Beefing up my 9x20

[dave2176]

It is looking really good. I gotta get some of those inside mics.

Dave

 

[chuckorlando]

They are a bit of a pain to use. But our instructor has beat into our head " calipers are for roughing, mics are for precision." An let me tell you this puppy is nuts tight. This was an area where I wanted tight. Most what I have done calipers would do fine

 

[chuckorlando]

Moving along.

After the two bottom bores were done we flipped the work. Turned the face down to a decent shoulder then camphored it. Then we drilled the 4 mounting holes and milled off the corners. Then we did a little trig to find my angle for a degree ring viewing slot. I wanted it angled so you did not have to squat so much to see it. I had to do 24* because I had no way to set the minutes and seconds. It worked out perfect.



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few more

 

[chuckorlando]

Then we milled a .085 recess in the bottom of the cross slide. The idea was to mill the bottom of the nut to fit the recess but have a larger lip for support. I failed to check to see if my drawing would fit the machine other then the cross slide. So in a pinch I turned the BP head to 45 and got it right. I drilled and tapped the top for a 1/4-20 and the nut it's self to a 7/16-20LH.



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few more

 

[Bill Gruby]

What material is that lead nut made from? Mine is Bronze and has been in use for two years now with no ill effects.

"Billy G"

 

[chuckorlando]

It's alum. I intend to make one from bronze with a turned nub to fit the oem hole. But my cast one is broke in half so I cant turn anything till I have a nut.

 

[Bill Gruby]

Good on ya. Aluminum would not hold the thread tolerance long with a steel lead screw. The back pressure during even a moderate cut would soon end up in more problems like Backlash. I have to strip the cross-slide on mine today. I will post a picture of mine.

"Billy G"


The turned nub is called a "Spigot".

 

[Bill Gruby]

Plain Jane. No need for anything else. I also did away with the Grub Screw that Jet had on it. It only cocks the nut causing more wear.

"Billy G"

 

[chuckorlando]

That would be great. I went with alum just for that reason. For a temporary solution I would just assume it leave no wear on the permanent parts. I had steel, alum, or cast iron so I just picked the softest.

Plus I learned alot through minor error. The next one will be much easier and cleaner I'd say. I would like to have machined the side angles as more then an after thought. I drew out the part and made it to the drawing. But in my hast I neglected to check the clearance on the carriage. My intent was a 1.0 x 0.9 nut. .9 is a .125 per side to much.

These cheap machines are expensive school books. Long as I'm learning

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Thanks Bill. I assumed that screw just screwed into the screw. My oem nut must have been broke in that area as the screw had nothing over it but the screw. The nut was in front of it. So thats how I made mine

 

[xman_charl]

Where is the beef?






Charl