Regulator

Thanks for the update Kev,

The removable insert does sound a good idea,looking forward to hearing how it performs,

Hope it works,

Only concern is the reduced inlet hole, will it reduce full power or will the difference be too small to notice?

fingers crossed

Kev

Right after a short time this morning using Timesaver to lap the valve in I have achieved an almost 100% seal under air ( 80 psi or so ) I am given to understand that air is more troublesome to get a good seal on so I am very hopeful that a steam test will give an almost perfect seal. This is still only a test piece at this stage and will need to be replaced with a proper bronze if we a certain it has the desired result. I have some things I must get on with despite being a sunny day so the steaming will have to wait until the week, better as less neighbours are in to get tetchy about the smoke.

My veiw on the hole size and opening are that the two stage set up unmodified at best gave half the main hole, closer to a third if you made sure the puck was far enough back past the hole to seal, even my modifed version ( an M2 nut soldered to the top section ) only gave half a hole. Considering I pulled the Black Pearl half size DCC around the miniatures area at Dorset and also ran up the main hill with two trailers and four adults I dont think there will be any real issues. Although the video of the second run up the hill shows the guys getting off to help it turned out that the stop block on the reg rod had moved giving only about a fifth of full opening on the reg hence the apparant lack of power.

Trust me when I say the need for FULL power in most circumstances either on a rally field or at play are few and far between, Brian perhaps has demonstrated the most need for power in his road runs and would be best to comment of his reg set up verses power. Given the choice between a slightly reduced power and not being able to close the regulator I know which one I vote for. This feels similar to the disussions about the turning circle thread which blew up early on, although the turning circle of the Road Loco is less than the agricultural I haven't even noticed it in use.

Thanks Kev,

Sounds like we are getting somewhere, I agree, rather have a safe controllable engine than a run away  never knowing for sure if you can stop the thing!

Kev

I like the insert approach but humbly suggest STW make it from steel based on experience from my day job:
1.) If use a steel like 440C (AMS 5630), it can be direct hardened and tempered to HRc 55+ then properly ground and lapped by STW. 440C will retain its hardness operating with steam at 180 psi (360°F) making it very wear resistant.
2.) Coefficient of thermal expansion for steel will closely match the casting so it won't try to work loose with temperature cycles.
3.) Keep the valve made from bronze/brass as it can be removed rather easily for repair on paper if necessary. Also, the dissimilar material pair (brass/bronze against steel) will be less likely to gall if any contaminant joins the party.
Best Regards,
Mike

I had wondered about the expansion causing the flange sealant to fail so I do like that idea, also the hard wearing nature means less need to remove which is also somewhat of a challenge.

Some numbers to give thought to..
10mm hole total surface area 78.5mm sq half open is 39.2 mm sq third open is 26.1mm sq quater open is 19.6 mm sq.
8mm hole total area is 50.27 three quarters open is 37.7 mm sq half open is 25.1 mm sq and quarter open is 12.5 mm sq.
the total throw of the regulator rod is 9.5 - 10mm so if you have your regulator assembly have a look at it in situ and see how far it moves for 10mm travel. The ammount of opening may surprise you.

Looking at my valve rod and the opening it is at least 3/4 open at full blast, also a slightly reduced hole may give better control without the need for a two stage style valve.

kev, sounds like you are on the right track and STW will be owing you a beer or two once this is done (knowing Dean and Steve I bet they already have the lorry loaded and waiting). After the video you put on the other day, I had another go at the starter valve and this time I have got it to work. I have no racing on and once I hit the button it kicked in and then wait back to a slow tick over. Now it works I am very impressed with it and would recommend that people stick with it and get it to work. The reason for the post is to mention that now I have the starter valve working the regulator is still working very well, I steamed for 4 hours without a problem with the solid regulator.

good luck

Dwain

I counter drilled the 8mm hole in Kevyn's insert 10mm so that operation with the puck stays the same (it sees a 10mm hole).  Given that 10mm hole is never totally uncovered I would not expect the reduction in diameter to 8mm lower down to be significant.  Also remember that the pressure drop across the regulator is related to how much steam is passing through per second.  ie steam passing through goes up with RPM.   Thus the less than perfect opening will only be significant at high RPM end load.  Having experence rocket mode on a 4" DCC it is plenty fast enough!

As to materials I would not recommend going for anything too exotic after all we are not building a nuclear reactor.  I suggested to Kevyn that the prototype parts that I made from brass should be replaced since I am worried about dezincification.  I know there is a school of through that brass can be used since dezincification only occurs under specific conditions and brass compositions. I am no expert hence I would play safe and go for bronze.

Please bear in mind that I suggested the valve insert for anyone without the skill and patience to scrap their face flat.  I know from bitter experence that attempting to use emery cloth or wet and dry in a restricted space quickly destroys the surface's flatness.

Dwain, I take no credit for any of the development or work involved in this trial, ALL credit has to go to Julia, I am simply the guinea pig tester who was fortunate enough to be the one who moaned long enough that someone volunteered their services. As Julia has said this is still at trial stage and I have yet to steam up to test it fully, but we are certainly going in the right direction.

Well done for sticking with the start valve, as you have found it is a very easy way to pull off and once you are used to it it is a very handy button. Eventually all these annoyingly little things will be a distant memory.

 SUPERB, EXCELLENT, OUSTANDING.   

Had a good steam up this morning after getting the valve to seal with air and it was excellent. As pressure rose there was the slightest let by but nothing like before and once all the components were back together the results speak for themselves. No pressurisation, very easy to stop, no issue getting forward or reverse, all in all a lovely engine to drive. I could tell it was much better behaved as when I tried to pull up and shut the regulator it just free wheeled as everyting is so loosened up now, even pulling into reverse ( without opening the regulator ) had no effect on it stoppping which shows there is no steam entering the HP side trying to combat the forward movement. ( this is not how it has been throughout the summer and I will need to relearn how it feels now )

Went for a drive up and down the local roads in all gears at all speeds, low end creeping along is still easily achievable, probably even better if a small notch filed into the port. Top end in third seems at least as good if not slightly better to achieve due to the single stage style vlave, havent got any hills or loads to try with, so I think the plan will be for Blackbeard to have a go at this mod and do a few road runs to gauge power but otherwise a very good trial. I am in steam at Portsmouth Docks on the 29, 30th Nov and 1st Dec so will be able to see how it fairs then and be able to compare with Tim as he will be there too.

A quick resume.. I have fitted the insert with the 8mm hole with no lapping at all just the machined finish, sealed to the block with Loctite 510 flange sealant held down for 24 hours. Very lightly lapped the valve itself on a piece of glass with 100 grade yellow Timesaver compund to get it as flat as poss and then used the existing stop block to locate on the rod. I have taken some video of it, just need to edit it ot one piece and then upload so hopefully a bit later on.

The original idea using the cylinder as it came is not a problem it is your ability and patience to get a truely flat sealable surface for the valve face. It has been demonstrated by Dwain that this is possible with meticulous care and time but it is quite a task to get right. Two qualities I so clearly lack!!!

All in all excellent!!! Even the wet and dry fall out has been cured but that was a pain for such a silly error.   

Fabulous, that is good news indeed.

With best wishes
Simon

well done buddy, this sounds great, you have worked hard, looking forward to meeting up at some point and having a pint. I have my fingers crossed for the 3 day event and look forward to seeing the video.

Dwain

Great news Kev,

I bet the smile is back now !

looking forward to seeing the vid, thanks for your trials and posting your results

Kev

Great post Kev, thanks for the feedback.

What is the resolution from STW, are they using this design?

All the best,

Brian

This should be the link to the new trial, the first is running single cylinder having had a mishap in reassembly, then with the LP side on. Next I have popped across the road to speak to father in law and we chatted for a few minutes with no pressurisaton in the HP side at all. Finally a quick shot of a road run tyring to find a slow tick over, it is quite easy but not so easy to film, steer and run at once!!!

Excellent. Crystal will be pleased when she wakes up with a new regulator block.

I have just posted some pictures of Blackbeard's regulator components after removing it on Tuesday evening for anyone who wants to see it, interesting to compare with the findings of others.

https://traction.forumotion.com/t743p330-road-loco-blackbeard#15320

Any news on the official regulator mod?

thanks

Kev

Hello All,

There are several pictures below of my regulator. Although not STW approved, I believe it will work nicely once lapped with the cylinder block. The first image is of the parts un-assembled, the base of the regulator has a width of 24.5mm



The next image is of the regulator assembled (obviously, I have left the spring off to show the parts assembled).



Hope this helps.

All the best,

Brian

Brian

That looks just like my regulator but without the addition of the additional base where you are putting the spring (one of those strong ones I gave you for the starting valve?). I think mine was 24mm if I recall and it is now working fine too, another steaming last Saturday doing some winching tested it once more.

Brian W

Is there an official STW version in the pipeline?

Thanks

Kev

Not been on the site for a while and I thought I would have a look around, interesting how the site has moved on i.e. new people and a lot of interest in the next set of people building and some of the same problems coming up about how to build x or y (not a problem really more of the same questions we all had). Anyway what is the outcome of the regulator mod from STW. Although I have done a mod I have not heard a dickie bird from STW. This issue has seemed to have gone away without it being resolved for the first batch of builders or did I miss a fix other than what Kev etc did. I know they are doing mods to the follow on batches but what about the first batch??

Good question,
I asked a while back but heard nothing

Kev

The last word I had from the factory was a stainless version was to be made and sent for me to try due to concerns the brass may fracture after repeated heat stress. That was about 6 -7 weeks ago..... The current set up was excellent at the weekend, I have learnt to be patient with the factory, whenever I have any other info I will post in the meantime anyone else who still has an issue needs to contact Steve to push it along.

Hi all

I have had a word with Steve last Friday over the modified regulator.

The stainless steel plate and aluminium bronze puck I made had become stiff over winter, but soon freed up and is working well. Stainless steel is definitely the material of choice for the base.

Tim