# What project to do with my grandson?



## Mosey (Nov 16, 2011)

My 15 year old grandson will be with me for 4 days over the school break, and I want to give him a machining project to do. He is a total machine-head, and has watched me work in the shop. What would be a good project for him to make over that period? I already built a finger engine for him. I want something that will teach him proper procedures, safety, precision, and give him some sense of personal accomplishment. Something he can take home and enjoy (he lives across the country). Ideas, guys!

Guess who gets the machine shop after me?


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## 90LX_Notch (Nov 16, 2011)

Mosey,

I would build a wobbler with him. It makes use of several machines and skills. A wobbler would also be more forgiving of errors and loose tolerances. My son will turn eight in Dec. and I plan to build one with him once he expresses more of an interest.

Bob


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## Mosey (Nov 16, 2011)

Can you suggest where I might see what a wobbler looks like? Plans?


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## Blogwitch (Nov 16, 2011)

Mosey,

There are plans galore on John Tom. Here is the link to Elmer's selection.

http://www.john-tom.com/html/ElmersEngines.html

There are some fairly easy ones to make, but for the period you have him with you, don't go for anything too complicated.

The Rocking engine was a favourite at one time. Just do a search on the opening page for Rocking Engine and take your choice.


John


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## Tin Falcon (Nov 16, 2011)

> Can you suggest where I might see what a wobbler looks like? Plans?


You are kidding right?????


http://littlemachineshop.com/Products/Drawings/2593OscillatingEngineAssembly.pdf
Tin


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## steamer (Nov 16, 2011)

oh yeah  Wobbler +1

And a Karma from me for teaching the craft to the next gen!

Dave


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## Jeremy_BP (Nov 16, 2011)

My first engine was a rocker. Ran smoothly right off the bat.


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## John S (Nov 16, 2011)

I have got my GS helping convert a mill to CNC but it's definitely not going to be a 4 day job.  

John S.


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## Mosey (Nov 16, 2011)

Tin Falcon  said:
			
		

> You are kidding right?????
> 
> 
> http://littlemachineshop.com/Products/Drawings/2593OscillatingEngineAssembly.pdf
> Tin


Not at all. I really didn't know exactly what a wobbler was until now. 
What I think might be fun is to make all of the parts for the engine before the kid gets here, hide them, and then let him make a few of the most important ones first. That way, if he runs out of time, he will have all of the parts so he can take home a complete engine. I will set him up to make at least 1 part on the lathe and 1 on the mill. I also think he should learn to mark out a part, drill, and final fit some pieces. If he is fast, he might get them all.
Who knows, I might have fun too! And we will discuss precision.
Perhaps he could benefit from learning about screwups and how that is OK too. It works for me.


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## Tin Falcon (Nov 17, 2011)

http://npmccabe.tripod.com/mccaberunner.htm
Another option for an easy simple engine.
tin


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## JohnS (Nov 17, 2011)

My 11 year old grandson built Elmers wobbler with just a little help. Hopefully a seed was sewn and he will return to model engineering at some later stage. You'll find a account of his build and much more on Elmers wobbler at http://start-model-engineering.co.uk/elmers-wobbler/


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## Mosey (Nov 17, 2011)

Very nice, thank you. I wonder who's going to have the most fun?


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## chucketn (Nov 17, 2011)

I think it's great that your grandson has an intrest in your hobby. My Grandsons took to archery when I was into it, but it didn't last. The memories did, though. Another Grandson was enamoed with fly fishing and tying, another hobby of mine, but he has moved on also.
As to a project, how about the EZ build steam engine, developed by members here? It was my first, and only runner! Even though it runs on compressed air, it demonstrates the very basic elements of a steam engine, cylinder, piston and valve. I have the plans saved if you can't find them. Here's a pic:







Chuck in E. TN


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## Mosey (Nov 28, 2011)

Well, I need some more of your help. The kid is coming for Christmas week, and I am going to help him make a wobbler! 2 kids having fun! Remember, he is 15, very big, smart, and interested in engineering.
But, where should I take him for a treat? It should be in the New Jersey, Philadelphia, New york area. My ideas, half lame of course include:

Franklin Museum, Philadelphia. Small, but interesting.
Princeton University Physics Dept. Machine shop. Very large and full of mind-boggling machinery and space exploration projects. Wow, if you are interested in this stuff.
Princeton University Power Plant. 21st century super-sophisticated computerized cool place, I'm told.
State Police or Air National Guard helicopter hangars, maintenance shops, etc.
Vikings vs Eagles game where Eagles get trounced. Only kidding. Wishful thinking.
Cowboys vs Eagles game where Eagles get trounced. Nice thought.
Any and all ideas welcome.


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## 90LX_Notch (Nov 28, 2011)

Mosey-

Steamtown in Scanton, PA. I believe there is also a Trolly museum adjacent to it. I don't know for sure,but the Trolly museum might have a machine shop.

-Bob


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## Mosey (Nov 28, 2011)

Yes, that is just the right kind of place. Thanks.




P.S.
for Steve,
thought you might enjoy seeing this tiny V12 on you tube. Very tiny!!



[ame]http://youtu.be/3YfTtGCsiD8[/ame]


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## Sshire (Nov 28, 2011)

Railroad Museum of Pennsylvania
http://www.rrmuseumpa.org/
About an hour from Philly and the Strasburg steam RR is across the road

http://www.strasburgrailroad.com/


Stan


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## Mosey (Nov 30, 2011)

What is a convenient way to supply compressed air to a wobbler in the house, as opposed to the shop where there is a compressor? ???


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## stevehuckss396 (Nov 30, 2011)

Mosey  said:
			
		

> What is a convenient way to supply compressed air to a wobbler in the house, as opposed to the shop where there is a compressor? ???



Figure out a way to attach a hose to a beach ball. Blow it up half way and sit on it. Then start the engine.


What did I win!?


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## mklotz (Nov 30, 2011)

An airbrush compressor is ideal for small engines. They're quiet and also can be used for powering, surprisingly, an air brush, which is a useful addition to any shop.

I was given a discarded medical inhaler compressor. Very quiet but low pressure and flow. It animates my smallest engines beautifully.


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## Ken I (Nov 30, 2011)

Use your car's spare wheel as a reservoir - make up a hose & fitting that depresses the valve when screwed on.

I used to do this for airbrushing before I bought a compressor.

Use an old aqualung or CO2 extinguisher bottle as a reservoir (don't use an LPG cylinder - not high enough pressure rating).

An old fridge compressor might work if the demand / pressure isn't too high - and they are pretty quiet - you can generally pick them up for nothing from a repair shop - they throw lots away.

Run a hose from your shop perhaps ?

Ken


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## Mosey (Nov 30, 2011)

Great ideas, keep em coming.
I think an old inner tube might be good, if there are any still around.
Steve wins 1 cu ft of air. It's in your mail box.


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## stevehuckss396 (Nov 30, 2011)

Mosey  said:
			
		

> Steve wins 1 cu ft of air. It's in your mail box.



More like in my head


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## steamer (Nov 30, 2011)

+1 for the spare tire....works well!

Dave


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## Mosey (Nov 30, 2011)

OK, please go kindly with the following ignorant question.
On the plans for the Elmer Wobbler engine, several holes are labeled with small letters in a circle next to the hole diameter dimension. They are single or combinations of the following: "C", "B", "F", "P", or "S". What do they mean?


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## stevehuckss396 (Nov 30, 2011)

Mosey  said:
			
		

> OK, please go kindly with the following ignorant question.
> On the plans for the Elmer Wobbler engine, several holes are labeled with small letters in a circle next to the hole diameter dimension. They are single or combinations of the following: "C", "B", "F", "P", or "S". What do they mean?



There are 3 drill bit sets in the garage.

1) Fractional set  1/16 thru 1/2 inch in 64th steps
2) Number set    #1 - 80   1-60 and 61 - 80 are in seperate case
3) Letter set     A - Z

Those letters might be the drill to use. Just guessing, I have not seen the drawings.

http://buy1.snapon.com/catalog/item.asp?item_ID=63042&group_ID=945


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## Mosey (Nov 30, 2011)

Too easy. The holes are marked like this: 1/8 C, or 3/8 CS, Take a look. 

View attachment Elmer Wobbler.pdf


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## rleete (Nov 30, 2011)

C= close fit
S= smooth (ream)
P= press fit 
CS= close/smooth (running fit)
B=braze (silver solder)
F=flat (lapped)


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## Mosey (Nov 30, 2011)

Ahhh, that's it!


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## Ken I (Dec 1, 2011)

Mosey  said:
			
		

> Steve wins 1 cu ft of air. It's in your mail box.



Funny I found a cubic foot of air in my mailbox this morning - thanks.

Ken


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## Mosey (Dec 1, 2011)

Ken,
Amazing how I got that cu ft of air all the way to you overnight, isn't it?
Mosey


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## shred (Dec 1, 2011)

Mosey  said:
			
		

> Too easy. The holes are marked like this: 1/8 C, or 3/8 CS, Take a look.


There's an appendix to Elmer's Engines that calls these out as well as providing some other useful information-- copies should be obtainable from the usual sources.


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## Mosey (Dec 1, 2011)

Thanks ,again.
Would you please give me the link to the appendix to these engines, so I can see what other information there is.
I have assembled all of the stock and will rough cut all of the pieces so that we are ready to go into production upon his arrival at Christmas. I want him to see the whole process from stock to finished running engine, so he understands it all, but not spend the few precious days doing time-consuming drudge work. I have reviewed the plans and have it all mapped out. I might substitute a nice 1/4" stainless shoulder screw that I have laying around for the locating pin.


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## techonehundred (Dec 1, 2011)

That link is on the same page where you got the plans. Here it is.

http://www.john-tom.com/ElmersEngines/ShopWisdomRevNov07.pdf

As a matter of fact, if you print off all of the plans and the index and the appendix, you will have the entire book.


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## stevehuckss396 (Dec 1, 2011)

Ken I  said:
			
		

> Funny I found a cubic foot of air in my mailbox this morning - thanks.
> 
> Ken



Was it addressed to me?


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