1943, 11th edition machinery handbook, its in there. You just have to know what your looking at. Your using 250 with with 1". Easy, convert 1" diameter to circumference, and that looks like this. 1 x pi ÷ 12 = .261. (÷12 because were using feet here.) Now you take your 250 ÷ .261 = 957 rpm. Now your hss, your using 1.5 and 100. Again. its in the machinery handbook, all the way back to 1943. Samething 1.5 x pi ÷12 = .392. Now take your 100 ÷ .392 = 255 rpm. Im literally looking right at this in my book.
i have always seen it as SFM*(pie)3.14/DIA but i feel like 3.82 could run faster and will try it i work with stainless steel which is harder than a lot of meatal.
My home workshop lathe has a max rpm of 500 and I do loads of smaller diameter which need loads more, any suggestions? Maybe change drive pulley diameter and lose torque? It is 3 hp 240volt 50 cycle motor single phase.
The diameter would be for the initial part. As the part gets smaller the speed may change but most times it`s close enough unless you are taking a part down a lot in size. in that case, you would want to change your speed as you go along. hope this helps!
Tooele Tech Automation Manufacturing Technician nice one; clear on that now sir! ok so the cutting speed is also contingent on the depth of cut (initial - final diameters) true? (based on the table of cutting parameters data)
Look up the sfm for your inserts what they’re rated for and this will change depending upon your material. Then you can program it in g96 which is Constant surface speed and the machine will figure out the rpm for you based upon how far it is from spindle center x0.0. You also need to set a spindle limit with a G50 followed by what you want your max rpm to be.
Great video but how do you do the maths with 1 and 3/8 inch ? I’m from the uk and we use mm so I have to convert mm into inch then try and do the maths!
Like if your part needs to spin faster than your machine will go? I would just run it at a slower speed. I have that problem with my end mills all the time.
Very helpful straight to the point
1943, 11th edition machinery handbook, its in there. You just have to know what your looking at. Your using 250 with with 1". Easy, convert 1" diameter to circumference, and that looks like this. 1 x pi ÷ 12 = .261. (÷12 because were using feet here.) Now you take your 250 ÷ .261 = 957 rpm. Now your hss, your using 1.5 and 100. Again. its in the machinery handbook, all the way back to 1943. Samething 1.5 x pi ÷12 = .392.
Now take your 100 ÷ .392 = 255 rpm. Im literally looking right at this in my book.
Where can I find the sfm recommendations for the various tools and materials that I work with thats my only issue
The manufacture of any end mill or bit should have this information.
how can we find cutting speed according to work piece material without considering spindle speed?
Great video. Thank you for the explanation.
So now that we have the rpms, how do we get the feeds?
I was cutting tool S7 steel today at 800 sfm, wondering why you’re saying 100 here
Would you happen to know the metric conversion formula?
I don't. sorry
How to define rpm in cnc machine if spindle rpm 24000, how much rpm required for portrait designing engraving on iron,
i have always seen it as SFM*(pie)3.14/DIA but i feel like 3.82 could run faster and will try it i work with stainless steel which is harder than a lot of meatal.
My home workshop lathe has a max rpm of 500 and I do loads of smaller diameter which need loads more, any suggestions? Maybe change drive pulley diameter and lose torque? It is 3 hp 240volt 50 cycle motor single phase.
Question: If my lathe has a one inch shaft, and I attach a 30" disk to it set at 6rpms, then how fast is the outter edge of the disc spinning?
So the SFM on a lathe, is whatever the recommended number is of the insert or drill or tap is?
Yes
If you're drilling on the lathe do you still use the diameter of the material or do you use the diameter of the drill bit for the equation
I would recommend using a drill bit chart. I find this method to be a little bit to fast for smaller drill bits.
the DIAmeter would be the final diameter OR the initial diameter of the workpiece OR the difference (which is to cut off)??
The diameter would be for the initial part. As the part gets smaller the speed may change but most times it`s close enough unless you are taking a part down a lot in size. in that case, you would want to change your speed as you go along. hope this helps!
Tooele Tech Automation Manufacturing Technician nice one; clear on that now sir! ok so the cutting speed is also contingent on the depth of cut (initial - final diameters) true? (based on the table of cutting parameters data)
Look up the sfm for your inserts what they’re rated for and this will change depending upon your material. Then you can program it in g96 which is Constant surface speed and the machine will figure out the rpm for you based upon how far it is from spindle center x0.0. You also need to set a spindle limit with a G50 followed by what you want your max rpm to be.
What about stainless steel? 250 still gonna work?
No. I don't think so. Stainless steel runs a lot slower.
Thanks very helpful
What about threading and tapping on manual programming?
Great video but how do you do the maths with 1 and 3/8 inch ? I’m from the uk and we use mm so I have to convert mm into inch then try and do the maths!
ua-cam.com/video/bVSgEJNfHLI/v-deo.html
What if you exceed the speed limit of the machine? What to do?
Like if your part needs to spin faster than your machine will go? I would just run it at a slower speed. I have that problem with my end mills all the time.
is this spindle speed is maximum ? and is it overcome whirling phenomenon in lathe with single supporting system?
How you calculated the feed rate onLathe
👍🏻
How to calculate the feed rate for the lathe? Based on formula please
Finish speeds are gonna be .007-.009 and ruffing is gonna be .010-.012
And you can slow it done more for a better finish like 0.005