Mill feeds and speeds

[DaveH]

Hello all.

Would it be useful if I gave some guidance on this topic

Or will I be wasting my time.

I don't want to re-teach what everyone already knows.

Dave

 

[JimM]

Go for it

 

[picclock]

Hi Dave

I've struggled with an uneasy compromise between playing it safe and wasting time by cutting too slowly since I've had my Mill (only about 8 months).

I've considered writing a small program that would allow entry of material type, cutter type, and number of flutes which would then pop up with the correct (?) feed / speed numbers. However, I am still too much of a newbie to be sure that the info produced would be correct. I am up for a collaboration on such a project if you wish, you supply the formula and info and I'll code it up.

The other info that seems confusing to me is the maximum depth of cut (I normally opt for 30% of diameter) when cutting the full width of the cutter. Also if you are milling with the side only what rules or recommendations apply there ?

So any further advice most welcome.

Best Regards

picclock

 

[DaveH]

Ok,

Give me 24 hours I will have it posted

Dave

 

[lazylathe]

That would be a sweet bit of info to have available!

Baie dankie!!!

Will keep watching this post!

Andrew

 

[Chaffe]

This will be very dependant on the machine used as well. Plus type of cutter, carbide endmill, HSS, indexable inserted etc.

 

[lordedmond]

I use as a guide say for steel

guide number = 90 so 80 * 4 / cutter dia in inches = max speed

also for steel the metric guide number is 29 so 20 * 320 / cutter dia in mm = max speed


I just keep a laminated sheet with the numbers on the workshop wall and use the w/s calculator to get me in the zone , then apply the fiddle factor if the mill protests , lower the speed until it stops complaining


BTW most speed calcs assume that you have coolant on , also the above relates to HSS tooling


Stuart

 

[deverett]

I use as a guide say for steel

guide number = 90 so 80 * 4 / cutter dia in inches = max speed

I just keep a laminated sheet with the numbers on the workshop wall and use the w/s calculator to get me in the zone , then apply the fiddle factor if the mill protests , lower the speed until it stops complaining

Stuart

Knowing what speeds and feeds are available on my lathe and milling machine, I made up two charts for the various types of metals I am likely to use to give me the speeds and feeds required. For the lathe, metal diameters from 1/2" up to 4" and cutters from 1/8" up to 3/4" for the milling machine. Metal type down the side, metal (cutter) diameter across the top and I just read off the nearest speed and feed. Much easier and quicker than working out the speeds each time.

Don't ask where I got the SFM cutting information, it was a long time ago so I have no idea now.

I'm not saying that I have the optimum data, but it seems to work OK for me.

Dave
The Emerald Isle


I made up a chart for the milling machine and lathe and laminated it.

 

[DaveH]

Hello Dave from the Emerald Isle.

I agree 100%.

Sometimes a a new guy at milling is just not sure where to start.

So it is just a starting point and once and the speed and feed rate has been arrived at one should write it down for future reference.


Dave from Sunny S.Africa.

PS. No you can't have any of our sunshine - get your own ;D