What type of steel to use for the 1/4 inch axles ?

[Brian JohnParticipant @brianjohn93961]

I need to buy some steel to make 1/4 inch axles for stationary steam engines.

1. What type of steel should be used for the axles ?

2. What do you call the flat machined part of the axle where the grub screws of the flywheel make contact ?

[Brian JohnParticipant @brianjohn93961]

[Neil WyattModerator @neilwyatt]

Hello Brian

1 In most cases ordinary 'bright drawn mild steel' without specifying a precise composition will be adequate, whether you use them at nominal size or turned down. No point in using expensive silver steel or high-tensile alloys.

2 I've always called them 'flats'.

Neil

[Boiler BriParticipant @boilerbri]

Hi Brian, Bn Q sell bright bar which machines ok.

The flats, well there are different types, a sunken flat with sides is usually for key that sits in it, a flat that is not sunk would usually have a gib head key, so you could call it a gib head key flat!

You could also leave the shaft round and gently tighten your grub screw down, then take off you flywheel etc and drill a small dimple where the grub screw has left a mark. This would locate the grub screw and stop the wheel coming off. I like this on small items as the shaft fills the hole in the wheel and looks nice.

Brian

[Brian JohnParticipant @brianjohn93961]

Which raise the question : How to drill the hole for the grub screw in the flywheels ? I do not have a drill press so can this job be done by hand or is this not advisable ? I notice that you do not get much room to manoeuvre as the drill bit, chuck, tap and tap wrench come up very close to the rim of the flywheel.

[Eric CoxParticipant @ericcox50497]

Don't drill the hole at right angles to the shaft. Drill the hole in the flywheel at an angle such as 45 degrees.

[Brian JohnParticipant @brianjohn93961]

Eric : Yes, I know. But even drilling at an angle of 45 degrees it is still a very tight fit on most of the flywheels that I have purchased.

Edited By Brian John on 14/06/2014 10:25:57

[Neil WyattModerator @neilwyatt]

Hi Brian,

Tapping is made easier by using a pion-vice to hold the tap. Alternatively, use a key to hold the flywheel in place

Neil

[Hugh GilhespieParticipant @hughgilhespie56163]

Hmmm, a pion vice is going to be a bit small –

"Abstract

The pion radius has been measured by direct scattering of 50 GeV negative pions from stationary electrons in a hydrogen target. We find the square of the radius to be 〈r_π²〉 = (0.61 ± 0.15)fm²."

Hugh

[JasonBModerator @jasonb]

Brian, one way to drill the hub is to take a bit of spare round bar, drill into the end of it with your tapping drill then loctite the shank of the drill into the hole. You then have a drill that is long enough to reach the hub at a shallow angle without the chuck hitting the rim/spokes. A bit of gentle heat will get the drill out of the extension. You can do the same with the tap.

It can be done freehand with a cordless drill or if you don't have a benchdrill fix it to an angle plate set at a slight angle on your lathe cross slide and hold the drill/extension in your 3-jaw chuck.

J

[Boiler BriParticipant @boilerbri]

Hi Brian. Not sure if you have a lathe? If you have machine a small bar say 8 mm diameter dril a hole in the end just a bit smaller than the square end of the tap, warm it up with a blow lamp or similar and then tap, hammer etc the square end of the tap into the hole, this will make you a long tap holder to allow you to get into the corner.

Bri

[Brian JohnParticipant @brianjohn93961]

Yes, I do have a lathe but it is not set up yet. It is still sitting in its box on the living room floor. I am building a workbench for it which should be ready next week.

[Ian S CParticipant @iansc]

Brian, some of my flywheels are drilled when finished, I angle the drill as close as I can to clear the rim, a long drill is handy here, I drill it free hand using an ordinary wheel brace (the battery doesn't go flat). My flywheels are fabricated, and when I remember I drill and tap before assembling the hub. Ian S C

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