Member postings for PatJ

Using glass on top of an iron melt achieves nothing (as far as any knowledge I have on that topic).

The slag from iron is easily skimmed off, and no additives are needed.

One large foundry (Lodge I think, the cast iron skillet folks) uses vermiculite as a slag coagulant, and they dump it on top of the melt, and then roll a rod in it, to wrap the slag around the rod, where it can be dragged out.

With a crucible melt, the crucible is not very large, and the area to be deslagged is small, so one or two passes with a skimmer is all it takes to remove the slag.

Iron slag is easily separated from the molten iron, and there is a very clear line of demarcation between the two.

I have seen more than one person who uses a method or material, and they create good castings, and thus they become convinced that the method/material that they used is the reason they have good castings.

Often the method or material that folks use has nothing to do with making a good casting, and they get good castings because the method or material had no effect on the melt.

One has to use a blind test to determine if something actually affects the melt, and often I see the wedge test used. There is another test that measures the fluidity of the melt.

I don't use any type of testing on my iron, but instead rely on the fact that my iron castings have no internal or external flaws, and no hard spots anywhere in the casting.

The art-iron folks sometimes use calcuim carbonate in their melts, I think for slag control and fluidity, but I don't use that. I never use any additive that is not required, ie: I don't try to fix problems that I don't have.

The instance I have heard about when using glass on top of a melt is with brass/bronze that has significant amounts of zinc in it.

The zinc tends to burn off before a brass melt is at pour temperature, and that is problematic.

My solution is to melt bronze mixtures that have little or no zinc in them.

If one does use a glass cover, one must be sure to skim it all off, else the glass will flow with the molten metal, just as slag will, and you will have glass inclusions in your casting.

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Edited By PatJ on 20/08/2022 23:33:13

There is generally an abundance of scrap iron laying around.

I use electrical motor end bells, and they are very nice gray iron.

I tried melting 1/2" diameter mild steel rods in my furnace, with my oil burner, but after an hour on the highest heat, they were red hot, but still very solid.

I think the cans would melt, but you would have to submerge them in a pool of molten iron, making sure that every bit of moisture was out of the cans (such as baking the cans at 400 F for about an hour).

I am not sure raw cans would melt on their own, or perhaps with lots of oxidation.

I think the tin would vanish quickly at iron temperatures, or perhaps just mix in with the melt.

I personally would not use cans, just due to the moisture hazard.

And scrap iron can be rusty, or painted, and you don't have to clean that off before you melt the iron, since all that comes off as slag. You do have to make sure your scrap is very dry before you drop it into molten metal.

I hold my scrap pieces in tongs in the exhaust stream of the furnace for about 30 seconds per piece, to drive off any residual moisture.

The slightest amount of moisture (even if you can't see the moisture) will cause a violent reaction if dropped into molten iron.

Good luck.

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No, I never name anything.

That is probably a good idea, but I don't think I would actually use that feature.

My models get so complex that it would be very time consuming to name everything, and I make a lot of 3D models, and my tme is limited.

I don't worry about constraints either; I basically totally ignore them, and I can't recall that ever creating a problem.

When I turn a 3D model into a pattern, I often add machining allowances, and sometimes some external draft, etc., and I generally name those features as "PATTERN", so that I can toggle them on or off.

I create 2D drawings with the pattern features suppressed, and 3D print patterns with the pattern features turned on.

I also use odd colors for the added features, and these features are not merged into the main body of the model, but kept as separate entities. If I forget and leave a pattern feature visible, it is immediately apparent.

I use colors to try and bring in some contrast.

I often make machined holes and surfaces a light red.

Exhaust passages are sometimes red (hot), and intake passages sometimes blue (cold).

I keep things as simple and fundamental as possible.

I do really like creating the screencaptures of every step, and for a complex model, the screencaps are well worth the time to create.

Edited By PatJ on 19/08/2022 00:41:28

It appears that only the liquid rockets on the Shuttle and other boosted rockets have gimble control.

I guess you could install graphite fins at the base of each solid booster, such as was used with the V2, if the fins would withstand the temperature.

I have to guess that the solid boosters gain the initial bulk alltitude gain, and then the after the boosters drop off, you can have fine directional control via the gimballed engines, and well as throttle control, and even on/off control.

I have seen some videos (I think it was a Shuttle launch), where the gimbal controls on the liquid engines rack around at light up, and then move quite a bit during liftoff.

Very impressive and accurate control system for sure, and also imressive that it works across such a wide temerature and vibration range.

You have to guess that the software control guys sweat a lot during launches. (probably all the designers sweat a lot during lanch and operation).

There was an interesting article about how the Russians tested individual engines, vs the US testing all the engines together at once.

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Edited By PatJ on 18/08/2022 19:39:11

I think my original statement was incorrect.

You can go back and modify things using synchronous mode, but in a different way (as i understand it).

Dave's description of how synchronous mode works is very helpful.

Using synchrounous mode would launch me into a big sea of unknowns.

In the end, you are modifying the same model database, but in a different way, with some different effects on the overall 3D model.

I guess it is a matter of using the method that is most effient for the user.

I am a rather methodical person, and I plod along with 3D modeling like a turtle, trying to think ahead about what the best path to a complete 3D model will be.

As far as remembering which sketch did what, I have gotten into the habit of doing a screen capture after each step in the creation of a 3D model.

It just takes a second to copy/paste these screen shots into a photoshop program, but it leaves a nice visual papertrail as to how the model came together.

I also use the screencaps in 3D tutorials that I make, to show the progress of steps to create a 3D model.

I have found the screencaps to be extremely useful when I need to modify a model, and when I can't quite remember all the steps I took. My 3D models tend to be complex, and after a few months, I can't recall how I made them.

In Solidworks, you can hover over the display list, and it will highlight the shape and/or associated sketch on the model.  This is another way to quickly review how the model came together.

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Edited By PatJ on 18/08/2022 19:29:40

"Live section" is another new term.

I can see somewhat what the benefits of getting away from the traditional sketch-based model would be, but to use live sections and sychronous mode required using a completely different paradigm.

Sort of like rearranging all of the controls in a 747 cockpit, so you can fly the plane better.

But first you must have a deep and fundamental understanding of the new paradigm.

It took me about a year to learn sketch-based 3D modeling, and I basically had to learn how to visually section a 3D object in my head, and find the best starting point for an initial sketch, as well as determining a rational approach to subsequent sketches to be added to the model.

How long would it take me to get fluent with synchronous mode?

Who knows. One would have to use it constantly for a long period of time (for me at least), and discover all the advantages, and how it all interacts with the model.

Being able to push-pull a piece of the model without affecting other parts is definitely an advantage, but doing this in a predictable, consistent and reliable fashion may take a bit of time.

It is sort of like me trying to drive in the UK.

Could I drive in the UK? Yes, I could.

Could I drive safely in the UK? No, I could not.

Would I attempt to drive in the UK? No, definitely not.

Would I attempt to learn synchronous mode? No, not at this point. I have gone to far to change horses in mid-stream.

If I were just learning 3D modeling, would I use synchronous mode?

Perhaps, but while I can see what they are trying to achieve with synchronous mode, I don't have a comprehensive feel for what it will do to the model overall, especially a somewhat complex model, such as an example like the Frisco Standard cylinder head below.

Edited By PatJ on 18/08/2022 17:19:14

I am having to learn new terms, such as "prismatic parts".

I guess this is a part that has facets, like a diamond, and not necessarily non-linear curves surfaces and such.

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Specifically the article mentions deleting a underlying sketch, which can cause severe problems, and I have to agree, this should not cause a problem, but the program can't seem to knit the pieces back together in ordered mode when you delete an underlying sketch, or make to much of a change to it.

Edited By PatJ on 18/08/2022 16:33:54

Ian-

Thanks for the link to the article.

I see what he is saying about the dependency on the sketches, and how that can sometimes cause the model to fail, but I will have to study the synchronous method more to figure out how it would work with a complex model.

The examples for the synchronous method all seem to be somewhat simplistic.

I have noticed that significant changes to an underlying sketch can really cause problems with a 3D model, to the point where sometimes I have to start the model over again with a different initial sketch.

I will keep studying synchronous mode, and see if I can get my head wrapped around it.

The ordered method is like a pyramid of stacked dominoes.

Everything is good as long as you don't disturb the base dominoes too much, but too many changes will bring it all crashing down.

Pat J

Edited By PatJ on 18/08/2022 16:33:04

Those solid rocket boosters seem like a quick and dirty way to get a lot of temporary boost for not much complexity or weight.

As I understand it, once you light them, they are not really controllable, but in the early stage, I guess you don't need much control, just heavy lift capacity.

A bit disconcerting to see this much money being spend as the economy starts the Titanic thing.

The Mars thing is pure suicide. That they are even considering that is the definition of insanity.

Technologically, some impressive hardware/rocket engines these days.

I recall standing next to a V2 at the Huntsville Space Center, and trying to figure out the various parts, and how the gyros controlled the graphite vanes that protruded into the thrust stream.

Lots of technology changes in a rather short period of time.

I learned programming using FORTRAN with punch cards on an IBM mainframe, with a line printer.

FORTRAN took us to the moon too. Great language.

The saying is "FORTRAN is dead........long live FORTRAN".

I still have my FORTRAN compiler, just in case I may want to do the Wallace and Gromit thing.

https://www.youtube.com/watch?v=T0qagA4_eVQ

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Edited By PatJ on 18/08/2022 07:01:11

I watched the video "Synchronous vs Ordered Mode in SE", and it appears that in synchronous mode, any sketches that are used do not remain as part of the model (I think in actuallity, the sketches are there mathematically, but hidden from view).

When I am modeling in Solidworks, I always hide the previously used sketches from view, else they clutter up the drawing, and I guess everyone does this.

It should be noted that with each added extrusion/boss, etc., SW gives the option of combining the new extrusion into the existing part, or keeping the new extrusion as as separate entity. This option can be handy when you don't want the new extrusion controlled by the other part geometries.

I have read that some like the synchronous mode, but I can say from experience that for the engines I model, using synchronous mode would be a disaster, since I frequently go back and modify existing complex sketches.

As far as SE being difficult to learn, from watching a few tutorial videos on SE, it seems to be almost exactly like Solidworks, with perhaps different graphics on the tool buttons.

So I guess I don't see the difficulty in learning SE, and I could use it right out of the box I think.

Just a few thoughts.

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Edited By PatJ on 18/08/2022 02:59:47

It is a zero sum game for us.

I make "X" amount of money, and so X has to be divided by all of my expenses.

If gas goes way up (it has), then we drive very little, don't take trips, and walk when we can to the store.

Ditto with other items such as food, utilities, etc.

When expenses go up, we cut back on everything across the board, until all of our expenses meet "X" again.

Right now we pay the utility bill, buy food, and that is about it.

We don't drive the car unless we absolutely have to go somewhere.

Energy prices can't remain high if nobody can afford to buy anything.

What we really need are stable prices on everything, not runaway inflation due to excessive gov spending.

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I have always liked to build/make my own stuff, even as a kid.

I could never play sports, and was the one they always told "go play somewhere by yourself while we play this baseball game".

If you can't play sports, then that sort of leaves a few other things to do, and so I passed the time by making things.

I do my almost all of my own home repairs because many of the local contractors are rip-off artists, and they assume that you don't know enough about what they are saying to object.

One HVAC guy many years ago charged me $350.00 for a "new relay".

I opened the air handling unit, and the old relay was missing.

I called him and asked if he had installed a new relay, and he assured me on a stack of bibles that he had.

I said "Then why is there no relay in the unit". He was a bit shocked, and finally said "Well the cost of the trip out makes it the same amount, and you really don't need a time-delay relay".  The unit is less efficient without the fan-off delay.

Diddo on auto repairs that are not done by a reputable dealer.

I took my car in to get two new tires on the front, and came back later to pick it up, and they handed me a bill for several thousand dollars of unnecessary engine work. They assumed I knew nothing about auto engines, but I use to help a buddy of mine rebuild his racing engines, and I knew everything about an auto engine.

It is a bluff game, and if you are dumb enough to sign the form, then they do thousands of dollars of unnecessary work. That was my first and last visit to that rip-off shop.  Needless to say I only paid for two tires, and they were very lucky that they did not do the engine work without getting my authorization first, else they would have done that for free.

I don't like people BS'ing me about stuff. It makes my blood boil, and it is an expensive scam too.

The general public gets scammed all the time around here. I guess it is a worldwide thing.

And all too often, a contractor will do a shoddy job, which also bothers me greatly, and he will assume that I don't know any better. I end up having to redo half of their work.

So I learned early on to just do it my self, and do it right the first time.

Knowledge is power as they say, and knowledge is also money.

As the US and UK lose their technological edge to other countries, the last thing in the world I want to do is give up any technical knowhow.

I basically want to know how to do anything and everything.

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Edited By PatJ on 30/07/2022 04:21:44

I quizzed my grandmother about how she and my grandfather survived the Great Depression.

She summed it up pretty easily as "Don't owe anyone any money".

She also told a story which I have never been able to verify, but she said that my grandfather, who owned his own lumber mill, was getting his shoes shined (this use to be a common thing), and the shoe shine boy said "I just shined the shoes of two bankers, and they said the stock market is getting ready to crash".

My grandfather supposedly immediately sold all of his stock holdings for cash.

I am not sure if the shoe shine boy story is true, but I have lived by the adage of not borrowing money, or if I borrow money, it is a 5 year or less situation.

My wife and I have only purchased one new piece of furniture in our 37 years of marriage, which was a new couch. The rest of our furniture is used and/or hand-me-downs.

I run my own consulting firm, and I survived 2008/2009 by selling my office building and moving my company into the 2nd floor of my house.

Working out of one's house is pretty recession-proof.

A guy who ran a local Chinese restaurant told me that the way to make it no matter what is to run a small grocery store. People have to buy food, and you will always have food.

We always keep our autos for at least 10 years, sometimes more.

I do almost all my own repairs around the house; electrical, plumbing, painting, siding, woodwork, floor refinishing, sheetrock, etc.  I do auto work too if it is not too complex.

I bought a commercial washing machine, which cost double what a residential unit cost, but it lasts perhaps 5 times longer.

I do all my own yard work, cut down my own trees, and cast gray iron in my backyard foundry.

I guess I am sort of a do-it-yourselfer, and a bit of a survivalist, but not a whack-job survivalist.

We keep about 10 cases of can goods on the shelf, a 25 lb bag or rice in an airtight container, water filters (from the backpacking days), propane, cook stove. We buy food from a bulk store, since that is a lot cheaper.

I have two generators, a 1.5kW and a 5kW, and since I run my business out of the house, they are both inverter-equipped.

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Edited By PatJ on 29/07/2022 21:19:30

As I understand it, the political members responsible for the last regime change in the US have put the screws to the US oil companies via limiting their access to money/loans/financing.

The green folks here have declared war on coal, oil, and even nuclear and natural gas.

It is insanity on a massive scale. Sort of like setting fire to the bottom of a tree, when you are at the top.

We were exporting energy right up until the regime change.

And duffer is right, who wants to spend a lot of money on capacity that probably won't be needed once the recession kicks into high gear.

I must say I am not too keen on nuclear energy ("Nucular" as George Bush use to say).

But I would not cut my own throat to spite nuclear. I would rather have nuclear than freeze to death, or roast alive in the summertime.

We can have four weeks or more above 100 F in the summer, with 70% (+) humidity.

They added all sorts of scrubbers in the local coal plant, but it was shut down for political reasons.

They built a natural gas fired plant right next to the coal plant, but of course the greenies will shut that down too.

I recall an old refrigerator that had a dumbell looking contraption, which was two spherical tanks joined by a pipe.

One pipe went out though a hole in the wall, and a fire was made under it.

The other sphere went in the refrigerator.  We may have to get back to such simple devices.

I have also seen natural gas refrigerators that work on the same principle.

It is getting rather pricey to travel these days, and filling up the gas tank feels like taking out a loan for a house.

We have basically stopped buying anything that is not immediately necessary, and critically necessary.

We were considering purchasing a new car, but will now be doing the Cuban thing with our 10 year old car, so that it will last 50 years.

Our spending now is basically tailored as if another Great Depression is coming.

Hope for the best, but plan for the worst, as they say.

If we only have a mild recession, then we are ahead of the game.

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Edited By PatJ on 29/07/2022 20:39:08

We have had two severe ice storms here in the midsouth (US) in the last 30 years, and one was in deep snow, and lasted 2 weeks for us, and 3 weeks for many in this city.

I was lucky to quickly find a generator for my invalid father in law, but it I had to drive through 30" of snow, and many fallen trees partially blocking the road, plus downed power lines.

I did not have a generator for my house, and so we had to get creative.

We did have a fireplace, and so cut up wood and built a fire.

We lived in front of the fireplace for two weeks.

We cooked on a dual burner propane gas stove.

Oddly enough, by the time it was over, we were rather sad to see the quiet life go away, and all the hustle and bustle of the city come back.

It was a very pleasant and relaxing two weeks, apart from the wood chopping I guess.

Photos of the frontier folk's shacks showed a wood stove with a compartment on the side which held hot water.

Food was preserved in salt, as well as goods that had been canned, and grains.

Lights were oil lamps. I think we actually used candles in each room, which were put in glass containers so as not to burn down the house.

The temperature inside the house was about 32 degrees in the rooms besides the one with the fireplace, and so one had to use multiple blankets on the beds.

Our water did not go out, but if it had, we would have melted snow and boiled it.

Some folks used the white gas powered Coleman stoves, and those work well too, but are not as simple as the propane ones.

Some grilled out every day on the BBQ grille, using either propane or charcoal.

The perishable food could be stored outside in a cooler, since it was cold outside.

Canned food is very handy, and generally can be eaten without cooking or heating if it comes to that.

You can always boil water on the stove and wash clothes.

An insulated work suit (coveralls) is handy to have if you have to go outside on cold days, to chop wood or whatever.

But like they say in the Boyscouts, "Be Prepared".

Go through the mental exercise of getting ready.

Better yet, go out and open the main breaker to your house, and then figure out how to live for a week.

It can be done. Nobody use to have electricity, gas, etc.

We purchased a tiny pop-up camper a few years ago, and we had a week-long power outage during the summer about a year ago. We used a 1KW generator to power the small A/C unit in the camper, and spent a lot of time in it, including sleeping in it all week.  It is well insulated, and has a propane heater.  A 600W electric heater is sufficient to keep it at 70F in the winter.

I went backpacking in the moutains of New Mexico for 10 days, and I wore quick-dry synthetic clothes, and just rolled in streams that we passed to clean up.

We had to carry and cook all of our own food, and carry water filters for drinking water.

No toilets, no showers, no phones, no TV, no magazines, it often rained hard, sometimes with sleet and snow, with elevations varying between 8,000 and 12,500 feet.

We did cook hot food and coffee on tiny propane or white gas stoves, and that was a luxury.

One really apreciates the good life after spending ten days in the stark wilderness.

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Edited By PatJ on 29/07/2022 18:48:15

My total utility bill has hovered around an average of about $180/month for as long as I can remember.

The last two months, my utility bills were $500 and $600.

My local utility company has gotten into the add-on game, where they keep coming up with new things to add to the bill, such as a rodent-control fee, a storm water fee, a solid waste fee, sewer fee, and street light fee.

These fees are in addition to the gas, electric and water fees.

The sewer fee I think is based on water usage, and so if you water your lawn, you still pay the sewer fee.

I am starting to think about a large rainwater storage tank, and installing separate potable and non-potable water systems, but unfortunately the bulk of the fees are electric and gas.

At the rate that the fees are increasing, I will end up having to section off part of my house, and only heat/cool about 1/3 of it.

Inflation is out of control for sure.

For the record, I voted for those who had the US as an energy independent nation, because that is just common sense. Now we are begging 3rd world countries for energy, which makes us I guess a 4th world country?

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Our city recently phased out its coal burning electrical plant, and installed a natural gas generating station.

The government, in their infinite wisdumb, said that the new plant must be as efficient as possible, so they drilled a well into the aquafier for cooling water.

They drew contaminates from the adjacent ground under the coal-fired station, and began contaminating the drinking water for a city of 600,000.

The midsouth US where I live is frequented by tornadoes and bad weather during the summer, and this city is full of large trees, so power outages happen a lot, and can last for up to two weeks depending on the severity of the storm.

Ice storms are the worst because the trees shed limbs, and knock down random power lines all over the city.

My house does have natural gas heat, and so far, the gas service has never been interrupted.

I can run my fan/coil unit on a small generator, and use the natural gas to heat the house.

My next door neighbor has an all electric house, and when her power goes out in the winter, she has no good way to heat her house.

After the last ice storm here, which I think was about a year ago, we were out of power for about a week, and so I purchased a 7.5KW gasoline genset. I work at home, and so it is critical that I be able to keep working regardless.

I use a 120/240 volt, 3-wire connection, and I use a large cord and twistlock plug to connect my house electrical panel to the genset.

I have a main breaker on my electrical panel, and so I manually open the main, plug in the genset, and then close the genset breaker. This allows me to operate my entire house on the genset, as long as I don't exceed 5.0 kw continuous.

The biggest thing to avoid is having a refrigerator/freezer full of food go bad.

For me, I have to keep working and remain on the internet at all times, and so that is also critical.

I have camped out in the winter in 18F weather, and that is no big deal, but there is nothing like having a nice warm house when the power is out during the winter.

The Honda genset I bought is super quite, and uses an inverter for clean power.

I can hardly hear the genset running from inside the house.

I despise loud generators, especially when trying to sleep at night.

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Edited By PatJ on 28/07/2022 13:46:27

I read an article that a British engineer visited industrial facilities in the US in the 1800's, and was astounded that virtually the entire US industry used leather belts, and not ropes.

This made me wonder about leather belts, since a cow is not a very long animal, and a belt is a very long thing.

I found a little bit of information about how leather belts were made, using some sort of built-up layering process, apparently using some very flexible and durable glue. It amazes me that belts work, but they do work well, they can transmit a lot of load, and can be used at relatively high speeds too.

The belt industry in the 1800's in the US was pretty high tech in my opinion.

And Charles Porter brought the first modern high speed stationary steam engine to England and displayed it at the London International Exhibit in 1862. His engine design was pretty much dismissed by the leading engineers all over the world at the time, some of which had to do with the lack of a condenser.

Charles Porter was a lawyer by trade, and so certainly there would have been a reluctance in the engineering community to accept what was considered a somewhat radical design for the time period.

The head of the London Exposition forbid Charles Porter from running his engine faster than 100 rpm, and luckily Porter ignored him and ran it at 150 rpm, and the rest is history.

It just goes to show that genius in the techical world is not necessarily limited to engineers or specific countries.

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Edited By PatJ on 27/07/2022 18:34:48

I think the reason that the thin nut on top works is that the thick bolt is torqued to some value, pushing the nut threads against the bolt threads on one side.

Then when the thin nut is added, it is not torqued to the same value as the thick nut, rather it is only torqued enough to prevent rotation of the two nuts.

If the thin nut were torqued as high as the thick one, then the thin nut would assume all of the load.

I think that is why the thin nut on top works; because it is not overtorqued.

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Edited By PatJ on 26/07/2022 05:04:57