[How do I?] Turn A Curved Surface?

[ArTrvlr]

I am totally new to machining, although I feel I have an understanding of the processes involved. I have just ordered a Grizzly G0765. Also ordered some tooling items from LMS. I have a machining project that inspired the lathe purchase, but am unsure on one of the cuts to be made.

It is basically a pulley shape. It is actually a roller for a sliding door. The bottom of the outer groove is curved, unlike a V-belt pulley, which has flat sides and flat bottom. I think I understand how to make the cuts for that flat bottomed V, but am unsure how to control the bit to create a radius at the bottom of the groove. Once I get the lathe and practice on it some, the answer may become apparent, but I thought some tips from experienced chip makers would help.

Thanks in advance, jp

 

[Wreck™Wreck]

Form tool, turn a groove to the depth of the radius tangent using a narrow square parting tool then rotate the compound to the correct angles (if required) and turn the sides of the groove to width at the same depth, buy or grind a radius form tool and plunge to depth. I added the angles to make it easier to picture the process.

Like so.

 

[mikey]

You can grind a form tool and cut the whole pattern in one pass or use a graver, which is used like a wood turning tool, to shape the sides.

 

[Andre]

As others have stated, use a form tool.

Not to burst your bubble, but bearings for sliding doors are very cheap, and almost uneconomical to make

 

[ArTrvlr]

As others have stated, use a form tool.

Not to burst your bubble, but bearings for sliding doors are very cheap, and almost uneconomical to make

Unless they are unavailable in the size you need. And, you can use the need to make something as an excuse to buy a new tool!

 

[Andre]

Unless they are unavailable in the size you need. And, you can use the need to make something as an excuse to buy a new tool!

Not to worry, pretty coon you'll be fixing door hinges and lawnmowers aplenty With great machine tools comes great repairs.....

 

[Charles Spencer]

Unless they are unavailable in the size you need. And, you can use the need to make something as an excuse to buy a new tool!

Yep. Once the wife wanted me to make a book case for her. Told her that I needed to buy a set of wrenches to do it.

Of course there's not a nut or a bolt in the thing.

 

[kd4gij]

As others have stated, use a form tool.

Not to burst your bubble, but bearings for sliding doors are very cheap, and almost uneconomical to make

Now why on earth would one buy a $2.00 part when he can make said part for $20.00 plus hours of labor?

 

[savarin]

Now why on earth would one buy a $2.00 part when he can make said part for $20.00 plus hours of labor?

Buy? BUY? wash your mouth out with soap and water!

 

[crazypj]

Unless they are unavailable in the size you need. And, you can use the need to make something as an excuse to buy a new tool!

Yep, our house was built in 1950's and has some very odd sized sliding doors made in Germany. I know we need new rollers in a few doors but they are too heavy to get out of tracks. Making new rollers is a simple thing to do, I'll probably make bronze ones eventually, should last longer than the cast aluminum in there now (which lasted over 50 yrs)