[dcook1987]

This is an idea I've been mulling over recently, and wanted to get some input from people on this forum..

I've recently been thinking about a situation where a Job Shop has a large number of different parts, low production quantities, and a variety of tools required for each part to make in a given day.

For argument's sake, let's assume a few things:
1) the shop has 10 different parts to make in one day
2) each part has a cycle time of 10 minutes
3) They need to make a quantity of (3) of each of the 10 part types (300 minutes of total cycle time = 5hrs of total cycle time for the day)
4) The shop only has one machine with a 16 tool ATC
5) The ATC has 10 standard tools in slots 1 - 10, and slots 11-16 are available for "special" tools that are available
6) The shop has the ability to preset tools for both length and diameter off-line and transfer that data to the CNC machine without manual data entry (barcode scan, RFID...)

Now, at the beginning of the day, the operator must load all the "special" tools into the machine, load the program, and hit cycle start. During the cycle time, he can be programming, setting tools for the next part, or doing whatever he sees fit, as long as he's ready to swap in the next blank for the remaining two parts, and then do the setup/tool change when the parts switch over to the next part type.

My idea comes up in the last run of a part in a given batch. As the tools are "used" in the last run of the batch, there really is no reason for these tools to be in the machine anymore (aside from standard tooling that is used on all/multiple parts). So, if I'm running the last part of a batch and I've just finished using T11, the machine will put T11 back in the ATC, and I have to wait until the cycle finishes to change the tool over to the proper tool for the next part I'm going to run.

The tool changer is reasonably isolated from the machine where it's feasible to have a "tool exchange" mechanism that lets you (while the machine is still running a cycle) safely pull a tool from the ATC, remove it, and scan/insert a new tool to put in that respective pocket. This would mean that while the last part of a batch is running, you can be loading the tools for the next part into the machine (along with the preset offset data) and be ready to slap a new blank in the machine, load the next part's program and press go.

Has anyone seen some kind of mechanism that allows you to swap tools in an ATC without stopping the machine, or requring the use of the spindle? I know there are some large shops that have custom systems to do things like this (essentially a centralized ATC), but I'm looking more along the lines of a self-contained CNC machine.

I could see an appreciable setup-time savings if you can shift the tool loading process from between-cycles, to during the cycle of the machine.

Any comments are appreciated!

[wizard]

I believe this is supported on some high end machines. Not that I have such a high end machine!

I would do this unless the machine itself had a way to identify each tool holder. The chance of a mistake being made with the wrong tool in the wrong slot is very high. Also this is a serious controls issue, the last thing you want is your hand ripped off because the machine decided to move the tool carousel and the interlock mechanism failed.

[dcook1987]

I believe this is supported on some high end machines. Not that I have such a high end machine!

I would do this unless the machine itself had a way to identify each tool holder. The chance of a mistake being made with the wrong tool in the wrong slot is very high. Also this is a serious controls issue, the last thing you want is your hand ripped off because the machine decided to move the tool carousel and the interlock mechanism failed.

Do you know what machines have this? I'd be interested to see how they work.

The idea is to have an axillary mechanism that would do all the "heavy lifting." The device would "bolt on" to the side of the machine, and would have an arm that would pull a tool from the carousel and bring it to a safe location to be pulled out of the machine (something like a small enclosure with it's own safety-interlocked door). You wouldn't need to reach into the ATC while the machine is running, just press a few buttons (like "swap tool" on the controls), and the machine would pull the tool from slot X, bring it to this device, let you load a new tool (and scan barcode/preset info) and bring the new tool back to slot X (or, any open slot on the ATC). The controller would then update the tool length/dia offsets accordingly.

[sudip]

I think we should know the details of working of ATC in CNC machine.This can help you

everything about cnc machine tools and components.

[Superman]

The idea is to have an axillary mechanism that would do all the "heavy lifting." The device would "bolt on" to the side of the machine, and would have an arm that would pull a tool from the carousel and bring it to a safe location to be pulled out of the machine (something like a small enclosure with it's own safety-interlocked door)..

Sound like a toolchanger's toolchanger
- but like Wizard said, doing it manually while the machine is running is a Health & Safety issue,
& the machine has to stop manufacture for you to run the program for this "tool swap" , you are not gaining any time.

easier to replace with a larger tool carousel, load ALL the tooling for the 10 parts in 1 go,... the only downtime is the billet & program change,, ( assuming part origin is unchanged )

[Mat Mexico]

We use a Mazak variaxis i600 for aerospace parts that actually work this way but you have to set some parameters to update the toll data while running

[murrayclair]

Our HCN8800II has tool Rfid chips in the pull stud and we do a similar thing. We have 120 tools but need to swap tools while the machine is in cycle. We dont run tool numbers but group numbers. This means a tool can go in any location and always be called correctly. If you use tool numbers you are asking for a crash as the operator will be required to put the correct tool in the exact pot.