Author Topic: Spark Plug Clips  (Read 2730 times)

Offline maury

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Spark Plug Clips
« on: September 22, 2014, 03:58:28 PM »
Y'all, this may be a not so interesting subject, but it has always been an issue with me. I have never been able to make a decent spark plug clip, and now I have to make 4. I know you can buy them, but this is about a learning and doing experience.

Has anyone used a favorite method for making these little clips? Sheet metal, wire, CNC, or just making a stamping die????

maury
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Offline Jasonb

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Re: Spark Plug Clips
« Reply #1 on: September 22, 2014, 04:07:45 PM »
I've always bought them but would have thought you could CNC them from thin brass sheet provided you could keep them in place, maybe leave them attached to the sheet near where the wire attaches then when you solder the wire through the slot it won't show where you snipped them off.

J

Offline sshire

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Re: Spark Plug Clips
« Reply #2 on: September 22, 2014, 04:34:54 PM »
Best,
Stan

Offline Dave Otto

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Re: Spark Plug Clips
« Reply #3 on: September 22, 2014, 04:43:43 PM »
Hi Maury

I have made some for the Rimfire plugs that Roland sells. I did what Jason indicated; they were cut out of flat BC sheet on the CNC, but I guess that brass would also work. There were two wings also included as part of the pattern. The wings were folded around to make the sleeve where the wire solders in. Then a small piece of shrink tubing was used for a strain relief.

I use real small high voltage meter lead for the wire and have covered it with fiber glass braid that I salvaged from some thermocouple wire. This gives it a period look with good dielectric properties.

My opinion is that most of the purchased wires while look fine on a small V8 really look out of place on a model of an antique.

I will post some pictures later today of what I did. I may still have the CAD if you want it.

Dave

Offline maury

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Re: Spark Plug Clips
« Reply #4 on: September 22, 2014, 05:56:37 PM »
Guts, thanks for the ideas. I have been hacking a simple model and playing with BobCam on it. I was going to give it a try this afternoon. Never believed this was a practical way to make these clips, bit I'm becoming a believer.

Dave, I would be interested in tour model, and also, what tool sizes did you use?

I have .031 brass, that seems a little thick to fit in my plugs, but not by much. Maybe a file will get ti to slide in.

More later.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline Roger B

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Re: Spark Plug Clips
« Reply #5 on: September 22, 2014, 05:59:23 PM »
The plug connector on my vertical engine was bent from 0.5mm dia piano (spring steel) wire and soldered onto the plug lead.
Best regards

Roger

Offline maury

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Re: Spark Plug Clips
« Reply #6 on: September 22, 2014, 06:16:01 PM »
Ok, we are not talking about guts here, that is supposed to say Guys.

Roger, I've seen wound spring plug clips too, Seems it might be a good way to go. Since I make my own springs, I may fiddle with that and see of I can get one that will stay on.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline Dave Otto

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Re: Spark Plug Clips
« Reply #7 on: September 22, 2014, 07:29:40 PM »
Here are a few pictures; I can't put my finger on the cad file, I will keep looking.
The material is .014" BC that was heat treated after machining and forming to make it springy.

Dave

Offline maury

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Re: Spark Plug Clips
« Reply #8 on: September 22, 2014, 09:49:13 PM »
Guys, here are some clips I knocked out real quick. They don't look that great, but they will do until I get some better ones and some wire like Dave suggested. I just had a simple model, didn't do the wire tabs on back. Also, my machine has a bit of backalsh in the Y and so the center hole isn't round.  I did want a center hole with a slot that was smaller than the hole so the clip would actually stay on the spark plug.

Dave, how did you get your clip to hold?

The expansion slot was cut with a small hobby hack saw from True Value Hardware. The part was cut from .020 brass sheet, I found some in the stock bin. I used a .0625 end mill.

By the way, I'm still looking for ideas on this, so please don't hold back.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline Dave Otto

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Re: Spark Plug Clips
« Reply #9 on: September 23, 2014, 01:26:16 AM »
Hi Maury

The slot was made as a nice push fit in the groove of the plug and with the heat treatment the material stays nice and springy. I have been using one of these on my Canfield for years and it has never come loose or fallen off the plug.

Dave

Offline gary hart

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Re: Spark Plug Clips
« Reply #10 on: September 23, 2014, 04:21:17 AM »
Another method


Use simple wire clips make from .015 music wire.     Wire is bent back on itself,  have to leave a little radius at the sharp bend or it will break.    Can be done without annealing.

The wire clip is pushed in the core of the spark plug wire and nothing else is needed to hold it there.

Using on spark plugs with 0-80 studs that have a washer and thumb nut.   If bent to the right shape it will snap on the stud under the washer.

The copper wire wraps on the wire is to identify which spark plug it belongs to.    The plug wire OD is 1/8".