Thread: Another Dumb Question

Ian, I know the Centres have 60 degree angles on them, and that those that make the bushings for this type of thing put a 60 degree end on them, but as to how and where they get that type of drill?? I am awaiting the answer to your dumb question so that I can be educated!!!!! Amos

I'm a teeny bit confused about what you're asking here; can you post the link to the tutorial so I can get a better grasp?

When you talk about turning between centres and using 60 degree drills I think of turning on a metal lathe. If this is what you are after I can post a picture of the type of drill you're talking about and name you some suppliers

Well Chief this is the link to the page concerened IAP Home on the right hand side of the page you will find the link to the tutorial concerned and the comments concerened are on page 10 of the 23 page tutorial. I am interested at what you have to say.

Cheers Ian

If it is possible to by a drill to do this I am keen to have a go at doing it. I had been told to use a number 4 centreing drill to drill out the ends of the bushes and that it would work. I did this with a set of gentlemans bushes I had and although this seemed to work it was not the success I would have expected.

Cheers Ian

I can't open the tutorial as I'm not a member (that might change though!) but the photo tells me what you need.

The drill bit is called a combined drill and countersink, often also called a centre drill. These are available from any engineering supplier such as blackwoods and also toolshops like Glenfords. The BGS might be able to special order them for you too and I'm pretty sure McJing sell them online.

I'm going to try to include a link to the relevant Blackwoods page here:

Chief this is the exact wordind he has in the tutorialit's hard to see in the first photo but these bushings have 60 degree holes in the ends which allow the 60 degree centers to center up the blanks when turning. these special bushings are available from several forum members but I just take a 60 degree center drill and drill out the bushings i buy from kit vendors or make my own on a metal lathe.

sorry for the long story but it may help

Cheers ian

Ian, centre drills are designed to drill in to solid material. They have a pilot drill part and the 60deg countersink part. In the case of the No 4 centre drill (and I'm going on memory here!) the pilot drill part is 3mm.

If you use a centre drill to countersink a bush with a hole that is already bigger than the pilot part you will finish up with chattering and and out of round countersunk hole.

As the bush-to-bush turning is designed to overcome out of round, that is exactly what you don't want.

I make my no mandrel bushes from stainless steel, the countersunk hole is drilled first and the bushes are solid, ie there is no hole going through the centre of them.

Edit:

To answer your second question, I buy my centre drills from CDCO in the US, usually get a few sets when I order other stuff, they sell them in sets of 5.

Thanks fred I will be getting some of the bushes shortly. I have checked out a couple of sets that you made for Sam its just I had been reading that tutorial and began to get a bit confused with the whole saga

Thanks Ian

how many different styles of bushes do you make ?

Originally Posted by Dorno

Thanks fred I will be getting some of the bushes shortly. I have checked out a couple of sets that you made for Sam its just I had been reading that tutorial and began to get a bit confused with the whole saga

Thanks Ian

how many different styles of bushes do you make ?

I have made them so far for most of the popular kits, but I can make them for any kit.

I have also made some custom ones, one that springs to mind is for a one piece Cigar using a Sierra tube. So the inside is turned for the Sierra tube and the outside on one bush is turned to the Cigar tip and the other to the Cigar finial.

Basically they can be made to any size.

If I find it neccessary to turn between centres I use my metal lathe without any bushes ,this produces a perfectly concentric tube and covering , it is cheating a bit though as I have full control over finished sizes ,depth and feed ,great for truestone lol. But in saying that standard bushes centre drilled may not solve a runnout problem as the bushes as supplied tend to be a little sloppy some times and don't penetrate far enough into the tubes for good support , I think the longer ones Fred makes is a great answer to this problem . Cheers ~ John

But Thats Cheating John what about us mere mortals who dont have that luxury lol.
Well thanks everyone for your imput and the verdict is ! If I want to do the properly that I will have to get the propper bushes so I will be contacting fred when I get a few bucks together I will be contacting fred to get some bushes (save on postage)

Thanks Ian