How much swarf?

For a bit of Sunday afternoon fun as you may have seen in the "What did you do" thread I have been machining the cylinder liner for the ball hopper Monitor. This is supplied as a cored casting approx 2.75dia x 7" long with approx 1.25" core.

This is the finished item, 1.808" average OD, 1.625" ID and 5.25" long

So who wants to take a stab at what percentage ended up as swarf? and for a bonus point the initial and final weights. No prizes except the fact everyone will think you are a know it all

J

I guess as follows:

Weight of original casting - 3.8265kg

Weight of final liner - 0.3005kg

Percentage of original casting, by weight, into swarf - 92.15%

Andrew

I guess 3.8 kg and 0.3kg. Percentage 92.1% *

I think I'd have bought a bit of pipe and kept the casting in the useful pile

Neil

*OK I'm cheating - Andrew won't be spot on, and my guess is he's a bit high. If I use values very close to Andrew's and just a teensy bit lower, I have a good chance of being correct.**

**I could never understand why contestants didn't use this strategy on the 'The Price is Right'.

For 'typical' cast iron, I get it at 3.905kg for the starting weight and 0.307kg finished weight.

Swarf is -92.138

EDIT. I'm cheating too - my result is straight out of ViaCAD

Martin

Edited By blowlamp on 12/01/2014 17:59:37

Well I get different figures.

I get heavy, light and a lot.

It always amazes me that the swarf off a job is more than not more than the material you started out with.

Recently I made some unions out of some 2 1/4" hex brass bar, it came as a 3.1 metre long bar and the first job was to cut it into 50 pieces on the saw, that generated an ice cream tun full of chips. next job was to drill a 27mm hole thru each piece.

That generated this.

That's one of those big bags of dog food and in this case it weighed 33kg.

The final operation, turning and threading generated another 22 kg in another bag.

Just be thankful it's not 100%

Plastics seem to produce more weight in swarf than the original bar. I am thinking of farming Nylon for a living!

David

John, look on the bright side, that swarf will be worth about £140

CG

Nylon is hygroscopic, it's possible that it could pick up more water from humidity in the air air when freshly machined swarf from the drier inside of a bar is released.

Do an experiment and write up a scientific paper - you could win an ig-nobel prize!

Neil

Three entries and three different winners.

Percentage was 92.3% so Andrew was closest with 92.15%

Weight of original was 3870g so Blowlamp was closest with 3905g

Final weight was 298g so so Neil was closest with 300g.

Neil it would have been better if they just supplied a length of 50mm CI bar plus it would have been nicer iron as this was quite grainy and hard.

J

I'll settle for 1 out of 3 given that the only maths I did was comparing magnitudes

Neil

I think Neil's tactics would be more suited to Play Your Cards Right - Higher, Lower, Lower......