Topic: TRV1A Problems (Read 13248 times)

Bee · « **Reply #25 on:** January 08, 2010, 12:52:01 pm »

If it stops with one piston at the top (or bottom) is it actually hitting the cover? Or perhaps a valve rod is, or the con rod hitting the piston rod gland, or the big end rubbing on the crank webs. It is possibly improving because the bearings are wearing to give clearance as a side effect. Is the crankshaft straight?
If you can feel the tight spot when turning by hand then keep investigating that way rather than steaming as that will anyway introduce effects such as trapped condensate.

steamboatmodel · « **Reply #26 on:** January 08, 2010, 06:33:26 pm »

Hi Andy,
Checking back over the posts I don't see any mention of Lubrication.
Do you have a lubricator for the engine and are you using proper steam oil?
When you were running it in with the drill were you lubricating it?
Are all the other parts being lubricated?
Regards,
Gerald.

andywright · « **Reply #27 on:** January 08, 2010, 07:50:31 pm »

UPDATE
Well its running a lot better now, still slightly lumpy one way, but as smooth as... the other way, It had a good run last night and was a lot more free after, so its carry on running, now it runs very slow on about 15psi, wheras it wouldn't run at all below 20psi.

Yes its been well lubricated right from building, I have been involved with largish marine diesel engines for the last 30 years so do know abit about lubrication, just lacking in knowledge with steam but learning fast! The lubricator works well.
I'm not out of the woodwork yet, but getting there, I may look around for a small compressor this weekend, it would make things a lot easier.

Circlip · « **Reply #28 on:** January 08, 2010, 08:01:51 pm »

Cheap compressor? Dead fridge or dehumidifier compressor unit.

Regards Ian.

gondolier88 · « **Reply #29 on:** January 08, 2010, 08:17:52 pm »

Or use your boiler empty as a reciever for a foot pump.

Greg

andywright · « **Reply #30 on:** January 08, 2010, 08:54:42 pm »

Good idea. Thanks.

tobyker · « **Reply #31 on:** January 08, 2010, 11:34:13 pm »

for a reasonably priced compressor see Everythingairbrush.com as recommended in the MB article. But still £60. I'n thinking of getting one so I can display various odd engines I've collected over the years - tho I suppose I should make boats for them!

HS93 (RIP) · « **Reply #32 on:** January 09, 2010, 12:59:17 am »

Try this firm i have used them a few times , they also have a presence on Flea bay very fast delivery.

http://www.rdgtools.co.uk/acatalog/AIR_BRUSHES_AND_COMPRESSORS.html

http://www.rdgtools.co.uk/acatalog/NEW_LINES_TO_RDGTOOLS.html

peter

tobyker · « **Reply #33 on:** January 09, 2010, 06:45:59 pm »

Thanks Peter - straight into my favourites file!

steamboatmodel · « **Reply #34 on:** January 10, 2010, 01:40:04 am »

Hi Andy,
Glad to here it has been properly lubed. I have over the years seen a number of engines that were "run in" dry with a drill. I'm glad to read that " its running a lot better now, still slightly lumpy one way, but as smooth as... the other way," . I guess it just needs a bit more running and a bit of fine tuning with the timing.
Regards,
Gerald.

andywright · « **Reply #35 on:** January 10, 2010, 02:10:36 pm »

UPDATE.
Firstly thank you everybody for your advice and information, the engine is running a lot better now, just needs more running in I think, a friend of mine who used to be a steam engineer at sea (I thought he was a motor man!), had a fiddle with the timing so its quite good now.
Will post any other updates on the TRV1A here. Meanwhile will keep the build post updated.
Thats not to say other constructive critism or advice is to be kept to your self, anything that helps is welcome here, I am sure we all can still learn something new everyday.
Regards Andy

gondolier88 · « **Reply #36 on:** January 10, 2010, 04:08:40 pm »

Good to hear mate- all the best engineers know about steam...so I don't know why I do

Have you got any pics of her assembled then?

Greg

Underpressure · « **Reply #37 on:** January 10, 2010, 04:10:57 pm »

Brilliant, well done Andy.

Frustrating though machines are, it is very satisfying (and educating) when we finally get them going properly.

Neil

andywright · « **Reply #38 on:** January 10, 2010, 08:59:59 pm »

This is the finished engine fitted in my launch. Further pictures here
http://www.modelboatmayhem.co.uk/forum/index.php?topic=3755.0

kiwimodeller · « **Reply #39 on:** January 11, 2010, 09:02:33 am »

[quote I am sure we all can still learn something new everyday.
Regards Andy
[/quote]
Thats exactly what my Dad said in his speech at his 90th birthday party Andy but he added "the problem arises when it is the same thing as we learnt yesterday!"

kno3 · « **Reply #40 on:** January 12, 2010, 11:28:27 pm »

Congratulations Andy, it sure it satisfying to get it to run well.

andywright · « **Reply #41 on:** January 13, 2010, 04:38:11 pm »

Now I've got to finish running it in and also run the shaft in, my shaft is a Mobile Marine Models with bushes rather than bearings. I've allways used them with electric tugs and they are a good product.

mogogear · « **Reply #42 on:** January 14, 2010, 06:18:49 am »

Congrats Andy--Welcome to the satisfying and frustrating world of steam!! She looks great

andywright · « **Reply #43 on:** January 14, 2010, 04:33:38 pm »

I'm now having problems getting the engine to self start again, finding it very tempermental, it will not self start when connected to the prop shaft, and the shaft is very free running, I guess the engine has had about 4 1/2 hours running now on steam. Even when free running the starting is hit and miss.

Andy

Bunkerbarge · « **Reply #44 on:** January 14, 2010, 05:56:26 pm »

Andy, apologies if I'm asking a stupid question but it's always worth airing all aspects with something like this. Not knowing how the crankshaft is constructed and whether it is solid or fabricated but I have to ask whether the two main piston cranks are 90 degrees apart?

andywright · « **Reply #45 on:** January 14, 2010, 07:25:28 pm »

Richard, Yes the crank looks like its 90 degrees.
Something I just discovered is the pressure relief valve seems to lift at between 25 - 30psi on the gauge, I know these model size pressure gauges are not the most accurate, give or take, but it must be some where near, I have tightened it down a midges and got the engine to run longer, its still a bit lumpy one way though, I will visit John at Miskin models hopefully next week, thats where I bought the kit, he has one of his own and he said he would have a look at it. In the meantime I will try to get the pressure relief valve checked more accurately, there is one running on air on You tube at 40psi, it run for about 4 mins during the video without stopping, instant reverse and forwards as well, I think it could now be a combination of not enough pressure, and still slightly out on timing. On nights tonight so its off to bed for an hour.

Andy

MONAHAN STEAM MODELS · « **Reply #46 on:** January 15, 2010, 05:55:30 pm »

I have a feeling it's still the timing of the valves which is causing your engine to run roughly. There is a few other things that will cause the same types problems. I've seen worn out piston o-rings cause similar troubles in the past. In fact I've seen small pieces of the piston's o-rings break off and become lodged into the steam ports which has cause erratic running characteristics on some engines. If you wish, you could send the engine to us and we'll be happy to take a look at it and try to figure out what's wrong?

MONAHAN STEAM MODELS · « **Reply #47 on:** January 15, 2010, 08:47:40 pm »

Also check to see if the D valves are completely flat against the port faces. That's another reason why the engine could be losing power. It may only be running on one cylinder and letting steam leak out the other due to poor valve sealing. It's just another thought.

andywright · « **Reply #48 on:** January 17, 2010, 12:02:13 am »

UPDATE.
fine adjusted eccentrics one way and the other to find optimum position, then adjusted the sliders so that steam is let in to the top of the cylinders slightly earlier, wound the threaded push rod in 1/4 turn at a time, when running clockwise (forward), this was the lumpy direction, engine now running about the optimum, maybe slightly faster in reverse, will go one more 1/4 turn tomorrow to see if speed evens out, though if this is the optimum at the present setting I will be more than happy, self starting perfectly. Now know a lot more about steam engine timing than I did a fortnight ago, if this is it I will be happy, hopefully have the boat on the pond next week for steam maiden!. Andy

andywright · « **Reply #49 on:** January 19, 2010, 08:45:51 am »

Now fitted in launch, ran and operated on radio gear, still runs better one way than the other, (very marginally), but can live with that, may order a left handed prop, as thats the way it runs the best, or more fiddling with the timing, but I feel like I've done enough. It runs on absolute tick over lefthanded, and I mean slow, but when running clockwise the same speed it does tend to stop now and again, when I say slow I mean slow, probably 30rpm its hard to tell without a rpm counter.
One thing about this engine it does teach you very rapidly and thoroughly about the workings of a steam engine, i am very happy with the out come, and the engine looks a dream in the boat running, will try to post video on you tube some time. Any way more pics in my build thread.
Andy

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Author Topic: TRV1A Problems (Read 13248 times)

Bee

steamboatmodel

steamboatmodel

Underpressure

kno3

mogogear

MONAHAN STEAM MODELS

MONAHAN STEAM MODELS