# Telescoping Jack Screw - FINAL PROJECT



## jlsmithseven (Apr 9, 2017)

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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## mikey (Apr 9, 2017)

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?


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## Terrywerm (Apr 10, 2017)

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.


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## mikey (Apr 10, 2017)

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.



Teach me, Terry. Where does it say the cap is crimped or swaged?


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## Terrywerm (Apr 10, 2017)

mikey said:


> Teach me, Terry. Where does it say the cap is crimped or swaged?



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.


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## mikey (Apr 10, 2017)

Okay, missed that. Thanks.


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## Terrywerm (Apr 10, 2017)

No problem, Mike, we've all been there - and more than once!


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## ddickey (Apr 10, 2017)

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


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## 4GSR (Apr 10, 2017)

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.


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## tomh (Apr 10, 2017)

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.


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## jlsmithseven (Apr 10, 2017)

mikey said:


> 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?



I believe it snaps on, but I could be wrong. We haven't done internal threading yet, or radius cutting. We formed a radius with our file, but never cut it yet. This project introduces like 3-4 new concepts that we haven't learned yet and it's due in a month. I'll keep you updated. I'll be starting it next week most likely.


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## Uglydog (Apr 10, 2017)

Am following closely as jacks are one of the projects on my to-do list.
The "Generals" I've got don't work as well as I'd like.

Daryl
MN


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## jlsmithseven (Apr 14, 2017)

I'm starting the "SM Jack Screw" today. I got everything turned down to the right diameters and I am going to thread the ends next. BTW we have to make two of these, not sure if I mentioned that. So once I do one thing on one end, I just flip it and do it on the other. Got a lot more done than I thought I would today. Was taking .100 cuts at a 329 RPM and .003 feed rate. I think I will bump it up to a .006 feed rate for my roughing passes because my chips kept tangling up. Anyways, enjoy!

Note: The last few pictures are for Mikey to show him how well I can clean a machine when I'm done with it. Thanks buddy.


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## Rustrp (Apr 14, 2017)

I noticed in the second photo there was a padlock. That's how they keep you there. 

Because machine tools and the processes interest me, I keep links to a few things that I probably will never have time to get back to or have time for. Your task of cutting the radius/ball challenged me to look for a link.

http://www.micro-machine-shop.com/ball_turner.htm

I'll be wating for the ball and swaging process. Nice work.


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## mikey (Apr 14, 2017)

jlsmithseven said:


> Note: The last few pictures are for Mikey to show him how well I can clean a machine when I'm done with it. Thanks buddy.



Wow, just as clean as Darkzero's machines! Good job, Justin!!!


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## darkzero (Apr 14, 2017)

mikey said:


> Wow, just as clean as Darkzero's machines! Good job, Justin!!!



Oh crap, here we go again. I'm going to delete all those old pics of my clean new machines. Well no I'm not, I like looking at them!

Justin, those Leblond Regals look very similar to the Regals I used at my local CC. But the ones they had were servo shifts. I really liked using them. I miss the collet closers & I wish I had a huge pull out chip pan like them.

We were required to clean up the machines we used after each day. Most kids were lazy except my lil brother. I was just happy to be able to be there to use the machines. I don't miss cleaning up the big Cincinnati horizontal mill when using flood coolant. What a mess!

I thought about going back just for the heck of it but I stopped going when I completed the course & my instructor retired. I never knew our local CC had the machining course. My lil brother needed a technical credit so he took it for 1 semester. I was his ride to get to & from there so I figured I might as well take the class with him. Glad I did, it was a lot of fun. My brother only took 1 semester, I went for 3 or 4 I think, I forget.


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## jlsmithseven (Apr 14, 2017)

Haha thanks. It feels good to arrive at a clean machine, I can't argue that....Lesson learned.
Yeah the leblond is easily my favorite lathe in the shop. It feels solid and cuts very nicely. I wish I had my own, it's a lot of fun.


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## darkzero (Apr 14, 2017)

Just glad to see conventional machining courses still available. None of my high schools had machine shops. Most colleges are offering only CNC now.


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## Sleddog (Apr 15, 2017)

Arrive at work fresh & ready to start your shift & the machines are a mess is akin to walking into the bathroom & un-flushed toilet!

Our high schools offered vocational machine shop for junior & senior students. Three area Vo-tech schools offered classes too. None of them offer any type of machining training now.


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## jlsmithseven (Apr 15, 2017)

Some footage of me taking .100 cuts at a .003 feed rate. My friend said he ran a .012 feed rate while taking .100 cuts, but I thought that was too quick for that much material...?


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## Silverbullet (Apr 15, 2017)

I remember those days in vokie, there nothing like getting out in the real world. You don't just watch your machine run , do your deburring. Clean up . At least when I started , still remember the worse job I had in any shop. Cleaning the sump on a big turret LATHE using your hands to scrap the foulest smelling crap out. That had to be done about twice a year on every lathe with water soluble oil. Sure don't miss that. But back to your project , I agree with the fine threads , but if your being graded I'd stick with the print , unless you get a revision on it . The Jack looks like it will be usefull , do yourself a favor make two. You will find many times over your need for more then  just one. I think it may be good to add for yourself some knurled nuts to lock one section. Just my observation.
I'd make them for both myself. The 1" and the 5/8"  threaded as each section.


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## jlsmithseven (Apr 15, 2017)

so what you're saying is my first job will be cleaning machines?


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## Silverbullet (Apr 15, 2017)

jlsmithseven said:


> so what you're saying is my first job will be cleaning machines?


No I didn't say that, I said you usually are asked to do more then just watch a lathe run . May be different now but when I started I had to do more things besides run a lathe or mill. While it did it's job I had to deburr ones that were done , or keep ahead of the chips by cleaning them out . Read the post don't jump to conclusions no one's attacking you. Just things I've been through. Has far as the cleaning of the sumps  it was part of working on the  machines . They didn't clean themselves . And they didn't hire cleaning people . Just part of the job


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## Rustrp (Apr 15, 2017)

Sleddog said:


> Arrive at work fresh & ready to start your shift & the machines are a mess is akin to walking into the bathroom & un-flushed toilet!
> 
> Our high schools offered vocational machine shop for junior & senior students. Three area Vo-tech schools offered classes too. None of them offer any type of machining training now.


Unfortunately, vocational programs are at the mercy of academia. Has anyone ever heard of anyone teaching a STEM class justifying the funding for their classs based on the number of students placed in a job/occupation based on their study? How many high school football programs have been shut down due to budgets? I know this isn't true across America, but when a school district reinstates a vocational program it's promoted as if someone had an epiphany, vocational training is a path to jobs and an improved economy, WOW! 

Okay, soapbox put away.


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## Rustrp (Apr 15, 2017)

jlsmithseven said:


> so what you're saying is my first job will be cleaning machines?


There are few cars on the road in good condition, where the owner didn't take of it. If your first job was cleaning machines would it be bad. If you had to clean machines that were supposed to be cleaned by the operator and they didn't, I'm sure you wouldn't be a happy camper. Otherwise the amount of cleaning you experience will be part of the job as long as you choose to machine, and it should be. 

If the cleaning is delegated to someone other than yourself how do you or will you know the condition of the machine you're running? Let's say you have a run of 500 parts to get done today and the cleaning of the machine is delegated to the apprentice and he's not happy cleaning nor understands why he must. So the fact that the chip auger had been getting sloppier for the last two weeks isn't a big deal to him, but it is to you and at 235 parts into your shift things fall apart. Maybe you would have seen the failure coming and a little preventive maintenance would have prevented the shutdown. The maintenance crew could have repaired the auger on the night shift...........?


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## TakeDeadAim (Apr 15, 2017)

jlsmithseven said:


> Some footage of me taking .100 cuts at a .003 feed rate. My friend said he ran a .012 feed rate while taking .100 cuts, but I thought that was too quick for that much material...?
> 
> Your chips are not blue and the finish looks reasonable so you could up the feed.  RPM looks slow for Coll Rolled. 100x4 divided by the diameter should get you in the speed.  Grab the closest you can get on the LeBlond; those lathes are pretty rigid.


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## jlsmithseven (Apr 15, 2017)

Sorry SilverBullet if I came across that way, just trying to get first-hand info of what its gonna be like at an actual shop because I've never worked in one before!


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## jlsmithseven (Apr 15, 2017)

Hmm, I was told to take 280 / workpiece diameter. That gave me 280 and I put 329 on the Le Blond. I usually run it at 436, but slowed it down some based on the calculation. The finish was actually pretty awesome, so I could have easily gone double the speed, at least for roughing I think. You said .100 x 4 / diameter and that gave me .001. Did you mean 100 x 4 / diameter, that gave me 400, which is similar to what I usually ran at...


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## astjp2 (Apr 16, 2017)

Well the place I work at hired 2 people to clean machines and change coolant, made the operators lazy!  I usually get the "well its been hammering for a week or so" or "its not working" when I find the 1" end-mill chunk that broke off laying in the auger and they have that deer in the headlights look and say it was the other shift.  My favorite was finding a 321 block in our chip puck maker, made it through 3 different augers before stopping up the feed auger just before it was about to get munched by the 60 ton ram...but no one knew who was missing a 321 block?


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## TakeDeadAim (Apr 16, 2017)

jlsmithseven said:


> Hmm, I was told to take 280 / workpiece diameter. That gave me 280 and I put 329 on the Le Blond. I usually run it at 436, but slowed it down some based on the calculation. The finish was actually pretty awesome, so I could have easily gone double the speed, at least for roughing I think. You said .100 x 4 / diameter and that gave me .001. Did you mean 100 x 4 / diameter, that gave me 400, which is similar to what I usually ran at...



I think you saw the period at the end of my sentence and read it at ".100.  The universal formula for calculating speed, be it turning, boring, drilling or milling is Cutting Speed x 4 / diameter  

So for 1018 or mild steel the cutting speed is generally listed at 90-100;   so  100 x 4 = 400/diameter

Cutting speeds for common materials are listed in books like the Machinery's Handbook,  South Bend How to Run  a Lathe and in many places on the internet.
This site just happens to be one I have printed the chart from because it fits on one page.   
https://www.wisc-online.com/LearningContent/mtl8202/MLT8202.htm


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## Wreck™Wreck (Apr 16, 2017)

I may give you some insight as to what you might expect in the real world, if you do not go directly from school to working for an aerospace/automotive/pharma contractor.
If your first employer is a job shop then you will be required to do exactly that, whatever is needed. 
You may have to deburr 1000's of parts or just run a saw for days at a time, degunk the coolant sumps and so on.

It will take a bit of time before they just give you a drawing and work order because they know that you can make the parts without supervision. At that point you will become entirely to valuable running parts and will no longer have to do the second operations and other simple tasks.

Good Luck


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## jlsmithseven (Apr 16, 2017)

I understand that every place is different. My internship is this summer.


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## Wreck™Wreck (Apr 16, 2017)

Excellent, do what you already know and go from there.


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## T Bredehoft (Apr 16, 2017)

Make an excellent impression, you may be able to get a job there based upon their experience with  you. 
You can always hope.


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## jlsmithseven (Apr 16, 2017)

T Bredehoft said:


> Make an excellent impression, you may be able to get a job there based upon their experience with  you.
> You can always hope.


The purpose of these internships is to get familiar with the place. We picked these from a list for jobs we would hope to have. I've heard good things about this company, so I believe it's a good fit. Then when I graduate, I'll already have experience with what they need me to do and we can go from there.


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## TakeDeadAim (Apr 17, 2017)

I've been in both roles in that I started as an apprentice and was given machining and repair tasks that slowly increased in difficulty based off my success in doing what I was given. I was also given many "duties various as assigned" jobs from going to pick up parts, cleaning, washing the shop truck and emptying the trash.  Ive also been in the spot where I dealt with new employees and gave them tasks much in the same way I describe above.  Mind you I was never and am never a guy who will  walk past a full trash can or dirty bathroom and then go get someone who is working to take care of it.  

I did however send people who were standing around to do things that were "theirs to do"; kind of a reminder that hey you need to take care of these things when you see they need doing. By them seeing me do it I always felt it was a good demonstration of just that, do what needs doing when  you see it.

Best advise I can give you is just that; don't walk in the door with the attitude "I'm here to make parts and only that",  The fastest way to make yourself recognized as a good worker is to do the following.

Show up to work on time and ready to work
Consider your appearance despite the fact you work in a shop
Do what you are asked to do when and how you are told to do it
Do the extra things you see need to be done;  If the paper towels at the wash sink are out, replace them, if the sink is dirty, clean it.  If you use a machine, clean it, if you use company tools, or borrow tools, return them.  De-bur everything you do, even the cut off's.  Label stock before returning it to the rack.  I hope you get the idea here and believe me they will notice if you do and if you don't.  There are many people here who have run shops and I am sure they can confirm that if you want to stand out these, and many others, will make that happen.

I wish you great success in your pursuits, it is great to see young people getting into what is and always has been a great career.


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## jlsmithseven (Apr 17, 2017)

Much appreciated TA. Very well said.


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## brino (Apr 17, 2017)

TakeDeadAim said:


> The fastest way to make yourself recognized as a good worker is to do the following.
> 
> Show up to work on time and ready to work
> Consider your appearance despite the fact you work in a shop
> ...



Absolutely agreed!
If I needed to sum it up in one word it would be "attitude".

......and from what I have seen on this site, Justin (the OP) is on the right track. He is always trying and pushing himself to do the best he can.

I think he will do very well........on this site, in whatever shop he frequents and in life!

-brino


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## jlsmithseven (Apr 18, 2017)

Thanks for the kind words everyone! It means a lot.

So anyways back to my project, I got done threading both ends of what will be my SM Jack Screws with the rounded nose on them. My next step my professor said was to put this piece in the collet holder and mill the edges to the hexagon nut. So I will do that a little later on. I got most of the lathe work out of the way on these, so I want to go ahead and start another section. Only reason is, people are still on other machines and we have a few weeks left. By that final week, it's going to be hard to get on a decent lathe. So I want to do all the lathe work I can as soon as possible. Would the LG Jack Screw be a good next section? Do it the same way I've been doing this section, with one on each end? Thanks and enjoy the photos and video!


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## mikey (Apr 18, 2017)

Threads look good, Justin. It might be a good idea to chamfer the ends before threading for smoother engagement of the threading tool. You can also do it afterwards but do it so the thread start easily and it looks better.


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## jlsmithseven (Apr 18, 2017)

mikey said:


> Threads look good, Justin. It might be a good idea to chamfer the ends before threading for smoother engagement of the threading tool. You can also do it afterwards but do it so the thread start easily and it looks better.



Did chamfer after these were taken, I originally forgot. Enjoy the threading video


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## kvt (Apr 18, 2017)

Mikey yes the chamfer would be nice, but looking at the drawing,  unless the instructor given them authorization to modify,   Does not show any chamfer on that end,  It just shows flat,  Which I would say is an oversight by the person drawing it.    OK my bad,  I see he did chamfer them now.


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## jlsmithseven (Apr 19, 2017)

So you guys who'd like to do this project will get to learn a few things today. At the expense of my mistakes lol.

I went in today at 9am. I turned down and knurled a section for the LG Jack Screw. Came back after a test at 1230pm and it dawned on me. I knurled before ever turning down my 1.375" sized stock to the 1.310 callout on the print. This was after I center drilled, faced, and cut sections out for the external thread. So, the key thing to learn here is that turn down your stock before knurling. Also note that knurling adds approx. 010" to your final dimension, depending on how much knurling you're doing.

Anyways, I started a new piece and got almost to tapping the inside. Was taking .125 thousandth passes here and a feed rate of about .006 and it worked out nicely. Lots of smoke, but I got to rip through the part and get a lot done!!

I drilled entirely through it so all I have to do is tap the inside, then do more external threads and done! Enjoy.


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## brino (Apr 19, 2017)

jlsmithseven said:


> and it dawned on me. I knurled before ever turning down my 1.375" sized stock to the 1.310 callout on the print. This was after I center drilled, faced, and cut sections out for the external thread............Anyways, I started a new piece and got almost to tapping the inside.



Could you not just take a skim cut to remove the knurling?

-brino


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## jlsmithseven (Apr 19, 2017)

brino said:


> Could you not just take a skim cut to remove the knurling?
> 
> -brino


Yeah I thought about it, but the piece was cut into like 3 different diameters so gripping it on the chuck wasn't going to be fun. I had another piece already cut so it didn't take me much longer to get back to where I was...


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## jlsmithseven (Apr 19, 2017)

So whenever I get on the mill, can anyone help me with this hexagon collet block thing. Is it hard? How exactly does it work?

https://www.amazon.com/5C-CB-5C-Collet-Block-Set/dp/B0007Q1Q50


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## Rustrp (Apr 19, 2017)

jlsmithseven said:


> So whenever I get on the mill, can anyone help me with this hexagon collet block thing. Is it hard? How exactly does it work?
> 
> https://www.amazon.com/5C-CB-5C-Collet-Block-Set/dp/B0007Q1Q50


You say; "whenever I get on the mill," but link to a 5C collet setup, which would be used on the lathe? Which piece of the jack screw are you planning on doing on the mill? In the mean time I will go back and read the details on your project.


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## mikey (Apr 19, 2017)

jlsmithseven said:


> So whenever I get on the mill, can anyone help me with this hexagon collet block thing. Is it hard? How exactly does it work?
> 
> https://www.amazon.com/5C-CB-5C-Collet-Block-Set/dp/B0007Q1Q50



Pretty simple. You find a 5C collet that fits your work piece diameter and slip it in the block, then put the work piece into the collet and tighten the black ring on the back of the collet to lock the work in solidly. Then you can turn the collet block in the vise to cut 3, 4 or 6 sided flats or features.


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## jlsmithseven (Apr 19, 2017)

So basically the same size as I've been holding it on the lathe chuck right? Like in the middle? Then keep turning it for the 6 sides I need in the vise jaw? I think I'm talking about the left picture in the link on Amazon...


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## mikey (Apr 19, 2017)

The diameter of your work piece has to be able to fit into a 5C collet but basically yes, you would put the collet in the hex-shaped block and lock it in place in the vise. Then you cut one flat, turn the block and cut another flat and so on until all six flats are cut.


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## Rustrp (Apr 19, 2017)

mikey said:


> The diameter of your work piece has to be able to fit into a 5C collet but basically yes, you would put the collet in the hex-shaped block and lock it in place in the vise. Then you cut one flat, turn the block and cut another flat and so on until all six flats are cut.


I like show and tell. When I'm in the shop I see it happening.

Edit: When I asked about the 5C collett it was because I got the distinct impression there would be a milling task to complete on the lathe and if it's in the description I missed it.


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## jlsmithseven (Apr 20, 2017)

hey guys, I'm not starting internal threading yet, but I want to keep it in the back of my mind. my teacher said drill bit 1/16 smaller and bore it .005 bigger than the minor dia. is this the minor diameter of the thread pitch (using 1-10 threads). Thanks!


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## Rustrp (Apr 20, 2017)

jlsmithseven said:


> is this the minor diameter of the thread pitch (using 1-10 threads).


With my limited knowledge of single point thread cutting I'll say yes.

Edit; Was this a trick question? The print shows 1-8 UNC.


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## mikey (Apr 20, 2017)

Did the call out change? The prints say 1-8 UNC, which has a minor diameter of 0.8647". Adding 0.005" would give you a target bore of 0.8697"; this would give you slightly looser fit but is typical practice. 

Here is the nomenclature: 






This is a good table to copy: http://machiningproducts.com/html/UNC-UNF-UNEF-Thread-Dimensions.html


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## jlsmithseven (Apr 20, 2017)

It has been changed to 1-10 UNS, sorrY!! I mentioned it in my last question. So Mikey it is minor pitch diameter then...or just the actual Minor diameter of the thread itself?


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## mikey (Apr 20, 2017)

jlsmithseven said:


> It has been changed to 1-10 UNS, sorrY!! I mentioned it in my last question. So Mikey it is minor pitch diameter then...or just the actual Minor diameter of the thread itself?



Okay, so 1-10 UNS. The process is the same. Go here and find the 1-10 UNS specs. Look at the tolerance range for a 2b (class 2 internal) thread and note that the larger end of the minor diameter range is 0.913". Adding 0.005" to that gives you a bore of 0.918". That hole should allow a 1-10 2a external thread to fit if the thread is within the tolerance range for that thread. So yes, the ID of that bore will be your minor diameter.

http://www.diecasting-mould.com/dat...t-Screw-Socket-Thread-Specification-Sheet.pdf
http://www.diecasting-mould.com/dat...t-Screw-Socket-Thread-Specification-Sheet.pdf
Pitch diameter is the mid-point between the major and minor diameters so no, we aren't talking about that. 

Hmm, let me see if I can simplify this. When you turn your external thread it will have crest dimensions that have to fit into the female root dimensions with adequate clearance, while also allowing adequate engagement on the flanks of the thread, right? Your instructor is giving you a method that allows you to provide a little clearance at the interface between the root and crest of these threads so the two threads will fit without contact at those points. Did that clarify or muddy things up for you?


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## jlsmithseven (Apr 21, 2017)

It helps thank you


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## jlsmithseven (Apr 21, 2017)

THIS IS WHAT I GOT DONE TODAY.
Drilled with the .500 drill about 1 inch in. Then drilled with the 57/64 drill. Worked pretty well and cut pretty good. Don't have updated pics, this was taken before lunchtime but I got both sides done! They look awesome, I hope I can internal thread. My plan is to cut each piece off and grip on the knurled end. Then just run the internal thread tool completely through the part. Others have internal threaded to a shoulder, but I want to avoid that when this is my first internal threading exercise. Sound like a plan? Thanks guys!


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## T Bredehoft (Apr 21, 2017)

Threading internally more than about twice the thread diameter is chancy. You'll get spring on a long enough tool to reach that far through the  double piece. 
You might try internal threading to a shoulder on a piece of scrap before  you start the final pieces.


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## jlsmithseven (Apr 24, 2017)

Unfortunately made a simple error today and cost me 10% of my grade on this project. Granted, I could do another one in a day based on my experience now, but it was a lot of work to mess up on the cutoff part of the procedure. My little end knurled is off by .010 and my total length is off by about the same. The sad thing is the knurled length had a tolerance of .010 and the length itself overall had a tolerance of .030. I believe my error was indicating the length on my lathe, then going back to the grinder and making sure the tip of my cutoff tool was sharp. Either way I messed up and it's 10% of my grade, but I have to worry about getting the other parts done because the Very Top Cap and the Top Ball part are due this Friday! I need some assistance.


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## mikey (Apr 24, 2017)

jlsmithseven said:


> I need some assistance.



What did you need help with, Justin?


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## jlsmithseven (Apr 24, 2017)

OK 

And for the cap, I turn down a bar to .69, then how do the .19 radius?


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## mikey (Apr 24, 2017)

First, have you spoken to your instructor to try and clear up these questions? If not, then it might be a good time to do so because I am not aware of a ball nosed cutter sized to cut a 0.19 degree radius. Maybe he intends the hole to be bored or drilled to a depth of 0.34"?

To machine the hex, you have to turn your OD down to 1.0046", then cut the flats so the span from flat to flat is 0.87". See this calculator: http://janproducts.com/Distance_across_corners.html

Then you need to turn the end of the work above the hex to a length of 0.530". Then you need to ask the instructor how deep to cut the 0.150" wide relief cut (under the ball) because it isn't called out and we can't infer it with the info in the drawing.

Then you need to file the radius on the end of the ball.

Then you need to make the cap. I'm not sure how he wants it done. I would leave the work long, lock it in a collet block, angle the block to 45 degrees and support the block with a jack or some other support to prevent movement. Then I would cut the V with an end mill. Once the V is cut, part it to length and drill or bore the hole for the ball.

I think there is enough uncertainty here to warrant a discussion with your instructor to clarify the above points.


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## MikeWi (Apr 24, 2017)

+1 to the above. Your teacher should be able to tell you everything you need to know in order to finish this project, or he's not doing his job. I'm not saying you shouldn't ask for help here, but it concerns me that you have to.


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## jlsmithseven (Apr 24, 2017)

I'd just like to get ahead of schedule.


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## jlsmithseven (Apr 27, 2017)

The radius was changed to .250 instead of .19. Here's what I've got this far.


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## Cadillac STS (Apr 29, 2017)

Would someone upload pics of how these are used?


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## francist (Apr 29, 2017)

Typically for adding support to parts as they're being machined. I have one though that I find really useful as a jaw spreader when cutting short lengths on the bandsaw (stops the vise jaws from going cock-eyed). The telescoping ones give larger range in a small package. The setup below isn't mine but it gets the idea across I think.

-frank


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## David S (Apr 29, 2017)

Holy crap that is one helluva set up there.  Just about every aid one could think of.

David


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## francist (Apr 29, 2017)

Yes, and perhaps the photographer was standing on a milk crate when he took the picture too....

(Like I said,  not my setup!  

-frank


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## jlsmithseven (Apr 29, 2017)

Yep, basically just like that. We are making two because if you have a really long bar and want to cut both sides maybe, you will have support on both sides. The nice thing about mine is that the 45 degree slot at the top of the caps allows me to clamp round bar in the vise as well.


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## Terrywerm (Apr 29, 2017)

Justin, the work you have done is looking pretty good, despite some of the problems you have run into. Don't forget that making mistakes is part of learning, and it's best to make them sooner than later.

Did you remove the drawings for this project? I noticed that they are gone from the initial post in this thread.


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## jlsmithseven (May 1, 2017)

Time to start my internship in a week; but I'm finally done.
Used 2 drill sizes smaller than the bore size. Go to measure it, it's right in the middle of the tolerance I need. I didn't even have to bore it and it was concentric within .001.


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## mikey (May 1, 2017)

Outstanding! So, Justin, spill it - did you pretty much get full credit for this?

If you approach your internship with the excitement and open mind that you've displayed here, you'll do great. Good luck!


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## jlsmithseven (May 1, 2017)

Well it hasn't been graded yet, but I think it's an A-. Thanks for the tips, I definitely will approach my internship with a positive attitude.


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## Rustrp (May 1, 2017)

jlsmithseven said:


> Well it hasn't been graded yet, but I think it's an A-. Thanks for the tips, I definitely will approach my internship with a positive attitude.


I know there were a few changes but I was looking forward to the crimping operation for the cap. Was this a change also?


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## jlsmithseven (May 1, 2017)

Not sure. The .19 radius was changed to a .250 radius so just used a .250 endmill to make little cuts on the end. Still has to grade the top so I can't crimp it in yet.


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## Silverbullet (May 1, 2017)

If you were advanced a bit you could cut a groove in the cap and use a o ring to keep the cap on instead of peening it on. After awhile you will be able to look at things and in your mind figure alternative ways of doing things. Or problem solving I call it. Think and do.


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## T Bredehoft (May 2, 2017)

Silverbullet said:


> After awhile you will be able to look at things and in your mind figure alternative ways of doing things. Or problem solving I call it. Think and do.



I find that I can sometimes "solve the problem" while trying to go to sleep at night. The mind is free to wander and often I'll stumble over an easier way to do something. Then, the next day, try to remember the solution, and what problem it went to.


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