toolchanger on MB3 VMC

[underdog]

Hi. I bought a used MB3 VMC and it is running with the exception of a tool changer hang-up. It works fine if I call for tools in pockets 6-22, but it will always hang up and fault out when pocket 4 or pocket 23 comes around to the tool change station. Since it works fine at the other stations, I'm thinking its in the rack that moves the tool mag around, but I'm not so great on electric troubleshooting (programmer you know). Help is greatly appreciated!

[gthlm]

I'd never heard of a MB3 before, so I looked it up and it appears to be 100% identical in all but name to my MD3, what the difference is I have no idea!

Anyway, being the same as my machine, the toolchanger index is a very simple geneva wheel mechanism, so if it works flawlessly most of the way round the chances of there being something wrong mechanically are practically nil. Short of built up chips jamming the mechanism about the only possibility is that the magazine is not stopping in quite the correct rotation at certain positions and the index pin isn't locating properly in the hole. There are limit switches on the index pin so the control would fault out in that case.

If you're sure the problem is electrical, the best place to start looking is the decoder box on top of the umbrella. If you take the top cover off the tool changer so you can get into the workings of it, you'll see a small box with six led's on it, that's the 6 bit binary counter that tells the control where the magazine is. The led's should light up in the following sequence in relation to the position of the magazine:


0 101001
1 100000
2 010000
3 110000
4 001000
5 101000
6 011000
7 111000
8 000100
9 100100
10 000010
11 100010
12 010010
13 110010
14 001010
15 101010
16 011010
17 111010
18 000110
19 100110
20 000001
21 100001
22 010001
23 110001
24 001001


Remember to use the diagnostics screen, it shows the status of every component of the toolchanger.

Gregor

[underdog]

Gregor,

Thanks so much. I will check that. yes the MD3 is brother to the 40" X 20" MB3.

Where did you get the binary sequesnce you shared with me and most importantly how do I get into the diagnostices screen?

Many thanks for your reply.

[gthlm]

I got the binary sequence from the schematics in my manual. They're far from comprehensive but seem to cover all the ancillary parts of the machine, like the toolchanger.

To get to the diagnostics screen, from the manual mode screen, press the "Change Tool and Diagnostics" softkey, then "Diagnostics". I can't recall right now if that's the exact wording, but it's near enough I think!

From there you can manually operate all movements of the toolchanger, apart from the magazine rotation, which you can operate from the button at the back of the machine behind the umbrella.

Hope all this is of some help.

[bloke]

It's possible you just have pieces of swarf in the slots for the binary counter. Look at it all the way round and remove any metallic crud in the slots. The MB3 (BX control) was the predecessor to the MD3 (Ultimax). We only sold one of them in the UK. Last time I worked on it, it was in Poole.