Halls Rotary Engine

[redhouseluv]

I'm really confused by the proceedure: (see 1st photo)

Do I drill to a diameter of 3/8" then use the tapered reamer all the way through?

OR

Do I use a boring bar set to 10 degress and if so what diameter am I trying to achieve: 3/8" again, before using the tapered reamer?

What has the diameter of the holding spigot (photo) got to do with the proceedure, I cleaned this up sufficiently to get a good round surface, no more?

I'm not sure how best to approach this and the sequence which I should do things; I have attached the CAD image if that helps (see 2nd photo)

[Jasonb]

The largest dia of the tapered hole needs to be 3/8" so you need to pilot drill to a size just below what the smaller end of the taper is then either go straight in with the reamer or set over the topslide and bore then finish ream. If you put a sharpie mark on the reamer where it's width is 3/8" you will know how far to go in or better still if the valve is already made use that to gauge the size.

Make valve and tapered reamer without altering the topslide setting so the two tapered cuts to make them match each other

Topslide is set to 5deg to give a total included angle of 10deg

For a one off or small run reamers I don't bother tempering just leave them hard, seem to work OK

[redhouseluv]

Thank you.....

Once I have a tapered hole all the way through, how do I make the 'main chamber' as I call it? This is a larger diameter than the tapered section?

[Jasonb]

very small boring/internal grooving type tool, grind your own or buy.

[redhouseluv]

Ah ha - that explains it!

I kept going over and over it in my head and couldn't figure it 

[redhouseluv]

Made the valve spindle today; it was tricky and I made a banana a couple of times!

The top diameter is not to the given measurement, I was afraid it would give way; not really an issue as long as the spring fits over it which it does. Bottom section is 1/4/" longer than needed and will be cut to size on assembly.

The tapered reamer and spindle look like they align, so fingers crossed, it'll fit together in the governor liner - that's the next job

[redhouseluv]

Made the valve liner using the tapered reamer and tiny grooving tool to open up the middle. The valve spindle sat on the valve seats snuggly after some cautious further reaming in miniscule amounts.

The whole assembly is then a push fit into the governor body which is where I discovered that the steam inlet did align (see pic).....so....I milled the steam port on the valve liner so that it is better aligned and I can't see it making any (or much) difference to the engine. Finally I reduced the top end of the spindle to approx 0.75", placed a spring on it and closed up the governor.

The spindle makes a very satisfying clicking noise as you push it up and down in the governor body 

[redhouseluv]

I need a little help with the Governor cam (photo 1) and a lot of help with the cam/end swivels (photo 2) please:

1. Governor cam - I was going to machine to size on the lathe and use a RCMT profiling tool to give me 3/16" cam radius?

2. Cam/End swivels  - I'm lost and the words ain't helping! So confused, I can't fathom how I end up with this shape with a circle in the middle and the pairs of sticky out bits!!! Not a clue, don't even know as to whether I'm using round or square stock and what order I use the mill and lathe 

[Jasonb]

You could also grind up a bit of HSS unless you already have a 3/8 button tool.

As for the other part

1. Machine a rectangular block of material to overall sizes.

2. Put in the central hole and the two smaller pivot holes while it is easy to hold and you have edges to set out from

3. Mill the two slots with the material held vertical in the vice

4. Set the work vertical in the vice again and mill the two sides of the clevises, you have CAD so can work out where the flat meets the curve and cut to that dimension

5. Either set up to mill the curves to the clevis and around the main hole or use filing buttons to round them.

The lower part would be done the same but 1A would be to turn the spigot while holding in the 4-jaw, you may as well do the main hole at the same setting.

[redhouseluv]

Fantastic, that helps a lot - just one quick thing, the article suggests soldering 2 pieces together in order to make both swivels at the same time. Could I use your procedure on 2 pieces soldered together or would this not work?

I've just had to use Mr Google to look up filing buttons, interesting and I can see how they could work in this instance

[Jasonb]

Yes you could solder two bits together, just have to unsolder before rounding the two clevises.

[redhouseluv]

Making progress with the swivels.

I made a mandrel to hold the work on a rotary table in order to mill the outer diameters. Drilled some holes at I'd at either end of the milling arc with an 1/8" drill bit and then .........

I used a 1/8" 4-flute end mill and in hindsight may have been better off with a wider 2-flute. I think it was flexing whilst cutting and has made a rough surface; I'll need to do some vigorous polishing!

Last job is to separate the 2 items then radius the clevises; the holes may be too close to the bottom of the clevis which means I may not be able to use a filing button 

[Jasonb]

Another small arbor and you can do them on the mill with rotary table, that is how I tend to do most of mine

[redhouseluv]

Thanks

and here they are, not the prettiest that can be made, a few dings and holes that look a little slightly misaligned .......... I'll do better next time! 

[redhouseluv]

I watched a Blondihacks video on making filing buttons using tool steel? Is this HSS steel as that is what I attempted use?

I managed to machine the stock to the required diameters ok, but when I tried centre drilling, the drill merely marked the surface and eventually squared off the centre drill beyond use - am I doing something wrong, using the wrong steel, wrong centre drill?

Here's the video - the part in the video is at 6:38


<a href="https://www.youtube.com/watch?v=uPtmIyON6zw" target="_blank">http://www.youtube.com/watch?v=uPtmIyON6zw</a>