Winner Ultra-Small Boring Head

[Bill Gruby]

:shotgun: :ups:

 

[Old Iron]

Looking good Billy I mite try to build one my self. I've been following along but it is hard to type with my 14 year old dog in my lap.

She only wants to be with me and she had sun downers, So around5 here its getting dark and she starts.

Only free time I get is in the morning cause she sleeps late. I've had her since she was 4 weeks old so you know she is like one of my kids.


I'll be looking for the finish on this project.

Paul

 

[Bill Gruby]

Go for it Paul. The original was made from 12L14. The nut, keeper and gib were the only Brass parts. Machining 12L is relatively easy. Mine is all Brass because it would have been off to the scrap yard soon. The only caution is in using the small endmills. It really is a fun project and a little challenge, but then challenge is what we live for.

"Billy G"

I hear ya about the clinging pooch. They are like little kids at time.

 

[Bill Gruby]

Someone has asked how the shoulder was cut in the 6-40 SHCS. Screw dia. at the shoulder is .133. The shoulder must be cut to .070-.080 at that place to fit the Keeper. I will make a few more today and photo document the process. I have to wait till tomorrow to proceed on the rest anyway.

"Billy G" :thinking:

 

[Bill Gruby]

This will take a little time as there are 9 pictures start to finish. OK, you do not want to damage the 6-40 threads so you cannot chuck the SHCS in the lathe. You need a way to hold both ends. In this picture are the tools I feel are necessary. The large disc holds the head and the arbor is threaded 6-40 to hold the threads.

"Billy G" :thinking:

 

[Bill Gruby]

How are they used -- The thread arbor goes in the lathe chuck and the disc goes into the Tailstock drill chuck. It has a small spiggot on the back side to catch.

"Billy G" :thinking:

 

[Bill Gruby]

You see how they go into the lathe, let's me show you how the SHCS goes in. You can make the thread holding arbor any length you wish to keep you away from the moving chuck. You will see what I mean soon. It is not dangerous if you use Common Sense and respect your tools and your limitations. I have used thei method for many years and it has proven to he safe.

The objective here is to capture the threads and to capture the head and while allowing the head move freely.

"Billy G" :thinking:

It will really help if you are a lefty, I am not. :lmao::lmao::lmao:

 

[Bill Gruby]

The TOOL. There are two ways to cut the shoulder. #1 use a 1/16 cut-off tool and turn the shoulder. That is the easy way. Myself, I can have the shoulder cut before you can mount the cut-off tool using a file. You are not removing a lot of material, only .030. If I were removing a lot of material I would surely use the cut-off method.

A few words of caution here. If you are new at machining please respect what can happen here. You are filing against the rotation of the chuck. You need not use much pressure on the file. Do not stand in line with the file. If you do and that file catches it will come back at you. If you have never done this before my advice to you is to use the cut-off method till you gain a little more experiance. If you try the filing method run your lathe SLOW. Be your own judge here.

OK -- Here is how I do it and the end result. This one is a little rough because I was in a hurry. Fast is not the way to do this.

"Billy G" :thinking:

 

[Bill Gruby]

The cutters will arrive today. They are on the truck for delivery.

THE MATH

I will leave you with these formulas for measuring Dovetails with pins. I will be back later to explain them to those who do not know them. Dovetails are not a mystery although they look like the should be.

"Billy G" :thinking:

 

[stevecmo]

http://www.hobby-machinist.com/attachment.php?attachmentid=46210&d=1359301808

Bill - This should be in the "Show us your shop monster" thread!

Nice work on the boring head!