I will have to make one.
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Ball Hopper Monitor - Casting Project
- Thread starter GreenTwin
- Start date
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STEP file sent.
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I am done for the night.
Good luck.
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Good luck.
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Thought for the morning, why are you splitting it the way your are?
If it is going to be indistinguishable from full size then I'm 99% sure they have a horizontal split line through the decorative bead. This saves having an ugly parting line right round the smooth surfaces and what line you get can easily be dressed on the bead. Probably why they had the bead there to start with. Also considerably simplifies all the draft angles around the bosses where the hopper bolts to the head. And also easy split where top rim joins the core.
Not worth wasting time on it until basics like this are sorted out.
Good job for you I'm not a betting man.
If it is going to be indistinguishable from full size then I'm 99% sure they have a horizontal split line through the decorative bead. This saves having an ugly parting line right round the smooth surfaces and what line you get can easily be dressed on the bead. Probably why they had the bead there to start with. Also considerably simplifies all the draft angles around the bosses where the hopper bolts to the head. And also easy split where top rim joins the core.
Not worth wasting time on it until basics like this are sorted out.
Good job for you I'm not a betting man.
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If you look very carefully at the photos of the original engines, you can see the parting line is vertical as I have shown it.
It is quite difficult to see, but that does appear to be how they did it, and they spit it that way to be parallel to the window.
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It is quite difficult to see, but that does appear to be how they did it, and they spit it that way to be parallel to the window.
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Ok, we give you a bonus for good effort, $1.50 consolation prize, but no cigar.
The basics were sorted a long time ago.
One only has to look closely at the photos of the original engines to see where the parting lines were.
Even without looking at the photos, it is obvious where the parting line must be on the water hopper, or rather is should be obvious where the parting line is to someone who does pattern work for castings.
You found almost 500mb of info on facebook, but have not looked at the photos yet ?
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Lone Star (Maury) posted photos of his matchplate, including the pattern for the water hopper.
Anyone want to bet on where Maury split the water hopper pattern ?
Not that Maury necessarily was aware of how the Baker company split the hopper pattern, but in this case I am sure he did actually know how Baker split it, and that is the split line that works too from a molding standpoint.
Some folks would lose a lot of money gambling here.
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Anyone want to bet on where Maury split the water hopper pattern ?
Not that Maury necessarily was aware of how the Baker company split the hopper pattern, but in this case I am sure he did actually know how Baker split it, and that is the split line that works too from a molding standpoint.
Some folks would lose a lot of money gambling here.
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I did check before posting and see more evidence of a horizontal split than vertical. 2HP I think may be the other way as the mounting lugs are different. PMD was horizontal.
But if you do go with verttical thos eundercut son the bosses may want looking at.
But if you do go with verttical thos eundercut son the bosses may want looking at.
I have not looked at the 2hp, only the 4hp, so I have no idea how they split the 2hp hopper.
The 4hp hopper pattern could be split horizontally, but I don't see the logic to that, given the draft angles on the window.
The draft angles on the window don't rule out a horizontal split though.
Barney did cast his replacement full size hopper with a horizontal split, but it is sealed by tape, and he is not a foundry person.
Looking at the photos of the interior of the hopper, they did fill behind the bosses, and I have done the same.
I think that shows in some of my images above, such as this one.
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The 4hp hopper pattern could be split horizontally, but I don't see the logic to that, given the draft angles on the window.
The draft angles on the window don't rule out a horizontal split though.
Barney did cast his replacement full size hopper with a horizontal split, but it is sealed by tape, and he is not a foundry person.
Looking at the photos of the interior of the hopper, they did fill behind the bosses, and I have done the same.
I think that shows in some of my images above, such as this one.
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The Pacific kit was modeled on a 4hp engine, and that hopper pattern was split vertically on the full sized Baker-manufactured engine.
Interesting that the Pacific hopper casting was split horizontally.
The Lone Star kit was modeled on a 2hp engine, and Maury split that pattern vertically just as was done on the 4hp.
I will have to look at 2hp photos to see if any parting lines are visible on the hopper.
It begs the question, why would Baker not split the 2hp hopper pattern vertically the same way they did for the 4hp engine ?
Edit:
I am seeing vertical parting lines on the 2hp hopper in the photos.
From a hobby standpoint, it makes no difference.
From a historical standpoint, it makes sense to match how it was originally made, at least for me anyway.
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Interesting that the Pacific hopper casting was split horizontally.
The Lone Star kit was modeled on a 2hp engine, and Maury split that pattern vertically just as was done on the 4hp.
I will have to look at 2hp photos to see if any parting lines are visible on the hopper.
It begs the question, why would Baker not split the 2hp hopper pattern vertically the same way they did for the 4hp engine ?
Edit:
I am seeing vertical parting lines on the 2hp hopper in the photos.
From a hobby standpoint, it makes no difference.
From a historical standpoint, it makes sense to match how it was originally made, at least for me anyway.
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Starting round 2 of the water hopper 3D 1/2 pattern print tonight.
The coreprints were acting very strange in the model, and so I deleted those, and created new coreprints from a different starting point, and then shelled the coreprints.
Solidworks can be very particular about things.
Luckily there are multiple ways of doing the same thing in SW, and so when one method fails, you back up and try another approach.
The intent of this exercise is to see if a pattern half can be 3D printed, and then cast in aluminum.
It is a proof-of-concept, and if this works, then we will make all the patterns in permanent 356 aluminum.
I need to thicken the casting wall, and that will be easy on the side of the hopper without the window, but I am not sure what this will do to the window side.
The added material is on the inside of the pattern, and so will not be visible.
Nobody could measure the thickness of the casting anyway without sectioning it.
So far, so good.
Not much backtracking tonight.
I will try to get to a point where I can attempt another 3D print tonight.
I still don't understand supports, so I will start with printing the side opposite the window for now.
Filling behind the bosses is too knarly, so I will leave that for later.
Added some registration holes in the corners that are not shown in the images below.
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The coreprints were acting very strange in the model, and so I deleted those, and created new coreprints from a different starting point, and then shelled the coreprints.
Solidworks can be very particular about things.
Luckily there are multiple ways of doing the same thing in SW, and so when one method fails, you back up and try another approach.
The intent of this exercise is to see if a pattern half can be 3D printed, and then cast in aluminum.
It is a proof-of-concept, and if this works, then we will make all the patterns in permanent 356 aluminum.
I need to thicken the casting wall, and that will be easy on the side of the hopper without the window, but I am not sure what this will do to the window side.
The added material is on the inside of the pattern, and so will not be visible.
Nobody could measure the thickness of the casting anyway without sectioning it.
So far, so good.
Not much backtracking tonight.
I will try to get to a point where I can attempt another 3D print tonight.
I still don't understand supports, so I will start with printing the side opposite the window for now.
Filling behind the bosses is too knarly, so I will leave that for later.
Added some registration holes in the corners that are not shown in the images below.
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Slicer gave a support warning, so I turned on "supports everywhere".
Double shrinkage factor.
Both coreprints in place.
Here we go with print attempt No.02.
Place your bets folks.
I feel good about this one.
I guess this approach is going to lend itself to the corebox method.
The 3D model modification required to make a corebox should be pretty simple to make on this model, since it is behaving much better than the REV that I was using last night.
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Double shrinkage factor.
Both coreprints in place.
Here we go with print attempt No.02.
Place your bets folks.
I feel good about this one.
I guess this approach is going to lend itself to the corebox method.
The 3D model modification required to make a corebox should be pretty simple to make on this model, since it is behaving much better than the REV that I was using last night.
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I'm not going to spend as much time on this but one comment on the latest pattern. I see you have added a machinging allowance now. However that is still a vertical face as are the ends of your core prints. It is usual to add draft to both of these surfaces so they can be extracted more easily from the sand.
Of the 500mb there is so little on the 4Hp. As I said what is there suggests to me a horizontal split more than a vertical. It does not matter to the window which way the split goes as the back face is not look vertical. But it does make it easier to pull the four bosses around the bottom as well as leaving a "cast" surface around the top as the line left where the core and mold meet can be around the lower lip rather than the top edge. Bonus is the core will have an easy vent with less risk of gasses getting trapped.
Of the 500mb there is so little on the 4Hp. As I said what is there suggests to me a horizontal split more than a vertical. It does not matter to the window which way the split goes as the back face is not look vertical. But it does make it easier to pull the four bosses around the bottom as well as leaving a "cast" surface around the top as the line left where the core and mold meet can be around the lower lip rather than the top edge. Bonus is the core will have an easy vent with less risk of gasses getting trapped.
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You can clearly see the side-to-side grinding marks on the parting line in this photo.
It is to the left of your left-most arrow in your photo above.
I am not sure why the face of the coreprint would need to have draft angle, but I guess that could cause some breakout.
Does not matter on the end of the coreprint though if you have breakout, because that is not casting down there, but rather where the core meets the mold.
I guess we will find out about the lack of slope, but I have not used slope on the end of a coreprint before, but have not tried to cast something with such a large coreprint either.
With bound sand, the mold could actually end at the end of the coreprint, but it would be hard to do that with greensand.
The core is vented through the center, with both ends vented up and out the top of the mold.
I will probably use a large vent through the center of this core; perhaps 1 inch diameter.
The core needs to be lightly flamed to drive off any residual moisture.
I think some folks neglect to flame their cores, and also neglect to vent them out the top of the mold from both ends of the core..
Edit01:
As far as layout in the mold, I may cast the hopper upright, so I can gate into the bottom flange, and avoid having to grind in an area that won't be machined.
The knife gate would be shaped like a horsehoe, and would be entirely below the bottom flange.
A three-piece mold would allow this.
Edit02:
The nose of the green twin base was pretty flat, and it tended to break out the mold slightly, but it did not matter since there is a hole in the casting at the front of the base where a belt goes. A little breakout is ok if it is in a non-critical spot.
Edit03:
A strip of mylar would stop any breakouts on the end of the coreprints.
I plan on using a mylar strip around the flywheel rim, in order to get a perfectly flat rim right out of the mold.
Nothing worse than trying to grip a sloping surface in the lathe chuck.
Edit04:
If you did not want to keep up with mylar strips on the ends of the coreprint, you could use an automotive feeler gauge, a thin one but still stiff enough not to bend, and just run that down around the end of each coreprint. Pretty simple solution.
It is to the left of your left-most arrow in your photo above.
I am not sure why the face of the coreprint would need to have draft angle, but I guess that could cause some breakout.
Does not matter on the end of the coreprint though if you have breakout, because that is not casting down there, but rather where the core meets the mold.
I guess we will find out about the lack of slope, but I have not used slope on the end of a coreprint before, but have not tried to cast something with such a large coreprint either.
With bound sand, the mold could actually end at the end of the coreprint, but it would be hard to do that with greensand.
The core is vented through the center, with both ends vented up and out the top of the mold.
I will probably use a large vent through the center of this core; perhaps 1 inch diameter.
The core needs to be lightly flamed to drive off any residual moisture.
I think some folks neglect to flame their cores, and also neglect to vent them out the top of the mold from both ends of the core..
Edit01:
As far as layout in the mold, I may cast the hopper upright, so I can gate into the bottom flange, and avoid having to grind in an area that won't be machined.
The knife gate would be shaped like a horsehoe, and would be entirely below the bottom flange.
A three-piece mold would allow this.
Edit02:
The nose of the green twin base was pretty flat, and it tended to break out the mold slightly, but it did not matter since there is a hole in the casting at the front of the base where a belt goes. A little breakout is ok if it is in a non-critical spot.
Edit03:
A strip of mylar would stop any breakouts on the end of the coreprints.
I plan on using a mylar strip around the flywheel rim, in order to get a perfectly flat rim right out of the mold.
Nothing worse than trying to grip a sloping surface in the lathe chuck.
Edit04:
If you did not want to keep up with mylar strips on the ends of the coreprint, you could use an automotive feeler gauge, a thin one but still stiff enough not to bend, and just run that down around the end of each coreprint. Pretty simple solution.
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Does look like the Pacific hopper had a horizontal split.
Very clean casting.
Someone knew what they were doing.
Professional foundry no doubt.
The Lone Star iron castings were also fantastic; the best I have ever seen.
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I don't see a video of Myfordboy castings his water hopper.
He may have split his horizontally.
His gas tank was cast in multiple pieces, and so I guess it is for looks only, with another tank somewhere, or maybe he got a gastight fit ?
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I don't know who's build this was (not my photo), but appears to be a Lone Star engine, 2hp style, and clearly a vertical parting line, which makes sense because Maury's matchplate was laid out that way.
The side pull at the boss does not appear to cause problems, but I would guess my pattern will take a slight amount of fill at the bosses on the outside.
I definitely need filler on the bosses on the interior.
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He may have split his horizontally.
His gas tank was cast in multiple pieces, and so I guess it is for looks only, with another tank somewhere, or maybe he got a gastight fit ?
.
I don't know who's build this was (not my photo), but appears to be a Lone Star engine, 2hp style, and clearly a vertical parting line, which makes sense because Maury's matchplate was laid out that way.
The side pull at the boss does not appear to cause problems, but I would guess my pattern will take a slight amount of fill at the bosses on the outside.
I definitely need filler on the bosses on the interior.
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Attachments
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This is a 28 hour print, with all the supports, so I will be back tommorrow with more photos, assuming all goes well.
I am sure I did not need this many supports, but I guess I will figure those out as we go.
Rather a waste of filament, but I am still very much in the learning curve on the new Prusa.
The exterior has a slight wave to it, but the lines are very minimal.
Any minor surface irregularities can be buffed out of the permanent aluminum pattern with a sanding sponge easily.
The grooves on the curved surfaces will have to be dealt with on the plastic pattern half, with a slow speed sanding sponge.
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I am sure I did not need this many supports, but I guess I will figure those out as we go.
Rather a waste of filament, but I am still very much in the learning curve on the new Prusa.
The exterior has a slight wave to it, but the lines are very minimal.
Any minor surface irregularities can be buffed out of the permanent aluminum pattern with a sanding sponge easily.
The grooves on the curved surfaces will have to be dealt with on the plastic pattern half, with a slow speed sanding sponge.
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