Made Some "Big" Threads

[Ultradog MN]

Though I love carbide, when it comes to cutting threads I'm still a fan of HSS bits.
Carbide likes more speed and pressure to give a good finish which increases your need for being totally on the ball. HSS allows you to work at a more leisurely pace and lets you take smaller cuts.
And with HSS a whoops means an inexpensive trip to the grinder to dress your tool instead of a $52 mistake.
Edit:
I meant to add, Nice job you did there.

 

[Janderso]

I make gages for fitting chuck backplates, and measure the spindle thread with wires or a thread mike and make the gage right on size, I form a knurled handle on them, it reduces weight and provides grip. I see your picture of the tool, same as what I use, when they get ground down from repeated sharpening, I taper them back at an angle as far as the angled mounting surface, this gives much better visibility of the tool point.
I have always set the compound at 30 degrees, and all the journeymen I worked with did likewise.

John,
Do you thread, feed in, with the compound or crosslide?

 

[Just for fun]

Looks good Kevin T!

 

[Kevin T]

Nice Job, hope the spindle collar turns out as well.

If you were making that in this area you may have brought on some much needed rain.

Have a good day
Ray

Thanks! Me too! I've been going at the collar for a couple days now getting ready to single point the big internal threads!




I definitely didn't account for how long it was going to take me to open up this I.D.



My WWII boring bar might need an upgrade to something with less flex!

Part is sized and ready for the next steps. That is a 3.5" O.D. Next to the part I am remaking. You can make out the blown out hole for teh spanner wrench in the shadow and the reason for the remake!

 

[Kevin T]

instead of a $52 mistake.

The Aloris threading insert I am using is HSS! It's a fancy L shaped affair with mounting holes in it.

I had planned on never needing to replace it, even though I make a lot of threads! My error to let the tool go around an extra quarter turn and cutting on the big dia was too much and the tool caught and twisted and about 1/3 of the 60 degree point cracked off. It is still usable because I ground it a lot to be able to finish but I have to run the tool high to be on center so I re-ordered. BTW Amazon sells Aloris cutters and they are cheaper than the company sells them for and free shipping if you are a prime member.

 

[rock_breaker]

You are doing great. My SIL brought home a shop made boring bar as a result of a shop clean up. It is 1.25" od with a groove in the end fir 0.25" x 0.25" HSS cutting bit and is approximately 10" long; manufacture of materials is unknown. I mention this in light of your rigidity problem. Would you be interested in using it? Hopefully the shipping charges wouldn't exceed the cost of materials to make one in Hawaii.
I have not attempted to make any mounting brackets for either of my lathes.
Good luck with your project
Ray

 

[Kevin T]

You are doing great. My SIL brought home a shop made boring bar as a result of a shop clean up. It is 1.25" od with a groove in the end fir 0.25" x 0.25" HSS cutting bit and is approximately 10" long; manufacture of materials is unknown. I mention this in light of your rigidity problem. Would you be interested in using it? Hopefully the shipping charges wouldn't exceed the cost of materials to make one in Hawaii.
I have not attempted to make any mounting brackets for either of my lathes.
Good luck with your project
Ray

Really nice offer thank you! I'm not sure I could hold it. I should check my assortment of boring bar holders. Shipping? LOL Shipping is the pain we have to endure out here.

What kind of mounting brackets are you referencing?

 

[jwmay]

Either way still a lot more than the cross slide.

I'm really having trouble understanding this.

heres how to get 0.0001" precision on your ancient hobby lathe

Criticism of what I describe here is WELCOME!!! Please, lets dissect this, tear it apart, and make it better. The good news is: I think I am getting control of diameters, +/- 0.0001" (tenths), on my ancient, worn out Atlas 10F lathe. I also learned something very important about manual lathes...

www.hobby-machinist.com

This thread seems to disagree with your math. But it could be that I'm misusing a word that changes the whole meaning of my statements. Curious.

 

[rock_breaker]

Hello Keven T. The mounting brackets I would (will sometime) make would be for a 4way tool holder to fit my Enco 13x40 lathe. It would have three pieces, the base to be clamped in the 4way , two 1/2" thick arms perpendicular to the lathe ways and having 1.250" holes bored. The 1.250" holes would be made to clamp the 1.250" boring bar. Different size holes would require different size arms or possibly split bushings. Clear as mud, right". Will try to make a sketch.

From your picture I think my clausing is near the same size, really a bit small for a 1.250" boring bar unless it was made to replace the compound rest. Probably not a good way to cut threads.
Have a good day
Ray

 

[Kevin T]

Hello Keven T. The mounting brackets I would (will sometime) make would be for a 4way tool holder to fit my Enco 13x40 lathe. It would have three pieces, the base to be clamped in the 4way , two 1/2" thick arms perpendicular to the lathe ways and having 1.250" holes bored. The 1.250" holes would be made to clamp the 1.250" boring bar. Different size holes would require different size arms or possibly split bushings. Clear as mud, right". Will try to make a sketch.

From your picture I think my clausing is near the same size, really a bit small for a 1.250" boring bar unless it was made to replace the compound rest. Probably not a good way to cut threads.
Have a good day
Ray

I do have a CXA-41D that can hold it but I found a special cutter in my pile that I think will work. Your offer to help is really appreciated though. I use that holder with a double sided adapter to run 1/2 and 3/4 dia tooling or stock so I didn't recall the major ID. My lathe is a 16" x 6' FYI.