Slipping machines: How to use the new functionality of Matra
Matra is a program calculating the drawing diagram for the dry drawing machines and wet slipping drawing machines. The slipping machines are included in the version 2.0 of the program. In this article the instructions to work with the wet slipping drawing machines. The instructions for the use of the program for the dry drawing machine are in another article of this site.The program can be downloaded from Apple Store and is working on iPhone 6S, 7, 7S, 8, 8Plus, X,XS,XSMax, 11, 11Pro, 11 ProMax, all types of iPad.

After the choice of the language and of the Measure Unit (Metric or Imperial), press the Button Slipping Machines.

With the button “CA” it is possible to clear all the page and start the data cleaning up all the fields. Pressing the button “List” you can see the data of the preloaded machines.

If your machine is one of them included in the List you can enter in the green field the number of the machine chosen. In this way all the data defining the property of the machine will be populated automatically. If your machine is not included in this list you can enter manually all the data defining the properties of the machine.
“Total Die Number” is the maximum dies number of the machine. This number, after entering the dies/group, must be the same indicated in the grey field aside.
“I° group of elong/reduct”. In the following photo you can see what is the meaning of group. In this machine of four shafts we have two groups of reductions. In many machines the reductions are the same in the first and in the second group, but sometime in the first group the reductions are bigger. In this case we can say the groups are two and we can specify for each group the relative elongations per pass. If the reductions are equal then you can consider only one group. In a six shaft machine some time the groups are three with different reductions.

In the machine n. 1 of the list in the following photo there is another situation. The groups are still 2 but the reduction of the die in the passage from the first to the second section is different from the other. In this situation we have to use all the three groups of elong/reduct as indicated in the machine n.1 of the List.

In correspondence of the first group, then, you can enter the elongations or the reductions of the relative dies. You can enter either because the program is calculating the other automatically.
“Last Die elong/reduct”. After filling all the data of the three groups you have to enter the elongation/reduction of the last die that normally is different from the others. Check now if the “Total die number” is the same value of the grey field and, if you want, you can check all the parameters of the wet drawing machine pressing the button “Check Machine Data”. Here following what you can see:

Now it is possible to enter the data to define the drawing diagram: after the insertion of the inlet and outlet diameter you must enter the slip you want per each pass of the machine. The slip is the amount of elongation we have to add to the wire respect the elongation of the machine in order to have the possibility to work. Pressing the push button “Slip Setting” we have the following window explaining in short the slip meaning.

In the column P you can insert the slipping you want considering the first number the slip for all the capstans (except the last) inside the bath. With the second number there is the possibility to give to the last pass a different slip.
“Suggested Dies”. After entering the slip, in this row are appearing the suggested dies needing to effect the drawing diagram from the inlet to the outlet diameter and in the following row are appearing the correspondent inlet reduction “Max Inlet Reduction”.
At this point you can effect the choice of the number of dies trying to choose a compatible reduction with the type of material of the wire.
After this choice the red button “Drawing Diagram” is enabled and you can see the result of your job: The green numbers are the machine data with the machine elongation, the red data are representing the drawing diagram with the relative elongation%, reduction % and the resulting slip% per pass.
