Screw forward timers in this day and age

[Ten Fingers]

Working in a new position I have started to process on Toshiba presses. I was surprised to find out that they use an injection timer setting that functions as a screw forward timer (hold time = injection timer setting - injection time). Are there any other presses that still work this way? I haven't seen this since I worked on presses controlled by limit switches.

[Suhas]

Yes, every machine is different.
However, I believe this is not a timer to transfer. I may be wrong. If your timer = 5 seconds, you will still transfer with position and let us say the fill time = 1 second, then the machine will automatically use the remaining time (4 seconds) for the 2nd stage.
Let us know what you find.
Suhas

[Jorge Villegas]

Yes, every machine is different.
However, I believe this is not a timer to transfer. I may be wrong. If your timer = 5 seconds, you will still transfer with position and let us say the fill time = 1 second, then the machine will automatically use the remaining time (4 seconds) for the 2nd stage.
Let us know what you find.
Suhas


Exactly. Toshibas, Haitians, and welltecs work this way. Even some Lien Yu. Although there is a problem with this setting with our toshibas. Let say for example you have a 1 second shot, 3 second hold and pack, and set the timer in 5. The 1 second left will be used in the holding stage... BUT... if you set the holding profile with something like this:

(sometimes the guys at our shop just forget to set the holding pressure right)
--------------------------
Press/ 0 /80 / 100
time / 0 / 2 / 1
--------------------------

The screw will have a 1 second of 0 pressure, that will make your screw bounce back, and in our case, cosmetic problems. if you set the timer right (shot time+hold time), you will have the hold time you set as parameter.

The other way around. if you set the timer less than the shot size, some machines alarms, the other machines will transfer early. And if you set the timer less than your set hold time, it will stop the holding stage when the timer is over.

The Haitians have a setting to disable the timers. With the Toshibas you can´t disable it

[Wittmann_Molder]

Working in a new position I have started to process on Toshiba presses. I was surprised to find out that they use an injection timer setting that functions as a screw forward timer (hold time = injection timer setting - injection time). Are there any other presses that still work this way? I haven't seen this since I worked on presses controlled by limit switches.

We have a handful that still work that way. All of our Toshiba Machines (both the older hydraulics and the brand new electrics) have it, JSW (again, the old electrics and the brand new electrics), and our Nissei as well. I will say that it's interesting when training new people with little / no experience in molding, but all in all it's just another line on the process sheet.

From what we have here:

Kawaguchi - uses a regular hold timer, set separate
Toyo - regular timer, set separate
Haitian (Mars series, 2009) - regular timer, set separate
TMC - regular timer, set separate

JSW, Nissei, Toshiba - all use an "injection timer" to govern pack & hold

[Airwinghma]

Greetings'

Our JSW electrics have the same timer, you have to make sure that it is set higher than your fill and hold time. I shoot for a bit less than .5 seconds left over and have a segment on the hold set at 5 or so %.

Just something else to work with.

Scott