Old CNC milling machines - lost parameters

[Robotstar5]

Older machines wouldn't have them I assume?
Forgive my ignorance but what is the advantage?

How old?, ballscrews have been around over 100 years.

 

[Agroshield]

...getting the poohoo treatment...

No-one is giving you the poohoo treatment. The answer to which you took exception is amplifying, expanding and complementing the valid points you had previously made.

In your career of building machinery, you will have learnt that life is not black and white - there are subtleties surrounding most questions.

In the context of this forum, what is the correct answer for a 40/5 commercial machine shop might not be practicable for an amateur or enthusiast on a budget.

So, please, do go on telling us best practice as it serves as a benchmark of what is attainable, but do not take it as a sleight if someone else suggests something lower down the scale as an alternative.

 

[mtt.tr]

It depends on the machine. The Hitachi Seiki 4 axis ,live tooling Cnc lathe I bought cost me roughly £1k to get the parameters put back into it after spending about £3k on parts. No way an after market set up would come close at that sort of money.

That's one hell of a machine, is it running now?

 

[minimutly]

You can have no backlash with an ACME thread. The penalty however is friction (or to put it another way efficiency).

Yes, it's all about the backlash but the reason why you pick a ballscrew over an acme is for the same backlash the ballscrew is something like 90% efficient while an acme is maybe 40% efficient.

Same goes for the rapids, the ballscrew means that you need smaller motors for the same speed (or more speed for the same size).

Well this is only true when the acme is new. As soon as it wears you get backlash.
If you think a new 30mm acme thread is cheap, try pricing a 1.5m long 30mm ballscrew - they are not cheap. You will need one of these, another half the length (but not half the price) if you want the knee to move, a way to lock it, and the others as @pressbrake1 mentioned, a smaller pair for the Y and the quill.
There is a cnc conversion forum - I forget what its called - hours of reading fun @fizzy - one guy on there spent £6k on his conversion! Now he may have just been stupid, but that cost to me was staggering. I think half that wouldn't be far off. And if you're doing this just to scratch an itch (as I was planning), I suggest there are better ways to spend your money.

 

[sako243]

How hard is it to set these things back up?

It really depends on if they know what they mean when they say parameters lost.

I've had intimate dealings with two robosoft CNC stuff and they have parameters that are tuned by the installers. They should make a note in the manual to say what they are and can be reprogrammed in. The battery backed up chips despite people saying they're not available have alternatives that are suitable for someone with knowledge to replace.

In other situations the battery backed up ram has wiped out enough of the system so the FPGA isn't programmed and then it's game over unless you can get the original files from the manufacturer. I had a back door contact to one of their ex service engineers and he said no chance in robosofts case.

In this instance its simpler to build a new completely bespoke controller for the system (CLH's big guillotine).

 

[Kayos]

The biggest power loss is the slideways not the screws
Yes you can have low backlash with a acme thread with sprung split nuts but friction and wear is high
How long do you think a spring nut acme( manual is no good) will remain good
Wear also means less long term accuracy
So you go for ball screws for long term accuracy
My experience is based on a career of building machinery not googling answers!
Sometimes I think I’m a prizeidiot for even posting on this forum and getting the poohoo treatment
Time for a break I think

It's not worth arguing with the googlers on here, trust me it becomes very old very fast.

Unfollow and ignore are well used options for me

 

[Kayos]

Also, depending on the size of the machine, beware of altering settings you don't understand

Kit maker Genie fined after M25 work platform death fall

Court hears how calibration error led to death of worker when 40 metre high mobile elevating work platform collapsed

www.constructionenquirer.com

 

[fizzy]

Also, depending on the size of the machine, beware of altering settings you don't understand

Kit maker Genie fined after M25 work platform death fall

Court hears how calibration error led to death of worker when 40 metre high mobile elevating work platform collapsed

www.constructionenquirer.com

Very worrying that a simple software error can cause this!
Older machines probably had simple limit switches etc.
My forklift was out of action for 6 months due to a simple sensor fault. I even had the main service engineers out who couldn't fix it. I managed it in the end but I wasted about 60 hours of my time on it. Older forklifts just had valves!

 

[Kayos]

Very worrying that a simple software error can cause this!
Older machines probably had simple limit switches etc.
My forklift was out of action for 6 months due to a simple sensor fault. I even had the main service engineers out who couldn't fix it. I managed it in the end but I wasted about 60 hours of my time on it. Older forklifts just had valves!

Wasn't a software error

Someone access a password protected section of the settings and altered something that knocked it out of calibration, the boom was not where it thought it was

Given the height these operate at I'd rather properly setup software than a valve and switch

 

[minimutly]

Good thing a cnc machine can only eat itself then....
I would suggest that if someone has converted, rebuilt or fitted a new controller they would be capable of setting the callibrations...

 

[Kayos]

Good thing a cnc machine can only eat itself then....
I would suggest that if someone has converted, rebuilt or fitted a new controller they would be capable of setting the callibrations...

I'd post some pics of arms wrapped around lathes or scalping injuries (hair pulled into machines and the scalp being removed) as a counter point to that, but I don't think it's necessary

I'm not all doom and gloom, but the access to large machinery, especially CNC that needs modifying, does come with certain risks and I was highlighting what can happen when settings are changed that are not fully understood

 

[minimutly]

I'd post some pics of arms wrapped around lathes or scalping injuries (hair pulled into machines and the scalp being removed) as a counter point to that, but I don't think it's necessary

Why? What is the connection here?

I'm not all doom and gloom, but the access to large machinery, especially CNC that needs modifying, does come with certain risks and I was highlighting what can happen when settings are changed that are not fully understood

And the risks are that the machine eats itself. Its as if you suggest it will chase the operator out the door?
Ok, if you're talking about one of the massive machines that @pressbrake1 has, yes, I could see it being potentially dangerous. Wouldn't put it past @fizzy to buy one....

 

[mtt.tr]

Yes. All sorted. Just putting all the covers on and sorting out the cover on the tail stock. It all fires up though, can reference axes, do toolchange from the turret or from the carousel at the back. Spindle is nice and quiet. It’s been a long haul to get here !

I want to see angled drilling now!!



The machine with unlimited crashing potential

 

[James1979]

The biggest power loss is the slideways not the screws
Yes you can have low backlash with a acme thread with sprung split nuts but friction and wear is high
How long do you think a spring nut acme( manual is no good) will remain good
Wear also means less long term accuracy
So you go for ball screws for long term accuracy
My experience is based on a career of building machinery not googling answers!
Sometimes I think I’m a prizeidiot for even posting on this forum and getting the poohoo treatment
Time for a break I think

I gave in a couple of months back and had a month away from here.

Final straw was some tard arguing about a law that had been put in place to protect him from what he was actually doing

Following this thread as I’m looking to move further into CNC but it’s on a budget

 

[pressbrake1]

Why? What is the connection here?

And the risks are that the machine eats itself. Its as if you suggest it will chase the operator out the door?
Ok, if you're talking about one of the massive machines that @pressbrake1 has, yes, I could see it being potentially dangerous. Wouldn't put it past @fizzy to buy one....

I think more people are killed by Normal sized machines.
Lathes and radial arm drills are the main killers though cnc with the safety bypass and probably no1 these days
Back in the last century I had to get someone out of a machine. He lived as it was short cycle. His arm had no bones left.

 

[minimutly]

People get complacent. A small machine has the potential to make you just as dead as a big machine,the only difference being a big machine will get the job done quicker….Neither stop when you cry enough…

Ai, but it doesn't need to be cnc to do it. Ultimately the machine if its cnc has a door switch...

 

[Robotstar5]

Also, depending on the size of the machine, beware of altering settings you don't understand

Kit maker Genie fined after M25 work platform death fall

Court hears how calibration error led to death of worker when 40 metre high mobile elevating work platform collapsed

www.constructionenquirer.com

Some of the robots i worked on had different access levels, we had to do extra training to be given level 4 access as changes could cause damage to the robot or worse an operator.

Some safety PLC's needed a course and if you passed you got a certificate, any changes needed the certificate No. entered before they were accepted so if something happened all the changes were traceable.