Need help with drilling calculations

[metiz]

Drilling calculations

Hi guys

I need to make a couple of drilling calculations for school but I've forgotten how.

The material is brass Ms58
Hole diameter is 6.5mm
Hole depth is 6mm

Can anyone give me a hand?

[kevin lee]

not sure what you mean, do you want to find rpm for drill?

formula is (1000 x S)/(Pi x D)

s = cutting speed for material in M/S
D = 6.5mm

[metiz]

Hey Kevin

Thanks!

Yes, RMP, the time it takes to drill the hole and the power (kW) it takes.
With M/S, do you mean meters per second?

Can you help me out a bit more?

[ganuganu]

Hey Kevin

Thanks!

Yes, RMP, the time it takes to drill the hole and the power (kW) it takes.
With M/S, do you mean meters per second?

Can you help me out a bit more?

Yes m/s is meters per second and i think its RPM(revolutions per minute)

[kevin lee]

Hi Metiz, i have been searching through my folders for the information, it was a very long time ago when i was at college/school. If i cant find anymore info today iam sure ill find it at work tomorrow.

There is a 'Engineering tips forum' that would alsmost certainly be able to help, but the only problem is that they dont allow students to sign up. When i was at university i joined up and pretended that i was an engineer at the time.


EDIT: here is the forum, you may find what you want by searching.
http://www.eng-tips.com/

If not ill see what i find tomorrow. And Ganu is correct, m/s metres per second. i used wrong units, should have been lower case.

[metiz]

No worries. Thanks for all the help!

[PyroJoe]

My apologies for the late response.
A Machinist Hand book should give us the feed and speed:
I don't have mine here at the moment.
http://en.wikipedia.org/wiki/Speeds_and_feeds

for drilling:
http://www.custompartnet.com/calculator ... d-and-feed

The feed rate should give the time required to drill to a depth of 6mm.

The KW rating is more difficult to find. I think the use of lubricants changes the power required by some factor, does it say whether lubrication was used or was it dry?

http://www.custompartnet.com/calculator ... horsepower

[kevin lee]

This is where i got too also.

I koped to use a work colleagues engineers handbook but unfortunately i didnt make it too work today long story short my girlfriend left me, we had been together 8 years

anyways back on topic i can definetly get my hands on an engineers handbook and could also photocopy/scan the relevant page and email it too you or post it here.

The KW is a toughy. Is the question asking how much power is needed to turn the drill whilst cutting the material. or the amount of KW consumed to do the entire operation.

[PyroJoe]

Damn, sorry to hear bout the girlfriend, hopefully you will be lucky in the future and find one that sticks to ya.

[metiz]

Thanks for all the help guys! Kw rating is just the theoretical amount of power required to dril to the material, not the time it takes for the drill to spin up of the time it takes for the dril to reach the top of the workpiece

[metiz]

does anyone know he maximum cutting depth of a 30mm face mill or how I can calculate it?

[kevin lee]

did you find the answers for drilling brass? i have found out that the cutting speed is 61 M/S

for depth of cut for a face mill, if its a tipped cutter ie has 6 changeable tips. you would generllay check the manufacturers specifivations. On the box fthe tips come in the, it will give you maximum, rpms maximum feed, rate and maximum depth of cut.

google these companines and you will most probably find what you want.
sandvik
guering
walter
safety

and also google 'corokey'

hope this helps, i will hopefully be able to find out the drilling next week, we are really busy doing jcb prototypes at the moment

[kevin lee]

also finds like whether you are machining a billet or forging or casting will make a diference and also intemittent cutting (machining over holes, pockets) can also affect things

[metiz]

Hey Kevin

Thanks for your help. I never realy figured out the drilling speed so I made an educated guess of 1sec. for a 30mm dia I took a cutting depth of 15mm (just a guess based on depths of other tools) I'll look into the companies but I have tried for over 90 minutes to find ANY company that sells these fuckers and have yet to find even one.

[kevin lee]

is this for a tool like this


or like this


and what material?

Iam sure i can find something usefull for the original question also





and thanks Pyrojoe it sucks but iam trying to get her back, hence me being quiet recently. iam trying to make stuff for her and sort somethings around the house