Casting a windmill gear in grey iron

I'm with Kelly on this. It would be pretty easy to test the question. Just put a piece of baling wire or light angle in the exhaust stream a few feet above the chimney. I would be willing to bet it will not turn red. It will get a few hundred degree maybe, but probably not enough to blue steel. I base that on the heat right at the chimney vent only being great enough on my iron furnace to turn steel medium cherry red. Much cooler only a foot above.

If I were melting in the next few days, I'd test it out, but I need to machine some existing castings and get them shipped.

If my guess it right, then a simple roof of corrugated steel on a light metal frame does the trick.

Denis

 

This is true, or perhaps just a very minimalistic one to keep the underside of the canopy clean.

I can just put the end of my pyrometer up in the air stream and measure the temperature exactly.

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I think you are correct.

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Note to self:

Two of these gears are required for one windmill, so I need to cast two in the same mold if possible.

 

I was going to mention that the other day, when I read something about one mold, two mold ...I was confused, but also on some pretty powerful meds.

Note to everyone ... foot reconstruction surgery SUCKS!

 

I went back and read our PM conversations again.
I was looking at the Prusa MK3 that you mentioned, and then noticed that you said "By the way, I need two gears".
I totally overlooked that, so I am glad I saw it.
I was hoping to cast two at once anyway.

Surgery in general is not fun, but sometimes necessary.
I had to have my shoulder fixed, and that was a long recovery process, but I can use my shoulder again, so well worth it.

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Wishing you a fast recovery Pat. Gods speed!
Joe

 

No my surgery was years ago, it is Ed who just had work done.

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My mistake but the same sentiments to either of you if in time of distress or pain . Get well soon Ed and again. Gods speed!
Joe

 

Thanks Joe, no worries on the mistake lol.

Last week I had major foot reconstruction surgery. Major as in cutting some bones in half, inserting titanium shims & plates, aligning it all back up and screwing it all back together (all in the arch & heal area). I have incisions on both sides of my foot, the one I could see today was about 8" long ... I also have incisions on my heal where they screwed the heal back on. They are figuring another 2-3 weeks for the swelling to go down. Then a couple months of non weight bearing to let everything grow together ... then start rehab. A long process to say the least.

It might have been quicker and easier just to cut the foot off, then we could have had a casting contest for a new foot design, LOL.

 

I don't have a problem with heat up 7 ft. A heat shield will only re-radiate to your roof at it's temperature, even a 300F heat shield does not radiate much heat. i have metal above and below my roof.

 

I ripped some 2x4's yesterday, and made some stock pieces of various thicknesses, ie: 1", 1.5", 2.0", 2.5" and 3.0".
Then I used the new box joint method to make some new flasks.
Everything worked well (so far), and I got flasks made for the windmill gears and the bearing cap.

I am going to combine the windmill gears with the bearing cap here (maybe David could merge the two together into one thread?).

I made a flask for the bearing cap and worked on sanding that pattern out a bit.
I forgot to take photos but will get those today.

The box joint method I came up with the other day worked flawlessly, other than I got the joints on a couple of pieces backwards and had to remake them.

And I patched the furnace with a bit of ITC200, and ground around the top outside so the lid lip would stop sticking.
Next time no vertical lip on the lid !
Mizzou has aggregate in it that seems as hard as diamond when trying to grind it.
Man that stuff is very tough.

I am taking notes of the dimensions of the sprue/runners/gates/riser, etc., and am making the sprue and runner about half of what I have normally been using.
I have been eyeballing the spure/runners/gates previously, and making everything "plenty big", but am trying to take a more scientific approach this time, keeping in mind John's 10 rules and Bob's advice.








Cleanup on aisle 5.

















And kayak season is almost here.

 

Pat, I'll offer some unasked-for comments that may or may not be helpful but are meant to be useful.

Based on my experience with "ridiculously" small runners lately, I am confident a 1/4 X 1/2" runner will be more than adequate to fill your gear. Your riser is 3 times taller than needed. Better too large than too small. It is nice to see the metal rise in the riser, but putting a scrap of insulating wool over the open riser insulates it and delays its freezing and helps it collapse on top where it is most vulnerable to collapse and will thus ensure the gear itself is not inclined to collapse. The last part of the gear to freeze will be closest to the sprue. If possible, position the sprue 1/3 closer to the gear and put the riser on the gear adjacent to the riser. That concentrates the heat from the riser, sprue and runner in that area and ensures late freezing where you want it under the riser.

I am unsure of the function of the round dowel 1" diameter in the lower left of the 3rd picture from the bottom.

Denis

 

I am always open to suggestions.
Most people here know a lot more than I do about casting metal.
I am an occasional caster, so it is difficult to get much experience in.

A smaller runner would probably work, but this is about as small as I want to try for this go around.
I am progressively downsizing the spure and runner sizes, but don't want to get too small on this casting, since I only want to cast this once.

I don't really think insulating the top of the riser will do much, but then again I don't have your experience, and so after I do more iron castings I may do a full circle and start doing that.

I could probably put the sprue a little closer to the pattern, and I could put the riser adjacent to the sprue.

The sprue and riser are generic/modular pieces that will work with mnay other flask heights and patterns.
They are made extra long so that they will protrude out the top of the mold and can be removed.
I have a core box that I use to make riser sleeves, and the sleeve height can be made to any dimension just by varying how much sand you ram into the box.
I would guess the sleeve will be 2"-3" above the top of the mold, as will be the top of the sprue.

I am not going to use a pour basin, and I don't think it is necessary.
Look at the multitude of castings that ironsides has made without a basin, and the results he gets.
With the relatively small (for me) sprue that I am using, I think I can fill it quickly.

To get rid of the initial air in the sprue and runners, I have swirl basins at the end of each runner, and the runner enters one side of the basin, just like a burner entry into a furnace.
The swirl basin will be at the same height as the top of the spure and riser, and will be open to the air.
I will probably use a sleeve on the swirl basin too to extend it up a bit above the top of the mold.

 

Did you consider one runner (with swirl risers) with a branch gate on each side to each gear?

 

Yes, the sprue and short runner will actually be sawed in half, so that two molds can be twinned (mirrored) and cemented together, since I only have and really only need one pattern.
One of the benefits of bound molds, you can lego-block things together.

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Here is the flask for the line shaft cap.
I started sanding on the filler on the cap and got it somewhat roughed into shape.
I still have more sanding to do, but I am getting there.


The original bearing cap thread is here:
http://forums.thehomefoundry.org/index.php?threads/casting-a-bearing-cap-in-iron.551/#post-14962

 

Huckleberry Cat???

 

Mountain lion.