Running on air tips

[charley]

Dear forum,

Over the next week or so I aim to see if I can get my chassis to run on air.

I see lots of tips for valve setting which I'm grateful for but can you give any tips for starting out the with a compressor. A sort of do's and definitely don't for when running on air.

Cheers

Charlie

[pault]

Don't forget to add plenty of oil to the cylinders if you don't have the cylinder lubricator fixed up. It should only take a fairly low pressure to get it running if the valves are set right. If they are not the temptation is to keep winding up the pressure and then the wheels may suddenly start thrashing round. Most important mind your fingers there are plenty of parts that will make a mess of your fingers even at low pressure

[GWR 101]

Hi Charlie, when I ran my Juliet on air some 12 months ago it was suggested that I put an airline oiler in the supply line with some airline oil with a small amount of powdered graphite mixed in. It worked for me and the chassis now runs quite smoothly, as Paul says watch you don't catch anything in the moving parts. Regards another Paul

[digger]

The first requirement is to have a compressor of large enough capacity, make sure the locomotive is suitably secured to the bench and cannot move, before connecting the air supply tube squirt some lubricating oil down the steam / air inlet pipe and turn the locomotive over by hand to check for any stiff spots or binding, oil all the bearings and slide bars, put the locomotive in full forward gear, then connect the air supply.
Now what is probably the most important part...keep your fingers away from the moving parts when you slowly open the air supply valve, if you have set the valves correctly the locomotive should run smoothly, let it run as slow as you can for at least half an hour, to bed things in, shut the air off then try it in reverse, taking the precaution to keep your fingers out of the way, if it runs equally well in reverse, then you have done a good job, again let it run for at least half an hour, before increasing the speed.
Never open the air supply fully till you have made sure that its free to rotate, use thin oil initally car engine oil is ok (steam oil is too thick)
Its a wonderful feeling when something you have made comes to life, and if it works you can feel proud, have fun!

Digger

[ejparrott]

If you can, arrange a screw valve on the compressor outlet rather than a 90 degree ball valve - way more control!

[arron]

All good comments above, the screw valve is a very good idea. I also found that it was important to support the loco via the axle boxes. If the axles are allowed to dangle they can move about. Also if they are at the bottom of their travel it can upset the valve timing as the axle center line is not inline with the cylinder center line.

I had this issue some years ago when trying to set the valve timing on my LNER A3. The outside valve timing was slightly out but the inner one being derived from the other two was miles off, this lead to very uneven running at low air pressure...and weeks of adjusting and head scratching before I worked out what was wrong!

[charley]

Thanks for the tips. Much appreciated. Will see how I get on next week.

Cheers

Charley

[jma1009]

hi charley,
i always use singer sewing machine oil when testing on air as apparently it doesnt break down the oil film when used with compressors which may produce droplets of water/condensate.
this 'tip' was gleened from an ME article in 1968!
cheers,
julian

[stan]

I agree with the oil supply when I ran my Black5 on air I relied on the loco oil pump with steam oil and it seized one of the piston valves, had to remove the cylinder and press out the bobbin hone out the bore and make a new bobbin.
Stan

[isc]

Make sure to drain any water from the compressor before you connect up to your locomotive, and, particularly if the cylinders are cast iron, watch for condensation in the cylinders. isc

[fostergp6nhp]

If you can get one get a combined water trap and oiler unit, they sometimes have them in the likes of Aldi when they have compressors etc.
www.machinemart.co.uk/shop/product/details/cmf3-filter-regulator-lubricator