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Running an Accucraft Edrig on compressed air

Posted: Sun Oct 04, 2026 3:22 pm
by BryanW
I have an elderly Accucraft Edrig which has steaming problems. In an effort to narrow down the issue(s) I would like to run it on compressed air. The problem I have is how to connect my standard hobby type compressor to the loco. From a basic internet search I believe the compressor - or rather the flexible hose end - has a 1/8" bsp fitting whereas the Edrig has a M!0 x 1mm fitting at what I call the "blanking plug" above the regulator turret seen in this photo (assuming of course that is a good place to attach the hose to.
PXL_20261004_141507980.jpg
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Does anyone know if an adaptor that can screw into both ends is available and if so where I may buy one?
Failing that is there anyone on here with the skill to make me one? - which I will of course pay for.
Thank you in anticipation.

Bryan

Re: Running an Accucraft Edrig on compressed air

Posted: Tue Oct 06, 2026 3:29 pm
by Old Man Aaron
I'm not aware of any 1/8" BSP to M10 adapters being commercially available.

I'd say it'll have to be a custom-machined fitting. Not too time-consuming to make, and I'd offer to do so myself - unfortunately my lathe doesn't have enough change-wheels for threadcutting..

Surely someone on here can help you out, or point you to someone who can..

Re: Running an Accucraft Edrig on compressed air

Posted: Wed Oct 07, 2026 3:43 pm
by BryanW
Thanks Aaron. However, I must apologise and submit a correction. The imperial size of the connection is 1/2" bsp not 1/8" - quite a difference.
As it happens a simple internet search on Amazon of all places found the very thing (I have tried putting in a link but for some reason it will not work but if you search for "2 Pack M10x1 Male to 1/8 BSP Male Carbon Steel Thread Adapter Straight Connector for Air Oil Water Lines" I am sure you will find it. The price at the time of writing is £8.99p for two.
Other than shortening the part that screws into the turret and adding a fibre washer it works! I have attached my hobby type compressor set at 30psi and the loco runs quite well on my rolling road in a forwards direction but is reluctant and is juddery in reverse. Lifting the loco off the rolling road (and therefore reducing the friction) allows it to run better. Clearly however I need to adjust the valve timing.
Here is a photo of the set up
PXL_20261007_140610612.jpg
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There is just one other thing. Normally my compressor will stop once it has reached the pressure I have set (it has a storage tank), however when connected to the loco it does not. This tells me that the air is escaping faster than the compressor can pump into it. I do not know enough about the physics (of compressed air versus steam) to know if this is normal or whether the leak is sufficient for me to investigate and correct. The loco is at least 20 years old (it is second hand to me) and my guess is it has not been "serviced" in all that time. Do I need to fit new o rings to the pistons? Is this a job for an Accucraft service engineer or can a reasonably competent chap do this himself?
Bryan