Telescoping Jack Screw - FINAL PROJECT

jlsmithseven

jlsmithseven

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So, our semester is reaching its completion on May 10th. I have ONE final project I need to do and I'm going to need some help with it. It introduces some advanced Lathe techniques. We have to cut it all with HSS tools and 1018 CRS material.

I haven't started it yet, but please keep it in mind because I will probably be back to this thread if I run into problems. Have a glance and see what issues you think might arise. Thank you guys!!! I want to finish this semester out strong.
 
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Looks like a cool project, Justin. Basic lathe work - turning, grooving, knurling, internal and external threading. The only thing that might be interesting is the ball on the end of the small jack screw. It has to match the inside of the top piece? Do you have a radius tool available? From the dimensions, it looks like the top just perches on top of the top screw; it doesn't snap on, or does it?
 
According to the print, the cap fits onto the top of the small jack screw and is then crimped or swaged so that the cap is retained on the ball at the top of the screw. Look closely at the print for the cap and you will see that its recess is simply a drilled hole and is not rounded to fit the screw at all.

But, like Mike said, it should be a rather straight forward project. Think through the steps for each part, even writing them down so that you have a good plan to follow and you will do just fine.
 
terrywerm said:
According to the print, the cap fits onto the top of the small jack screw and is then crimped or swaged so that the cap is retained on the ball at the top of the screw. Look closely at the print for the cap and you will see that its recess is simply a drilled hole and is not rounded to fit the screw at all.

But, like Mike said, it should be a rather straight forward project. Think through the steps for each part, even writing them down so that you have a good plan to follow and you will do just fine.
Click to expand...

Teach me, Terry. Where does it say the cap is crimped or swaged?
 
mikey said:
Teach me, Terry. Where does it say the cap is crimped or swaged?
Click to expand...

It's on the top left print which shows the entire assembly, titled "TELESCOPE JACK". In the right center of the print, it says: "NOTE: Crimp Edge of Cap When Assembled."

It could probably be swaged with a punch and a hammer, or maybe a swaging tool for use in a press could be made just special for this project. Personally, I would just go the hammer and punch route as it should go pretty easy since only about 2/3 of the diameter will actually be available for swaging or crimping.
 
Order of ops will be important. Using one part to hold the other. Looks very similar to the one I made copying from a crazy canuck. A Jack screw should be a fine thread imo which doesn't count for much. LOL
 
I agree with ddickey, It needs to be fine threads instead of coarse threads. 1.000-14 UNF and .625-18 UNF. Some people may think 1.000-12 is correct, in my neck of the woods, it's 1.000-14 UNF. I would make the base a little larger diameter, too.
 
That lazy machinist did a 7 part? series on a jack like yours. He is a retired shop instructor, so watch his video as he shows the proper sequence of operations and assembly. This is a project he had his students build.:encourage:
 
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