Need help getting a screw made.

[Tunar]

Hello all,

I figured this would be a good place to start with this task. I have a screw I need to replicate /replace and I'm not sure where to start.

I'll try to attach the images, hopefully I can do that here from my phone, otherwise it will have to wait until this evening.

This is a brass screw that telescopes as is turned. It opens a vent window in the roof of a greenhouse, whose manufacture has gone out of business. Being about 25 years old, and brass, the threads have worn at the end to the point it no longer works.

I could try to change the entire opening mechanism by adapting some other type, but I'd first like to try to keep it the same.

I think the best solution would be to replicate this screw in stainless steel. It threaded on the outside to screw into the mounting bracket. As it's turned the inner portion telescopes out, making each turn twice as efficient abs keeping the mechanism compact.

Any thoughts out there as to whom I should approach? Anyone capable of machining this or can refer someone that can?

Thank you,

-Josh


Note: some of the close up photos may show the thread damage.

 

[DennisK]

Which is damaged, the left hand acme thread or the right hand acme thread?

 

[TRWham]

https://www.window-openers.com/traditional-window-openers/

I think you'll find most of these suppliers are in the UK, but you are looking for a screw jack window opener.

 

[firebirdparts]

It looks like it would be pretty easy to make. Some parts more so than others. I'm also curious about which part we're making, if we just wanted to save most of it.

 

[matt_i]

Personally I would attempt to re-engineer using 60 degree standard threads. Even if you have to upsize the diameter to increase pitch (decrease TPI) or live with more turns for the same distance.

Then you can buy cheap threaded rods, you can buy taps, you have a choice of several materials, you can weld if ferrous or silver-braze if non-ferrous. I would advise against making both parts out of SS304 or SS316.

Ultimately what's I think is going to make it un-feasible due to cost is having to re-tap the acme thread in another rod. That's an expensive proposition. It might not be your problem today but if one part of the thread is worn then the mating part is probably so. Increasing lube and increasing cleaning to remove dirt & grit will help any survivors increase their lifespan.

 

[infinkc]

Buy this?
https://windowparts.co.uk/telescopic-screw-jack-manual-window-opener.html

or from here https://www.simplyscrewjacks.com/

 

[Tunar]

Awesome, thank you. I tried searching for that and couldn't find it. Thank you so much for the tip.

-Josh

 

[BillK]

Josh,
I know somebody that can/would make it but the price would probably be in the $200 range ?? Personally I bet you can find the correct replacement with a little bit of searching. That type of hardware typically is used for many many years. Do a Google search on "Greenhouse window hardware" and start asking.

https://www.google.com/search?clien...hUKEwj515WsioPvAhXEMd8KHX7YBfUQ4dUDCAw&uact=5

 

[finn]

Just bring the worn pieces to a local machine shop. They can either replicate it or tell you who can.

I did this the first time when I was a kid in need of a spring compressor, and later when we needed a part for my neighbor’s Coats tire changer (the part was still available, but it was thirty dollars cheaper to have a local machine shop make one).

The previous owner of my Carri Lite fifth wheel had a new leveling jack screw (Acme threads) made at a different machine shop.

I even had a bung welded into an aluminum fuel tank for my hot rod by a local shop that primarily serves aerospace and tier 1 auto suppliers. They have millions of dollars of high tech machining equipment and only charged $20.

 

[The Cobbler]

I don't think it would be wise to make it out of stainless. stainless threads gall easily .

 

[532r5]

If your not worried about keeping it original, replace it with a linear actuator wired to a wall switch.

Sent from my SM-G965U using The Garage Journal mobile app

 

[Tunar]

Thank you, I was wondering if stainless steel would gall.

I don't think it would be wise to make it out of stainless. stainless threads gall easily .

 

[Tunar]

Thank you all for the suggestions, I really appreciate it.