February 11, 2025
David
7

G76 Chamfer End of Thread

G76 Chamfer, this is another myth exploding article about the G76 threading cycle.

It’s so easy to use cycles like G76 day in day out and never really fully understand how they work.

I certainly did and then one day I thought “Fuck this I need to know more”

That’s when I sorted out the number of passes thing. If you don’t know how to calculate the number of passes in a threading cycle then you should read the article above.

(G76 Chamfer) I want to talk about the P

G76 P011560 Q20 R.02
G76 X16.93 Z-25. P1534 Q485 F2.5

G76 Threading Cycle First Line
P01 One spring pass 15 Chamfer 60 Thread angle
Q Minimum depth of cut
R Finishing allowance

G76 Threading Cycle Second line

X Core diameter of thread
Z Thread end point
P Depth of thread (as a radius no decimal point)
Q Depth of first cut no decimal point.
F Pitch of thread

Six Figure P Number Holy Shit

G76 P011560 Q20 R.02

First two digits are easy, spring cuts. No it’s not the latest haircut for April.

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David
0

Hitachi Seiki Made Some Brilliant Machines

Category : New Stuff

Hitachi Seiki made some amazing machines many of them are still around. Read about one that I recently trained on and the typos in the manual.

I have pondered for a while about writing this article because what triggered it was a miss print. Actually I don’t know what you call it. Maybe a translation error. If you read to the end you’ll see why.

This article is purely frivolous so if you are seeking CNC Programming knowledge there’s not much. (Except for the bit about the Hitachi Seiki machines)

Read one of my other articles which are crammed with useful programming tips and information.

CNC Programming

Are You a Self Taught at CNC Programming?

It is very common now a days to be self taught in CNC Programming. I don’t have a problem with this because really I fall into the same category.

The problem seems to be with some people is that once they get everything running enough to satisfy the boss they stop learning and look no further.

The thing with me is that while my contemporaries were reading the Daily Mail reinforcing their racist, sexist, homophobic, misogynistic views, I spent my time reading the boring shitty old manuals.

This in turn gave me knowledge that I could use in later life to charge people much inflated prices for CNC Training.

These manuals really were absolute dog shite in terms of the way they were written.

I mean they were full of mistakes and misspelt words and even the smallest thing took ages to understand. Fuck knows why I persevered and learnt, but I did.

Remember there was no YouTube no TicTok not even an Internet. Platform shoes were mandatory even the mullet hadn’t been invented yet.

I still do it to this day, read manuals that is.

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David
9

G10 Using G10 on a Fanuc Type Control

Tags : G Code Milling G Code Turn

Category : Fanuc Mill Fanuc Turn Haas Mill Haas Turn New Stuff

I am always amazed that so many companies still don’t use G10 in their CNC programs. If you know you know.

I must admit I fuckin hate a lot of the things that young people say like “can I get a Latte”. (Get behind this fuckin counter and make it yoursef if you want to “get it”).

Anyway I kind of like “If you know you know”

No G10… Is this you?

I am sure you have your reasons which I will accept. But if your reason is that you don’t understand it then that’s just not good enough.

So you make a part, it’s all setup and you need to break it down.

If you can fix the work holding in such a way that you can reload it in exactly the same place then you need G10.

Let me explain, watch this video to see how single point location works.

G10 No need to spend loads of money.

You could just bolt a sub plate to your machine table so that vices and chucks etc can have dowels to locate them.

But the main idea is that you can relocate your work holding in exactly the same place every time.

This is your work offset page on a Fanuc control.

These figures are written in by hand or by automatic setting.

If you had written this line in your program.

G90 G10 L2 P1 X-440.500 Y-265.200 Z-443.00

They would have been written in automatically when you ran the program.

So the work offset page could have any values in G54 but as soon as you run your program this G10 command will replace them with its preset values.

Make Sure Your in Absolute

Try not to forget the G90 (Absolute) because you may accidentally be in G91 (Incremental). What would then happen is it would add these numbers to what is already in the work offset. Oh dear me.

In G90 it will always replace them.

You can write to G54 G55 G56 G57 G58 or G59 just by changing the P number.

G90 G10 L2 P1 X-140.600 Y-265.923 Z-400.00 (G54)

G90 G10 L2 P2 X-125.500 Y-236.865 Z-313.865 (G55)

G90 G10 L2 P3 X-800.500 Y-563.200 Z-125.00 (G56)

G90 G10 L2 P4 X-440.500 Y-265.200 Z-169.369 (G57)

G90 G10 L2 P5 X-440.500 Y-265.200 Z-123.568 (G58)

G90 G10 L2 P6 X-410.500 Y-235.200 Z-443.00 (G59)

The code above would setup all six work offsets.

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January 21, 2025
David
0

Learn CNC Canned Cycles G81 G84 G73

Tags : CNC Programming CNC Programming Course Fanuc Programming G Code Milling Haas Programmer Training learn cnc programming learn to cnc program

Category : Fanuc Mill Haas Mill Mazak Mill

Learn CNC Programming (Canned Cycles)

Call David: 07834 858 407

A Canned Cycle What is It?

If you want to learn CNC programming then you need to know what a canned cycle is.

I’m going to have to be honest here it is a funny choice of words “Canned Cycle”. But a wild guess would be that all the information to drill a hole would be kept together in a “Can” ready to use.

In a Can…….

So let’s learn CNC Programming….

Make sure you read the end of this article to see a really cool way to drill equally spaced holes.

First of all we state the cycle:

G81 Z-20. R1. F100. X50. Y50. F200.

The machine will move to X50. Y50. then rapid to 1mm above the part (this is the R1.). It will then feed down to Z-20. at a feedrate of 200 mm per minute F200.

Finally it will rapid out of the hole.

It then sits ready for the next move.

All you need to do now is just keep giving positions.

G81 Z-20. R1. F100. X50. Y50. F200.
X60.
X70.
X80.
X90. Y60.
G80
The G80 at the end will cancel the canned cycle. It just means “Look I am a bit pissed off with drilling holes so can you stop”

So that’s it Canned Cycles it really is that easy you put all the information in the “Can” then each time you give a position you get another hole.

Want to know More?

Thought you would. You want to learn CNC programming don’t you?

There are loads of these canned cycle but I am not going to talk about every one in detail. No sorry you will have to read the boring old manual for that.

Not to Worry They Are All The Same

Well sort of. You state the cycle then it repeats at each position given until you cancel it (and that applies to all the cycles).

Anyway Here are a few:

G84 taps holes, tell it the pitch depth usual stuff.

G73 peck drilling is the same as drilling (G81) but you give it the peck depth.It pecks the hole breaking up the swarf.

G83 same as G73 but with each peck the drill comes right out of the hole. For deep holes or swarf that clogs.

G76 bores a hole, stops at the bottom, moves over and rapids out to avoid marking the bore.

Ok let me tell you this, you are doing great so far. This is how we learn CNC programming. Nice small steps.

G98 G99

I already wrote a post on this click to see it all (it’s truly amazing). I purposely didn’t include it in the cycle above which is ok. The idea was to keep it simple.

G43 Z50.H1 M8

G81 G98 Z-20. R1. F100. X50. Y50. F200.
X60.
X70. G99
X80.
X85. G98
X90. Y60.
G80

All it is in a nutshell. G98 returns to the Z point you were at before you started the canned cycle.

G99 will return to the R point (R1.)

Why you ask?

Easy you can jump over shit.

Clamps, high sections on a part, tall buildings, anything.

It Gets Better.

G81 Z-20. R1. F100. X50. Y50. F200.

The Z-20. the R1. the feed-rate etc are all known as parameters. These are the things that control your cycle.

These can be altered at anytime and stay in until you alter them again or cancel the cycle.

G81 Z-20. R1. F100. X50. Y50. F200.
X60.
X70. Z-30. (From here onwards the holes are drilled 30mm deep not 20)
X80.
X90. Y60.
G80

Now let’s alter the feed

G81 Z-20. R1. F100. X50. Y50. F200.
X60. F300. (Change feed)
X70.
X80.F200.(Change it back)
X90. Y60.
G80

Remember it stays in until you say otherwise.

I Think you Now Need to Learn About Modal Information

Read the above article. Modal means that the information stays in the control until you cancel it or change it.

Do’s And Don’ts

Do Not………

Put in a rapid command G0 X50. Y50. it will cancel your cycle and the machine will just sit laughing at you. (No hole drilled).

See this post G0 cancels canned cycle.

G81 Z-20. R1. F100. X50. Y50. F200.
X60.
G0 X70. (Rapid to X70. no hole drilled)
X80. (Rapid to X80. no hole drilled)
X90. Y60. (ETC)
G80 (You already cancelled the cycle with G0)

Do Not Repeat Axis Moves.

G81 Z-20. R1. F100. X50. Y50. F200.
X60. Y50. (Don’t need Y50.)
X70.
X80.
X90. Y60.
G80

D0…….

Always use a canned cycle if possible it saves loads of time. It is also really easy if you need to edit anything.
Make your CAD/CAM system output canned cycles, not long hand code. I saves loads of time if you need to edit.
Love engineering and be nice to your cat.

Really cool way to drill equally spaced holes

Imagine you need to drill and tap this part. Nine M10 holes.

Quite simple but 31.63 added up nine times? Mmmm I never learnt my 31.63 times table.

O0001(Drill and Tap M10)

T01 M06 (20mm Spot Drill)

G90 G0 G54 X0 Y0 S1500 M3

G43 Z3. H1 M8
G81 G98 Z-10. R1. F100 L0
G91 X-31.63 L9
G80
G0 G53 Z0
ETC
M30

Learn CNC Programming? How easy is that?

The programme moves to the datum X0 Y0 which is the middle of the part at the right hand end.
The G81 has an L0 at the end. L0 is not a Lionel Richie song it just means don’t do one. So it moves to X0 Y0 and does nothing.
The next line, G91 means incremental move so it moves incrementally nine times (L9) X-31.63 and drills a hole each time.

Brilliant I told you it was worth waiting for.

Thanks For Reading

Don’t forget there’s loads more folks.

And a YouTube channel

Call David: 07834 858 407