Gear cutting speed

[Ernienoatrainz]

I would like to know what spindle speed should I use in cutting gears in brass for a clock. I am going to use a 1 inch diameter single tooth cutter HS steel in the mill spindle. The gear is about 1/16 inch thick. Better yet how do I calculate the spindle speed form a surface/cutting speed table?

 

[British Steel]

Calculate spindle speed in rpm from surface speed in feet/min by dividing surface speed by the cutter ( or work, on a lathe) diameter (in inches) divided by 4, or the other way round, 4 times sfm then divide by diameter (you're dividing sfm by the cutter circumference in feet, basically) - so your 1" diameter cutter would rotate at 600 rpm if you wanted 150 ft/min, a 2" cutter at 300 for the same surface speed.

Brass cuts pretty easily, so those may be in the ballpark, I'd start slower and use a VERY slow feed, you're only taking one bite per spindle revolution! You'll probably need to keep feed below 1" per minute at 300 rpm, giving about a 3 thou" depth of cut? It's a good idea with something that flimsy (1/16th brass) to clamp the gear blank between a pair of thicker e.g steel discs for support, too...

Dave H. (the other one)

 

[Ernienoatrainz]

Calculate spindle speed in rpm from surface speed in feet/min by dividing surface speed by the cutter ( or work, on a lathe) diameter (in inches) divided by 4, or the other way round, 4 times sfm then divide by diameter (you're dividing sfm by the cutter circumference in feet, basically) - so your 1" diameter cutter would rotate at 600 rpm if you wanted 150 ft/min, a 2" cutter at 300 for the same surface speed.

Brass cuts pretty easily, so those may be in the ballpark, I'd start slower and use a VERY slow feed, you're only taking one bite per spindle revolution! You'll probably need to keep feed below 1" per minute at 300 rpm, giving about a 3 thou" depth of cut? It's a good idea with something that flimsy (1/16th brass) to clamp the gear blank between a pair of thicker e.g steel discs for support, too...

Dave H. (the other one)

Thanks for the quick reply. The gear is going to be mounted between two large thick disks for support. Every thing will be held in collets. My first attempt was in the lathe, but I could not get a ridge set up and I started very slow. Changing the speed on the mill is a pain, but I needed to get it right or as close to the right speed for the process. I'll post some photo of the set up once I get it all mounted. en

 

[Ernienoatrainz]

Here is the set up I sued on the first practice gear It all worked good until the gear slipped on the mandrel. With this issue solved I should be able to have some success. The speed was just right. Thanks.