Ball Hopper Monitor Patterns/Castings Attempt

[Casting Iron]

I was able to add a window in the side of the hopper, but it does not have any draft angle.
I may hack in a bit of draft, or just fill it after 3D printing to get the draft angle.
I will get it as close as I can in the 3D model.

Edit:
What I really need is a way to add a draft angle, but only on some surfaces, not all of them, when extruding a shape that has draft angle.
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[Jasonb]

Alibre will let you add it at the extrude stage or add it individually to any face after it has been extruded parallel. Pic shows the two options.

This is where the Booleen comes in handy as you can make triangular extruded cuts across a solid to add draft and then you just use the subtract to remove that resulting solid

Another option would be to do two 2D sketches and loft from one to the other. depending on the offsets of the sketches you will get different draft.

[Casting Iron]

SW is falling short on this part, but I think it is due to my lack of how to use the program.
I have used the loft across different shapes; its a little tricky to use that feature.

I am somewhat pleased with how the window is, but the rest of the model got damaged a lot in the process of making the window.

I played with boolean the other day, but I find it very quirky in SW, to the point where I can't make it work correctly.

What I will do is a save-as, and make one part a hopper with a hole in the side, and with the other file, trim away the round hopper from the widow, to make a window only.

The two parts will then be glued together for a pattern.
I think this approach will work ok.

Sort of a manual boolean thing.
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[Jasonb]

I  suppose it could just be that you are using quite an old version of SW and things have improved over the years.

[Casting Iron]

Generally speaking, Solidworks seems to do pretty much everything, if you can figure out exactly how to do it.
Sometimes ytube videos are useful, and sometimes not so much, such as boolean.

I am using 2012, so that is a bit dated.
One-time perpetual license thing, so no updates ever.
I bought it for the occasional work project where I have to work things out in 3D, due to multiple levels, alignment issues, etc.

I know some folks who use AutoCad's 3D program (forgot the name), and it is perhaps $1,500.00 per year fee.
That is why I purchased SW; one time lump-sum fee; no yearly fee.
13 years times $1,500 per year is $19,500, so I have saved $15,500 so far.

I can do 99.9% of my modeling without boolean, so I am reluctant to deep-dive into something I don't really need.
I have used it a bit to create views of cores and such, like the one below for the water jacket and bore on this engine.
I think I used a simple add or subtract feature to create this; I forget exactly, but it was simple.

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[Casting Iron]

I am going to work on the water hopper window a bit more tonight, and then I am going to have to pause for a week or so on the BHM, since I have had to large projects come back from client review, and they need to go to 100% ASAP.

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[Casting Iron]

Here is my "manual boolean" on the side of the water hopper that has the window.

I cut a clean hole in the side of the water hopper of the appropriate size, and saved that file under "hopper".
I then saved that file under a new file name "window".

In the "window" file, I added the window, and cut away the hopper.

In the assembly, I added the hopper with the window hole, and then added the "window" part into the hole.

Seems like this will work ok.
The hopper and window will be 3D printed seperately, and then glued together to make a pattern.

It is much easier to see/manipulate/modify the window when it is not part of the hopper.

Now the carb/intake valve chamber/valve stem fit in the window.

I will print two windows, cut out the sides of the existing hopper right side pattern half and right side corebox, and glue in new windows; or perhaps just reprint those two halves.

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[Jasonb]

Pat, have you tried doing a new assembly of just your hopper with the hole and the "window frame" ?. If that is saved as a STEP file it can then be treated as a "single" part and you would then be able to print it rather than having to do two prints and manually assemble them.

I've sent whole engine assemblies to people and they have printed the whole engine as one part from that single file.

[Casting Iron]

I figured there must be a way to print an assembly, but I was not sure how to do that.
Saving the hopper and window assembly as a STEP file I think would do it.
That would ensure alignment too.
I will try that.
Thanks.
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[Jasonb]

This is printed from an assembly saved as a STEP file. Actually He Mirrored my single engine and printed a twin a sa single file. Scaled down and Resin printed Stuart Victoria

[Casting Iron]

That is a pretty cool feature, and nice engine !
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[Casting Iron]

I am going to try and make a mold for on of the fuel tank pattern halves tonight, assuming I don't stroke out from the heat.
I have to re-read my notes on the fuel tank patterns, since they will double as a core box.

I will start with the flat side of the tank, since that would probably be easiest.
The plan is to cast a permanent pattern half in 356 aluminum.

Below is the piece I will be molding and attempting to cast (the smooth side).
This is where we left off a few weeks ago.

I think I will put the pattern half entirely in the cope, vent the high points, have two V-shaped runners in the drag, with a tuning fork shaped runner system, knife gates down both sides of of the entire piece, completely in the drag, spin traps on the ends of each runner, short sprue that does not extend above the top of the cope.
Resin bound mold, ceramic mold coat.

Here we go.
At least I don't have to waste money on having a club membership with a sauna; I have my own hot box/sauna.
I could probably rent out time to the health club types.

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[maury]

Just a note on the Monitor gas tank. When I was producing the Monitor kit the foundry had serious problems with blow holes in the gas tank casting.Their process was air set molds with a gassed resin for the cores, don't know what the resin was.
To solve this problem we set the casting vertically in the mold and gated the casting from the bottom. The cavity filled from the bottom letting the core out gas as it filled.
After doing this the blow hole problem was solved.
maury

[Casting Iron]

Maury-

Thanks for the feedback.
Those Lone Star BHM castings were the best iron castings I have ever seen.
You obviously had a very good foundry make those.

I was thinking about core venting last night, and the fact that I will use four graphite rods to secure the core in the mold cavity.
There will be holes through the core in a T-shape, which connect to the rod locations, but the rods will block the vent holes.
I finally decided to use a larger graphite rod at the tank fill boss, since that hole will be larger, and drill a 1/4" hole through that rod, so I can vent out of the mold.

I will be using resin bound molds and cores, and I have found that it helps to flame the molds and core lightly with a wide low velocity propane flame, to drive off residual moisture, and to also burn off residual surface resin.

I plan on casting the tank horizontally, and I think if I can get the venting right, this will work.
I have seen crankshafts cast vertically.
I would say that a commercial foundry with an induction furnace could have better luck filling thin parts, since they could easily superheat the iron far beyond what I can.
I don't have an iron pyrometer, but someone I know who does who uses an oil-fired furnace and burner like mine seems to routinely get a pour temperature in the 2,500 F range.

This gas tank will be a good test of whether I can get iron fluid enough to fill these long thin parts.

I watched a number of videos that were made by Bob Puhakka, and his methods vary quite a bit, but the theory behind what he is trying to achieve does not.
I basically am using a Bob Puhakka approach/thought process/methology/mindset on the sprue, runners, spin traps, gates, etc., which is basically a hybrid approach taylored to suit this casting.

I may enlarge the vent hole in the center of the core; I think I can do this and still maintain the 1/4" diameter at the ends.

This casting will be about 10" long, 4 inches diameter.

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[Casting Iron]

The body was not cooperating last night, so I did not make it out to the shed.
I did some some final sanding done on the 3D printed gas tank pattern half.

The mold will be made just like the green twin base, ie: place the mold half on a flat surface face up, with the sprue going through, ram the cope, rotate, add the runners, spin traps, spure, etc. and ram the drag.

The intent is to produce a permanent aluminum pattern half, which will look like the images below.
There is no core; the drag sand will protrude up into the underside of the pattern.

There will be a few small vent holes at the high points of the cope mold.

Hopefully I will make it out to the shed tonight and begin the molding process.
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