Lathe charging.

[Munkul]

One thing to bear in mind with pricing, is, is there something you're missing? Can someone else using the latest and greatest technology do the job in a fraction of the time it takes you? If so, can they do it cheaper?
2 hours in a well set up CNC lathe with the right inserts and £60/hr machine time? Or 4 hours at £30/hr manual lathe with sub optimal inserts/setup? Your customer gets the same result (assuming you can make it to required tolerance) for the same cost.
But if you're charging that much and your customer knows he can get it done in a single £60 hour down the road...
So just something to think about.

 

[ukracer]

What happens with the keyway? Recut?

No mate it's big enough being 5mm less apparently.

 

[Brad93]

I used a 40mm bar.

There are grades that chip less easily. Another way is to fill the keyway in, not sure with what, or if it would have much effect in hard materials

 

[Hood]

A guy I knew once got asked to price a job. It was some sort of carbide tubes that were fractionally undersize. He said can't quote as I have never machined that before but if you give me a sample I will give you a price.
He got the sample, ordered a diamond insert and did the cut, piece of cake, one hit (it was only 0.2 DOC or something) and he gave them the price.
Big mistake, he got the job and a load of the tubes arrived, he tried to take a cut and it wouldn't the insert was knackered so he bought another and managed one from that insert, he ended up needing a new insert for every tube, he worked for days doing them and his quote had just been a bit more than the insert cost so basically he worked for nothing.
He was kicking himself, he knew he should have tried a few more cuts on the sample to see how the insert stood up, he never made that mistake again and it is not one I wish to repeat either

 

[ukracer]

One thing to bear in mind with pricing, is, is there something you're missing? Can someone else using the latest and greatest technology do the job in a fraction of the time it takes you? If so, can they do it cheaper?
2 hours in a well set up CNC lathe with the right inserts and £60/hr machine time? Or 4 hours at £30/hr manual lathe with sub optimal inserts/setup? Your customer gets the same result (assuming you can make it to required tolerance) for the same cost.
But if you're charging that much and your customer knows he can get it done in a single £60 hour down the road...
So just something to think about.

Exactly why I was asking the Gurus. Not only do I not know how long it should take on an engine lathe with all the correct tools and decent operator I don't have a clue about a CNC lathe.

All I know is when ever I have tried to get a quote from a CNC place they want to do hundreds or not really interested.

I have done the job already. I am not quoting or competing but want to be fair to both of us knowing it did take me a fairly long time...due to my inexperience.
I was intrigued how people price things though. And fully expect a quote if I was a customer...seems that's not the case.

 

[ukracer]

There are grades that chip less easily. Another way is to fill the keyway in, not sure with what, or if it would have much effect in hard materials

I went through this when I bored the ring on the mill. Lol

Expensive those CBN seemed to be not sure they did them for the bar I used.

 

[northwest]

I have a hole specially drilled between my two front teeth. If the job looks complicated or difficult I suck a LOT of air through the hole. It reassures the customer that it's complicated and confirms that it is going to be expensive.

:-)

 

[mtt.tr]

I have a hole specially drilled between my two front teeth. If the job looks complicated or difficult I suck a LOT of air through the hole. It reassures the customer that it's complicated and confirms that it is going to be expensive.

:-)

haha this is something im learning

 

[ukracer]

I have a hole specially drilled between my two front teeth. If the job looks complicated or difficult I suck a LOT of air through the hole. It reassures the customer that it's complicated and confirms that it is going to be expensive.

:-)

I have a missing tooth . perhaps I could use that?

 

[Wedg1e]

I just had a word with my machinist mate Chuck Norris... he said he'd turn up a cylindrical broach on his Clarke minilathe, harden it over a fag end and knock it through the bore with a 4lb club hammer; couldn't see what the fuss was about?

 

[Munkul]

Having a quick look around on PM, two reccomendations for Seco th1000 carbide for hard steel interupted cuts

HARDENED STEEL INTErRUPTED TURNING

Hey everyone. so I'm trying to cut down on some insert usage because i do a lot of interrupted cutting on some hard af steels. i usually turn full hard D-2 steel and full hard CPM 15V. does anyone have any ideas for interrupted cutting of these hard materials. if tried two kinds of Mitsubishi...

www.practicalmachinist.com

At between £8-12 per insert in CN1204 shape/size, if they do the job then they won't break the bank, and should be able to run the job a lot faster next time... if there is a next time

 

[ukracer]

Having a quick look around on PM, two reccomendations for Seco th1000 carbide for hard steel interupted cuts

HARDENED STEEL INTErRUPTED TURNING

Hey everyone. so I'm trying to cut down on some insert usage because i do a lot of interrupted cutting on some hard af steels. i usually turn full hard D-2 steel and full hard CPM 15V. does anyone have any ideas for interrupted cutting of these hard materials. if tried two kinds of Mitsubishi...

www.practicalmachinist.com

At between £8-12 per insert in CN1204 shape/size, if they do the job then they won't break the bank, and should be able to run the job a lot faster next time... if there is a next time

This is what I used.


I did try the one I purchased of yourself and first cut it was perfect but then it appears to be touching the bore.
It's got a much more acute angle to it.
I have a couple of 32mm bars as well now but not yet made up the holder Hood sent me.

 

[Brad93]

Why have they hardened in the first place? Is it a part they’ve bought in and is too small? So then they’ve needed to bore out?

That part should be bored undersized, keyway cut, hardened and then finished to size on a bore grinder or at least with a toolpost grinder in my mind?

 

[ukracer]

Having a quick look around on PM, two reccomendations for Seco th1000 carbide for hard steel interupted cuts

HARDENED STEEL INTErRUPTED TURNING

Hey everyone. so I'm trying to cut down on some insert usage because i do a lot of interrupted cutting on some hard af steels. i usually turn full hard D-2 steel and full hard CPM 15V. does anyone have any ideas for interrupted cutting of these hard materials. if tried two kinds of Mitsubishi...

www.practicalmachinist.com

At between £8-12 per insert in CN1204 shape/size, if they do the job then they won't break the bank, and should be able to run the job a lot faster next time... if there is a next time

Those you posted seem to be a bigger radius as well . Which my guess is that for an interupted cut would be better.
But I don't have a bar for those.

As I have tried to be clear on I don't "need" the money as in my bills are paid each month. Anything I do get a third goes in tax. But this work makes my son more indispensable as it's his work place I do the jobs for.

I don't want to be a busy fool (I have loads to do) (my wife thinks 7 days a week work is normal) but don't want to be greedy.
This task was because the company was sent the wrong size bores. They will cost £1700 to get the correct ones and have been told to keep them and also been refunded.

So I could charge what I like. But in the past I have been stupid done things cheaply and that's then the expected price in the future. Hope it's clear where I am coming from.

 

[ukracer]

Why have they hardened in the first place? Is it a part they’ve bought in and is too small? So then they’ve needed to bore out?

That part should be bored undersized, keyway cut, hardened and then finished to size on a bore grinder or at least with a toolpost grinder in my mind?

Thanks Brad. That was what I was expecting people to say. But see my reply about company being sent the wrong size. The new machines are a smaller spindle but it's 8k to replace it in the old machine.

I am actually trying to make a silk purse out of a sows ear.
I would be interested in a photo of the grinding bit that would be used. I do have a tool post grinder but never used one.

Why have they hardened in the first place? Is it a part they’ve bought in and is too small? So then they’ve needed to bore out?

Exactly that Brad.

 

[Munkul]

Nice big boring bar. I'm surprised you tried with that 25mm bar, interesting that it managed the job ok (and I don't think the bar or insert was anything particularly good!)

I forgot it's boring, not turning, so insert choice will be more limited... are you using a TC or a TN insert atm?

Worth emailing Seco, Iscar and Mitsbishi tooling reps with the job details and the boring bar you're using, and see if they can recommend an insert for it.

The fact that you CAN do the job (albeit slowly) to me, means it's entirely possible to do by machining not grinding. It's then working out if you can do it any faster.

If you're recovering some lost parts for a fraction of their worth then charge what you like it's either you at your rates, or a commercial machine shop at £60+/hr...

 

[Hood]

CNMG would be my choice as it has more strength than the TNMG you are using. Obviously if you don't have the bar to suit then... I could always sell you one

 

[ukracer]

Nice big boring bar. I'm surprised you tried with that 25mm bar, interesting that it managed the job ok (and I don't think the bar or insert was anything particularly good!)

I forgot it's boring, not turning, so insert choice will be more limited... are you using a TC or a TN insert atm?

Worth emailing Seco, Iscar and Mitsbishi tooling reps with the job details and the boring bar you're using, and see if they can recommend an insert for it.

The fact that you CAN do the job (albeit slowly) to me, means it's entirely possible to do by machining not grinding. It's then working out if you can do it any faster.

If you're recovering some lost parts for a fraction of their worth then charge what you like it's either you at your rates, or a commercial machine shop at £60+/hr...

Yep that's about the sum of it.
What I realise is that I could cut a lawn in 30 mins using a lawnmower or 30 days using scissors. But trying to charge for 30 days is not only greedy but counter productive long-term. BUT we all know how long a lawn takes to cut.
If all I had was scissors I would not attempt cutting the lawn.

But using a push mower and charging for an hour is reasonable if the guy with the power mower is busy elsewhere.

BTW I wil try most things once. Lol

 

[ukracer]

CNMG would be my choice as it has more strength than the TNMG you are using. Obviously if you don't have the bar to suit then... I could always sell you one

It would be nice to have around but cash is limited till I get paid. I will keep it in mind.

 

[mike os]

How many do you have to do?