How to make springs

[GAHorn]

For those who truly enjoy the challenge of making things yourselves.... here's a pretty good article on how to make springs:
http://home.earthlink.net/~bazillion/types.html

[Indopilot]

Thanks George,

With our 180 conversion involving a different cowl, of course the oil doors latchs had bad springs. Checking A/C Spruce they list the Hartwell 5000-2 latchs for $92.00 or surplus for 10.00. I found I was able to pull the rivets and recover a old spring for a pattern. Using .032 piano wire and a simple form I was able to make the springs for a whole lot less. Not counting the satisfaction factor. So your post made interesting reading. To See what else you can make. I had gotten the idea of making springs from this forum when we were refered to the 120-140 web site for door springs.

[GAHorn]

... Checking A/C Spruce they list the Hartwell 5000-2 latchs for $92.00 ...

Holy Moly! I guess the batch I bought for $5 ea. was a good deal? (I wasn't concerned about where I tossed 'em until now.)

[alaskan99669]

Well Spruce still wants $92 for new Hartwell H-5000-2 Trigger Lock latches. They now want $20 for the surplus H-5100-2:
http://www.aircraftspruce.com/menus/ap/latches.html
Wicks still has them for $10:
http://www.wicksaircraft.com/catalog/pr ... index.html
I tried making the tandem double torsion spring, but not having much luck so far. Does anyone know where you might buy just the spring? Or where to get the 3/32" stainless rivets. They are like a brake pad rivet, solid except for the end 1/8" for flaring. One is 7/8" long, the other 5/8".

[blueldr]

I've replaced the rivet/pins in those latches with cotter pins because I couldn't find the right kind. I've never had a cotter pin wear out.

[alaskan99669]

I've replaced the rivet/pins in those latches with cotter pins...

That's a good idea, now if I can find / make the springs. The first picture looks like a home made spring compared to the ones in my latches.

[jrenwick]

In a couple of my latches, the original spring has been replaced by a couple of small coil springs from a hardware store. This works well enough. Sorry I don't have a photo.

John

[alaskan99669]

In a couple of my latches, the original spring has been replaced by a couple of small coil springs...

I know what you mean. My right side latches are that way, but they don't work quite as well as the left hand side latches. It is odd that they are all pre-drilled as if made for this alternate spring method.

[Dennis]

Check out your local Cessna Dlr. The Hartwell latch your looking for is P/N H50002-032-064. The Cessna P/N is S1188-1 for $26. Wicks and spruce latches have different dash numbers and will not fit. Dennis

[lowNslow]

Check out your local Cessna Dlr. The Hartwell latch your looking for is P/N H50002-032-064. The Cessna P/N is S1188-1 for $26. Wicks and spruce latches have different dash numbers and will not fit. Dennis

Just installed a replacement Hartwell H5000-2 latch I ordered from Wicks for $10 and it fit perfectly including the rivet holes.

[alaskan99669]

UPDATE:

I received my three $10 latches from Wicks. Dennis is right that the original Hartwell part # is H-5000-2-032-064, and lowNslow is also correct that the H-5000-2-091-142 from Wicks replacement will fit just fine.

Here is a picture of the three I got from Wicks:

Two of three had 3/32" pins smashed on each end while the other had 3/32" brake lining type rivets (like my stock latches). The rivets are not stainless as they are very much attracted to a magnet. The pins in one of the latches are stainless while the other one with pins was not. Here is a close up of the smashed pins:

Compared to the rivets:

Here is a comparison of the stock latch parts to the left and the Wicks on the right:

As you can see from the picture and by the part number, the wicks latches will stick up about 0.07" higher than the stock latch, but that just may make the Wicks latch flush with my cowling as my stock latch is set into the cowling slightly as pictured below:

I dismantled one of Wicks latches and used the spring in my latch. I used Blueldr's suggestion of using cotter pins instead of rivets which worked out great!

[alaskan99669]

For those as talented as Indopilot, here is what the spring looks like:

[MPKnolle]

For those as talented as Indopilot, here is what the spring looks like:

http://cessna170.org/forums/download/fi ... &mode=view

Howdy, I know this is an old post, but the cost of H-5000-2 latches just keeps going up. Has anyone measured out the specs for the spring on the latch? It seems that there are a couple of custom spring companies in the US that can make a batch of springs at a reasonable cost. Anyone with experience just removing broken springs and putting in a new one?

Thank you!