Getting 2 Holes Machined In Oil Pump Drive Disk

[Hood]

Everyone seems to think that programming a CNC machine is a long drawn out process that involves either hand writing thousands of line of code or use a CAD/CAM to generate the code. For a very simple thing like this it is a few minutes, at most, programming via the conversational programming.
Go into the wizard( as Mach calls conversational) tell it the tool number and cutter diameter, feed and speed then go to circle wizard, type in coords of circle centre, type dia of circle, type depth of hole, type pitch you wish to go in each pass (ie it ramps down rather than plunge which is much nicer for your cutter) then press Post Code, repeat for second hole but this time you only have to change the Y position because all of the other numbers are the same. Press Post Code and then Exit and you are ready to press the start button. Tool rapids in, starts to do circular interpolation to the depth required, rapids up, rapids to next position and repeats and you are done.

 

[doubleboost]

There is no answer to the manual / CNC argument
I know that I could do that job on manual machines in my garage
It would be just as accurate as a CNC job but would take more time
How many CNC operators could do the job with a rotary table and a mill

 

[Hood]

There is no answer to the manual / CNC argument
I know that I could do that job on manual machines in my garage
It would be just as accurate as a CNC job but would take more time
How many CNC operators could do the job with a rotary table and a mill

I could but then again I am neither a CNC operator or a manual machinist to trade.
Having said that, I could ask the inverse of your question, how many manual machinists could do it via CNC

 

[MattH]

Worth pointing out that in manual mode there’s no need for a rotary table on this job if your mill has a DRO.

 

[Hood]

Worth pointing out that in manual mode there’s no need for a rotary table on this job if your mill has a DRO.

Assuming you have a cutter the right diameter or you use a boring head.

 

[graffian]

Worth pointing out that in manual mode there’s no need for a rotary table on this job if your mill has a DRO.

Find the centre and zero the dro.
Find an existing hole and now you know where the new holes need to be.
Go to where the new holes need to be and drill the holes.

 

[Hood]

Find the centre and zero the dro.
Find an existing hole and now you know where the new holes need to be.
Go to where the new holes need to be and drill the holes.

That is assuming you have a 9.8mm dia cutter or drill and if you do then you could do exactly the same on a CNC by using the mpg ( hand wheel) or better use MDI line as you would get nice controlled feeds and not have to worry about watching the depth or position.

 

[WorkshopChris]

That is assuming you have a 9.8mm dia cutter

This is exactly the bit where the cnc comes into its own over manual milling.
Chose a smaller cuter and then mill a circle.

 

[Hood]

This is exactly the bit where the cnc comes into its own over manual milling.
Chose a smaller cuter and then mill a circle.

Exactly.
Many other things as well make CNC the better option, even simple things like drilling hole patterns are a dawdle in CNC and just take seconds to programme.
As I said before people seem to think programming simple things on a CNC is time consuming, it is not.

 

[Hood]

Just did this quick vid to help people understand how easy it is to programme simple things like this job.

 

[MattF]

Exactly.
Many other things as well make CNC the better option, even simple things like drilling hole patterns are a dawdle in CNC and just take seconds to programme.
As I said before people seem to think programming simple things on a CNC is time consuming, it is not.

Doddle. Dawdle tends to suggest it's time consuming & ineffective.

 

[Ianb]

Hood - I should send you the disk and you could do a video showing how easy it is to mill the holes

Seriously though, they do look incredibly simple to operate as like you say people like myself always though it was a case of writing code like a computer programmer.

 

[Hood]

I could do it but you might not see a lot for the coolant

 

[PhillipM]

This is exactly the bit where the cnc comes into its own over manual milling.
Chose a smaller cuter and then mill a circle.

This, a common 6mm cutter or similar and I'd have that programmed, set up, centred and finished in 5 minutes.

 

[scott0031]

There is no answer to the manual / CNC argument
I know that I could do that job on manual machines in my garage
It would be just as accurate as a CNC job but would take more time
How many CNC operators could do the job with a rotary table and a mill

Uhh Well i could! So could Hood and probably a few others here. Whilst i grant you a lot of CNC guys are not generally machinist as such, a lot also are. It's a bit wrong to think in categories on this subject just because it's all you have seen. A lot think like this and it's not really correct.

I'm not sure what i am missing here but seems to be pretty overly complicated discussion. If it is 9.8 and that is what he wants, simple, 9.8 drill. Pilot and drill then flat bottom the 9.8 drill. Pretty standard practice. Of course this convo is a bit mute until you know it the part if hard or not for definite. If its hard then CNC is probably the way to go as hood correctly says because of interpolation which means you are not restricted by standard tool diams. I really hate jobs like this and will rarely take them on. If it is hard... its all very well saying just mill it with carbide... hmmmm thats until you lose 2 or 3 cutters if it doesn't pan out which it can often do and it ends up costing you money to do the job.... most in the trade will say the same who have experience of manual and CNC.

 

[scott0031]

This, a common 6mm cutter or similar and I'd have that programmed, set up, centred and finished in 5 minutes.

I'm not meaning to be particularly pointed at you as an individual. It's just annoying when you see people making this kind of very sweeping statement... so the reality is..... what is your hourly rate? 40 quid? 50 quid? Lets take 45 as its a common cost for general cnc shops...... 45 div by 60 = 75p a minute.. now lets times that x by the 5 minutes you quoted that's £3.75..... what a darn bargin! Ianb this is your man for the job!


Please send me your address, I want to send you all my work. I will be one very happy man In fact i think i want to marry you!

 

[PhillipM]

I know how hard they are, I've machined 4 of them before, along with housings and vernier gear when I locked them off on one of the V10 motors.
They don't need to be exactly 90*, so spending 10 minutes clocking that up is a waste of time, the only critical thing is the PCD and hole tolerance for the drive pegs, they just redrill them at 90 to get to fresh material, you could eyeball it dropping them far tighter than they need to be. All you need to clock up is the centre.

As I said, 5 minutes, unlike the manual nay-sayers on here that have never touched them.

 

[Ianb]

PhillipM - Would you mind telling me how hard they are? I didn't think to check whilst the cover was off. Also would you say that for a disk and hub with no visible damage it is something worth doing still? Or should I leave alone as wouldnt the tabs and holes have worn in and have good even pressure on both tabs? Even if the new holes are drilled perfect how accuratly have the hubs been made, possibly causing one tab to take all the load until they have rebedded in?
Thanks

 

[PhillipM]

They're not as hard as you'd think, they machine pretty well, HSS will drill them fine - think more like key steel in terms of machining. 30-35RC I'd imagine but it's been a few years. Certainly didn't have much trouble but then all my cutters I was using to shape them were carbide so I didn't really pay it too much attention.

They drilled and tapped fine with HSS though.

 

[Ianb]

Thankyou