Tool Override Home Position - Turning

[Steinwerks]

The single Home Position in Turning is too limiting. We frequently have three turning tools, an insert drill, a boring bar, etc. in the turret, and prefer a 10" retract from the face to change tools to the insert drills (which are up to 5" long), but only a 1" retract to change to the finish turning tool from the rougher.

Instead of the "Go home" options currently I'd like to see a Home Override checkbox and distance field so a finishing tool can retract to 10" on "Go Home at End" before calling the insert drill and the Setup can have a standard Home position of 1" (or whatever is preferred) for the turning tools and cutoff.

[Lonnie.Cady]

I have asked for this for a long time.   They really need more control over the home position per tool change.    I work with parts 12" long and have 14" long spade drills that I drill thru from one side. Then bore 1/2 way.   Using OD tools and long ID tools has never worked well IMO

[Rob.Lockwood]

 What's the best way this should be implemented? It seems the standard fanuc way is two home positions (g28/g30) where you set g30 as your 'stay close' position and use g28 when full safety is needed.. I don't believe there's currently a way to cause this to happen automatically, and surely some logic could be built into posts to handle this in various ways.. But some GUI that directly supports it would be better.

[Steinwerks]

@Rob.Lockwood

I'm talking about the Home Position set in the Setup under Work Coordinate System. In our post at least when the toolpath ends this is where it sends the tool. In the case of long tools this almost caused a crash the other day when sending an insert drill home at beginning and end would have run the back of the turret into the tailstock. However it didn't have to go home once the tool offset was activated, but the tool before it DID have to go to home if the home position were 10" so during the toolchange the drill wouldn't hit the stock, or chance hitting it on positioning while moving to Z1. once the drill was active.

Yes, logic could be built into the post, but it would be much nicer to add a checkbox called Custom Home Position that activates a field to input a number, and the original pulldown can remain the same. This isn't cluttering the UI, it'd be intensely convenient for shops that have standard tools that rarely leave their holders (like us).

No dragging is a feature our old CAM doesn't have, but it has this and it gets used.

[Lonnie.Cady]

Never ran a lathe with 2 home positions(20years).  So not sure how many would benefit from a solution that relies on it.

[Rob.Lockwood]

@Lonnie.Cady really? i've only ran fanuc lathes, but assumed that was pretty universal functionality, or at least that the Haas lathes would have it. Strange omission. 

[Lonnie.Cady]

@Steinwerks believe me I know what you are saying.  I reported this many times even took pictures of a setup where I had to face it with a short tool and then drill 12" and them Bore 12"

Option 1 is to set the home position in setup to 13" so when you are done facing it and need to bore it them machine is retraced far enough to clear the part on its initial ZX move.   Problem is when the boring bar retracts it goes to 13" and collides with tailstock.

Option 2 is set it to 1" and then when you are done facing it and it indexes to boring bar it tries to travel thru the part on its first move.

One thing I tried that did work partially was to add some logic to the post to check if it was the initial move and if it was I split the move into separate lines, moving z by itself first to clear part then x to initial bore position.  It worked okay as long as the part diameter was not so large you could not index your long tool over top of it.

One thing I also think causes an issue is that the tool does not always return to its initial position after an operation like you would have in a G71 situation.

[Lonnie.Cady]

@Rob.Lockwood I know you can get it on a haas mill, i don't even see the option on the lathe side.

[Lonnie.Cady]

@Steinwerks @Rob.Lockwood @al.whatmough

I wonder if there would be any way that you could take the suggestion of changing confinements to work like height for mill and incorporate into this tool change position.  What if your z tool change position was one of the heights you could set on the confinements. 

Probably not a great idea but may spur some other ideas.

I still think for safety reasons the default post processors should do a single z move to a clearance plane while the x axis is at the machine zero.  This helps to ensure the long tool clears the part prior to making an x move after tool change and also positions the od tools close to end of part which can help avoid the tailstock in shaft work.

[Rob.Lockwood]

@Lonnie.Cady I love the first idea, actually. Seems logical to me.

The second part, all of the gang tool posts i've done (a couple at this point) we've modified to do exactly that; I don't see any reason that turret ones wouldn't, couldn't, or shouldn't do the same.

[Steinwerks]

@al.whatmough

Any word on this? I'm sure more control of the home position depending on tool length would be most welcome!

[al.whatmough]

Thanks for the poke @Steinwerks   

This certainly feels like low hanging fruit that should be prioritized given the number of higher priority things that have now been completed for Turning.

[Steinwerks]

Thanks @al.whatmough!

It was actually the shop manager here that asked if there had been any movement on this one, so I'll pass it on to him 

[cj.abraham]

@Steinwerks I have a quick hypothetical:

Let's suppose you have a setup with the home position 1" from the front of the part (Z0. is model front). You've just used your shortest tool on the turret to perform an operation, and the program is getting ready for a tool change so it moves to Z1. If the turret is fully retracted to G28 U0. at Z1., does your longest tool have clearance if the turret spins around 360deg?

[Steinwerks]

@cj.abraham

Yes, but when the 10" drill travels 10" back to Z1. home it will hit the chuck, jaws, part, or if very lucky, nothing. Conversely being at machine home means it is likely to hit the retracted tailstock.

Right now our post is brute-forcing a location, but this is not ideal.

[cj.abraham]

CAM-8655

[cj.abraham]

@Steinwerks 

I must be misunderstanding the visuals here, because if your turret is retracted to machine X home position it shouldn't be hitting the chuck or part when it retracts in Z.

[Steinwerks]

@cj.abraham

A long tool, traveling in two axes, can collide with something along that path when moving from where a stick tool was previously at the same Z position, or conversely setting a long retract position, besides being intensely inefficient, can crash into the tailstock when you have grossly different tool lengths.

Our last software CamWorks, that I truly love to hate, had by-tool retract positions because to be efficient and safe they are needed. @Lonnie.Cady has also said so and offered evidence that this would be a welcome change.

[Lonnie.Cady]

@Steinwerks, it is unfortunate that nobody took the time to understand the issue when I took the time to take pictures of the machine setup with tool locations and document it pretty clearly.

I think it was @Rob.Lockwood that showed a picture of how NX handles some it it by allowing the user to decide if it positions 

X and Z

X then Z

Z then X

for the initial move.  

[Lonnie.Cady]

@Steinwerks

It is under review here but accepted in the fusion idea station back in Feb of 2016 and "already had a ticket and in the backlog"

https://forums.autodesk.com/t5/fusion-360-ideastation-request-a/the-ability-to-change-the-home-posit...

Which is it????

#groudhogday

[cj.abraham]

@Steinwerks the question was if the turret/tool would hit anything while changing a tool if it was retracted fully in X, not when it would approach in XZ at the same time.

The reason I ask is because a post can be made that would handle a tool change as follows:

1. Use T101
2. Retract Z to setup home position (Like Z1.)
3. Retract to X machine home
4. Index Turret to T202
5. Position new tool to Z1. (T202)
6. Approach X
7. Enter cut

If the turret can spindle freely in all Z positions when the machine is fully retracted in X, then this would be "safe" and would have minimal Z motion. However, I'd imagine there are cases where, even if the turret is fully retracted in X, the turret cannot spin freely if the tool at the beginning of the tool change process above is short relative to the rest of the tools. In that case, the Z1. position for the next tool would be applied before indexing the turret, and would look like this:

1. Use T101
2. Retract Z to setup home position (Like Z1.)
3. Retract to X machine home
4. Position new tool to Z1. (T102)
5. Index Turret to T202
6. Approach X
7. Enter cut

The trick is deciding which method to use, which would be nice to automate. In order to automate it, the post needs to know which tool is longer. If it can be automated, you get the shortest safe Z retract for a tool change without having to think about it.

Also, today it is possible to create a manual NC command in your post that you could use to override the tool change position and do exactly what you are asking. It would look something like:

• Operation 1
• Manual NC Action: toolChangeZ,#.####
• Operation 2

You would just have to decide up front whether you want the position to be relative to the workoffset or to be a machine coordinate. I can do this for you today if you'd like. Just send me the post.