Renewal Parts
Frequently Asked Questions
- We have some flash on the nozzle, but we have no operational problems. Should
we be concerned?
- Should we raise the ingot out of the melt pot when we shut the system down?
- The sprue is sticking in the sprue hole, and I have to push it out to clear the
hole for the next injection. What is the problem?
- During our IMA system's sequence of operations, the cycle proceeds to a certain
point and then stalls. Why is this happening?
- Our operator has noticed that he has to wait five or six seconds for the sprue
from the previous cycle to melt back into the nozzle. Why is it taking so long?
- Instead of melting back, the sprue simply falls over. What is the problem?
- We honed the sleeve in the gooseneck so that it was round again, but the
system still isn't operating properly. Did we repair it correctly?
- When I pull the chain on my new ingot feeder, nothing happens. I checked the
air supply, and it seems okay. What is wrong?
- My ingot feeder goes one "click" and then stops. Why is this?
- I replaced the bushings in the Moving Mechanism Yoke, and now the operating
head won't fit between the bushings. Why?
- I have an AM 43 IMA system with a horizontal cable head on it. Can I upgrade
it to an Option 1 Cable Processor Module?
- The Watts lubricator on the front of my zinc alloy IMA system won't pump
lubricant. Why?
- My IMA system is an older model, and a couple of cylinders move slowly even
though I open the flow controls all the way. Do I need new flow controls?
- What should I do with all the runners that I break off the terminations in my
cable operation? Should I put them back in the melt pot?
- When we first got our IMA system, the sprue would shear cleanly, leaving a nice
smooth surface. Now the area is raised, with a little bump. What is the
problem?
- We have alloy escaping between the nozzle and the nozzle seat even after
following your nozzle alignment procedure. There seems to be a big gap
between the nozzle seat and the nozzle. How can that be? Shouldn't the limit
switch keep his from happening?
- I get good service life from the injection nozzles, but when I try to remove
them, they break off. Why is that?
- I installed a new injection unit, and it plugged up very quickly. Why did this
happen?
- Within a few days of installing a new nozzle, the tip was pitted. What caused
this?
- Customers periodically call us about the plunger seizing in the gooseneck, so we
thought we would pass on the advice that was given to them ...
- We have some flash on the nozzle, but we have no operational problems. Should
we be concerned?
Yes. You can operate with flash on the end of the nozzle, but the zinc alloy gets very hot and erodes the nozzle tip. It will eventually have to be replaced. [top]
- Should we raise the ingot out of the melt pot when we shut the system down?
It is a good idea for two reasons. The zinc alloy will reach operating temperature faster, because the heating element doesn't have to heat up the mass of ingot which solidified in the melt pot. Also, as the alloy solidifies, it shrinks, and the ingot puts strain on the ingot feeder. While the ingot feeder is a strong component, with a spring built into the hook to compensate for the strain, the few seconds it takes to lift the ingot out of the alloy will add to its longevity. It also makes it possible to remove the pot covers while the pot is still frozen. [top]
- The sprue is sticking in the sprue hole, and I have to push it out to clear the
hole for the next injection. What is the problem?
This can relate to either a mechanical or tooling problem. To determine which it is, examine several of the sprues you pushed out. If the sprue has about 2-3mm (1/8 inches) of straight shank that appears to have been frozen and then pulled out of the nozzle, you probably have a mechanical problem in your IMA system. The assembly is not being held tight enough as it rotates to shear the sprue, or in the case of a Horizontal Cable system, the locating ring in the tooling may be worn.
If you are certain the sprue is shearing properly, but the sprue still stays in the fixed tool and has a substantial tail on it, you have a tooling problem. The cavity end of the fixed tool sprue hole could be chipped or damaged, or the sprue hole could have zinc fused to the tapered surface and be in need of cleaning.
In either of these cases, a visit from a FisherTech Service Technician to evaluate your system could save you frustration, time and money.
If there is no tail on the sprue, it is likely a timer or a temperature problem. Check the coolant system in the tool, lower the torch flame, or increase the injection time a little to allow the zinc alloy to freeze further into the nozzle. [top]
- During our IMA system's sequence of operations, the cycle proceeds to a certain
point and then stalls. Why is this happening?
If your IMA system has a Relay Logic Control sequence panel, the contacts in the mechanical relays could be degrading. There are several solutions: change the position of the relays on the sequence panel and see if the system will complete the cycle, or replace the old relays with new ones. Another possibility is that either the Head Closed switch failed to close during the cycle, causing it to be interrupted. Check the function of the switches. [top]
- Our operator has noticed that he has to wait five or six seconds for the sprue
from the previous cycle to melt back into the nozzle. Why is it taking so long?
In your "sprue" type of operation, the sprue should melt quickly and completely back into the nozzle within one to two seconds after the operating head and tool retract from the nozzle. If it takes longer to melt, the nozzle is too cold. If it is melting faster, the nozzle is too hot. A hot nozzle may cause the sprue to stick in the sprue hole and plug it. [top]
- Instead of melting back, the sprue simply falls over. What is the problem?
In your sprue-type operation, one likely cause is contaminated zinc alloy. Have a sample of the alloy from the melt pot analysed for iron content. If iron is present, clean out the melt pot and put in new alloy. [top]
- We honed the sleeve in the gooseneck so that it was round again, but the
system still isn't operating properly. Did we repair it correctly?
You've completed only half the job of repairing the gooseneck assembly if you just honed the sleeve. A plunger must also be fitted to the new sleeve diameter. This is what FisherTech does when reconditioning an injection unit. [top]
- When I pull the chain on my new ingot feeder, nothing happens. I checked the
air supply, and it seems okay. What is wrong?
The ingot feeder waits about one minute from the time you pull the chain until it actually feeds the ingot. This prevents too much zinc alloy feeding into the melt pot in a short time, which can lower the alloy temperature. To speed up the process, pull the chain and depress the manual override button on the valve located inside the access port on the end of the feeder. [top]
- My ingot feeder goes one "click" and then stops. Why is this?
Check the screw holding the slide assembly to the cylinder. To do this, insert a long 5/32 inch (4mm) Allen wrench through the small hole in the end of the housing and tighten the screw, if necessary. When the screw comes loose, the cylinder cannot put the slide assembly back far enough to "close" the pneumatic switch, which reverses the direction of the slide. [top]
- I replaced the bushings in the Moving Mechanism Yoke, and now the operating
head won't fit between the bushings. Why?
You are probably using up your old stock of bushings. There is a fit dimension of 3" +.005"/-0 (76.2 mm +0.13mm/-0) between the heads of the bushings. It may be necessary to grind the heads of both to achieve the proper fit. We have changed the specifications, and the bushings we ship today should fit without grinding. [top]
- I have an AM 43 IMA system with a horizontal cable head on it. Can I upgrade
it to an Option 1 Cable Processor Module?
You most certainly can. This requires a "raised" pot kit, a different nozzle, a new programme for your Programmable Logic Controller and a constant air supply valve. You will also have to change the length of some of the hoses. Contact your FisherTech Sales Representative to receive a quote. [top]
- The Watts lubricator on the front of my zinc alloy IMA system won't pump
lubricant. Why?
Many customers try to use mold lubricant mixed with some sort of thinning agent, but the Watts lubricator requires a high viscosity lubricant. All IMA systems are shipped from FisherTech with Die Slick 175 lubricant (with no thinning agent) installed. We recommend you continue to use this lubricant, or an equivalent. [top]
- My IMA system is an older model, and a couple of cylinders move slowly even
though I open the flow controls all the way. Do I need new flow controls?
Not necessarily. Remove and clean the mufflers at the back of the machine. Sometimes they become so plugged with oil and dust that exhaust air cannot escape fast enough to allow the cylinders to move properly. [top]
- What should I do with all the runners that I break off the terminations in my
cable operation? Should I put them back in the melt pot?
No! They may contain impurities. Save them up and make arrangements to return them to your zinc supplier for a credit. Let him melt them down and remove the impurities. [top]
- When we first got our IMA system, the sprue would shear cleanly, leaving a nice
smooth surface. Now the area is raised, with a little bump. What is the
problem?
The shut height is not properly adjusted. As the tool rotates to shear the sprue, the tool faces are coming apart too soon. Rather than cutting the sprue cleanly, they are pulling the sprue apart. There may also be damage to sprue hold. [top]
- We have alloy escaping between the nozzle and the nozzle seat even after
following your nozzle alignment procedure. There seems to be a big gap
between the nozzle seat and the nozzle. How can that be? Shouldn't the limit
switch keep his from happening?
The limit switch is only sensing that the mechanism has moved to its full stroke, not that the nozzle seat and nozzle tip are in contact. Proper alignment procedure ensures the nozzle seat is in contact and locked onto the nozzle tip. Before trying to inject alloy, it is important to verify the nozzle alignment by performing the 'tissue test' described in Volume 1, Issue 1 of ENGAUGE. [top]
- I get good service life from the injection nozzles, but when I try to remove
them, they break off. Why is that?
This is easy to prevent with a little routine maintenance. Remove the nozzle from the gooseneck once a week and coat it with a high temperature lubricant. When it does wear out, it is very easy to remove. [top]
- I installed a new injection unit, and it plugged up very quickly. Why did this
happen?
Remember to always skim the dross from the top of the melt pot before installing the unit. Otherwise the dross is driven down into the injection unit, causing it to become plugged. [top]
- Within a few days of installing a new nozzle, the tip was pitted. What caused
this?
The flame is too hot, plus there is likely poor alignment of the nozzle tip. This allows the zinc alloy to stay on the nozzle tip, causing it to pit when it gets too hot. [top]
- Customers periodically call us about the plunger seizing in the gooseneck, so we
thought we would pass on the advice that was given to them ...
Never leave the plunger in the gooseneck (particularly when newly installed) for more than 1 hour without cycling the injection system, unless the temperature of the melt pot has been turned off, or turned down to the point where the metal solidifies.
If by chance, the plunger does seize in the gooseneck, the unit will have to be rebuilt. Give us a call and return the seized unit. We can have a new or re-built plunger and gooseneck assembly to you within about 24 hours. [top]
