Make sure your bolts are tight!

Our engines get shaken around a great deal on the road.

At GDSF last week I had an interesting 'failure to proceed' as the M5 bolts that hold the 2nd shaft drive cap had all come out with the last one failing at the bottom of the play pen. No harm done, fortunately, but worth checking they're all present and tight! At the same time I noticed that the tender straps were not tight on the offside, behind the hind wheel.

A few weeks ago I took up slack on the bolts on the near side horn plate, possibly a function of the strain imparted by the belt when generating. To reduce this strain, belt dressing and anti-slip materials maybe advisable. They made a difference when I borrowed some on the three evenings I was generating at Dorset. Anyone know of suppliers of this stuff?

Tim

on a saw bench they use black treacle teo stop belt sliping

Hi. Tim,

Rocol do a belt dressing spray which I have used with my stationary engine with some success and it is available on ebay.

Best wishes
Simon

Hi Tim,

It was good to have an opportunity to chat with you on Sunday morning at GDSF (in the sunshine) and thanks for answering my questions on our Showmans build. Eager to crack on with it and the Foden 6" now. The belt compound I had seen was 'Revvo belt stick' and Craftmaster sell it.

Carl

Hi Tim,

Thanks for the advice on the second shaft.

I too had issues with the bolts coming lose on the horn plates (even though I originally used araldite on the threads).

Recently I rechecked all the bolts and used JB Wield, as the araldite had broken down on them all. An important point to make is for those people checking the bolts, don't forget the two behind the drive gears.

ATB

Brian

A few weeks ago Steve sent round a note advising builders to check that the piston nut was held up tight and centre punched around the periphery to ensure that it kept tight.

Yesterday, I had the cylinder covers off whilst centrering the piston within the bore (as determined  by Steve Traill, the piston head should just come up to the anterior steam port).   What I found was that the LP piston nut was finger loose and the piston itself was movable.  Not sure how many more steamings it would have done before coming adrift, but the consequences could have been dire!  As I had the con rods removed, it was easy to block the cross head against the motion support bracket with a piece of wood to avoid any chance of straining the crankshaft when centre punching the nut onto the piston rod.

It will be interesting to see if centering the piston has any effect on the engine's performance. Next steaming will be at Portsmouth Historic Dockyard Victorian Chirstmas at the end of November.

Tim

It doesn't just happen on models. On the Talyllyn railway the nut came off jammed the engine and broke the rod! £20,000 of damage, a few months before it's 150th birthday

Tim, I centered my pistons after Dorset mine were as much as 10mm out!! Not sure if it has made a difference but Andy and I pulled the scammel after having made the change and it certainly worked on that!! Not doing Portsmouth docks this year as it can be quite a drag especially as its busy and they are strict on times as you well know. Have a nice time!!

Kev.

OK how do we centre the piston in relation to the ports when the piston position on the piston rod is fixed and the connecting rod length and crank position are also fixed??? Did I miss something?

Brian
The piston rod can be screwed forward or backwards into the cross head. It is not essential to be screwed right home on the thread as it is locked into place with two Allen screws and there is plenty of length to adjust. I found that my two pistons were between 5-8mm too close to the crank. Remains to be seen whether it makes any difference to performance.

Tim

I did no of this whacking with a hammer business, I used star washers, very effected and cheap...

ATB,

Brian