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darwenguy

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Hi all,
Wonder if any of you have any ideas to add to my casting setup.
Ive been casting for about 5 years now and have been trying to improve and remove labour from the task since i started. Anyone who has done any casting im sure will agree its quite labour intensive.
So far to speed up production, ive made an automated riddle for i dont know what els to call it. But it saves having to grate the sand through a sieve like chedder cheese. Its just a pessure cooker with a screen in the bottom and a geared sawing machine motor and a spring loaded paddle pushing against the sieve.
20210511_143652.jpg

20210511_143701.jpg

I use oil bonded sand to remove the hasle of tempering sand.
I made all my flasks the same and not overly heavy.
I make all my patterns as matchplates so only have to add sprue and riser when making molds.
I made a muller,, (a cement mixer with iron cannon balls inside it.
20210511_143729.jpg

So i still have to shovel the sand out of the mixer/muller into the black tub under the bench, i then have to handball it from the box into the flasks And then beat it in with a rammer.
20210511_143643.jpg

When the molds have cooled they are shaken out into a large bucket to carry the sand back to the mixer.
20210511_145836.jpg

Soo to avoid all this humping sand around and getting a bad back, this is my lastest idea. Its based on my understanding of a jolt squeeze machine.
20210511_145022.jpg

20210511_145212.jpg

The sand is fed down from above and drops into the mold via the flexible pipe. To ram the mold the top cylinder arm is swung out and over the mold and a pnumatic cylinder forces down onto the sand (the 'squeese' bit) then a foot pedle opperates a more powerfull cylinder under the mold to lift it just 10mm and back (the 'jolt' bit)
This works great and the molds come out great. And the sand falls down perfectly fine and as good as the faceing sand from the autoriddle.
BUT this is were im stuck!
20210511_145028.jpg

My screw elavator jt dosent like to move the sand, the sand goes up the arcemedies screw just fine the problem is at the bottom the casting sand doing what its supposed to do just bridges the gap at the 1ft sq bottom of the hopper.
I aleady tried to make the hooper to screw section bigger.
20210511_145036.jpg

And added some knarly breaker bars to the screw.
20210511_145042.jpg

It also has a large vibration motor on the back side of the hopper but this just seams to make the sand compact even more.
It works fine for half a mold untill the bridge forms and then you have to poke it with a bar to get it to spit just a handfull of sand out. This makes the whole machine pretty usless now.
My next plan is to make basicaly a motor gear box drive probably hanging over the top with a slow moving mixer paddle to break up the sand and keep it moveing. Then maybe a new round cone shape hopper to go with it.
When i get thus section sorted il make it so the mixer can empty straight into the hopper and remove more of the shoveling.
Any ideas very welcome, cheep and simple always the best.
 

Tim Wescott

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It just makes me want to carve up some patterns and come visit.
 

Scott_M

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Very nice !
It sounds like the sand packs up as soon as it stops moving. Maybe feed the screw directly from your running cement mixer. Set up some sort of tilting device for the mixer so it will pour at the rate the screw can handle. This way the sand is always moving. Control the tilt and screw with your foot pedal.
Just a thought.
I really like your set up, and I saw your castings in your generator post . Really nice work :)

Scott
 

darwenguy

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Very nice !
It sounds like the sand packs up as soon as it stops moving. Maybe feed the screw directly from your running cement mixer. Set up some sort of tilting device for the mixer so it will pour at the rate the screw can handle. This way the sand is always moving. Control the tilt and screw with your foot pedal.
Just a thought.
I really like your set up, and I saw your castings in your generator post . Really nice work :)

Scott
Thanks, this idea would work i think.
As you noticed i already have the elevator linked to another foot pedle.
I do intend to make a better muller, one with a fixed drum and moveing rollers. So that could sort of dose it at a steady speed. if it had a small trap door feeding into the hooper and i can get them to run at a simular speed.
This would be good as would avoid having to tilt the muller and so can just shake the molds straight into this. That would be perfect actually would only ever have to move the molds and the sand moves its self :)
 

Robsmith

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Coal feeders in power stations work with gravity. The coal falls from a bunker onto a measured speed conveyor (feeder) that then lets the coal fall off the end of the belt down a chute into the Mill . To be ground into fine dust. The major problem here is when the coal is wet. It either clogs in the chute from the bunker or the chute from the feeder to the mill. The solution was to line the chutes with a slick liner. As coal is very abrasive they had to use a very expensive product. Try to find a cheap slippery "plastic" to line your hopper. That might help along with the vibrator.
 

darwenguy

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Coal feeders in power stations work with gravity. The coal falls from a bunker onto a measured speed conveyor (feeder) that then lets the coal fall off the end of the belt down a chute into the Mill . To be ground into fine dust. The major problem here is when the coal is wet. It either clogs in the chute from the bunker or the chute from the feeder to the mill. The solution was to line the chutes with a slick liner. As coal is very abrasive they had to use a very expensive product. Try to find a cheap slippery "plastic" to line your hopper. That might help along with the vibrator.
Thanks, i suspect the casting sand will act much like the wet coal did so would unfortunatly probably just block the next hopper. I got the screw elevator as payment for a job, and had the option of this or a hopper and paddle conveyor belt that fed bottle caps into a machine. I know from experiance the bottle feeder was never much good and ive worked on many elevator conveyors and they just always seam to be very messy and jam often. Im keeping my eye out for some suitable lining material so thats worth a try cheers.
 

Robsmith

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Thanks, i suspect the casting sand will act much like the wet coal did so would unfortunatly probably just block the next hopper. I got the screw elevator as payment for a job, and had the option of this or a hopper and paddle conveyor belt that fed bottle caps into a machine. I know from experiance the bottle feeder was never much good and ive worked on many elevator conveyors and they just always seam to be very messy and jam often. Im keeping my eye out for some suitable lining material so thats worth a try cheers.
Yeah ..Just a thought/ suggestion. ABS or teflon sheets. might work. Most plastics suppliers will be familiar with your needs. Good luck.
 

SmithDoor

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When sand mix is just right it stick to every thing.
Foundry use belts to move sand.
Mixers are great for dry sand add water or oil it will stick to inside.
Muller will fix this problem.

If use natural bonded sand it makes life easier. If you get lucky it is outside door.
This just add the water mix let set for a hour and ready to mold.

A air sand rammer is a very good tool for molding. The make small size just right for small flasks

Dave

Hi all,
Wonder if any of you have any ideas to add to my casting setup.
Ive been casting for about 5 years now and have been trying to improve and remove labour from the task since i started. Anyone who has done any casting im sure will agree its quite labour intensive.
So far to speed up production, ive made an automated riddle for i dont know what els to call it. But it saves having to grate the sand through a sieve like chedder cheese. Its just a pessure cooker with a screen in the bottom and a geared sawing machine motor and a spring loaded paddle pushing against the sieve.
View attachment 125470
View attachment 125471
I use oil bonded sand to remove the hasle of tempering sand.
I made all my flasks the same and not overly heavy.
I make all my patterns as matchplates so only have to add sprue and riser when making molds.
I made a muller,, (a cement mixer with iron cannon balls inside it.
View attachment 125472
So i still have to shovel the sand out of the mixer/muller into the black tub under the bench, i then have to handball it from the box into the flasks And then beat it in with a rammer.
View attachment 125473
When the molds have cooled they are shaken out into a large bucket to carry the sand back to the mixer.
View attachment 125474
Soo to avoid all this humping sand around and getting a bad back, this is my lastest idea. Its based on my understanding of a jolt squeeze machine.
View attachment 125475
View attachment 125476
The sand is fed down from above and drops into the mold via the flexible pipe. To ram the mold the top cylinder arm is swung out and over the mold and a pnumatic cylinder forces down onto the sand (the 'squeese' bit) then a foot pedle opperates a more powerfull cylinder under the mold to lift it just 10mm and back (the 'jolt' bit)
This works great and the molds come out great. And the sand falls down perfectly fine and as good as the faceing sand from the autoriddle.
BUT this is were im stuck!
View attachment 125477
My screw elavator jt dosent like to move the sand, the sand goes up the arcemedies screw just fine the problem is at the bottom the casting sand doing what its supposed to do just bridges the gap at the 1ft sq bottom of the hopper.
I aleady tried to make the hooper to screw section bigger.
View attachment 125478
And added some knarly breaker bars to the screw.
View attachment 125480
It also has a large vibration motor on the back side of the hopper but this just seams to make the sand compact even more.
It works fine for half a mold untill the bridge forms and then you have to poke it with a bar to get it to spit just a handfull of sand out. This makes the whole machine pretty usless now.
My next plan is to make basicaly a motor gear box drive probably hanging over the top with a slow moving mixer paddle to break up the sand and keep it moveing. Then maybe a new round cone shape hopper to go with it.
When i get thus section sorted il make it so the mixer can empty straight into the hopper and remove more of the shoveling.
Any ideas very welcome, cheep and simple always the best.
 

ajoeiam

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Yeah ..Just a thought/ suggestion. ABS or teflon sheets. might work. Most plastics suppliers will be familiar with your needs. Good luck.
I'd suggest uhmw sheets.
Often used for lining troublesome metal boxes to provide a slicker surface.

I don't think you'd find the teflon as 'slick'.
 

Noitoen

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Since the screw is belt driven, you can run 2 shafts in th hopper above the screw with some paddles driven by a small pulley on the main motor. This would stir the material above breaking down the bridge
 

SmithDoor

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I think most try screws to move molding sand. But molding sand is right the screw just stops working.
FYI I too try screws back in 1976 gave up. Just used shovel and a handy employee.
We could turn out 70 to 100 molds (12×18×4) a day with roll conaiver to set the molds on.

Dave

I'd suggest uhmw sheets.
Often used for lining troublesome metal boxes to provide a slicker surface.

I don't think you'd find the teflon as 'slick'.
 

Richard Carlstedt

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Less expensive than UHMW is Formica and it comes in thin sheets at home supply stores.
We used Formica when our hoppers would hang up with wet material.

Do not run the vibrator UNLESS the auger screw is turning- They are a joint operation, else you get packing

Also, Vibrators are directional motivators..
Pay attention to the direction axis. Moving the location can change the effect.
.Like up/down moves can pack, while rotate will give feed

rich
 

ignator

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You've probably thought of this, but your knarly breaker bars, maybe some added weldment to the ends that will make a much larger cross section to stir the caking material. They should tend to push the material in the same direction as the big screw.
 

timo_gross

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You could try to figure out how the bridge forms. Switch your auger off and try to poke it with a stick to get a feel what is going on How persistent the stuff is. Did you look into adjustment of sidewall angles? Some hoppers have asymetric specific profiles. Wider is not always better.
Preventing the material from having even pressure from two sides and forming stable arches is the goal.
For example a piece of sheet metal that makes one side vertical is an uncomplicated trial.
Special shaped triangles to keep it from compacting under its own weight.
Air nozzles, ( they give a short burst in certain intervals, I guess for this your hopper must be somewhat closed ).
Moving side walls similar to a jaw crusher, vibrating or slow moving.
Small piece of vertical belt conveyor, or chain conveyor to keep it from forming a bridge.

What is your budget? You could ask Solutions for foundries | Kuettner Group sales. "State of the art automatic molding line" sounds like exactly what you want :) .

Just kidding.

Greetings Timo

p.s. the video is the next best I found.
 
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