be an engineering overkill.

Put your autobrake knob where it belongs, on a  shaft long enough to clear the monitors and attach that shaft to the 30°indexed rotary which you hold in place with a bracket (bracket attached to whatever structure available)
It requires a little bit of ingenuity but much easier than what you were contemplating.
Cheers
JP

[matta757]

Jack,

Thanks for the idea, but the monitor is RIGHT BEHIND where the autobrake goes, it completely blocks the area where the autobrake panel is located. That's why I wanted to use the encoder.

Matt

[jackpilot]

Ooops....well, drill a hole through the monitor!

I suppose this is the Auto break panel circled in red. 12 position at 30°index.

One way could be to cheat a bit and raise the Autobreak panel  ¼"+ to have more clearance
(Phil744 could make a special one  for you)

I saw some flat rotaries which could be adapted...not sure though
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=7072891

One other way (as my "super shaft" could not apply) would be to use flat pulleys or gear and locate the rotary down.

Super thin rotaries must exist..

[makoy]

Jack was quicker 
I was thinkin something like this, maybe you need just two.

Marco

[jackpilot]

Stef, I see you're around any idea?

[phil744]

What thickness/material is your MIP?

[matta757]

I am using MFD for my mip.

The mip itself is 1/4 inch thickness, then I have the autobrake plate which can either be another 1/8 or 1/4 inch.

Matt

[phil744]

Hmmm tricky one isn't it, I'm faced with the same problem but i dont have 1/4 mdf to use to my advantage

The part Jack mentioned would work fine but you wont have any real feeling when switching it, and they are quite fragile also

if your using 1/4 MDF or 6.3mm that's some room you can use, do a search on mouser for a SR1712F-0108-20F0A-N9-9, then have a look at its datasheet, even though the MIP forms the light plates backer what you may want to do is build a separate back plate for it, basically like any standard pedestal part, that rotary has a body depth of 7.5mm, ignore the pins as you can just bend those up out of the way, make your backplate 3mm with a 9mm hole to fit the rotary, but machine out a recess to a depth of 1.5-2mm so the body of the rotary is recessed into the backplate, if you make the recess 2mm then the body of the rotary only sinks into the MDF MIP 5,5.

Obviously cut a hole in your MIP to accommodate the body of the rotary with an exit channel on the MIP rear side for the cable from the rotary, then insert the backplate with the rotary in from the front, light plate over the top of that then screw to MIP, the fascia of the lightplate will be 3mm FWD than the real but just make your lightplate 4mm then its the same depth, also remember that the knob does not fit flush to the panel on the autobrakes, about a 3mm standoff and the knob is not backlit also

It will be tight but that's how i would do it

[jackpilot]

Pretty sure it would work... a few mm more will not even be noticable.
JP

[matta757]

Phil,

You took my train of thought EXACTLY. The encoders that I have are exactly like this rotary switch. I am so glad you posted this particular switch because it will work perfectly. I actually have already done exactly what you suggested for my altimeter with one of my encoders and that's why I asked if I could make the encoders into a switch. Thanks for the input everybody!

Regards,
Matt