Casting a windmill gear in grey iron

Nice castings.
Yep, I would like to see those.

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I am getting the mold making stuff re-orgainized (relocated), and set up for mold making.
Things had gotten a bit scattered when I added the portable garage and moved a lot of things out there.

Getting close to making sand molds.
I just need to decide if I want to use a resin-type bound mold, or a sodium silicate bound mold.

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Here you go Pat, works for me.

A better system would use a wedge or a clamp,

Cheers Charlie

 

I see what you are doing.
I am not sure exactly how mine molds will end up.
I tend to morph things as I go along, and let the needs drive the design.
I don't really adhere to many of the traditional methods of molding.

I am really hoping for a dry weekend.
Swimming in the driveway is just no fun when trying to do foundry work.

Edit:
I seriously need David's pole barn, but it is not going to happen.
I am considering a metal canopy of some sort to allow wet weather foundry work.

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Yes good move; water in the foundry is so yester-year,

Cheers Charlie

 

I had to do a driveway cleanup tonight.
I had stuff from the iron pours last year scattered around, plus stuff I pulled out of my shop when I cleaned it up a few months ago, and scrap metal from the recent furnace build, plus some unrelated junk.
And getting all the grass mowed down low in the side yard.

I just can't do iron pours with junk in the driveway.
I need a clean and clear driveway with no obstructions during an iron pour, and so that work is almost done.

My furnace was still set up for the drip-style burner test that failed so spectacularly, and so I swapped the old reliable siphon nozzle back in place, and started getting it set up again.
That test was really a bust, and I am kicking that burner style to the curb, and will make it into a Delavan gear-pump pressurized type nozzle, so I don't have to use my air compressor.
I have seen ornery mules that behaved better than the drip-style burner in the video below.
And of course to add salt to the wounds, Ironman says his works perfectly, but everything he does turns out perfectly, not that you can duplicate it though.



My siphon nozzle burner will become my backup burner and my gear pump burner will be my primary burner.

I will definitely do an iron pour this week, if nothing else then at the F.I.R.E. event on Saturday evening.
The $100 question is "Can I get windmill gear and bearing cap molds made this week?".

The weather is suppose to clear this week (knock on wood).
It has been raining most days for over a month now, and the ground is like some sort of bog.
If the weather is good this week, then that is going to help very much.

I am going to make an all-out effort to get the gears and bearing cap cast this week.

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Great video!! Who doesn't like fire?

My drip burner worked great first time, and has for months now. Maybe you needed a valve in your fuel line, it looks like you had plenty of fuel.

Seriously, what do you think went wrong?

My drip burner is so simple, just a piece of steel brake tubing down the middle of the air tube with a side inlet for starting propane.

 

I am not sure what exactly was going on, but I worked with it for a while and could not get it to stabilize.

The big flare-up was when the fuel tank ran out of fuel, and so a big gust of air/fuel came out the tip of the burner, thus the mega-flames.

When it was working in a semi-stable fashion (which was a few brief periods), it was not as stable as a siphon-nozzle burner, and I could not keep it stabilized.
I was using a needle valve, but that did not help matters.

My siphon nozzle is so rock solid that I will never use anything else, except I will be using the similar gear-pump spray model which I have not finished.
With a pressurized fuel tank, I can start the siphon nozzle, make a minor adjustment to the needle valve (sometimes this is not needed), and it will run without any fluctuations as long as there is fuel in the tank, and the needle valve never has to be adjusted during the pour.
It works so flawlessly that I have no desire to change to anything else (except the gear-pump model I mentioned, which is about the same thing but eliminates the use of compressed air).
And I eliminated the 0-ring in my siphon-nozzle so there is no danger of that ever failing.

Edit:
The big flare-up is at 1:00.
I did not have to clean my pants out, as I have done stuff like that before experimenting with various burner designs, but I did show that to my wife, and told her "See, the old fart can still move quickly when the need arises".
She knows better than to come outside during burner tests.

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My drip burner may be cheating, I'm using a pressurized fuel tank. I was asking because I had bought a Delavan tip but never installed it because my drip tube works so well. Thanks for the details.

A hot crucible is all that matters no matter how we get there.

 

I like my drip burner way more than the delavan. Too much fiddling with it, air pressure, thinning the oil, don't get it in too far or it will burn up the O-ring...

 

My oil gets filtered but I use cooking oil, old gasoline, gear grease, motor oil, liquids that smell like they'd burn. I really thought I'd burn off the end of the drip line by now bu tit just needs to be rodded out every four hours of burn time or so.

 

I'd like to see that, that'd be a blast.

 

Some people have a knack for making any style burner work well, and hats off to them for having that ability, but I have not had any luck with several burner types, and have not been able to make them work reliably and consistently, despite spending a considerable amount of time trying.

Clarke (porositymaster) can take a shoe string, a wad of bubble gum, 12" of baling wire, and some duct tape and make an oil burner that functions far better than anything I can make, and ironsides is also in that same league.

The Delavan siphon nozzle design works well for me with iron, and it continues to work flawlessly time after time for iron melts.
Instant startup power; no preheating, no adjustments during the melt; total consistency during the melt; repeatable every time.
I could not ask for a better performing burner.
And you have to be careful not to get too much performance out of a burner, else you end up like the problem Clarke had where he was only getting three melts out of a clay-graphite crucible due to excessive heat generated by his Urstuz burner running at its maximum.

The only change I am going to try is a gear pump driven pressure-atomization Delavan nozzle, to eliminate the compressed air.
If the gear pump design works as well as the siphon nozzle, I will be a happy camper, and that will save the wear and tear on the compressor.

The o-ring issue with a Delavan is easy enough to avoid by either pulling the burner back from the furnace when you turn off the burner, or eliminating the o-ring from the design entirely as I did.
But the real issue with a siphon nozzle is the requirement for an air compressor, and that is a valid concern, not with function of the burner but with wear and tear on the compressor over time.
This is the reason that Clarke went with his Ursutz-style burner (his air compressor wore out).

Gear pumps are cheap enough, and the spray nozzles that go with a gear pump are also reasonably priced, easily changed, have a built-in filter (you should still use an inline fuel filter), and pressure-atomization type spray nozzles don't have o-rings.
The reason pressure-atomization type nozzle does not need an o-ring is because you do not need to separate compressed air from oil, (you are only pumping high pressure oil to the nozzle).


Bottom line: If you build a burner, and it works well, no matter what style it is, don't go to the other side because the grass looks greener; stay with what works for YOU !

Edit:
There was a guy who got on the other forum, build a delavan siphon nozzle, tried to run it, and was jerking the compressed air and needle valves wildly, all the while complaining loudly "What the heck is wrong with this PIECE OF JUNK ?"
The last complaint I hear from him was when he posted "This piece of junk burner just blew the lid off of my furnace and it flew over the top of my house".

So the moral of this story is "garbage in, garbage out".
If you are clueless by nature, and prone to self induced "accidents" (that you always blame on others), then perhaps you should choose a safer hobby.
Not trying to be snarky, but I have seen some folks on forums who have no business trying to operate a furnace/burner, mainly because they don't listen, and won't learn how to do it correctly.

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Cleaning and organizing again today.
And it did not rain today for the first time in a long long time, so I was able to use the leaf blower to clean off the driveway.

As luck would have it, the extension cord welded itself onto the prongs that project out of the back of the leaf blower, and removing the extension cord will require either breaking the back off the leaf blower, or taking it apart (I guess I could cut off the cord, and then cut apart the end, but if the prongs welded, then they will probably weld again, and so need replacing).
Now what are the chances of that happening?
And this is a good reason why all appliances should have cords, and not just two prongs sticking out.
One time I had an extension cord arc at the connection point and start to melt, but never had one just weld itself on permanently.
No amount of leverage is breaking it loose without the back of the blower starting to bow out.

Found my respiratory hose (it was in the trunk of the car).

Set up a molding table.

Sand and resin are in place.

Mixer is cleaned and ready.

Part of my problem was renovating a relative's house about 1.5 years ago, and many of my tools and equipment got boxed up, moved over to another house, used for 7 months, and then all moved back in boxes. That really turned my stuff upside down, and I am still sorting things out from that. Some of my stuff is still over at that house.

I think I will be set up for mold making tonight, so I need to decide on what to mold first.
I think I will go for the windmill gear first, since I expect it to potentially offer the biggest challenge, with no draft on the gear teeth.
I will probably try melterskelter's silicone spray on the pattern, and hope that works well.

I am out to the shop for more setup/work.

Moldmaking tonight?
We shall try.

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Melterskelter is not representing silicone spray as likely to allow release of a rather deep zero-draft
pattern in silicate-bound sand. Boy, that pattern had better be slick as and smooth as can be cuz if there is any surface irregularity, that sand will be wedged tightly in that/those irregularities. Yikes! Keeping my fingers crossed for you on this one.

In this sort of situation if you have a pattern like this one with zero draft and rather complex shape that would make application of draft after the fact difficult, one out might be to cast a two-part urethane mold from the plastic pattern from which you could cast a 30 durometer urethane pattern. Then the pattern itself can bend and stretch to allow it to draw from a hard sand mold.

Denis

 

I would have no idea as I have not played with PLA. Maybe that will be the answer. But something has to give. And I don't think it will be the intact sand.

Denis

 

Well there goes my excuse to blame someone if this does not work.

I ended up using the Alumacoat.
Damn the torpedoes; full speed ahead.
I have to try something; win, lose or draw.

I have been told that I could not pull patterns that do not have draft from resin bound sand, but I have found that sometimes you actually can.
I have not attempted to pull a zero draft pattern from resin bound sand that is this deep, so we are in uncharted waters.
Nothing ventured, nothing gained as they say.

I decided to cast one gear and the bearing cap first, and see how that goes.
If the first gear does not turn out, then no need to try a second one.

As I think about it, and after seeing David's lost PLA work, the gears are an ideal candidate for the lost PLA process.
I am not set up for lost PLA though, so that is out of the question.
As far as having some sand breakouts, I believe that would add material to the casting, and so the gears could be cleaned up/filed/die ground, and the defects ground off, assuming the defects due to sand breakouts are not serious.

As far as surface finish, the teeth can be cleaned up and smoothed a bit before use, and they will wear in.
Cosmetically they may not be perfect, but the bound sand makes for a very dimensionaly accurate casting, and in my mind having a perfectly round gear is far more important than superficial surface defects.

The trick with pulling patterns out of bound sand is to use a side hammer, and break the pattern loose with a sharp impact force.
The 3D print is quite good, so we will see if the pattern pulls or not.
Sometimes with 3D printed patterns, the impact will pull the screw out of the plastic, especially a piece that has a low percentage of fill in the center.
I will probably use a round wood dowel the size of the end of the gear boss, and hit that with a hammer.
And maybe put the mold over a hole that is the size of the gear to prevent mold breakage.

I am putting perhaps 4 coats of Alumacoat on the pattern.

I almost got to the point of mixing sand tonight, but not quite.
I still have a little flask assembly work to do.

Photos tomorrow.

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If your current mold strategy doesn't give you a useable mold perhaps you might consider making your drag in 3 or 4 sections like a sculptor would when pouring plaster on a clay sculpture to get around undercuts. Then glue the pieces together. ie set your pattern, partition the flask, place and cure your sand in that section. Then remove one partition and place it in its next position, dig keys into your cured sand and cover with Saran Wrap, then place your next section. Lather rinse repeat. Of course you would have to come up with a strategy to incorporate gating and sprues, etc. The fact that you're using bound sand would make this method very do-able.
I know, I know..... "Alls ya gotta do is...." Lol.

Pete