4 Axis substitution

[herricam]

I'm trying to use 4 axis substitution wrap and i would like to post the program so that the top face of the job is zo and not the centre of the cylinder, i still want it to rotate around the centre of the cylinder, can anyone help, I'm using mcx.

[c-hook]

Just set the top of stock to the size of radius you are cutting. For example if you are cutting a 3" diameter part, set the top of stock setting to 1.5".

[c-hook]

Ok. after re-reading your post I think I gave you the wrong info you were looking for. In version 9 the way I do this is by setting the tool plane in the T/C Plane settings to whatever the radius of the part you are cutting and the depth to the same number only negative. For example, on a 3" diameter part the tool plane would be set at 1.5" and the depth would be set at -1.5". Then when you post, the program should come out with the "z" going to 0 instead of 1.5".

[herricam]

I don't seem to be able to change the tool plane without it changing the WCS and Construction plane

[c-hook]

If you go back and manually change the numbers it should work. By default, everything changes automatically relative with the tool plane.

[crazy^millman]

Well you are going at it the old school way. Z0 to the center is all I every do for 4th axis work VTC or HMC method. I think axis sub only work correctly from center of the part. If you try to axissub from a point outside of the Dia I think Mastercam will get lost. I always got from center when doing axis sub and not sure the results you would get doing it the way you are talking about. Also when using C-planes to control your A axis output you should always work from the center of the rotation to make sure you get the desired results. If you would like ot share the file I am sure someone can point you in the right direction.

 

HTH

[Jack Neelands™]

+1000 To ya Ron

 

So now for the OT

 

Welcome to the forum

 

What part of Brisbane you from Herricam?

 

Can you share the file on the ftp site ...or a close facsimile of it?

[herricam]

Thanks for all the advice,

Our Workshop is in Salisbury on the south side,

I would be glad to share the file if it's going to help, I'm starting to think I will have to do it from the centre. The thing is I don't want to change the rotation point from being the centre just want zo not to be the centre.

 

ps. how do I share the file on the ftp site?

[New Job]

linky to ftp upload instructions

[Sambo]

lol ... I had to do this just today. Leave the Z axis at zero. Then just define your top of stock. Presuming the part is round, this will be the radius. Then define the depth of cut.

 

I used this in a 2D contour and while it looked goofy in verify and backplot it worked wonderful on the machine.

 

Sambo

[herricam]

Sam I have tried this and it all looks good in the backplot but when I post it the z values still come out working from the centre as Z0.

[Guest]

Honestly get into the habit now of programming from the center of the rotation, it will save you many, many headaches crazymillmans advice was spot on.

 

BTW, Welcome to the Forum

 

[Kannon]

quote:

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Honestly get into the habit now of programming from the center of the rotation, it will save you many, many headaches crazymillmans advice was spot on.

---

I agree..after learning this....I consider no other way to go.

[lowboy]

I think he wants to touch off his tools from the top of the part

[crazy^millman]

Ok what do you have in for your top of stock?

 

Depth? are they Incremental or Absolute? You can email me your file and I will be glad ot put it on the FTP if you can not get it to work. I also have the FTP as my netwrok place on my computer so I do not have to hassle with FTP to go to it.

 

Oh yeah welcome to the Forum!!!

[Guest]

quote:

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i would like to post the program so that the top face of the job is zo and not the centre of the cylinder,

---

[Jack Neelands™]

Salisbary eh?

 

Not too sure if im familiar with that territory

Isnt that somewhere south of Mooroka or north of Coopers Plains?

no wait tis west of Mt Gravatt or is that east of Sherwood

 

j/k mate I used to work at EGR there

 

You need to put that file on the ftp site or email it to Ron or myself and we can better assist you with your problem

 

I would pick Ron first though he was the first to offer

[herricam]

I'm just up the road from EGR in Tarragindi rd

 

I've emailed the file to Ron, it dosen't seem to matter what values I put into top of stock or feed plane, incremental or absolute it still works from the centre of the cylinder. I think this is just the way I will have to do it.

[Jack Neelands™]

I lived on the other side of the highway in Upper Mt Gravatt...Had to go all the way under the highway and around the stadium to get to work everyday.....heck of a commute

 

The reason Ron is steering you into a single WCS is that you have more options for toolpaths in multi axis

[crazy^millman]

The file is 34MM AHS WB 500.MCX and I put it in the MX2 folder on the FTP. I will take a look at in the morning and see what is going on.

[crazy^millman]

Ok I see a couple things wrong with this operation.

 

1: you can not have your retract lower than your top of stock. 10mm for retract and 18.064mm for your top of stock.

 

2: You have your depth set at -.05 absolute so if you go from the center of the part where and that is Z0 you will get have nothing left on the clyinder. I am thinking you want -.05 incremental.

 

OK so I am thinking maybe you do not have a clear understanding of absolute and incremental. Absoulte is what it means and you are an absolute distance from Z0. So if you say 10mm you are 10 mm away from Z0. Where as if you say 10mm retract incremental you are retracting 10mm away from your top of stock. By looking at the code below I think you can see what I am talking about.

 

code:

---

%

O0( 34MM AHS WB 500 )

( DATE=DD-MM-YY - 17-01-07 TIME=HH:MM - 05:13 )

( MCX FILE - C:MCAMX2MCXMILL34MM AHS WB 500.MCX )

( NC FILE - C:MCAMX2MILLNC34MM AHS WB 500.NC )

( MATERIAL - ALUMINUM MM - 2024 )

( T7 | 1. FLAT ENDMILL | H7 )

N100 G21

N110 G0 G17 G40 G49 G80 G90

N120 T7 M6

N130 G0 G90 G54 X17.6 Y0. A-180. S4500 M3

N140 G43 H7 Z46.128<-- RETRACT INCREMTNAL 10MM

N150 M8

N160 Z38.128<--- 2MM INCREMENTAL FEED PLANE

N170 G1 Z18.014 F100. <---- -.05MM INCREMTNAL FEED PLANE

N180 A180. F500.

N190 G0 Z28.014

N200 Z46.128

N210 X20.6

N220 Z38.128

N230 G1 Z18.014 F100.

N240 A-180. F500.

N250 G0 Z28.014

N260 Z46.128

N270 X21.6

N280 Z38.128

N290 G1 Z18.014 F100.

N300 A180. F500.

N310 G0 Z28.014

N320 Z46.128

---

HTH

[herricam]

I see how you came to this conclusion but yes I do understand absolute and incremental, the program you have posted is still not what I'm trying to achive. I want my retract to be Z10. feed plane to be Z2., and my top of stock to be Z0. I now believe this is not possible to do when using axis sub. Thanks for the help.