Preparing the Master Caster for Automation

[chloe123]

Apart from connecting air lines, flow regulator, etc., my machine appears to accomodate automation (You'll find a progress report on prev page)

Wonder if an ingot pre-heat shelf could be constructed in a way to release ingots in set time associate with the displacement of lead. Instead of a sens. servo motor, perhaps a small cylinder(s)could open a hinged door to release lead into top of pot. Based on the success of your automated machine, apart from the return hiccup, lead supply seems to be a limiting factor

[Tazza]

There were a few ideas about this posted in another thread, i don't believe any were used though.

It does take time to get low enough to need more lead, the idea of the automation was so you don't need to be there all the time, but so you can be doing other things and check on it from time to time.

You could always have a run counter so you can work out how many cycles use the same amount as an ingot and have it drop into the pot. Remember you have "waste" in the form of the sprue, not just the weight of the projectiles.

Another idea was like a counter weight, so you have a weight in the melt that will float, as it lowers it can allow more molten lead in, like in a carburetter and a float that allows in more fuel as required.

If you do automate ingot addition, do let us know, this would be very interesting.

[chloe123]

Threaded a few holes and I'm full of ideas. I have no idea if it'll even operate yet. The dependence on the operator is noted. And it's a good general safety point: don't expect to have the unit run without oversight

Before I started reading about your guys' accomplishments on this forum, I never really thought too much about the sprue size. Do you try to minimize sprue size as it can be controlled?

...while I was at Magma, the owner showed me the 2 part float system of the bullet master. Till then, I wasn't aware of such a system.

The extent of my own innovation:

[Tazza]

I was the same. I had done all this work and i was hoping it was not all for nothing. I had it wired up like a bomb, control module, wires all over the place, just for proof of concept. It functioned, so i knew it would be alright. As you have gotten the same parts as Wyman used, and drilled holes where he said, especially for the main ram, it will be fine. The rest is just fine tuning and wiring.

Keep the sprues larger, ideally make it so they join together, as if one breaks free, they both come off the plate. You also want enough so that the projectile fills out correctly. It will also need the reserve to draw in a little more as it cools. If you look at the sprue on a cooled drop, you will notice a dimple on each cavity, it's not much, but if there is not enough there, it will come from the base of the projectile where the sprue touches the mold. Again, all of this can be fixed later, just small adjustments.

Keep us updated on your progress, and remember, we all love pictures

[HATCH]

Based on my experience you want to initially set the lead pour for the largest sprue that it will hold. This is done with a full pot.
What happens is the lead pour is a fixed amount based on time.
When the pot is full of lead the flow rate out of the pot is higher versus when the pot is 1/2 full. So 1 second of lead pour might be 300 grains when full but only 280 when 1/2 full (times and amounts just for discussion's sake)

I had the same thought that you did. Make a smaller sprue so you can cast more boolits out of pot.
So I set it to make sprues the size of chocolate chips. Well after a while they were flowers and the bases of the boolits had small pin holes in them.
So now I make them Hershey's kisses

[jmorris]

Based on the success of your automated machine, apart from the return hiccup, lead supply seems to be a limiting factor

How much lead does the master caster hold?

When I built my machine I made the pot good for more than 60lbs, you can cast thousands without having to top off.

[HATCH]

40 lbs

thats around 1000 250 grain boolits before you run totally out of lead.

I normally cast about 1400 158 grain 38s then stop the machine to fill up with lead again.
Thats 30 lbs worth and 2 1/2 hrs casting.

If I am really paying attention, I can throw another ingot in (5lbs) without stopping the machine but this only works if I do it when its got over 30lbs of lead in it.
If I put more then 1 ingot in at a time the recovery rate is so slow that I risk the chance of the lead pour freezing up.

[Tazza]

Mine seems to recover pretty well. I get to to operating temperature then drop the sprues in, the top freezes but the bottom stays molten and the machine keeps clunking away. If i add an ingot, i keep it length ways so it doesn't cool the entire pot.

I do tend to keep my casting temperatures down, I set it to 330C.

[jmorris]

Mine uses a 3500 watt element for heat and takes awhile to get up to temp. I generally only add the sprues back in while I am casting because my ingots are over 20lbs each and freeze the mix when dropped in.

I just figure it is part of the time to setup and put away. I guess one could have another pot above the machines pot and dump melt into it at any time.

[Tazza]

Wow, 3,500 watts should be more than enough to keep it toasty warm. I thought the MC ran 1,200 watts?

Yet a 20lb ingot would freeze pretty well any melting pot

[chloe123]

The extent to which one could add lead without affecting their rate, that's what I was thinkin' with the comment of preheated lead to the pot . Though I haven't used my MC since the updates (or with the Magma digital controller), I'd like to test adding lead ingots to an otherwise at temperature pot. I'm presuming there's a certain boolit casting temp threshold that can be maintained for average style pistol bullets. When I get mine running, I'll test adding 1 or 2 ingot weights to determine temp drop and affect on boolit cast

[Tazza]

Making a rack or shelf over the pot is a good idea, it does pre-heat them some, not heaps but anything is better than it going in icy cold.

Trial and error is a good way of doing it. You may be surprised at what you can get away with, without having the pot freeze.

[chloe123]

Thought this air consumption guide was excellent. I felt like it was a recent discussion point on a "Star" thread but don't recall specifics


I calculated .45CFM, I believe, with 10 cycles a minute with 3/4" bore 15" length and ~75psi. I think my cheap pancake compressor quotes".6"

I was trying to locate 5" cylinders with heavier return springs (than 3lbs) online and found the chart from Ingersoll Rand

[Tazza]

I'd have thought it would be able to keep up easily.

Did you want to do that or go for a double acting cylinder? that way you are ensured that it will return every time.

[chloe123]

Did you want to do that or go for a double acting cylinder? that way you are ensured that it will return every time.

Yeah, if I hadn't already bought the parts

...it's okay. I thought a heavier return spring in a single acting C may overcome the occasional need for a definitive close that the double acting cylinder provides.

All this talkin' about the incomplete closures made me pause on installing the return spring. That and the comment from one CB member who mentioned attaching the return spring to the arm/handle of the Master Caster . Of course, I'll still do it. Just felt good to take a break from it

[Tazza]

ahh whoops!

An upgrade for later on if you feel it is needed i guess

[chloe123]

Very annoying that the orientation keeps getting switched.

It's stroke appears an inch too short but could it just be moved one inch forward? That seems like a heck of a deal.

(Ingersoll Rand)

[Tazza]

The price is right on that one.

Is 4" enough? I think that is about all i squeezed out of mine, but it does sit lower than what Wyman did on his.

[Tazza]

The other thing is, it says the body is thermo setting epoxy, so i assume that is not steel like the others, i wonder how that would hold up in this situation.......

[chloe123]

Well, it's not the same length. I think the pneuma on the rear is a 5" (per the W. Winn model). This is 4". But, at least from the comfort of my chair, it appears one could move it forward while still giving extra room for extension/retraction as he specified in his '12 Automation thread


...just saw your reply. Good observation. I couldn't expand the photo On their site and posted it pretty quick. I was hoping it would have been in stock locally. $10 is equivalent to foregoing lunch one day

It's late on this side of the hemisphere. Have a good one