First threads!

I think the Accusize and Shars mics are identical; so is the price. They should work just fine.

Hate to tell you guys that I paid just a bit more for my Tesa 0-1 and 1-2 thread mics than it would cost for the imports. Yeah, I'm bragging! Right place, right time, mad eBay skills ...
 
mikey said:
I think the Accusize and Shars mics are identical; so is the price. They should work just fine.

Hate to tell you guys that I paid just a bit more for my Tesa 0-1 and 1-2 thread mics than it would cost for the imports. Yeah, I'm bragging! Right place, right time, mad eBay skills ...
Click to expand...

:you suck:
 
Well done @mikey, yes the usual admonitions apply as @ttabbal brought forward in a timely fashion.
I was looking at the Mitu mics and promptly fell of the sofa.
 
Yea, you do have eBay figured out.
 
David,
I love your progress, which in some ways mirrors mine, although you're more adventurous in big gulps than I.
I'm hoping you won't mind my joining your thread here, no pun intended, but my issues are square in the same subject. My threading is also getting a lot better, using HSS on 12L14. I had good success this past weekend with 1/2-20 and then 5/16-18. Didn't, of course, have a nut to match to the 1/2-20 (duh...), but did for the 5/16-18 (top picture is Home Depot nut/bolt. Got very close to finished, measured with wires, and then lost track of my cross-slide location and couldn't get it back right, so it got messed up.
I definitely have the litany of threading down, and it's fun.

20200407_093549.jpg
The main issue I'm having now is real estate, my eventual goal being making small threads on soft material. I'm working towards the headstock, with a dead center holding things still, and there just isn't enough space to hold the work and position the tool; particularly so when using the wires...there's just no room for both of my hands, the wires, and a micrometer! I think I need to have more centered length, with the threaded portion somewhere in the middle, and a relief groove at both ends. I'm quite comfortable working in close to the chuck at these speeds, at least so far.
Any comments or tips would, of course, be appreciated. Looking forward to my next session, probably next weekend.
Thanks!
Tim
 
I have a couple sets of Shars 0-1" and 1"-2" thread mics and one 2"-3" set. I have an abbreviated chart showing the pitch diameters of common threads setting in the micrometer cases (thread below has a pic). I have no idea where my thread wires are since I picked up the thread mics. One thing of note on the mics is they are specifically for 60 deg. threads. You can't use them on Acme threads, thread wires would be your best option there.

Bruce


www.hobby-machinist.com

Thread depth

How do you calculate the compound depth for a given pitch? Trying to figure out the calculation is kicking my ass.
www.hobby-machinist.com www.hobby-machinist.com
 
@DavidR8, Awesome job! You are making some real progress forward.

The 29.5 degree angle thing gets a lot of rookies on their first time (myself included). I prefer to skip the compound angle and thread with the cross slide only. It saves time and I haven't seen any difference in the quality of cut between the two. Plus it makes it much easier to advance on the diameter directly (skipping the trig for the compound slide). Try it out at some point and make a decision which you like better.

I do almost all my threading with carbide (and turning too!). There is not really a minimum speed limit for carbide, the big difference is the maximum speed you can cut. If you find carbide is not working well for a particular application, you may want to look for a sharper insert with a ground edge. These are often advertised as being for aluminum but they work very well on soft steels and stainless as well. I see it is easy to find the 16ER insert with this edge geometry, although I haven't tried them personally yet.

Soft metals like aluminum, 1018, etc don't like to make pretty threads in my experience. Try picking up some 41L40 and threading on that. You'll be amazed at how professional your work will look.

I usually use the threading tool to create a relief behind the thread I am about to cut (about a thou or two below the full depth of cut). This gives you room to disengage the half nuts.

Thread mics are great and very fast, however you should pick up a cheap set of thread wires and get used to using them. You can use them for any diameter thread and any pitch. They will get you out of a tough spot where you can't use the mic.

Thread tables are my most used chapter of Machinery's Handbook. I use these to copy the major diameter and pitch diameter tolerance range to my notebook before heading to the lathe. I also use this website frequently to calculate the tolerances of threads that aren't in Machinery's Handbook: http://theoreticalmachinist.com/Threads_UnifiedImperial.aspx

Keep up the great work!
 
a friend in manufacturing gave me a metal chart i attached to my engine lathe that shows tpi, single cut (straight infeed) and 30 degree infeed dimensions. it's always worked for what i do. his co doesn't use wires, etc but they do use a series of thread gauges for inspection. i guess per iso they have to replace those regularly so i have a set but rarely use them
 
deakin said:
a friend in manufacturing gave me a metal chart i attached to my engine lathe that shows tpi, single cut (straight infeed) and 30 degree infeed dimensions. it's always worked for what i do. his co doesn't use wires, etc but they do use a series of thread gauges for inspection. i guess per iso they have to replace those regularly so i have a set but rarely use them
Click to expand...

Those are incredible you expensive to put a set together. You’re lucky!
 
You must log in or register to reply here.
Back
Top