Question regarding Tiny

[Alex]

What about silver steel for axles and pins? Is it overkill for these kinds of engines?

 

[rake60]

I use what I have on hand.
I've made 3" flywheels out of bronze that I picked up at a local scrap yard
for $5 Current market for 3" 660 bronze rod is about $14/inch.
Sure silver steel will work if it's something you already have, but I
wouldn't pay the extra to buy it just for the models.

 

[Bogstandard]

Hi all,
Drill rod is an American term for silver steel here in the UK.
Usually it comes in 13" lengths, and is actually a carbon steel rod that is ground to fairly close tolerances. It is ideal for making shafts because of the close tolerances it is made to. If you use it for shafting, you can in fact harden it by heating to a cherry red and quenching in oil or water, and it goes very hard. I use it mainly for making tools for the lathe or hand punches, but it must be tempered after hardening because it is too brittle to use and is likely to snap. You can temper it by first polishing the surface then bring it very gently to a straw colour using a blowtorch, then quench again. This still leaves it hard but not so brittle or prone to breakage.
The cost is very cheap.
Hope this explained it ok for everyone.

John

 

[rake60]

Thanks John, we do have different specs for different materials.
It’s helpful for all of us to understand those differences.
Here drill rod is annealed, ground, general purpose tool steel.
You won't cut it on a home shop machine. I believe that was what
Elmer Verburg was referring to in his plans for the "Tiny" but I still used
carbon steel. When it wears out I'll make replacement parts. :wink:

 

[Airhead]

Hi, every one. I hate to start out here disagreeing with the site owner, but...
Rake, it sounds like you're saying that drill rod isn't machinable in the home shop. In fact it machines easily with HSS tooling. At least as well as common 1018, maybe a little better.

I keep a range of sizes on hand because it's so handy. It has a nice finish because it's ground to size (I believe within a half a thou, close enough for what we do). For guys that are lucky enough to have collets for work holding I think it would be invaluable. It is also pretty cheap, all things considered.

In the USA it comes in three foot lengths and in three different flavors. Water hardening, oil hardening and air hardening. Water hardening is the cheapest and what I keep in the largest range of sizes for general purpose use. The problem is that it is the most likely of the three to grow and warp when you try to harden it. I've even had pieces crack! This is why I keep oil hardening drill rod in 3/8 and 1/2 inch, the sizes that fit the collets of my mini-mill, and so the sizes I use to make custom cutters that need to be hardened. I have not had any problems quenching and tempering any of the (admittedly few) cutting tools I have made with it. Air hardening drill rod is the most expensive and is supposed to be the best at holding its shape and size when quenched. Buy only when needed for those properties.


Rick

 

[rake60]

I have a tough time with 4140 steel in my basement.
Maybe all the aluminium, brass and cast iron has me spoiled.
I've worked with drill rod a few times and was never able to get it to
cut. What I was getting had a hardness of 57 Rockwell.
I ended up grinding it.

 

[Alex]

To cut silver steel, is it best to hacksaw near the desired length and face to correct length, or just cut it off with a parting tool?

 

[1Kenny]

Tonight I cut the column for the Tiny Engine out of stainless steel. Then cut a rod/piston from bronze. Fun so far. Have to set-up for the flats tomorrow.

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[rake60]

I like the direction this is headed.
How about a category on metals?
I sense a poll coming. :lol:

 

[rake60]

Lookin good Kenny

 

[Alex]

You've got a great start on your little project there. How are you planning to mill the flats. May I suggest using the lathe?

 

[1Kenny]

Hello Alex,

Yes, I am going to clamp the column sideways and off-set in the 4 jaw chuck. After cutting the flats on the first side will rotate it 180 degrees and use a large tool bit between the chuck and column to square it. Then cut the second side...............At least thats the plan.

 

[Alex]

Are you going to face the column instead of milling with a milling bit? Sorry if I seem slow- just new to this.

How do you make sure that it's rotated exactly 180 degrees? When I build mine I'll leave one side round, I think.

 

[1Kenny]

Alex,

Yep, just going to face the column on the lathe. Seeing Rakes pictures has sure helped. Thanks Rake.

 

[Alex]

Kenny,

Did you make the column and base plate in one piece?

 

[1Kenny]

Ok, got the flywheel, crankwheel turned, ready to do the rod pin hole. I used a #3 centering bit last night when boring the crank bushing. What a mistake as the 1/16" drill bit traveled off center on the far side. Found the #1 center bit and will make another.

Still haven't made the flats on the column. An end mill in the tail stock while the column is off set spinning sounds like an easy way to face the flats.

 

[1Kenny]

Yes, the column is one piece of stainless steel. Faced the base first so the under side would look pretty and polished it before sawing it off the bar stock.

I should have made the flywheels first. I could have made the boss for the center line of the crank bushing a little higher on the column. Could have used the center hole of the flywheel to set the crankshaft center line.

 

[Alex]

You are a fast worker, Kenny! Looks good!

I just made an order for the material- hope to get started soon. Oh yes, got to get a lathe also. :wink: While in the tools section, has anyone of you guys heard about a company called Meec Tools? They make two small lathes which would suit my little shop. Know if that's anything worth to lay some money on?

 

[1Kenny]

Flats on the column are done, Once the crank hole is centered it can be used to keep everything square with the drill bit and a block on the chuck face. Still had to off-set it to do the top flats. They are with in .003.

Cylinder is next.

 

[Alex]

It's getting together beautifully.

A little question regarding 4-jaw chucks. I've seen that there are two different types; self-centering and individually adjusted jaws. Is it possible to put a workpiece off center only with the later type?