RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

MPX 4000 - sequenced gear & doors

Reply

Old 12-07-2004, 04:09 PM
  #1  
E.C.
Member
Thread Starter
 
Join Date: Feb 2004
Location: DelftNH, NETHERLANDS
Posts: 37
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default MPX 4000 - sequenced gear & doors

I am trying to program my MC 4000. I want the gear doors to open and close automatically when the landing gear is lowered or raised.
Both servo's are connected to the RX on different channels.
I tried the method described in the EVO tutorial , and it works, but only if the gear is driven by a servo.
I am using pneumatics, so the gear servo should move at full speed and than, after a few seconds, the doors should close.
I am sure it is possible, I just can't figure out how.
Any ideas??
E.C. is offline  
Reply With Quote
Old 12-08-2004, 06:28 AM
  #2  
HarryC
My Feedback: (1)
 
Join Date: Feb 2002
Location: private, UNITED KINGDOM
Posts: 3,560
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: MPX 4000 - sequenced gear & doors

I do the full sequencing with pneumatic retracts and pneumatic doors.

Give the retract control a time delay in both up and down directions. Start with 4 seconds and adjust it once you have got everything working.

Assign both servos to the retract function. However, both will come up with the name retract in the servo menus so I assign the door servo to servomix, input 1 is retract, servomix allows you to rename a servo so I rename it to doors. That makes it easier to know which servo is which in the servo menus.

For both servos, select a 13 point curve.

For the retract servo, set all the points to be at one or other end of travel, see photo 1. The position of the jump between the two ends of travel will determine where in the time delay the retracts operate - at the middle, or towards one end.
For the doors, you can choose a simple doors open legs down, legs up doors closed sequence, or a full sequence such as P51 Mustang or jet (the photos are of my Sabre program) where the door opens, legs come down, door closes again. Photo 2 shows the full sequence curve for the doors as per Sabre or Mustang, if you want the simple sequence then either point 1 or point 13 will be at the same position as points 2-12 depending on the direction of travel.

Harry
Attached Thumbnails Click image for larger version

Name:	Ay74549.jpg
Views:	9
Size:	128.0 KB
ID:	200640   Click image for larger version

Name:	Av69266.jpg
Views:	8
Size:	143.5 KB
ID:	200641  
HarryC is online now  
Reply With Quote
Old 12-08-2004, 07:46 AM
  #3  
E.C.
Member
Thread Starter
 
Join Date: Feb 2004
Location: DelftNH, NETHERLANDS
Posts: 37
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: MPX 4000 - sequenced gear & doors

Thanks Harry!
I am sure this works fine if the gears don't move too slowly. However, there is one problem with this method: there is always a delay between the moment the doors are fully opened and the moment the gear starts to move. The length of this delay is about the same as the time it takes for the gear to move.
For example, if the gear takes 3 seconds to move from up to down, the total sequence will be like this:
doors open, wait 3 seconds, gear down, doors close.

I don't like the waiting before the gear start to move. I think it should be possible to avoid this by using logic switches, but I just can't figure out how.
Is is possible to program the gear to stay where it is UNLESS the doors are opened?
E.C. is offline  
Reply With Quote
Old 12-08-2004, 04:52 PM
  #4  
HarryC
My Feedback: (1)
 
Join Date: Feb 2002
Location: private, UNITED KINGDOM
Posts: 3,560
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: MPX 4000 - sequenced gear & doors

If I understand correctly, you are using pneumatics but for some reason such as restrictors they are slowed to take 3 seconds to travel, after the the valve triggers them to move. The servo simply moves the valve to its trigger points but the position of the legs is then quite independent of the valve/servo position due to the slowing effect. What you want is a Tx that knows where the legs are and can operate the doors to suit. Astonishingly, the 4000 can do that, though it simulates where the slowed legs are rather than actually knowing. To do that you will need to use a virtual servo, so you need a spare channel, if you are already using all 12 channels this method can't be used.

Assign retract valve servo to retract, assign door servo to servomix with input 1 and input 2 set to fixed val, assign servo 12 to retract. Servo 12 will be the virtual servo.

Assign control switch 1 to servo 12 at +98% and assign control switch 2 to servo 12 at -98%.
With the retract switch in the legs up position, set Log switch 1 to OR, input 1 is C112* and input 2 is C212 no asterisk.

Go to menu 1, servo:
retract servo, give it 2 seconds up and 2 seconds down
door servo, input 1 set to switch Log1* and set travel to +100% (or +75% if you do not use Mpx servos with mpx plugs)
door servo input 2 set to switch Log1 no asterisk, set travel to -100% (or -75% if you do not use Mpx servos with mpx plugs)
Servo 12 should have default -100% ,0%, +100% travel

Harry
HarryC is online now  
Reply With Quote
Old 12-09-2004, 07:34 AM
  #5  
E.C.
Member
Thread Starter
 
Join Date: Feb 2004
Location: DelftNH, NETHERLANDS
Posts: 37
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: MPX 4000 - sequenced gear & doors

Harry,

Thanks for taking the time to explain this.
You are right about my setup with the restrictors.

Last night, when I almost fell asleep, I suddenly realised how I could solve this problem, so I just HAD to get up again and started programming.....is that weird?? Some people seem to think so....

My solution is very similar to the method you discribed in your first reply. The only problem with it, is that the delays for the gear and the doors are the same . What I need is a delay before the gear is moved equal to the time the doors take to open (1 sec) and a delay between opening and closing the doors, equal to the time the gear takes to move (3 sec).
All I needed to do was to assign the gear servomix to a multimix and the door servomix to another multimix, remove the slow function from the gear switch an set the delay in the two multimixes. Now I can independently set the delay time for gear up , down and for doors open , close. It seemed to work "as advertised"

However, I will try your method this evening, maybe I'll learn a few new tricks.

Once again, thanks for your writing in this forum. Reading all the discussions about the 4000 is what really convinced me to buy this transmitter, and so far I am very very pleased with it.

Eelco
E.C. is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service