Member postings for PatJ

Welcome Jack-

The joke is we are separated by a small lake (in our case a continent), but whichever side of the lake we are on, we still have a passion for small engines.

Its a small world after all.

Pat J

Edited By PatJ on 18/10/2022 14:50:44

I am reminded that I am aging, since many of my doctors, dentist, etc. are retiring.

The AARP keeps sending me membership paperwork, trying to get me to join (I am not retired).

My wife and I attended an outdoor festival the other day, and the woman at the entrance booth to one look at us and said "I can give you a senior citizens discount".

I said "No thanks, we WANT to pay full price".

I was thinking that Greta Thurnberg phrase "How Dare You !".

My wife said "Discount is fine", overriding the old man (thanks a lot honey).

I may look old, but I don't feel old, and I don't think old.

I still have my CR500, and ride it on occasion when I get time.

I hope to be buried with my trusty CR500. No finer bike in my opinion.

I just laugh when people say silly stuff like "you need help with that", or "can I help you step up here?".

I think to myself "If they could only see my 'ride' ".

You are only as old as what you ride.

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This is not my photo, but this is exactly the same bike I have.

When I die, they will have to pry it out of my hands.

230 lbs, 60 hp, quite a handful if you open the throttle.

1/4 turn on the grip gives full throttle.

Its a breathtaking machine to ride; and lifetaking if you are not careful.

Edited By PatJ on 17/10/2022 03:50:06

Edited By PatJ on 17/10/2022 03:50:56

I despise the new electronic thermostats, and electronic devices in general.

The problem is no two operate the same. You can't repair them either.

In my older car, it has some simple buttons for heat and air.

My new car has a computer screen, and you have to have a PHD in physics to navigate through the multitude of levels, even to do something simple like reset the clock.

The electronics in microwave ovens do seem to work well.

People don't seem to know how anything works anymore; they only know how to use apps.

My central air/heat system has an electronic control module, and when it goes out, it is about $300 to replace.

My daughter's central air/heat has a gas valve with thermocouple, and there are no electronics to go out.

A thermocouple is about $25.00, and they last for many years.

I am seeing a worldwide shortage of chips/electronics in general now, and so does anyone know how to go back to mechanical relays? I do, but few others do.

And I don't like to be a slave to a smart phone and its apps.

When I retire, I am going to be phone and app free.

For similar reasons, I don't have DRO on my shop equipment.

I aways know that when I got out in my shop, those hand knobs will always work, and never break.

I do use digital vernier calipers.  The batteries don't last very long, but I can't really live without digital calipers in the shop.  Electronics do have their uses, but they seem to overload everything with electronics, more as a marketing thing.

My daughter's new car has apps that the car company tries to get you to subscribe to monthy, so you can use all the features of your car.  This is basically blackmail, in my opinion, but his is the trend, and there is a term for it, which I forget.  Soon there will be an app to use the loo.

Edited By PatJ on 05/10/2022 16:11:59

The problem I have run into with Solidworks is that it is version-centric, ie: one version cannot necessarily read another version.

Perhaps backwards compatible, but not forward compatible?

I forget which way it works, but I have sent folks files, and they cannot read my SW files, and sometimes vice versa.

The alternative was to purchase another product that had a mandatory annual fee of perhaps $1,500.00 or more (perhaps changes every year).

Solidworks was a one-time fee for perpetual license, which is why I purchased it.

So I would look at how versions will affect you, since that can lock you in, in ways you may not anticipate.

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There is a fellow on ytube called Olfoundryman, and he die-casts aluminum using I think a steel mold.

He says you have to spray on a special ceramic coating onto the mold, else the aluminum will stick.

You could cast a permanent mold in gray iron, but that would be a rather tedious thing to do.

The standard reusable mold material is greensand or perhaps oil-based sand (Petrobond).

Aluminum typically pours at 1,350 F, or 732.2 C.

Temperatures in excess of this will give a poor surface finish on aluminum.

https://www.youtube.com/watch?v=KUJDB1jnomg

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Edited By PatJ on 30/09/2022 22:22:01

That is just too cool !

I purchased some babbitt, but have not used it yet for bearings.

I found some high-temp putty ("high" being relative to molten babbitt temperatures), and have not used that either (I am waiting on retirement to shift into high gear, and use all the materials I have purchased).

I played around with casting some small parts with babbitt, just for fun, but got an incomplete mold fill on some of the parts due to the low temperature that babbitt is poured.

Great solution.

Thanks for the pictures.

Edit:

I have heard that sometimes the inside of the bearing shells are tinned, to help with babbitt adhesion.

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Edited By PatJ on 29/09/2022 12:05:36

XenForo is what I see a lot of forums updating to, and it works well.

I love this forum and the folks on it, but this software is tedious to use compared to something modern like XenForo.

I am not one to upgrade software on a whim, and I am in gereral anti-upgrade for almost all software.

But having used XenForo, and then this software, I know this forum is well past due for an upgrade.

This has been discussed forever, and so I think I can safely say that this forum's software will still be unchanged 50 years from now, which as many have said is what folks here like and want.

If the users don't want modern software, who is to argue that point?

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Edited By PatJ on 21/09/2022 22:53:37

Learning 3D modeling is like taking a ride on a jet aircraft, and departing during a thunderstorm.

Looking out the window, everything is foggy, menacing, foreboding; dark clouds, streaks of lightning.

After a few minutes of very low visibility, sudden you break through the cloud cover, and you may see a magnificent sun on the horizon, with a spectacular clear view of an untold distance in all directions.

While you are down in the mix, it all seems like total chaos.

When you hit "that level" where you break through the fog, then all of a sudden you can see clearly where you are going.

It was like that for me, but I was in the fog for quite a while (about a year), and it took me a long time to figure out which way was up.

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Edited By PatJ on 20/09/2022 12:18:29

Learning 3D modeling can be described as being much like the Wright Brothers and others learning how to fly.

Lots of crashing and burning in the beginning, and for a long time.

Nobody really understood what the rules of aerodynamics were.

3-axis control was not understood.

People stood around and studied birds in flight, which is somewhat of a poor design to copy for human flight.

In the end, the Wright Brothers and later Curtis made it all look relatively simple.

The "crash and burn" period of learning 3D is definitely no fun, and I recall that period vividly when I was trying to learn 3D.

Then I got to the "lock-up" or "blow-up" phase, where the model would either explode into something that was not repairable, or lock up and stop working correctly.

I recall saving a unique file after every step, so that when things hit the wall, I could open the previous model version and try to figure out what happened.

But it is shocking how powerful 3D modeling is once you get the hang of it, just like when you master controlling an aircraft. You can go places with 3D, and the sky becomes the limit to where you can soar.

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Edited By PatJ on 13/09/2022 23:46:48

I seriously considered starting a casting kit company at one point, but when you get into the logistics of it, it is not practical from many standpoints, lease of which is profit.

People have not shown much interest in the green twin.

One guy did build and publish a bar-stock version of the green twin in Live Steam recently, and it was pretty decent.

What I really want to cast is a Frisco Standard single.

I have not done any IC work, and am itching to learn it.

And you can't get Frisco Standard single iron castings anywhere in the world, unless you make your own.

We have the technology.

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Edited By PatJ on 23/08/2022 11:49:59

Here is one of the white papers I have studied.

The approach is very scientific, with many options and variables considered.

There are many other white papers like this on the Steel Founders Society of America webpage.

https://www.sfsa.org/tutorials/rotordisc/rotordisc.pdf

Not yet.

I have had a "work-a-lanche" ever since covid started.

I really want to cast a green twin full size, which would have a 10" diameter flywheel.

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I have noticed that portable generator manufacturers inflate their kW ratings by using "peak" instead of a more practical "continuous".

Peak may help a bit if you are starting a motor, but if you exceed continuous, you open the breaker on the genset.

I do like the new quiet generators, since you can barely hear them running, even standing close to them.

Very nice on the ears.

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I have always said "If it works well for you, use it".

Everyone has to find the methods and materials that they are confortable with using, and the methods and materials that make sense to their specific application and uses.

There is no "one-size-fits-all" in hobby metal casting.

The hobby can range from simple open-faced molds, to the most complex lost wax castings you can imagine, or anywhere in between.

I must say that metal casting has been one of the most enjoyable and rewarding things I have ever tried, perhaps because I failed for so long, and then finally got it down pretty good.

Some of it is that you get to play with fire !

My wife tolerates my metal casting hobby, as long as I don't set the house or car on fire.

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Crankshaft fill simulation.

This one is for die casting a cylinder, but still some useful information to be gained from this video.

Here is a great example of why many castings have so many defects from excessive velocity and poorly placed gates.

My sources of foundry infomation include a subscription to "Modern Casting" magazine, white papers about how to convert from weldments to to ductile iron castings, and case studies on the best approach to casting various parts in different metals, using different sprue/gate/runner/riser configurations.

Another source are the videos on youtube about mold fill simulations.

The mold fill simulations allow you to see the results of excessive metal velocity, and accompanying splashing and churing of the molten meltal in the runners and mold cavity.

Solidification simulations allow you to diagnose how a part will solidify, so you can avoid things like hot tears and shrinkage.

I will try to find some links to the better white papers and videos that I have found.

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Edited By PatJ on 23/08/2022 09:16:47

Here are a few random responses to Jason's questions:

A commercial chemical respirator is perhaps $24.00, so no big deal.

A box of nitrile gloves is another $12.00.

Most commercial foundries use resin-bound sand of one variety or another, especially with ductile iron and steel castings. Resin bound sand with a ceramic mold coat makes an absolutely superb iron or steel casting.

My first order of resin binder was 5 years ago, and I am still using that product without problems.

The resin was difficult to find.

You really need to use a commercial foundry sand such as OK85 if you use a resin binder.

Bound sand is not easily recyclable, but you can get very significant casting improvements using bound sand.

Bound sand molds harden, and so you can use a far thinner and lighter mold than with green sand, so my resin-bound molds can be perhaps 30% the size of a greensand mold for the same part.

One less expensive alternative to resin-bound sand is sodium silicate bound sand, which is suppose to work well even with iron. I have used sodium silicate with some molds, but more with cores.

The best way to use sodium silicate as a binder is to use a catalyst, so that it hardens without CO2.

If you can't find the catalyst, you can harden sodium silicate bound sand with CO2, but don't over gas it (5 second gas only).

Sodium silicate does not have the problems as far as chemical exposure that resin-bound sand has.

I looked back in my albums, and you are correct about there being a lot of casting defects with my resin-bound sand molds.

The photos I took in 2012 show all sorts of casting defects, when I used resin-bound sand.

The difference between then and now is that in 2012, I had absolutely no idea what I was doing as far as foundry work, other than pressing a pattern in sand, and then attempting to get iron hot enough to pour into it.

In 2012, I was like a blind man stumbling through the forest, trying to find his way, and hoping for good luck, and ditto when I was trying to learn 3D modeling.

I did not know how to tune a burner so that I could reach a good iron pour temperature, and I did not have a clue about the correct sprue/runner/gate/riser configuration.

Fast foward 10 years, and have studied John Campbell's methods, read many many casting books, watched endless casting videos, etc.

I have now use a much lighter mass furnace now, which fires much faster and reaches iron pour temperatures quicker.

I am now very familiar with how to optimize the temperature of an oil burner.

I know now how to do sprues/runner/gates/spin traps, vents, risers, etc. in a repeatable and consistent way.

In 2012, I was lucky to get any type of casting at all.

Today, I can lay out a flask, pour a part in gray iron, and pretty much guarantee anyone that the part will be easily machinable, with no inclusions, hard spots, voids, bubbles, or any other defects.

People have said "I don't believe you can consistently make very high quality gray iron castings".

My response has been "Come over to my house, bring some patterns, and we will make some iron castings. You will very quickly become a believer". So far nobody wants to see it for themselves.

Talk is cheap, but throwing some high quality iron castings on the table pretty much speaks for itself.

I can match or exceed the quality of commerical grade iron castings easily, and repeatedly, but it took 10 years to learn the tricks.

Yes, that is the real cost.

Prices have been skyrocketing this year, and so you can be generous and say that using resin bound sand adds perhaps $12.00 per flask.

I see people "saving money" by using greensand, and often the have to re-cast a casting more than once to get it right.

Compared with the time spent trying to correct a bad casting, $12.00 per flask is very cheap in my opinion.

You have to factor in the cost of mis-casts that you get when using less reliable methods and sand/binders.

I can't remember the last time I had to recast anything; it just does not happen these days with me.

I have basically made every conceivable mistake that can be made in casting metal, and now I know exactly what to do, and more importantly what not to do.

The slurry that is used for lost-was and lost-PLA castings does appear to have a pretty short life, perhaps 1 year, and you cannot let that material freeze.

I am not trying to toot my own horn, but I do have the gray iron casting thing down very well, and while setting up a home foundry may a bit pricey, stepping up from greensand to resin-bound sand is about $12.00 per flask, best I can tell, and that is on a hobby level.

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Edited By PatJ on 23/08/2022 08:39:27

I learned how to extrude basic shapes in 3D modeling, but then I got stuck trying ot figure out how to extrude something that was not on the standard front, top, side planes.

It took me a while to figure out how to insert a plane in the correct place, and then how to rotate it to where I needed it.

That was a quantum leap in ability once I figured out the plane thing.

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