Role of the Master Caster Fan

[chloe123]

I experienced disintegrating boolits yesterday. I was cycling my automated Master Caster with 45 caliber boolits. When things happen automatically, you gotta figure out a way to inspect your product. This particular mold is challenging as it's a dual cavity design. The weights differ, so ensuring your pour is generous on the smaller cavity is crucial to fill out the base of the larger cavity. I had stopped to inspect the boolits. I didn't see any deformity so I resumed. At some point I recognized lead particles spewing in several directions upon the carrier opening, instead of boolits dropping down into the bucket. I stopped the machine.

Temperature, low 700s. Under 750 for sure. Remember, it's automated so cooling time is fixed. Manually, this has never happened. My hunch is that the core temperature of the mold increased beyond a typical temperature to cool the boolit in that timeframe. 452 size is an interesting size for a Magma in that it's the greatest diameter permitted for a 2 cavity mold. Does that chamber size play a role in possible overheating in a Magma sizes mold? And is there a temperature at which an iron mold becomes difficult to cool from simply the surrounding air?

Remember, the machine's pour, and dropping of boolits, is automated so I couldn't just let it sit in a post-pour, pre-drop position.

My design has a "Big Boolit" feature and Hatch recently advised how to get a little more flexibility out of it. I was able to run this mold with that feature enabled. Basically it enhanced the cooling time--probably 'bout 50% more time. Although the boolits cast were atrocious(previous issue resulted in lead splatter on face of mold), they didn't fly apart when the mold carrier opened. I'm confident in future casting with this mold as long as I extend the cooling time.

However, I'm still baffled about it all. One unique feature of my automated Master Caster, and some others, is that the fan is inoperable. Or, it doesn't serve a purpose, as the mold doesn't remain under the direction of the fan. The mold carrier is either in the lead pour position or it is extended in the open position to release the boolits.

When casting by hand, I'd always allow a mid step to the throw. This intermediary position allowed the fan to blow on the sprue. It was an indicator, for me anyway, when to pull down completely. Once the shine of the sprue was gone and it hardened, I'd pull the handle. At that time, I never really thought about the temperature of the mold, and whether this step allowed the mold to maintain a equilibrium temperature.
i just thought of it as cooling the sprue.

There are members who have automated their Master Casters and have designed them in such a way as to retain this mid point in the cycle. I know this only through videos posted on this board. Though I'm running a Hatch design, and am pleased with it, I wonder why others have chosen a more complex automated cycle. Not clear whether they may have experienced specific issues with the original design or simply wanted to mimic the manual movement. As down-up-down seems more complicated from a control standpoint, I do wonder about their motivation. In general, ya try to make things as simplified as possible. There's gotta be a reason why others have chosen a different method. This role of the fan is intriguing to me. In retrospect, I wish I had a way of knowing the temperature of that 45 mold when the issue occurred. If I could compare it to other successful cycles, it would provide some correlation.

The issue of boolits falling apart as I mentioned above has not occurred with casting of any other sizes. I have cast larger;however, those molds are single cavity and require the respective orifice plate.

[Tazza]

The fan really does it's job when the mold is at the bottom, not a lot when it's under the lead pour spout. Without the fan the mold would get too hot and you would need to slow right down.

Mine was used when i got it, it came without a fan so i built one so it would direct some of the air over the mold when the arm was under the spout to assist in cooling somewhat.

How long does it sit under the fan to cool down?

[jmorris]

Temperature, low 700s. Under 750 for sure. Remember, it's automated so cooling time is fixed.

When casting by hand, I'd always allow a mid step to the throw. This intermediary position allowed the fan to blow on the sprue. It was an indicator, for me anyway, when to pull down completely. Once the shine of the sprue was gone and it hardened, I'd pull the handle. At that time, I never really thought about the temperature of the mold, and whether this step allowed the mold to maintain a equilibrium temperature.
i just thought of it as cooling the sprue.

There are members who have automated their Master Casters and have designed them in such a way as to retain this mid point in the cycle. I know this only through videos posted on this board. Though I'm running a Hatch design, and am pleased with it, I wonder why others have chosen a more complex automated cycle.

I cast at lower temps than that (at least according to my PID/thermocouple) I tinkered with the machine I built for quite a while before I found where it worked best and it's in the bottom half of 600 deg F, again according to what I have.

Your cooling time doesn't have to be fixed, seems like one more timer and maybe another solenoid would be all it would take to hold the mold at the bottom of the stroke.

I didn't do anything complicated to have your "mid point", just only had 30 rpm gear motors when I built mine so it's just always slow. FWIW I rarely need to use a fan or the cool down timer.

[wymanwinn]

i routinely cast 230gr-.45acp and 250gr-.45Colt bullets on my HATCH/wyman automated Master Caster without the issue you are having....the fan is running at wide open all the time and my pot temp is 725 casting wheel weight alloy at the 10 second interval as originally set....about the only thing i change is the lead pour time.....

[chloe123]

I should have mentioned...I have and, cast in auto mode, with a 250 grain mold (2 cavity) . I believe that was the mold I used in the first run of the machine in auto mode.

The mold I had problems with was the same diameter, but a total of 660 grains(360/300).

I can try to run the fan to aid in cooling but it'd seem the only purpose would be to maybe circulate air a bit, as opposed to cooling the mold/sprue. The location of the fan suits a mid point. But I'll look again. I could be mistaken.

Add...I felt the mold carrier simply being in the top position, underneath the pot and surrounded for the most part by structure, hinders cooling. The J Morris design, post pour, seems to dump quick as it's always moving but it's also an open design. For me, it was more of gaining an understanding of an ideal temperature range, or trend, across the running cycle. And then there was the proportion of casting lead within a mold. There just topics that I thought were relevant.

[Tazza]

The fan may not look like it does anything, but it really does. With mine, i can put my hand under the chute that the projectiles fall down, its cold till the mold drops the projectiles, then you can feel hot air as the air cools the mold. It only needs a little, without one your cycle times would need to be much slower.

As for lead temperature, i run mine quite cool. It is the minimum that the lead will stay liquid and still fill the mold out. It is about 330C (626f), seems very cold vs others but it works for me. Lower pot temperature means it doesn't need as long to cool in the mold before the sprue is cut and projectile dropped out. With a lower pot temperature, you need to be careful to not add ingots too fast or the pot may feeze stopping production or making voids in the projectiles. I watch my PID when i add lead, when it's cooling down, then hits the point it heats up is when i add lead so that it is heating to melt the ingots.

[HATCH]

The mold stays at the bottom for two seconds.
the fan cools the mold.
with the fan off the mold will overheat.
when the mold overheats the lead will not solidify in the allotted time that the default time allows.

You need to keep the fan on when casting.

jmorris, his problem is that he doesn't own a windows based computer.
so he is unable to reprogram the default timers.

D, I am not sure how casting two different sized boolits in the same mold that are 60 grains difference are going to work that well on a master caster

[HATCH]

Also keep in mind that I designed the default times for boolits that were smaller then 250 grains.
In your case you may need to run heavy boolit settings when casting larger then 250 grain.

[jmorris]

It only needs a little, without one your cycle times would need to be much slower.

As for lead temperature, i run mine quite cool. It is the minimum that the lead will stay liquid and still fill the mold out. It is about 330C (626f), seems very cold vs others but it works for me.

Both are likely reasons why mine works, will admit that is not by design, rather all I had.

[jmorris]

jmorris, his problem is that he doesn't own a windows based computer.
so he is unable to reprogram the default timers.

I didn't realize he was using one of the PLC machines.

I was thinking in terms of time delay relays.

Not sure how your system works but would it be possible to add another self exhausting solenoid with a T in the line and a time delay relay that keeps the ram extended, even after the PLC tells it to come back up? Sort of a "stacked" delay. Seems like it might, if the process won't let it pour before the mold is back "home".

[HATCH]

Yeah but to be honest it would be cheaper to just buy a used notebook from eBay.
He already bought a cable

http://pages.ebay.com/link/?nav=item...d=271625026482

That's under $100.00 shipped and would work fine for this.

He needs to reprogram the default double tap timer anyway.

I set the default times based on my machine.
If you stray from the standard machine setup as designed by Wyman then you will need to make program adjustments accordingly.

[chloe123]

Tazza , I hadn't appreciated your comment about the fan when I read it. You're right, the way it's situated, the air column is over the top of the mold regardless of whether at a mid point in cycle or at the bottom.

I read the comments and ran it. Interesting how when you cast, traditionally, with the MC you hold the mold in the middle after pouring lead to cool the sprue and get an indicator of when to release the mold, whereas in this case, the fan is used moreso to mitigate escalated temp of the mold

Tazza, you're system is inspiring. I just saw a video on photobucket though as much as I enjoyed what I think was a buffered dual acting--reversed--cylinder and home spun design, I nor my wife are willing to have a pic of it on the wall



Ill have to read the Jmorris comment a few more times to get a handle on it.

Choosing a custom mold with dissimilar cavities was very poor judgment. I didn't know any better at the time. But, as long as the proper settings are repeatable, there shouldn't be a problem.

I just need to review your guys' archived comments on smoking molds and such. That particular mold needs cleaning. All others I have tried have cast well--about 5 probably

Yes, I did deviate because I didn't know how to handle certain tasks but for the most part the pneumatic design is pretty much similar to the W Winn write up. His detailed instructions are spot on. I'm very fortunate to have that guide and his advice, as well as a Hatch control panel operating the unit. Yes, the double tap doesn't work but maybe I messed something up--I dunno. I'm not ready to spend more cash yet, but will approach a solution soon enough

[Tazza]

hehe my setup has changed some since that picture was taken. The electric solenoid is gone, replaced with an air ram. The main cylinder is now double acting.

The fins on the air box, i feel it does something. It directs some of the air to the mold, not a lot but i figure something is better than none at all.

As you don't have a windows based machine, can you take it to a friend with a windows based machine to program if for you to fix the code in the plc?

[HATCH]

Please don't get my post wrong.
There isn't a perfect setup. There isn't a wrong way to do it.
However since you lack the tools needed to adjust the plc then you will have to adjust the mechanical side to fit the electrical side.

I would be willing to convert your program over to touchscreen style and you could get a touchscreen to make changes.
You would just send me your plc and touchscreen for reprogramming.

[jmorris]

I would be willing to convert your program over to touchscreen style and you could get a touchscreen to make changes.
You would just send me your plc and touchscreen for reprogramming.

Might not be the cheapest route but likely the best. You won't need to buy a PC at least.

[HATCH]

You can get the same touch screen I have for under $150/shipped


EA1-S3ML

[Advil]

I cast small bullets but I like to keep the speed up. 110gr to 140gr. It's still very easy to have the mold overheat and not let the sprue cool enough even with smaller bullets. The number one issue is streaking and build up on the sprue plate and mold face.

I improved the situation a lot by tossing the MC fan and putting two other fans in its place. One high flow 40mm fan that points at the mold when it's up (with a shield to direct air away from the pour spout so it doesn't freeze instantly) and another fairly high flow 60mm that points at the mold when open. I have a cheap computer fan speed control with a dial for the 40mm so I can set it to where it will cool as much as possible without spout freeze. It really extends the time between having to clean the mold face and helps keep the speed up.

The MC fan as it comes stock doesn't really do anywhere near what we need with the machine automated. Not unless you have some fancy system that holds the mold out where it can cool te sprue before cutting.

[Tazza]

I found the same issue, if i go too fast i get lead smears. I did find a drop of synthetic oil did seem to cut down on build up.

I too noticed that it does take some time to cool before the sprue can be cut off. Ideally a small movement to get it under the fan would be helpful but that makes things more complicated. I added fins to my cooling fan so it does blow a little on to the mold. I can't get enough air in there to freeze the spout though.

As Hatch has mentioned before, the automation was not all about speed, it was so it could be working away while you are doing other things. Slowing it down at the end of the stroke a little more is not a big deal if it gives more constancy and reliable operation.

A touch screen is the ideal way of doing it, you will have total control of every aspect of the operation of the machine. It is not a cheap addition, but i bet it won't take long to get your money back with the savings you will be making over buying factory projectiles. I for one am way ahead, my machine is more than paid off with what i would have spent buying from the gun shop.

[HATCH]

If you want commercial volume then you need to purchase a machine that is rated for that volume.
Magma rates it at 500 to 800 boolits a hour.
Thats 250 cycle to 400 cycles a hour (based on dual cavity molds).

If you are running my program using default cycle times then you are operating at around 10 to 10.5 sec cycle times or about 720 boolits a hr.
That is towards the high end of what Magma Recommends for their machine.
Can the machine be pushed to be faster. Sure it can. I had it running for over a hr at 1200 boolits per hour !!!

Wyman did pneumatic because his shoulder was getting sore.
I automated it because I didn't have enough time to get everything done.

Also let me mention a couple of factors....

(1) Modified machine is worth at least $2K USD - this is a fact because I know of two that have been sold for that much or more!
(2) Life expectancy - If you run the machine within Magma recommend cycle times then it will out live you. I can't tell you how long the PID, valves or air cylinders will last but so far no one has worn any of those parts out and I know of a machine that has over 100K cycles on it.

[bbqncigars]

The simple trick to making solenoid valves and air actuators last is to ensure that they only see clean dry air. My job involves pneumatic controls in water treatment plants. They have to work all the time no matter what. The way it's done is to feed them clean dry air. The seals will last as long as the water pipes will (current seal record is 55 years). Air dryers (even the solid state variety) might look expensive until you figure down time and actuator repair/replacement cost.