Cockpitbuilders.com

sign up .

September 24, 2020, 11:20:30 pm

Login with username, password and session length
30 Guests, 0 Users
Members
Stats
  • Total Posts: 55840
  • Total Topics: 7446
  • Online Today: 57
  • Online Ever: 582
  • (January 22, 2020, 08:44:01 am)
Users Online
Users: 0
Guests: 30
Total: 30

COUNTDOWN TO WF2020


WORLDFLIGHT TEAM USA

Will Depart in...

Recent

Welcome

Elecromagnetic Tubular Solenoid Recommendations?

Started by MistyBlue, February 11, 2020, 04:57:52 am

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

MistyBlue

I'm looking for some 12V tubular electromagnetic solenoids to actuate some things in my TQ rebuild.  Does anyone have any recommendations for some good ones, preferably strong.

ame

I got some of these:
https://m.aliexpress.com/item/32974509060.html

Specifically I needed something small (for my 3D printed contact breakers). They're not super strong, but they are adequate, and small.

There are many to choose from on AliExpress, just narrow down the choices based on voltage, current, size, mounting, and push/pull.

MistyBlue

Thanks.  Yeah, something along those lines might work but may be too weak for this application.

I may also consider latching solenoids, since they maintain each position without requiring continuous power.  Might be better suited to keeping the spoiler lever lifted during automated movement and the reversers locked out.

I was also considering some small linear actuators like this one where a little more power is needed:

https://www.progressiveautomations.com/products/micro-linear-actuator?variant=18277344575555

It has a screw drive so it'll maintain some holding force at any position.

I'll post back if I find any good solutions.

ame

If the solenoid is operating a latch you could maybe use a micro servo motor to move a lever between two positions. Or something.

Do you have a picture of the thing you are trying to simulate? And a brief description of its operation?

MistyBlue

Sure.  In the attached pics I've pretty well gutted the older RSP TQ I had and re-doing much of the internals.

So in Pic 1 you can see the spoiler handle.  Movement is about 0.33 INCH to get it to unlock from the detents and about 10-12 pounds of force needed.  I'm thinking of using a strong push solenoid to push the spoiler handle up so the servo motor can push the lever to FULL UP and back, then release the solenoid and let the existing spring takeover for manual operation such that the detents I added will be felt.  Since the solenoid only needs to hold for a minute or so, heat shouldn't be a problem if I can find a strong enough continuous use solenoid.

Also in Pic 1, I'll need something to move the spoiler lever stop (the black arm) into position during flight.  It's about a half inch movement.  I'm thinking something with good holding force to prevent forcefully moving the spoiler lever past the stop.  This is where the linear actuator might work well, but a strong latching solenoid would probably also work.

In Pic 2, I'm debating how I'll move the large black reverser lock the half inch it should rotate.  It doesn't need to be a strong solenoid, maybe 1 Lb force.  Just enough to move it into place and override an minor friction.  I'm thinking a latching solenoid will do fine.  Originally there was a servo motor on each side, but controlling the servo to make sure it only moves the exact amount would require micro switch stops or a potentiometer for feedback and that's more complicated than it needs to be.

Fun stuff!


ame

I'm not sure a solenoid is what you want, although it looks like you have plenty of space for a pretty big one.

An RC model servo driving a pushrod would give you a powerful linear force. However, it will maintain the force unless you stop sending position pulses.

For Pic 2, a servo can be programmed to travel to specific points. It already has a potentiometer inside, so it can measure its own position. Once there it will try and maintain position (unless you stop sending pulses).

MistyBlue

February 12, 2020, 02:48:00 pm #6 Last Edit: February 12, 2020, 03:40:11 pm by MistyBlue
Hadn't thought about the model servo route.  Worth considering.  But since the Prosim signals are either on or off, how would I set the servo up to travel to the pre-set travel limits?  Usually I see servo cards operate based on a variable input signal (like from a pot on a lever or knob).  On/Off (and thus min/max pre-set position) is something I'm not familiar with setting up.

EDIT:  Just tested this with the sync lock feature, which turns a gate on when engaged and off when not.  Using my Phidgets servo card, nothing happens when I assign the servo output to the gate.  I'm thinking it's not possible to get it to work in this way.

ame

I am currently reading about Phidgets servo cards and Prosim, which is a very specific combination. I'm very comfortable with how servos work in general however.

If you can explain in detail how the servo should move under what conditions in Prosim then that's half the problem solved.

The servo position is controlled by a repeating pulse signal. The repeat period is typically every 20ms (so the frequency is 50Hz). The 'on' time is some period between 1ms and 2ms (so the 'off' time is 18ms or thereabouts). The width of the 'on' time dictates the servo output position. Generally 1.5ms is 'centre', 1ms is 90 degrees one side and 2ms is 90 degrees the other side. There is some variation between models and manufacturers.

So, if you have a way of generating a repeating pulse every 20ms and you can control the width of the pulse then you can control the position of the servo output.

That's what the Phidgets board does. You send it a command for what you want and it deals with sending the pulses over and over.

I'm not totally sure about the link from Prosim to Phidgets, but the data flow is going to look like the following:

Internal simulator value -> some scaling and other shenanigans -> a number between 1.0 and 2.0ms -> servo driver -> servo motor shaft

I think Prosim has a scripting capability so it should be possible to generate a sequence of servo positions over time, which is triggered by the change in a simulator variable, instead of using the actual value of the simulator variable itself.

Is this any use? May be related, maybe not.
http://www.flaps2approach.com/journal/2013/12/22/b737-throttle-quadrant-automated-thrust-lever-movement.html

MistyBlue

Thanks for the explanation.  Confirms what I read the other day about the servo pulses and ON times.  I have a Phidgets servo card I'm testing with, FYI ;)

Before we talk about the servo method, today I cannibalized the trim wheel brake solenoid that was originally in the RSP TQ and used it to test the parking brake.  I am able to activate the solenoid via Prosim's brake gate and a Phidgets relay card.  It works perfectly and has good holding power. I now just have to work out how to tie the solenoid into the existing lever mechanism. 

The downside to solenoids is they'll get super hot and burn up if not designed for continuous use.  Fortunately this particular solenoid seems like it may be up to extended holding (it gets very warm but not so hot you can't touch it).  I'd like to find more of these solenoids but this one has no markings on it whatsoever so I have no idea of the specs.  So if anyone knows what solenoid is in the RSP TQ I'd appreciate the info.

Anyway, given this approach worked, I can probably use it for the other needs like the speedbrake handle release, speedbrake lockout and thrust reverser Sync Locks. 

With regard to using servos instead, your guess is as good as mine as to how to get a On/Off gate state to translate to a limited servo movement.  I envision, for example, that when the Sync Lock gate is activated by Prosim (during a thrust lever movement on the ground) a command would be sent to some interpreter (scripting?) that would convert that command to a MIN/MAX servo travel signal then convey that to the Phidgets card somehow.  When the Sync Lock gate changes to OFF (reversers are stowed), the servos would return to a preset min limit. 

Likely the Phidgets app would not be able to be running in the background to send commands to.  I think it causes a conflict with the Prosim Phidgets drivers. But maybe the Prosim scripting you're talking about would work.  Don't know anything about it but will look more into it.  Couldn't hurt.

I also ordered the micro linear actuator to play with and I'm waiting for it to come in.  That has an internal limit switch so when it hits its limit it stops movement and cuts off power.  So I can have a Prosim gate sending a continous ON or OFF signal to the relays and not worry about burning anything up. The downside is you need two relays (one for each movement direction).  And it takes up more space than a solenoid.  Still, looking forward to testing it.

Btw, thanks for the link to Flaps2Approach.  He always has some great stuff on his site.

757Simulator

You guys, I love your passion, but your trying to re-invent the wheel. The EPIC card can do what your begging a Phidget card, or whatever, to do. I'm not even aware of what a Phidget card does. But seriously, you might want to reevaluate your approach and acquire what is used among the best builders. EPIC can control motors, pneumatics, etc. with extreme precision.

All the best.

757Simulator

And I meant to add that many of us "EPIC" users are here to help including sharing code to help others.

ame

Sadly, whilst everyone has heard of Phidgets, and it's trivial to get an Arduino to generate a servo control signal, nobody knows what an EPIC board is. Not even Google. :(

Trevor Hale

I just ripped one out of my sim AME  Only us old guys know what those are.
Trevor Hale

Owner
http://www.cockpitbuilders.com

Director of Operations
Worldflight Team USA
http://www.worldflightusa.com

VATSIM:

bernard S

question ..what does MS Ds and Noah have in common?  they are both as old as EPIC lol

jackpilot



Jack

MistyBlue

Quote from: 757Simulator on February 15, 2020, 12:00:28 amYou guys, I love your passion, but your trying to re-invent the wheel. The EPIC card can do what your begging a Phidget card, or whatever, to do.

Wow, that was an "Epic" comment, lol.  Never had the pleasure of working with them since they were before my time building sims, but I do remember hearing about them once upon a time.

Why did they fall out of favor?

ame

Quote from: MistyBlue on February 15, 2020, 08:19:09 am
Quote from: 757Simulator on February 15, 2020, 12:00:28 amYou guys, I love your passion, but your trying to re-invent the wheel. The EPIC card can do what your begging a Phidget card, or whatever, to do.

Wow, that was an "Epic" comment, lol.  Never had the pleasure of working with them since they were before my time building sims, but I do remember hearing about them once upon a time.

Why did they fall out of favor?
My guess is Arduino (started in 2005).

My second guess is Raspberry Pi (released 2012).

The R&R Website is dated 2004. Price and availability is not stated (or at least I couldn't find it).

Even knowing what an EPIC card is doesn't really help. Nobody is using them. Nobody is talking about them (except us, now). In fact this conversation is going to skew the Google results and make it suddenly seem popular.

So, since I can drive a servo with  a couple of lines of code in an Arduino which costs a couple of dollars, I expect the EPIC card has gone the way of the dodo.

MistyBlue

Well, I decided to give some Ledex tubular solenoids a go, both the push and the pull type (ordered a few of each) along with the spring returns.  I'll let you all know how it goes.

757Simulator

Quote from: Trevor Hale on February 15, 2020, 04:37:37 amI just ripped one out of my sim AME  Only us old guys know what those are.

Help them. They always want to take the cheap way out. LOL

ame

Quote from: 757Simulator on February 17, 2020, 01:08:49 am
Quote from: ame on February 15, 2020, 12:38:22 amSadly, whilst everyone has heard of Phidgets, and it's trivial to get an Arduino to generate a servo control signal, nobody knows what an EPIC board is. Not even Google. :(

And keep daisy chaining your phidjoes until you "semi" achieve what you could have accomplished with EPIC months ago. Food for thought.............
Do you have a link with price and availability?

ame

Quote from: 757Simulator on February 17, 2020, 01:08:49 am
Quote from: ame on February 15, 2020, 12:38:22 amSadly, whilst everyone has heard of Phidgets, and it's trivial to get an Arduino to generate a servo control signal, nobody knows what an EPIC board is. Not even Google. :(

And keep daisy chaining your phidjoes until you "semi" achieve what you could have accomplished with EPIC months ago. Food for thought.............
Quote from: ame on February 17, 2020, 01:56:25 am
Quote from: 757Simulator on February 17, 2020, 01:08:49 am
Quote from: ame on February 15, 2020, 12:38:22 amSadly, whilst everyone has heard of Phidgets, and it's trivial to get an Arduino to generate a servo control signal, nobody knows what an EPIC board is. Not even Google. :(

And keep daisy chaining your phidjoes until you "semi" achieve what you could have accomplished with EPIC months ago. Food for thought.............
Do you have a link with price and availability?
Never mind. I found it on a website called 'flightlink.com', which is no longer working. The base module for the EPIC system was listed as "from $499". Sorry, but a $3 Arduino will do most of what an EPIC board does.

757Simulator

Ame,

Kidding aside. I enjoy the banter back and forth. I hope you understand I wish you well and all this is in good teasing. If not, I am teasing and I do mean you well and much success in your project.

ame

Quote from: 757Simulator on February 18, 2020, 12:42:47 amAme,

Kidding aside. I enjoy the banter back and forth. I hope you understand I wish you well and all this is in good teasing. If not, I am teasing and I do mean you well and much success in your project.
Do you have a link with pricing and availability?

Garys

Epic.... LOL, in 2020 can you still even find a PC running windows XP?

ame

Quote from: 757Simulator on February 18, 2020, 01:23:47 amHave you contacted Ralph?
No. Who's Ralph? I expect to be able to go to a website, see the products that are available, and the price, then choose what I want and order it. I also want to be able to download a manual and look at examples of what can be done.

I don't want to email some rando and say "hey, do you still have any of that stuff from 2004?"

I don't actually want an EPIC board. I seriously entertained your suggestion, since it might have helped to solve the OP's problem, but I can't find anything of substance about it. I have found a general description of it. It's a microprocessor-based board with a USB interface, a bunch of ADCs and GPIOs, and some sort of programming environment.

Sounds like an Arduino to me, and looks like it did what SimVim (for example) does now.

Like the Website ?
Support Cockpitbuilders.com and Click Below to Donate