14XX ongoing

[mott]

Things are quiet just now. I guess holidays and hot weather have diverted attention away from our locos.

I have done about 10 miles now with 1451 and have a few issues which others may already have sorted.

Priming. I find it difficult to stop the boiler priming. If I stop to get steam up (our track is all gradients) and when back up to pressure as soon as the regulator is opened out pours water from the chimney. The loco accelerates well but steam pressure soon falls. The paint work on the boiler barrel has even soften which indicates to me, at least, that steam is disappearing too quickly allowing the barrel to get too hot.

Water Gauge. I was worried that the bottom nut didn't have enough clearance above the boiler crown so put a sleeve round the glass about 1/4 inch high and have been aiming to keep above that level.

It looks as though driving this loco is a real balancing act between keeping enough water in the gauge whilst avoiding priming. The injector is powerful and maybe is over filling the boiler, I haven't yet found a setting where the inflow balances the consumption of water and whilst driving on gradients there is a surge in the boiler which adds to the complexity of it all. How can you get the injector to work at lower pressure - I get nothing below about 55PSI.

The loco is presently using massively more water than I expected. I feed the injector from a tank on the ride on trolley. I guess that goes back to excessive priming! but could the piston rings be blowing. I cant quite understand why so much steam pressure is need to move the loco - at least 50 psi anything less and it comes to a stop.

Lubrication is also still a concern. I cracked open the pipe joint at the one way valve and found water where there should be oil at the end of my last steaming. I hear some folk have moved the lubricator to between the frames under the smoke box door to shorten the feed but can't quite work out how they get an eccentric drive off the front axle. Anyone done this?

The loco successfully received a renewal of it's boiler certificate yesterday with favourable comments from the boiler testers and no leaks were found from the fittings or regulator of any significance so that was good news. I must be doing something right?

Mott

[greasemonkey]

Hi Mott
Injectors are not designed to be used as continuous supply items. You switch them on and off as when you need them, the best way to fed to feed a boiler continuously as you seem to be trying to do is with an axle pump. I did fit a small injector to my engine for an efficiency competition last year and had some success with it but even then I had to keep switching it of. If your injector is to large then you need to fit a smaller injector that better matches the size of boiler. The pressure an injector works at is a function of the steam, combining and delivery cones Most commercial; injectors are designed to work at between 75 and 90 psi but will continue to feed at lower pressures if you restrict the water supply as the pressure drops. My injectors stop feeding at about 40psi.
Excessive water consumption is a sign of front end problems usually piston or valve blow past.
Have you got one or two check valves in your oil delivery pipe? i found more success with two. The clack at the bottom of the ram is really only good to stop the oil being sucked out of the pipe as the ram rises.
When your engine is warm does it push along the track easily? If it doesn't then you may have a clearance problem due to expansion.

Andy

[mott]

Andy, Thanks for that. Time has gone by but I am still more or less where I was. Since last posting I have put in clupet rings and new pistons very carefully worked to meet the tight spec for groove size etc. I have also visited the valve chest again but it was fine with the slide valves held on to the cylinder ports by the oil when I opened it up. the timing seems right though I know this is tricky. When I steamed today, I seemed to be back several weeks with priming but later raising steam to 80 psi, opening the regulator and managing 25 yards before steam pressure dropped to 50 psi and we came to a standstill. As I have changed and improved the pistons and rings and checked out the valve chest with no improvement, I can't think of anywhere else to look. Maybe on a track like ours with gradients this is just too much for a weak loco.Mott

[Phil Sutton]

Mott,just a thought,is your coal suitable?We have had some right rough old stuff occasionaly,which seems to produce a lot of clinker,so make sure you keep the fire well cleaned through.The other thing is to try running with the blower on and see if that helps.Our club Simplex can be quite cantankerous at times and often needs the bower on full time.

Phil

[greasemonkey]

Hi Mott
Well at least you know it isnt likely to be the cylinders now. At the risk of teaching granny.... What about an air leak in the smokebox. Does the door seal all the way round, has the gap around the base of the blast pipe been fully sealed and has the join between boiler and smokebox been sealed? I use a silicone sealant for the last two areas and make a plate up to fit around the base of the blast pipe curved to fit the smokebox floor, this is then placed on top of the sealant and so stuck in place. Have you checked the alignment of the blast pipe and chimney. The blast pipe should point straight up the middle. What is the spacing of the grate bars? Are you actually getting enough air through? the ash pan can also have an effect here but not as much. I assume that you havent got a leak in one of the pipes in the smokebox/ firebox. I know it sounds daft but I know someone who's 5" Brit stopped steaming and he traced the problem to a leak in the superheater. What size coal are you using? I like to use lumps that just fit through the door, it comes down to personal prefrence and your style of driving but might be worth a go. If I think of any more I will let you know.

Andy

[mott]

Andy, Thanks for your comments I think I have covered all points though making the smoke box airtight is a bit tricky. As we found the clupet rings were letting blow by the next logical step has been to examine the cylinder bores. I do not have the capacity to measure the bores but its seems pretty obvious that this is where the trouble is. It is mainly at the front of the bores where there are hard spots. With the piston and ring in place but the end plates removed when I shine a torch down the barrel I can see that the ring is only touching the bore here and there. I can get a 0.10mm feeler gauge between ring and wall. I am away to visit Debbie at the factory with the loco soon so will post when I have their comments. This could account for the very rapid wear of the O rings also.People in my club are also critical of the exhaust clearance of the valves 0.5mm, which they don't like to see in models.(However Martin Evans does say it is permissable but prefers "line - for - line"). ModelWork are, as usual, difficult to get through to but once contact is established, couldn't be more helpful so I am optimistic now. Mott

[greasemonkey]

HI Mott
Out of intrest have you seen Pete Thomas's notes on his 1400 which was the first one running? They are availbe here if you want to read them.
web.archive.org/web/20021114110620/195.60.10.124/winson/thomas/1400INRETROSPECT.HTM

Andy

[mott]

Andy, Brilliant, I had not seen them before. I am back from the factory where they replaced the cylinders and serviced the valve chest. Ian did all the work personally and was very thorough. Unfortunately on the next steaming we did not get any improvement so attention is now turning to the regulator and steam collection pipe. We have already had a new regulator and extended steam collection pipe but the indications are of a leak from the boiler, down to the valve chest. How else can cold water get down there? It then blows out when the regulator is opened and reduces the temperature of the steam following thru the super heater. Anyway that's my theory and it will be put to the test tomorrow. Mott

[pannierstan]

When I built my 14xx Mott I had real trouble getting steam and then found a huge hole under and behind the smoke box effectivly between the seat and the boiler

As the smoke box slides on there is a seal all round the boiler apart from at the bottom.

Does that make sense?

Stan

[mott]

Stan, yes of course. They give you a sealing plate which is supposed to block it off. What do you use to seal the boiler flange to smokebox - silicone type or fireclay type stuff. Ian recommends bedding the sealing plate in silicone using the arguement that it is easier to remove when you want to take it out! - as you do!! Mott

[greasemonkey]

HI Mott
I use a silicone sealant and dont have any problems, but I would get a reasonable quality one and not a home brand!!

Andy

[mott]

Andy, weve made progress today. The boiler, regulator, steam pipe are all sound with no leaks.We have found the possibility of a steam leak on top of the valve chest and have re engineered the joint. Piston and valves have been examined and cleaned up but with no problems found. Draughting has to be improved and we are making a new sealing plate to the bottom of the smokebox.To be totally bombproof we will be machining new pistons for the clupet rings. Then its try again. Mott

[greasemonkey]

Hi Mott
Good to hear your getting somwhere. I look forward to hearing of your first successefull steaming.

Andy

[pannierstan]

I didnt get that seal from what I remember Mott but I used High temperature silicon for flue joints which will handle 300+ deg. Look out for it in Plumb Center, its orange though

I just filled the gap under the back and it draughts like a beauty.

Stan

[mott]

Hi Guys, Tomorrow will decide. I have had the help of an expert engineer who established that the new cylinders as supplied by ModelWorks were just too large for the c.i. rings, 33 mm bore.We have made new pistons, a close sliding fit and used soft packing for rings. the loco runs fine on air now. We have done several other mods,but the valves seem absolutely fine, no leakage so tomorrow will decide, given fine weather. I will report back. Mott

[mott]

Hi Guys, The weather was fine and 1451 did actually steam. The blow passed the pistons has been cured. The timing was obviously off because the loco was jerking all the time - this down to me!Hope to get it right for next time.. The guy who has been helping me sort the problems commented that the fire was covering the lower tubes in the boiler which he thought unusual. As the grate stand on "legs " in the ash pan its height could be changed. I will ask ModelWorks about that on Sunday at the Show. Has anyone made any changes to grate height? So while the test was not a total success good progress was made. I think, had the timing been better we would have had a good result. Mott

[Phil Sutton]

Hi Mott,Good to see you've got results.A bit of fine tuning and you'll be there.

Cu Sunday

Phil

[mott]

Hi Guys, Towards the end of the last steaming, we noticed a tendency for the loco to want to move forward from a standstill when the regulator was closed which seemed odd. On investigation I found when pressurisng the boiler with water and using the hand pump that water would flow freely out of the blast pipe nozzle when the regulator handle was in the closed position. All sorts of possibilities arise as to whether the leak was in the steam collection pipe joints or in the regulator itself.The steam pipe was removed and checked. A new bolt was machined up for the banjo fitting and all was carefully re-assembled but on test it still leaked.Finally I found the problem by accident using a magnifying glass.There was a speck of metal - possibly solder - lodged in the seat of the poppet valve on the top of the regulator.This is accessible through the inner dome. It was only the size of a pinhead. It was just preventing the valve from seating and allowing a flow of water straight out of the boiler to the steam chest etc. Once removed the leak stopped.Something for 14XX builder to remember if their regulator starts "acting up". Mott

[mott]

Hi Guys, I am pleased to report I was able to send the following e mail to Debbie at ModelWorks:-Hi Debbie, well we had a successful steaming today before the rain arrived. The loco ran really well and carried me and friend - both well build lads - on our tough track with gradients- without difficulty.The loco rides very smoothly. The trick seems to be to keep the water level fairly low and be gentle with the regulator. We found if we opened the regulator too aggressively on the start of an upgrade the boiler would prime, the valves would lift and we had a waterspout from the chiminey. This is where my loco is different from others in the club. Nonetheless with four club members having a drive we all agreed it was a servicable loco.Attached are some pics. Best wishes,Mott.

[Phil Sutton]

Congratulations Mott ;D ;D ;D

Phil