[sputnikprec]

We brought a Bridgeport interact 308 TNC2500 which I am told was a USA build. This machine has a problem with toolchanging.
It will perform endlessly without a toolholder but with a toolholders in the carousel it will do as follows.
On commanding of tool call the tool, will orientate correctly, however when the toolchanger is finished and it is to retract back,
the toolchanger will slide back a very small distance and all will stop there. It seems a bit stiff at the point where the toolchanger departs from the tool nose.
If I lever it away with a piece of wood, it will resume faultlessly.
We have another 4 bridgeport machining centers and all have a pneumatic driven toolchanger. This is electric! and We do not have a maintenance manual and do not wish to
start dismantling blindly. I suspect that the toolchanging height might not be correct. The nearest machine we have is a Bridgpeort VMC412/2500 but has a pneumatic driven changer.
For the VMC412 toolchange z height is effected through parameter 4210.16. ON this machine it is another parameter as I changed it with no effect.
I need a manual particularly that which deals with the toolchanger. ANY HELP appreciated. Thank You!

[CroCole]

We brought a Bridgeport interact 308 TNC2500 which I am told was a USA build. This machine has a problem with toolchanging.
It will perform endlessly without a toolholder but with a toolholders in the carousel it will do as follows.
On commanding of tool call the tool, will orientate correctly, however when the toolchanger is finished and it is to retract back,
the toolchanger will slide back a very small distance and all will stop there. It seems a bit stiff at the point where the toolchanger departs from the tool nose.
If I lever it away with a piece of wood, it will resume faultlessly.
We have another 4 bridgeport machining centers and all have a pneumatic driven toolchanger. This is electric! and We do not have a maintenance manual and do not wish to
start dismantling blindly. I suspect that the toolchanging height might not be correct. The nearest machine we have is a Bridgpeort VMC412/2500 but has a pneumatic driven changer.
For the VMC412 toolchange z height is effected through parameter 4210.16. ON this machine it is another parameter as I changed it with no effect.
I need a manual particularly that which deals with the toolchanger. ANY HELP appreciated. Thank You!

Hello i have solved similar problem on Bridgeport with TNC2500 machine but it was not problem in z-axis position but in tool changer mechanism... Underneath toolchanger there is a big nut that mounts the toolpots (whole "drum" with tools) to the mechanism... believe it or not it was loosen due to transport so the whole toolpots (drum) was a little down and the whole mechanism coudnt move back when it place the tool in spindle... U may first check that
Second that control is some kind of hybrid Heidehain controler as i recall so there could be few things in Z axis that u could check... First u may check how is the Z axis positioning working.. Set the position screen to lag--schleppfehler so when it reaches the toolchange position it should be 0,000 or +-0,005 or +-0.010 but if the axis parameters are correct ur machine wouldnt go to next operation if that number is much greater... If that is ok return ur screen to Act--Ist if it is not then there could be problem in the Z axis (regulator offsets or even mehanical problem or lubrication problem) and the parameter for positioning is set too high (1030.3 )
And if all above is ok u may want to locate position parameter for Z toolchange... It should be the Z position number u see on the screen when u are at toolchange position with Z axis (parameters 4210.0, 4210.1, 4210.2 etc to 4210.31) .. If there is no parameter do the next calculation REF Z position - TOOLCHANGE Z position = NUMBER so check if there is this number in parameters.. And the last one u can try is to change the parameter referent point position for Z axis for the amount u need..

REMEMBER Before u do any change to parameters write down the old ones and be careful with the calculation of position diffrence in Z because u could damage the toolpost....

[sputnikprec]

Hi CroCole,
Many thanks for the leads. In another forum, practical machinist, somebody dismantled to pieces (a months long job) and rebuilt. Done an ultrafantastic job. He posted lots and lots of photos of progress and i managed to get an idea of the toolchanger dismantled to smithereens.. There is a plastic cam, couplings and linear bearings. I will look into the comment of the changer undone from bottom as it has some play. I suspect the problem to be mechanical. This toolchanger works via an electric motor and i suspect that the load is greater when it is being pulled back from the toolholder grooves. when i lever it with a bar away from tool nose position, it would be real stiff until I get them apart and then i could push away by hand. Something tells me it may be stiff due various possible reasons in this position or the toolholder is mispositioned slightly and this extra stiffness at this point would trigger the motor to stop trying....
Where would be my best guess to get my hands on a maintenance manual for this machine? . I have all programming manuals and nothing service. I gave three other tnc2500 controls and as i have said, the vmc412 i have had a pneumatic toolchanger but thus machine is different in some ways....

[sputnikprec]

Hi,
I have sorted a multitude of problems on the tool-changer but a problem remains...
Apparently, this machine was involved in some mishap by the previous owner. We noticed that the star where the tools fit was not same height and in some places was even around 3/16 (some 4 or 5 mm) tilted.
we found a crack and it seems that somebody lowered the head when the toolchanger was out and the casting was bent badly and also cracked. I cannot understand what kind of impact was involved which would easily have broken the tool holder flange. There was no bending. We welded it thoroughly and then painstakingly brought down the whole facing down parallel and then compensated the distance with a spacer of the size we removed. We dismantled the changer thoroughly. Thanks for the parameter because I found it and changed it to get the spindle align perfectly, however I have something not right.
Although previously the changer would stick every time at the spindle nose before retracting, now it works OK.
However sometimes, it would clamp the tool from the tool-changer and just stay there without the changer attempting to go back. It would stop there for ever. If I lever it off with a stick, it would go back and everything resume. There is no stiffness involved, because I moved it to and fro by hand very easily.
do you think I should follow the lag check advise?

[CroCole]

Yes i would advise to look at lag when it does the toolchange ... In parameter 1030.2 is inputed what is IN POSITION WINDOW so whatc the lag and if it is greater than that number then machine stops until it get in position window.. For trying ---- If the number is greater u can change the parameter to higher number than the lag.. But it makes ur machine more inaccurate.. The problem can be mehanical, motor (brushes, tacho brushes) or simply u need to offset the Z regulator to get the axis in position

[sputnikprec]

Thanks so much for your advise.
I will let you know how it goes.
Tonio

[RobertPost]

HELP pls...Could you please send me the parameter list you are using on the Bridgeport Interact 308 TNC2500 to [email protected]?

Thanks a bunch,

Rob