Next Project Boring Head

[bill70j]

Two things that I am wondering about. One is what size boring bars should I drill the holes in the head for? I don't have any metric drills and my imperial drills are in 1/64 increments. I am leaning towards 1/2" boring bars. Other choices under consideration are 3/8, 10 mm & 12 mm.

You might consider making your boring bar holes as large as is feasible, which gives you the flexibility to sleeve for smaller diameter bars. The boring head I use has 1/2" holes, and so far I have made sleeves for 1/4", 6mm, 7mm, 8mm, and 10mm boring (and threading) bars.

 

[mickri]

That sounds like a good suggestion. Right now I have the holes at 1/2." I could go maybe as large a 3/4." Is it important for any reason to have the inner hole centered in the head?

 

[Norseman C.B.]

The only changes I made to the original plan were reducing the drive shank to 3/4"
and using a piece of round bronze for the adjusting nut instead of a small steel rectangle, also went to 1/2" boring bar holes instead of 3/8".
The plan is solid for use as written keeping it centered is crucial to me for adjustment YMMV ...........................

 

[mickri]

Need some help. I have never used a dovetail cutter. Don't own one and have never even seen one except in pictures. They are not expensive but not cheap either. I am thinking about buying a couple. My problem is what size do I need to buy to cut a 60 degree dovetail that is 3/8" high and goes in around 3/16." I have searched the web for the sizes of dovetail cutters. Based on what I found I would need a 1" dovetail. That seems pretty big to me. Are these made to standard dimensions? Or is every manufacturer different? Help me out.

 

[bill70j]

Mickri:

I bought a 60deg X 25mm HSS dovetail cutter from Banggood for $9.99 to cut dovetails for some AXA tool holders. It worked great and is still sharp.

I have had good experience with Bangood's Chinese HSS dovetail cutters, as well as with their carbide end mills. Here is the selection of dovetail cutters they offer, including a table with specific dimensions. You can see from their sizing chart that the 25mm cutter will cut a dovetail 10mm deep, which is just over the 3/8" that you need.

Unfortunately, you will need a way to hold these cutters, all of which are metric. Since I have a number of their carbide end mills as well as their dovertail cutters, I invested in a set of metric R-8 collets to hold them.

HTH, Bill

 

[mickri]

I use metric ER32 collets in the mill/drill so metric isn't a problem. And 25mm is basically a 1" cutter which is what I had found as the size I needed in my research. Thanks for the use report.

 

[Latinrascalrg1]

Bill70j, I think you posted a dead link, not working for me at least.

 

[bill70j]

Bill70j, I think you posted a dead link, not working for me at least.

Hmm, I just tried it and was successful. This is the direct address - maybe it will cut and paste for you.
https://www.banggood.com/60-Degree-...p-1027926.html?rmmds=myorder&cur_warehouse=CN

 

[Latinrascalrg1]

Hmm still dont work, probably my firewall, thanks for trying again anyway.

 

[Cadillac]

I’m not seeing how you’ll adjust the head. The head of screw is usually cut into top and bottom pieces then the head is grooved to interlock with I believe top portion. Bottom has a ear on it to engage the screw so it has two flat surfaces. Or flip flopped. Just a thought.