(Dumb) Power feed question

[walterwoj]

I have a Chinese power feed on my induma mill that I've used for a couple years. I always set the power feed speed by 'feel' usually almost as slow as it will go. Lately I have been getting braver at pushing the mill feeds and speeds so I've been thinking.... How do YOU set the feed rate on the power feed? I have tables that tell me the feed rate but have never figured out how to get the speed they tell me. The power feed gives no feedback on how fast it's going so I have no clue how fast it's moving!

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[MyLilMule]

I use FSWizard on my phone to set my RPM on my mill and it also calculates a feed rate.

Feed rate is essentially a function of the RPM of the machine, the diameter of the cutter, the number of cutting edges, the type of cutter, and the appropriate chip load of each cutter.

 

[pontiac428]

FSWizard is great if you have a 25 hp CNC pushing carbide for the shortest cycle time possible at ultimate theoretical removal rates. But I use mostly HSS on manual machines, my mill and lathe are only 3 and 8 hp respectively, so the ol' wizard is useless to me. I have joked about using the wizard and dividing by 2 before, and people groaned, but that is a very sensible rule of thumb for manual work.

Until someone comes up with a calculator specific to HSS tooling with a real power ceiling, I'll continue to watch my chips for form, color, and cut, and set my feeds and speeds using the feedback the machine gives me. Looking up the maximum, bleeding-edge cutting speed is not harmless and will result in broken tools and ruined work.

 

[benmychree]

FSWizard is great if you have a 25 hp CNC pushing carbide for the shortest cycle time possible at ultimate theoretical removal rates. But I use mostly HSS on manual machines, my mill and lathe are only 3 and 8 hp respectively, so the ol' wizard is useless to me. I have joked about using the wizard and dividing by 2 before, and people groaned, but that is a very sensible rule of thumb for manual work.

Until someone comes up with a calculator specific to HSS tooling with a real power ceiling, I'll continue to watch my chips for form, color, and cut, and set my feeds and speeds using the feedback the machine gives me. Looking up the maximum, bleeding-edge cutting speed is not harmless and will result in broken tools and ruined work.

I agree 100%.

 

[MyLilMule]

FSWizard is great if you have a 25 hp CNC pushing carbide for the shortest cycle time possible at ultimate theoretical removal rates. But I use mostly HSS on manual machines, my mill and lathe are only 3 and 8 hp respectively, so the ol' wizard is useless to me. I have joked about using the wizard and dividing by 2 before, and people groaned, but that is a very sensible rule of thumb for manual work.

Until someone comes up with a calculator specific to HSS tooling with a real power ceiling, I'll continue to watch my chips for form, color, and cut, and set my feeds and speeds using the feedback the machine gives me. Looking up the maximum, bleeding-edge cutting speed is not harmless and will result in broken tools and ruined work.

OK. If you say so. My 2HP Bridgeport disagrees. Because, you know, facts. Math doesn't change.

 

[aliva]

The OP wants to know how to set a specific feed rate using the power feed dial.

 

[Nutfarmer]

Forget all the fancy tables and math. Start on the slow side of things and look at the chips and the finish. Most of the work we do an extra minute in machine time doesn’t matter. Set up time is where most of our time is spent. Most of the time running a little slower will make the tooling last longer. The fancy tables and such are for production where seconds per part are money. On the feed, if you are roughing run the feed on the higher side if you want a light finish fine cut you can slow the feed down. If you are running high speed steel look at the color of the chips coming off. If they are blue slow things down.

 

[MyLilMule]

 

[benmychree]

Forget all the fancy tables and math. Start on the slow side of things and look at the chips and the finish. Most of the work we do an extra minute in machine time doesn’t matter. Set up time is where most of our time is spent. Most of the time running a little slower will make the tooling last longer. The fancy tables and such are for production where seconds per part are money. On the feed, if you are roughing run the feed on the higher side if you want a light finish fine cut you can slow the feed down. If you are running high speed steel look at the color of the chips coming off. If they are blue slow things down.

I quite agree with Nutfarmer, The most technical that I have used are a few slide rule speed/feed/horsepower calculators that have served my needs for nearly 50 years now in addition to the seat of my pants sense and eyesight and hearing, I suppose if I was into ultimate production work and never experienced manual machine work and the insight that it gives by observing what is possible and practical in terms of what cutting tools and machine tools are capable of, I might feel otherwise, maybe not ---

 

[Video_man]

I think the OP's question is how to set a feed rate on the power feed unit. Mine has a dial graduated in meaningless numbers, so I took a stopwatch and a scale and timed how far each number moved the table in one minute. Then I made a chart which I posted next to the power feed unit so I could look up how many inches per minute corresponded to a number on the power feed unit.