#4894167
Im interested in finding out how you built your door closing mechanism. The purpose of this thread is to discuss how best to do this and get ideas for the community on different methods used. Please share what you have come up with!!!
#4898023
I scored a Kenner trap for my son over the weekend and I had to take it apart to figure out why the pedal wouldn't open the doors. Basically the pedal and hose attach to a cylinder that holds a lightweight piece that connects to the doors that when pressed forces air into the chamber, the piece raises, there by opening the doors. I really think this rudimentary mechanism could be translated into a full size trap using the same methodology. Hypothetically you could make the cylinder and raising piece and rig up a pump bulb under the trap foot pedal
necrosapien87 liked this
#4898048
DarkSpectre wrote:I scored a Kenner trap for my son over the weekend and I had to take it apart to figure out why the pedal wouldn't open the doors. Basically the pedal and hose attach to a cylinder that holds a lightweight piece that connects to the doors that when pressed forces air into the chamber, the piece raises, there by opening the doors. I really think this rudimentary mechanism could be translated into a full size trap using the same methodology. Hypothetically you could make the cylinder and raising piece and rig up a pump bulb under the trap foot pedal
I was thinking about the kenner trap which I knew used air, but wasn't sure how. Any chance you have pics of it as you disassembled it?
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By Batfly
#4900174
#4902497
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The easiest and cheapest way that i found is to get 2 cheap 5g servos off ebay, a durable spst switch that can hide in the trap bellows, and the $17 Spark Fun servo trigger. it only does 90 degrees but you cant beat it and it looks fine. just give it 5v and youre good to go. all you need is VERY basic soldering skills.

EDIT: more info

Doors are easy and super cheap to do

The control board is from spark fun

https://www.sparkfun.com/products/13118

its only seventeen dollars! all you do is connect both servos together solder the servo wires, pedal switch and power supply to the board and youre done. super easy. no programming. anyone can do it and its really cheap. the only catch is, that is as fast as the doors open and close (kinda slow) and it only does 90 degrees of travel instead of the 120 or so that the movie traps do. but for how easy and cheap it is, i think its fine.

i also wired in a hidden switch to cut power to this board to keep the servos quiet when its hanging on your belt. servos like to make a lot of noise all the time as you can tell from the video.

here's some cheap servos:

https://www.ebay.com/itm/Tiny-Mini-5g-r ... SwbYZXY1Lv

youll need SPST/SPDT switch that is small enough to hide in the pedal bellows, but is also heavy duty because youll be stepping on it with a lot of force. this switch fit perfectly and the pedal base only needed a little dremeling to get it to work

https://www.ebay.com/itm/151915471015

its even SPDT so you can use the other contact for something else if you ever wanted to.

i used a 12v power supply and a 5v voltage regulator to power the servo board which needs 5v.

like this:
https://www.ebay.com/itm/Car-DC-12V-to- ... Swr8xZ8FjV


the 12v battery is rechargeable and never leaves the trap
http://www.batteryspace.com/nimhbattery ... robot.aspx

2200 mAh is pretty decent and should last a whole day of use
grogking liked this
#4903163
Hi there,

well - there's actually not much to see here yet i think i'll show some of the internals that i did for my trap. It may be a weird way to make this work, but i my case it performed pretty well. I prefer working with wood's n metal rather than using pvc or resin materials.

Here you can see how one of the doors is hinged within the right 'ear'-element that sit on either side of the bargraph-case:
Image


This is the internal mechanic solution i did choose to make it work: using two pretty small servos. Their actual orientation had to be changed later in order to work funktion somewhat more reliable, but this picture has bee taken before - so figure this with the servos faceing towards each other rather than to the outer sides:
Image

I tried to keep it as low profile as possible to serve as much space, as i could for the bargraph-assembly which had to go there too. Maybe some day i'll redo this in a bit more elaborated way, but for the time, this will do.

So - WHO's the matty now? ok... i know i'm weird :wink:
ccv66, grogking liked this
#4903193
grogking wrote:Theodric, Love your design, thanks! Is there any way to show it in action?
Hey - thanks :-D

Since i haven't had too many fancy chains 'n gears to come up with, i was forced to find a not overly complicated solution to realize the functionality, using just plywood, wire, screws and of course small servos.

Well sadly i haven't got some decent photos (nor a video) of the complete and final mechanism in action - maybe i will take some on day... but since this will require a major disassembly of my trap (which is possible, but i won't want to do unless serious necessity) - this will not be too soon, you may recognize :wink:

This (it's actually kinda 'half the way' but the best i got, yet) might give you an impression of how this moves:
Image
grogking liked this
By grogking
#4903202
Theoderic wrote:
grogking wrote:Theodric, Love your design, thanks! Is there any way to show it in action?
Hey - thanks :-D

Since i haven't had too many fancy chains 'n gears to come up with, i was forced to find a not overly complicated solution to realize the functionality, using just plywood, wire, screws and of course small servos.

Well sadly i haven't got some decent photos (nor a video) of the complete and final mechanism in action - maybe i will take some on day... but since this will require a major disassembly of my trap (which is possible, but i won't want to do unless serious necessity) - this will not be too soon, you may recognize :wink:

This (it's actually kinda 'half the way' but the best i got, yet) might give you an impression of how this moves:
Image
Thanks thats great! How did you keep the metal rod from popping out of the holes on the disk and the door arm?
#4903415
grogking wrote:
Thanks thats great! How did you keep the metal rod from popping out of the holes on the disk and the door arm?
Actually not much - the bend hooks on the wire are a bit longer so they will stick through the lever and the transrotation disks. The rod sticking in the lever (which is actuating the door) simply has not enough space to come off, since it's all in that small recess within the 'ear'-assembly the most of the moving angleway (you may be able to tell from the image). The other side of it, which is sticking in the disk isn't secured either, since i need it to be able to disassemble the mechanism for fitting and possible maintenance/repairs by just pulling it off the disk with some small pliers. Because it is actually sticking a bit through the disk, it will not come off too easy while the normal operational use (well - at least that's what i hope :wink: ).

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