Another Prop related project!

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
Working on a "special" project and doing some electrical work. I've got everything wired correctly and it's all functional. The next hurdle before I can finalize it is that I have a control board that I need to:

A: See if I can at all re-size it/cut part of the board off to condense it, as it will need to fit into a small space, aka, an arm-glove.

B: Remove the Tact switches, and essentially extend them from the circuit board to extend to a desired length.

To give you an idea, I'm placing the control board into a glove/sleeve on my arm, probably on the bottom-mid arm area. I need to operate the switches from my palm (think Spider-man web shooters).

I already removed the tact switch and was testing but I cannot seem to figure out the right way of going about it. It has 5 holes, 3 of which actually appear to be in contact with the etched circuit pattern. I'd like to see if someone would be able to help me to figure it out!



As for cutting it down, I don't think I could honestly do it without affecting what I need, but it's a long rectangular board and the smaller the better for this application

Here are some pics of it:



Other side










Thanks for the help! It'll be a cool thing to show when it's all working as I envision it!!

-TC
 

JohnInTX

Joined Jun 26, 2012
4,787
The tact switches are SPST i.e. single pole, normally open switches. Each pair of leads is connected internally always. The two pairs of leads get connected when you push the button. The 5th hole may be ignored.

On your PCB, the big broad area is one switch pole, the elongated area with the trace going off to the left in the photo is the other pole. Note how each area picks up the two internally connected leads on the switch. The connected pairs of pins run in 2 vertical columns in your photo - pressing the button connects the left and right pairs. Extend your wires from each column.

These are made by E-Switch. You can search their catalog for more info.

BTW: the reason they are made that way is so that you can make X-Y arrays of tact buttons on a single sided board. The internal connection between two leads allows a trace to run between the connected pins - a built-in jumper.

Have fun!
 

MrChips

Joined Oct 2, 2009
30,824
SPST tactile switch shown has four legs arranged in a rectangular pattern.
Legs on the wider spacing are connected together.
Hence the switch Normally Open SPST switch contact is between any two pins on the shorter dimension.
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
Strange...I'll have to try it again, as that was the first thing that I tried. It didn't seem to work...perhaps my connections weren't good?
 

tracecom

Joined Apr 16, 2010
3,944
Strange...I'll have to try it again, as that was the first thing that I tried. It didn't seem to work...perhaps my connections weren't good?
It's easy to get confused about which leads to use on those little switches. There are four legs, but two of the legs are electrically the same, and the other two legs are electrically the same. I have marked that on the attached snip; the two legs on the left are one side of the switch and the two legs on the right are the other side of the switch.
 

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Thread Starter

tubachris85x

Joined Oct 25, 2013
33
It's easy to get confused about which leads to use on those little switches. There are four legs, but two of the legs are electrically the same, and the other two legs are electrically the same. I have marked that on the attached snip; the two legs on the left are one side of the switch and the two legs on the right are the other side of the switch.
I appreciate the help, but it's not that part that I'm confused about. I've wired the proper leads from the tact switch to the through-holes on the board, just how it was originally placed, and it's still not functioning. However, when I took it all apart, and place the tact switch back into the holes as it was designed, it works. Can't seem to understand what I'm doing wrong
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
Alright...well I messed up. One of the through holes is not taking any solder. At all. I think it was due to damage from my soldering iron. Idk. I'm not sure even trying to repair/replace the barrel on the eyelet will work..

I tested the switches on the side I wasn't using, they both still work, though when I feed the wires through, nothing..
 

tracecom

Joined Apr 16, 2010
3,944
Alright...well I messed up. One of the through holes is not taking any solder. At all. I think it was due to damage from my soldering iron. Idk. I'm not sure even trying to repair/replace the barrel on the eyelet will work..

I tested the switches on the side I wasn't using, they both still work, though when I feed the wires through, nothing..
All is not lost. The tracks on the PCB that connect to the switches are plenty big enough to use. All you have to do is pick a spot on each track that is big enough to drill a hole for the wire to the switch. Scrape away the green solder mask and drill a 1/64" hole. Tin around the hole (without covering the hole itself), insert the wire, and resolder it. (You can even get by without a hole; just lay the wire flat on the scraped area on the track, and solder it.) Repeat for each damaged pad. Also notice that you only need a total of three wires for two switches; the ground side is common.
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
All is not lost. The tracks on the PCB that connect to the switches are plenty big enough to use. All you have to do is pick a spot on each track that is big enough to drill a hole for the wire to the switch. Scrape away the green solder mask and drill a 1/64" hole. Tin around the hole (without covering the hole itself), insert the wire, and resolder it. (You can even get by without a hole; just lay the wire flat on the scraped area on the track, and solder it.) Repeat for each damaged pad. Also notice that you only need a total of three wires for two switches; the ground side is common.
I see! Now, I noticed that the through-hole is slight off-set from the track. If I am to attach the wire directly to the track, should it be directly on top of the track then VS how the holes are placed?

Thank you!
 

tracecom

Joined Apr 16, 2010
3,944
I see! Now, I noticed that the through-hole is slight off-set from the track. If I am to attach the wire directly to the track, should it be directly on top of the track then VS how the holes are placed?

Thank you!
I am not certain that I understand the question, but maybe this will help. You can attach the wire anywhere on the track, with or without a hole. The track is electrically just like a wire, so you can connect to it wherever is convenient.
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
I am not certain that I understand the question, but maybe this will help. You can attach the wire anywhere on the track, with or without a hole. The track is electrically just like a wire, so you can connect to it wherever is convenient.
Yea, stupid question was stupid
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
Alright,well I gave it a shot. Unfortunately, while I was able to get the switches to run properly as I was trying (so now I know) I managed to FUBAR the board by shorting out a few of the surface mounted components. This makes me realize that:

A: I really need to invest in better soldering equipment
B: A PCB can fly approximately 15 feet before hitting the wall.

It's ok...only a $16 mistake.....
 

tracecom

Joined Apr 16, 2010
3,944
Alright,well I gave it a shot. Unfortunately, while I was able to get the switches to run properly as I was trying (so now I know) I managed to FUBAR the board by shorting out a few of the surface mounted components. This makes me realize that:

A: I really need to invest in better soldering equipment
B: A PCB can fly approximately 15 feet before hitting the wall.

It's ok...only a $16 mistake.....
A sense of humor is a great asset when learning a new skill.

Seriously, soldering can be made much easier with the right tools. Imagine trying to drive finish nails with a 20 ounce framing hammer. Sometimes you get lucky, but most of the time your results are less than satisfactory.
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
A sense of humor is a great asset when learning a new skill.

Seriously, soldering can be made much easier with the right tools. Imagine trying to drive finish nails with a 20 ounce framing hammer. Sometimes you get lucky, but most of the time your results are less than satisfactory.

Yea, I mean, I was pissed last night, especially all the time I put into getting it all to work. It's not that I won't get a new rig/proper equipment, it's just right now my financial investment is geared towards the overall project, and this RC-servo is just one small part of the greater whole. While it's not necessary to have it, it's a "want" VS a "need" for the costume. It will add a cooler sense of realism to the prop.

So I've already invested about $800 into the costume pieces alone. Despite this hiccup, It would be cheaper for me to get a different RC car to do again, as I feel I can do it right w/ my current available tools.

The thing that irks me is that I actually attempted this exact thing when I was 15 (10 years ago), using a much smaller RC cat toy we had, which was significantly smaller. I got it working in the proper function, but what stopped me was the fact that I didn't know that I needed to remove the servo's control board, so I set it all aside, and bam...still cannot find that set up. Possibly threw it out.

sorry for the mini-rant. I'll get it done...it will be awesome
 

Thread Starter

tubachris85x

Joined Oct 25, 2013
33
Alright well I'm back!

Been a frustrating weekend with other issues, but happy to say I got this working as I'd need it to. Not finished entirely but for the most part it's about read for installation once I get the rest of the helmet finished.

Here's a short video showing how it's going to be used. Of course, this is a trial run and just to see how it will work with the rest of the helmet. You'll notice the stalk wiggles a bit, but that is corrected by the mounting of the servo inside.



Images of the boards

Built a box for the board and sealed the entire thing. Needs to be able to withstand heat and humidity for lengthy periods since I'll be wearing this inside and outside



The controller. Not pretty by any means, but I'm planning to have this in it's own protective sleeve and contained within the arm glove. Not entirely sure though. I'll need to make it such that I can put it on before the arm glove and have ease of use for the buttons. I'll figure it out.



Here's the antenna for the controller. While I used the excess antenna to extend the receiver's range, I think this little guy is why I need to stand so close to get it to work. The receiver's wire is pretty lengthy and I'm going to have it wrap around the lower rim of the helmet.

My question is for extending this white wire, is can I use any wire? Or is it a special type?



Thanks!

-TC
 
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