Clayton Steering

[bigwood]

After a long break from Model Engineering I made a fresh start after inheriting the contents of my late fathers workshop. I have made good progress with my 2" Clayton but one thing I am not happy about is the steering shaft and nut. It should be a 1/4" two start thread, Acme I think. The nearest I can get to this is 1/4 Whitworth. OK it works but will I really would like to  improve it, there is a lot of slack and very slow steering.
Many years ago Blackgates sold a turned shaft and nut. I cant find a 1/4 Acme tap and die and really dont fancy trying to screw cut this on the WArco Mini Lathe. Any ideas, perhaps an Engineering company that would take on a one off job.

[fostergp6nhp]

See if anybody does feed screw blanks and nuts is the size you need.

[bigwood]

Dec 19, 2016 20:05:03 GMT fostergp6nhp said:

See if anybody does feed screw blanks and nuts is the size you need.

Thanks for the idea. I have found a company that advertise 1/4" Acme 2 Start Threaded Shafts and Nuts. I will contact them and see what sort of price they would charge me. I only need about 6" of Acme threads. The shaft in place at the moment is in two halves pinned together, I think this was the suggested way of making the shaft in the ME magazine. 

The original design in the magazine has seen a lot of changes when the Clayton was still popular. Once the steering is improved my thoughts will turn to the drive train. I think the second shaft and gears will make big difference having driven a Clayton with the standard gearing, It was a bit too fast to be able to steer fire and keep the boiler full.

[bigwood]

Jan 3, 2017 19:03:42 GMT bigwood said:

Dec 19, 2016 20:05:03 GMT fostergp6nhp said:

See if anybody does feed screw blanks and nuts is the size you need.

Thanks for the idea. I have found a company that advertise 1/4" Acme 2 Start Threaded Shafts and Nuts. I will contact them and see what sort of price they would charge me. I only need about 6" of Acme threads. The shaft in place at the moment is in two halves pinned together, I think this was the suggested way of making the shaft in the ME magazine. 

The original design in the magazine has seen a lot of changes when the Clayton was still popular. Once the steering is improved my thoughts will turn to the drive train. I think the second shaft and gears will make big difference having driven a Clayton with the standard gearing, It was a bit too fast to be able to steer fire and keep the boiler full.

[bigwood]

The steering issue has gone on hold for now. The quotes were silly for 6" of 1/4 Acme thread and a nut. After re-adjusting the valves the engine runs really well on air. As other people have said it dosnt appear to have a mid gear. There is a point were pulling the reverser back it almost stalls. Any further back it reverses. What it will be like on steam under load should be interesting. My other Clayton had "O" rings. This time I have fitted piston rings.

[Nigel Bennett]

I made my steering nut and screw 2-start with no problems. I simply screw-cut the thread in the lathe as a fairly conventional Whitworth form, and made a tap out of silver steel at the same time, to cut the thread in the nut. I think I used a thread chaser (old Coventry die-head insert) to cut the threads - but it was some time before 1990, and memory grows dim. If you choose (say) an effective 12TPI, you set the lathe to cut 12TPI but you can use a 24TPI chaser to do the doings. Depth of cut for the thread will be the same as for 24TPI.
If you haven't made the boiler yet, make it about an inch taller, as per the original full-sized Penglaze artic. You will also need the additional 2:1 reduction gear that Ron Cockerill described in ME a few years ago unless you intend running slightly downhill on smooth tarmac all the time.

[bigwood]

Hi Nigel. Thanks for the advice regarding the steering shaft. This an unfinished project bought in with some parts already made, the steering shaft for one.
It came with a part boiler kit and I think the outer shell is cut to the right size already. The fire box tube is about 2" longer than plans, typical. Also the cab front has been made as per drawings rather nicely.
The reduction in the drive ratio is high on my list of mods but the Ron Cockerill notes are hard to find. This maybe a suss and boggle job to my own ideas.It is nice to see how some one else approached the job.
Whilst running the engine on air I noticed a lot of slack in the pin for the reversing lever on the end of the slide shaft. Once I got the side plate off the crankcase and wriggled the shaft out I found the pin had been loctited in place !!!.
The slide shaft is case hardened and the pin is silver steel. Three drill bits later and it is pinned together now. I will get the sump back on in the morning and see how it runs. At least you can run the engine on the bench to fault find.

[bigwood]

Hi Nigel, Another side issue I forgot to mention is regarding the die blocks. After pulling the slide shaft out I discovered the die blocks are slices of 1/4" square brass that are a sloppy fit in the slides. I may try to make some die blocks out of something better wearing.Considering how well the engine ran on air it should make quite a difference once I have got the slack out of all the valve gear parts running on steam.

[bigwood]

I got the engine back together and tried running it on air. It was difficult to start forward but starts and runs well one notch back from mid gear???.
Once again the valve chest cover was taken off. The valves are only just opening in full forward but in reverse they are fully clearing the ports. Now I have got the slack out of the slide shaft pin it wont tilt back to fully open the valves without the vibrating levers hitting the slide shaft edge.
The back of the slide shaft has been filed away for some reason, maybe it was catching the con rod???. Rather than taking it all to bits again I may see if I can get the Dremel in there and take a little off the back of the vibrating levers at the point they catch.
My late father built the engine for my first Clayton. I never got as far as fitting it into the chassis because he took it back to fit the sump. When we cleared his estate the engine was missing so I sold the rest of the chassis. For all its problems I still want to finish building this Clayton if only to chuck round our garden.