Best Way to Bore Out Auto Rims

[CJ5Dave]

I need to bore the centers out of some auto rims for a 4 wheel trailer and a single axle. The axle has 5 lug 5 1/2 inch rims and needs a hole center about 4.1 inch in diameter. This is the same bolt pattern for older Ford 1/2 ton trucks but the factory rims have 3.6 inch centers. I have a lot of these rims and want to bore 2 out for this axle. The 4 wheel wagon is 4 lug which is a really odd wheel. Have looked for them for years and found some VW rims with the correct lug pattern but 3.1 inch holes. the trailer needs 3.6 inch center holes. I tried my milling machine and boring head and the cutters (Chinese HSS) chatter and wont cut the rims out. Someone suggested hole saws but 4.1 and 3.6 inch are not standard sizes. Any other ideas for this job? My lathe dose not have a face plate and its not big enough to hold a 15 inch wheel.

 

[Pevehouse]

I need to bore the centers out of some auto rims for a 4 wheel trailer and a single axle. The axle has 5 lug 5 1/2 inch rims and needs a hole center about 4.1 inch in diameter. This is the same bolt pattern for older Ford 1/2 ton trucks but the factory rims have 3.6 inch centers. I have a lot of these rims and want to bore 2 out for this axle. The 4 wheel wagon is 4 lug which is a really odd wheel. Have looked for them for years and found some VW rims with the correct lug pattern but 3.1 inch holes. the trailer needs 3.6 inch center holes. I tried my milling machine and boring head and the cutters (Chinese HSS) chatter and wont cut the rims out. Someone suggested hole saws but 4.1 and 3.6 inch are not standard sizes. Any other ideas for this job? My lathe dose not have a face plate and its not big enough to hold a 15 inch wheel.

I would think a boring head on the mill would do it. What kind of problems are you having when trying to bore them out?

 

[CJ5Dave]

Cutter is chattering. New cutters, tried a couple. They are 3/4 brazed carbide cutters. I said HSS but they are not. Mill is making some noise in back gear mode when the cutter gets well engaged. Tried my slowest speed on non-back gear on Bridgeport.

 

[metalmaster1]

they could be cut with a rotary table if one is available, use an endmill in the boring head, they work great

 

[GrifterGuru]

Do you have access to Carbide boring bars?

Have you locked the boring head dovetails?
How much stick-out do you have with the boring bars?
Have you polished the edges of the inserts? Some need re-touching before use.
What feed-rate are you using?

 

[Charles scozzari]

I use a 16" adaptor plate on my 10" rotary table for that.

 

[matthewsx]

What material are the rims?

I've read here that the brazed boring bars we get from overseas don't have the right grind on them. You could try using an end mill in the boring head.

John

 

[Firstram]

Cutter is chattering. New cutters, tried a couple. They are 3/4 brazed carbide cutters. I said HSS but they are not. Mill is making some noise in back gear mode when the cutter gets well engaged. Tried my slowest speed on non-back gear on Bridgeport.

Start by reading this fantastic thread! It focuses on the lathe but the cutting geometry crosses over to a boring head. The cheap carbide bars need a ton of work to cut properly! The right bar will let you enjoy boring!

Thread 'A Boring Primer'

Jan 4, 2019

Boring on the Lathe for (New) Hobby Guys​

A Primer



​

Being able to bore an accurate hole on the lathe is an important skill every hobby guy should have. We may not need to bore a precision hole all that often but when we need to, we should be able to.

As we all know, that is easier said than done.

I don’t know about you guys but when I started I didn’t really understand how a boring bar actually worked. I certainly didn’t know how to choose them and I didn’t know how to use them because nobody ever told me. Even the manufacturers of our bars...

• mikey
• Replies: 168
• Forum: A BEGINNER'S FORUM (Learn How To Machine Here!)

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I pieced together a set of used/new cobalt boring bars that cut beautifully, cheap enough on EBay.

 

[CJ5Dave]

They are pressed steel. Not very hard.
Feeding by hand, all speeds. No rotary table.
Various length bars. Shortest is 2 inches.

 

[MrWhoopee]

I've bored them before on a mill with boring head. If you have those cheap import boring bars, they need a ton of grinding before they are suitable for a boring head. The problem is that the top surface of the carbide is well above the center line of the boring bar. When you rotate the bar to put the cutting edge on center line of the boring head, the top now presents a negative rake. (I'm having a deja vu here). Here's a picture of the grinding require to get the carbide just to a neutral rake.