Member postings for PatJ

In the early days of forums, I am guilty of straying a bit sometimes and posting political or other perhaps not appropriate things on forums (not this one).

Live and learn as the say.

These days, when I post, I ask myself (before I hit the SEND button):

1. Is this post appropriate if my grandmother were to read it?

2. Does this post help others, and advance the state of the engine modeling hobby?

3. Is my post diplomatic, and make its point without sounding harsh and aggressive?

4. Does my post put things in a positive or negative light? Its the question "Is the glass half full or half empty".

I like to be on the "half full" side.

5. Am I bored and just trying to use up time, or should I get out into the shop and do something productive, and then post about that work?

In the end I think we all want to feel good about ourselves, offer support to others when we can, and make this hobby the best we can.

I wake up every day and try to do things that make this world a better place.

We all have that opportunity every day.

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Edited By PatJ on 19/02/2021 17:43:43

Edited By PatJ on 19/02/2021 17:44:24

Edited By PatJ on 19/02/2021 17:44:49

Edited By PatJ on 19/02/2021 17:45:27

All water in a city of 800,000 contaminated.

Utility issued a "boil water" warning.

Its getting interesting around here.

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I ran across this video yesterday.

I can see that I am missing a lot of function by not using equations in Solidworks.

There are also a lot of functions that he uses in the video that I do not, such as creating relationships between objects/lines.

I really need to get better at Solidworks, since using these functions would save me a great deal of time and grief.

And I could make one model of a standard spur gear (as he does), and then quickly change that model for any number of teeth, or make it into a helical gear of either left or right hand.

Very nice tutorial.

Edited By PatJ on 18/02/2021 18:12:34

We are still frozen in here.

The snow got significantly deeper yesterday.

Some water systems in this region are starting to fail.

We still have natural gas, water and power. The water company is beginning to send out ominous warnings about curtailing water usage, so we are stocking up some coolers to store water.

We can always melt snow and drink that.

I have two generators, so we will be fine as long as we don't run out of gasoline. If the power goes out, so do the filling stations, and so then no gasoline.

At that point I would probably pull out my oil burner, and start using that for heat somehow.

I have quite a bit of diesel to burn.

We don't eat much, and so don't need a huge stock of food. We have some spare food, and a propane cook stove.

We also have a fireplace, and in the past during extended ice storm power outages, we have build a fire, and stayed warm that way.

We are prepared (as they say in the Scouts), and we have had storms like this in the winter with power out for 10 days.

And my wife and I go out hiking in the snow every night for exercise.

We walked 2 miles in the snow last night. It was majestic to say the least, and so quiet.

The very essence of a "winter wonderland".

I am considering building an igloo.

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Edited By PatJ on 18/02/2021 18:04:02

Edited By PatJ on 18/02/2021 18:05:20

That is some nice work indeed !!!

I have admired those drawings for many years, but I am not sure I will ever gain enough skills to make something that complex.

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It has a forged-blacksmith look to it, so I would guess steel or something similar to steel.

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I think the look and feel of this forum can be mimicked very closely; perhaps not exactly, but it should be close.

Beyond that it is a matter of creating a more functional site.

I never change things for the sake of changing them, and I am anti-change for the record, but I have used new forum software (Simple Machines and Xenforo), and there are some distinct advantages to both as far as usability.

Not to be critical, but rather just to point out a comparison, this site is like flint and stone, when you could just use a modern striking match.

Sure a flint and stone works fine, but there is real function to be gained with an update.

Its not like this forum will be updated every year; it may be many years before another update.

I would say there is a very real possibility that after using the new software for a year, if it was proposed to go back to the old software, there would be an equal amount of pushback, because people will have tried the new software, appreciated the improved functionality, and realized that yes, there is a much better way to do things.

There will be an expected initial knee-jerking reaction against the slightest perceived changes, and lots of moaning and groaning, but next year, I would predict that many would say "we were doing it the hard way".

I can speak from experience. I have had the same reaction to change; initially against it, and then realizing how much can be gained from it.  For the record, I hate change in general, and I hate software upgrades in particular, but I encourage this forum software to be updated.

Try it, you may like it far better than you think. I did, and I am a believer now.

As I said, I think visually things can be matched pretty well as far as color/layout/contrast, etc., and so if we can get over that hurdle, then perhaps we can focus on improved function, and there is much to be gained.

Just my 2 cents, but just saying don't panic. It may be much better than you imagined after you try it.

Don't give up on it after trying it for one day.

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Edited By PatJ on 17/02/2021 18:50:40

I ran across an indignant fellow in the hardware store about a year ago, and he was ranting about the new light bulbs for sale that said "12 year life".

He said "12 years, that is crazy ! Who the heck knows what they will be doing in 12 years?".

I looked at him and said "Changing a light bulb; of course".

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I got "arthritis" in most of the joints in my body, and was shopping for a wheel chair.

It was too painful to stand, and I could barely use my arms and hands.

The doctors said "well, you are just getting old, nothing we can really do except prescribe a bunch of steroids".

In desperation I researched online, and ran across celiac's disease.

I was a poster child for most of the symptoms.

I was not aware that glutton could cause arthritis symptoms.

I stopped eating all glutton (wheat, rye, barley, and for good measure oats), and within five days, all of my joint pain vanished.

A few years later it started up again, and I was scratching my head.

This time I got off all dairy, and again the pain cleared up completely.

So I am allergic to all dairy products, all glutton products, and even allergic to "glutton-free" products that contain any type of grain.

Beware when the doctor mentions arthritis.

Maybe it is, and maybe it is not.

Perhaps this can save someone the pain I suffered for about a year.

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On the weather side, we have been sitting on 9 F all day with snow.

Quite unusual for this part of the country. I don't recall ever seeing single digit temperatures around here.

It will be a bonanza for the plumbers in a few days, as the houses and plumbing around here are not set up for single digit weather. I have heaters on both of my outdoor hose bibs.

For those who live up north, I am told this is child's play, but it is a significant event down this way.

We had an ice storm a few days ago, and the trees are still loaded with ice in a dangerous way.

Ice storms in a city that has a heavy tree canopy can be a deadly thing, and lots of houses get damaged when the big trees and limbs come crashing down.  I don't have any large trees very close to my house, just so that I won't have problems during events like this.

Needless to say, when things begin to thaw, driving will be a full scale demolition derby.

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Edited By PatJ on 15/02/2021 20:13:00

Edited By PatJ on 15/02/2021 20:14:09

Thanks for the information Andy.

I am slowly getting there (I think) with the helix gear thing.

I have always been a slow learner, and have had learning difficulties (many would say that "learning difficulties" is a polite way of saying I am just dumb; LOL, well it is what it is, call it what you will).

But I am tenacious, and so like the tortoise and hair story, I will get to the finish line, but I won't be setting any speed records.

I began college as an ME, but then changed to an EE, otherwise I think I would have mastered this in machine design classes a long time ago.

It is late in the game for me to start learning gear design, but then again it was late in the game for me to learn Solidworks, and look where I am now.

I never thought I would figure out Solidworks, but it is second nature to me at this point.

You never really know what you are capable of without trying and often failing.

Failure is just an opportunity to learn what you did wrong, and get it right the next time.

If I live to be 150, I am going to embrace change every day. I don't really have a choice in my field since the changes that have occurred to electrical equipment in the last 35 years are quite dramatic as far as all the electronics that have been added.

I have to take continuing education classed every year to remain registered, and so change is part and parcel to what I do for a living.

I read this entire thread again from the beginning last night, and started comparing online formulas with Rods spreadsheet, and things are starting to fit together in this puzzle.

I think given another 50 years or so, I will have a full understanding of helical gears (LOL, just kidding, I am making good progress).

Again I really appreciate all the feedback from everyone here.

This forum group is the best in my opinion; nice folks and knowledge above anything I can find anywhere else in the world. A big hats off to you folks !!!

I hope to finish up this diversion into helical gear design soon, and get back to the business of making the Frisco Standard.

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Edited By PatJ on 15/02/2021 20:03:38

Edited By PatJ on 15/02/2021 20:05:01

I did more research last night, and also have been studying the spreadsheet that Rod sent.

It is interesting to see which helical gears are available commercially.

The inch crossed gears available here are somewhat limited, and they all have a 45 degree helix angle.

The metric teeth go by "module", and there is much more of a selection in metric.

All the metric gears have a 21.5 degree helix angle.

Information from McMaster-Carr:

For gears to mesh correctly, they must have the same pressure angle and pitch.

To change speed and torque, pair two gears with different numbers of teeth.

Crossed helical gears, also known as screw gears, can be configured to transmit motion at a 90 degree angle if paired with the same tooth direction.

Another supply site give a series of boxes on the left side of the page, and you can go down the list and select the parameters you desire.

It is interesting to note that as I go down the list and select module, and number of teeth, the list of available gears becomes identical for everything except bore diameter and left/right hand.

I mentioned this earlier, that if one were using commercial gears for the Frisco Standard, one would have to select the gear pair first, determine their center-to-center dimension, and then scale the engine design up or down to fit this dimension, which may give a very odd scale factor (I don't always use standard scale factors anyway, but just saying the design has to start with the gears and radiate outwards).

With 3D modeled gears such as the ones Jason sent me, I can scale them with impunity, and I don't have to adhere to any standard module/pitch size, or any standard gear cutter size, assuming I will cast the gears (I will be casting these gears).

I looked at diagrams indicating the triangle that has been mentioned here several times, and that is slowly starting to sink in.

So I would guess that the commercial gears that have either the 45 degree angle, or the metric with the 21.5 degree angle will mesh if they are the same module/pitch, (both must be either 45 or 21.5 degrees of course), and the same diameter gears will produce a 1:1 shaft speed ratio.

Changing shaft speed or torque with commercial helical gears seems to indicate that the tooth ratio dictates the speed ratio, since the angle is fixed for all the gears.

So it would seem that our gear example of two helical gears with the same diameter and differing too count is a bit of an oddball compared to what can be found in the commercial world ?

There is no doubt that Jason's gears work; I have the 3D prints in hand, and they do indeed mesh perfectly.

I have to guess that this configuration is perhaps not very suitable for any significant power transmission, and I think I have read that on some of the gear sites.

This is a fascinating study in gear geometry and gear terminology.

I played around with cutting one spur gear a few years ago, but I had no idea there was such a variety of gear types, and no idea that there could be so many variations within just the helical gear type.

This is a rather eye opening experience for me.

I must say I feel rather insignificant by being ignorant of most gear technology, but I am slowly catching up, and I think I will get there at some point as far as a good working understanding of helical gears and how they mesh/operate.

If my proposed bound sand method does not work for casting these gears, I will invest in the ceramic slurry process, and purchase some of the type of 3D filament that cleanly burns out.  I do have a burn-out kiln, and so I can do lost-filament castings if I purchase the slurry.  The slurry has a fixed shelf life, so I will have to delay the purchase until warmer weather (if the bound sand does not work).  The slurry cannot be shipped in freezing weather either, since it is water-based.

Edit:

9 F here today, and that is without wind chill.

And it is snowing too.  We very seldom see this kind of weather, and our houses are not designed for this weather.  There are going to be a vast number of broken pipes all over town in a few days.  I added light bulbs to my two outdoor hose bibs, and wrapped insulation over them, since they will freeze the pipes in the wall at this temperature without some heat.

My friends north of me tell me that 9F is a mild winter for them.

LOL, glad I don't live up north.  I would not get much casting done.

Edited By PatJ on 15/02/2021 15:47:47

Edited By PatJ on 15/02/2021 15:53:09

Thanks much Andy and Jason-

More ideas to consider.

I am hoping that a light bulb will pop on in my head, and it will all be clear, but at this point is it about half clear, half muddy water.  I expected this to be crystal clear to me a long time ago, but alas it has not crystallized yet.

I will ponder this geometry and pray for an inspiration in math.

Its not like I don't do math, or can't do math (I can, and I do use math every day).

Its just trying to get a visual representation of what is happening with the motion, and how that related to spur gears, worm gears, gears in general, and helix gears in particular.

The 3D modeling helps immensely from a visual standpoint, and helps visualize machining too.

I just need to study the geometry a bit more.

Thanks again to all for suffering me on these endless questions.

I do appreciate it very much.

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Edited By PatJ on 15/02/2021 00:37:17

So are you saying that you could have used 8 and 16 teeth, or 12 and 24, as long as the correct angle is worked out?

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I think it would be well worth changing the forum software just to read the comments in this section.

Not trying to be negative, but lots of good conversation and pro's and con's going on here.

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Jason-

That is good information, and makes slightly more sense as far as where the angles were derived, but I still have questions, and it seems like we are dancing around the answers, so here are my questions, if you have the patience for endless query about this topic:

1. Will two helical gears mesh and operate properly at 90 degrees if the angle is not 26.6 and 63.4, as long as the sum of both angles equals 90 (yes/no) ?

2. Is the 2:1 shaft speed ratio determined by the 2:1 teeth count or the ratio of the angles? (don't say both or I shall have to scream).

I should not be lazy, and I should make up a few gears, 3D print them, and try it for myself.

Things that do make sense as far as trying to relate helical gears to spur gears (which may be a false analogy) is that the gear with 10 teeth rotates twice for every rotation of the gear with 20 teeth (I would expect this).

And this gear arrangement seems to operate much like a worm gear arrangement, except both gears are the same diameter, whereas with worm gears, generally a small gear drives a larger gear.

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Edited By PatJ on 14/02/2021 18:11:05

Edited By PatJ on 14/02/2021 18:11:39

And after getting my Prusa print head adjusted to the right height, which solved my bed lifting problem, I was able to print both gears at the same time.

They mesh perfectly, and the surface finish is quite good.

It amazes me how these gears mesh and work so well.

You nailed it Jason B !!!!

Next I will make a resin-bound mold, heat these patterns, and carefully retract them from the sand.

I will probably try an aluminum casting first.

This is such cool technology.

Designed by JasonB, and sent across the world with a touch of a button.

Perfect fit.

Thanks again Jason. Too cool.

Edited By PatJ on 14/02/2021 04:41:55

Edited By PatJ on 14/02/2021 04:42:34

Edited By PatJ on 14/02/2021 04:42:54

Edited By PatJ on 14/02/2021 04:43:32

Seems like I have seen people arc weld iron with a nickle rod.

As I recall, the part had to be preheated, and the cooling had to be very slow, ie: use an insulating blanket immediately after welding.

I have had things shipped across the pond, so it can be done.

All I would need are the dimensions of the piece in order to make the pattern.

So shipping would be one way only.

Local repair makes more sense though.

Edit:

Seems like from what I am finding, stick welding cast iron is not nearly as good at gas welding with bronze.

I saw my dad repair a number of large machines that had cracked frames, and he was very good with the bronze and gas torch.  I never saw one of his repairs fail or crack, and there were machines with cracks several feet long that he repaired.  I recall him preheating, and using insulating blankets after.

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Edited By PatJ on 14/02/2021 02:00:10

Edited By PatJ on 13/02/2021 22:28:40

Edited By PatJ on 13/02/2021 22:29:21

Edited By PatJ on 13/02/2021 22:30:17

Edited By PatJ on 13/02/2021 22:30:50

I started a 3D print on my Prusa of Jason's two gears.

The print kept lifting off the bed.

I tried the purple glue, but that did not help at all.

I cleaned the bed, but again to adhesion.

I have never really had adequate time to play around with my Prusa and really understand it, so today I started playing with print head heights.

I went into head height adjustment, and cranked the head down with a piece of paper below the head, to the point where there was slight tension on the paper.

This setting was at -0.425 (don't know what units this is), and this did not work.

I raised the head to -0.355, and this is now working well.

I watched the Prusa video again an head height adjustment, this time with closed captions on.

This time I was able to pick up what Prusa said, which was "the correct head height adjustment is critical for first layer adhesion".

In the past, I had tried to eyeball the head height, and approximate what looked correct by observing the filament stream shape.  This method did not work well at all, and I was unable to find the correct height by using the visual method.

The method I mention above with the paper seems to work like a charm, and I did not clean the bed between the first two attempts and the attempt that is now working. So it is not so much a clean bed problem, as it is a head height adjustment problem, and a first layer adhesion problem due to improper head height.

I understand that the bed must be kept clean, but when a clean bed will not adhere, then it may be a print head height problem, as I discovered today.

So I am printing Jason's gears, and will be checking them for mesh.

If all goes well I may attempt a casting, but the weather will have to get a bit warmer.

We are anticipating single digit F temperatures tonight, and the houses in this region are not set up for this temperature, so the plumbers will be super busy next week.

I am getting ready to put heat lamps on my outside hose bibs.

Its the only solution for single digit temps, other than using heat trace cable, which would be difficult to install after the fact.

Edited By PatJ on 13/02/2021 22:17:35

Edited By PatJ on 13/02/2021 22:19:05