New Project Started!

[Bernd]

Are you making the base out of ally? if so you could try making the edge trimming D bit from case hardened mild steel it may just work as a one off, I think Bernd used a one off mild steel cutter on his south bend indexer thread.

Stew,

I went back and checked that thread because I couldn't remember either. But it wasn't that thread. Somewhere around here I think I mentioned I made a counterbore using silver steel (drill rod).

Your right that you can make a one off to do that though.

Bernd

[sbwhart]

Hi Bernd thanks for following that up

Cheers

Stew

[Bernd]

Stew,

I think I wrote that up about the c'bore overon HMEM. Now that I think about it.

Bernd

[bogstandard]

Nick,

Don't under any circumstances give up on what you have already done and start making new bits.

First off, give the inside of the bore and pistons a clean out with meths. Just a small amount of oily substance or residue in there can stop it running.

Double check your timing first, then warm up the cylinder for about 20 seconds with a blowtorch, don't hold it in one place just play it all over, let the heat penetrate for a few seconds, only then give it a dose of flame at the port.

Notice where I have my burner, it has to be around that point somewhere, 1/2 a millimetre up or down or side to side will make all the difference to it running or not.

It took me hours to find the correct sweet spot spot for the flame.

Don't spin it over too fast, you will soon wear yourself out and also lose your temper, a gentle flick is enough. The engine will start to show signs of life when it is warm enough and the flame is near the correct position. It might only be a couple of extra revs on the flywheel, but you will get some sort if sign.

Perseverance is the way to win with this type of engine. Once you find the sweet spot and correct timing, you will be on your way.


John

[chuck foster]

nick , as john said work with what you have made. all the parts you have made look good, these engines are a bugger to
get to run right but once you figure them out you will be very happy with what you have made.

keep us posted.

chuck 

[sbwhart]

Nick

As the guys say, keep at it, and keep your cool, and you'll have a runner.

Good luck

Stew

[NickG]

Thanks for the encouragement guys.

I gave it a quick try while I was supposed to be making the tea last night! I gave it a quick clean first as there was a nasty brown deposit. Then set the timing and tried to position the flame as per Jan's and yours John. Still couldn't get anything out of it, but the characteristics seemed different. There was sort of more whooshing sound and the flame kept blowing out if I flicked the flywheel too fast. THis time the thing gummed up with that deposit really quickly. I am just using an old bottle of methylated spirits, is there anything I can easily get that will burn cleaner?

At this point I have an apology to make for being stubborn / not listening. You may remember me asking questions about the crankpin, and that John recommended doing it in a certain way. Well I stubbornly did it my way, the way I had done on my hot air engine. This was for 2 reasons, 1. to make it simpler to make, and 2. because I wasn't mega confident everything would be dead straight so I thought allowing a little floating of the bearing on the pin would let things self align. Well I think it all is pretty much inline, but because of the relatively long rod, it does float quite a bit side to side, sometimes getting close to the crank disk. I can't feel any undue friction and it doesn't seem to touch it ever but it is annoying me now. The other main point that John mentioned at the time was ease of disassembly to clean everything out - well on mine, it's not exactly easy to take to bits. So it'll be getting a nice knurled screw (if I can manage to do a nice knurl - not done that since uni days) as Bogs suggested with the right clearances built in. So feel free to give me a  and  and I hope you accept my apology, I didn't do it blindly - I had a couple of reasons but I should have digested what you were saying more.

I was also trying to think which way would be best to spin it, but it really shouldn't make any difference at all.

Jan suggests a small clearance between striker assembly and cylinder when at TDC and when at BDC there should be about 1-1.5mm overlap of the valve and port. Is this about the same as yours?

Thanks,

Nick

[NickG]

Quick check in.

Last night I realised a difference in the way Ihad made the valve rod which may have affected things. John's rod has a 90 deg right angle silver soldered - this allows limiting the travel of the valve into the cylinder and Jan's new method with the bend is bent in such a way to limit this. Mine however, ended up with a slightly different bend allowing the valve to travel further in which could alter timing. So I turned up a coller with a set screw in it to limit that travel, just as I can at the other end by the striker block.

Tried the engine again, still no signs of life that I can detect. Sometimes it sounds like it might kick a bit but that could be my mind playing tricks! I'm at a bit of a loss what to try next. I think it is set up as per the plans and it seems to pass the tests Jan suggests. If anything, I've never been happy with the fit of the piston / valve. I might need to re-lap the bore and carefully make a new piston and valve.

It also needs a burner and base making to stop it wobbling about and me having to hold the burner in place.

So still trouble shooting. I thought it might be tricky this one!

Nick

[Rob.Wilson]

WOW Nick 

great looking engine ,great build log too

Regards Rob

[NickG]

Thanks Rob!

Noticed you said great LOOKING, that's all it is at the moment if I can't get the damn thing running! 

Keeping all my fingers and toes crossed though.

Nick

[bogstandard]

Nick,

Make the burner first before making anything else, you just cannot hold the flame steady enough by hand for the engine to fire up, as I have said before, the flame position is the most critical part, that is why mine are screwed down, they can't move out of position.


John

[NickG]

Ok, thanks John, will do. I've spent the last 3 nights pratting about trying to get it to run but without a proper burner! I've studied all the other internal valve flame lickers I can and it all seems to be in order. I think this is where I need to be patient and methodical - oh dear! 

Nick

[Rob.Wilson]

Hi Nick

i did not mean it that way , i no these engines can be a pian to setup ,,,,O i did call into Darlington Steam  they do some big stuff with a big price tag

Regards Rob

[NickG]

Rob,

No worries, just kidding! 

  Those prices are astonishing aren't they! 

I just noticed that some are on ebay too now think must be same company - we are talking more than a lot of peoples homes for a 6" scale traction engine!

http://cgi.ebay.co.uk/NEW-6-Scale-Fowler-Traction-Engine-LIVE-STEAM_W0QQitemZ280432658216QQcmdZViewItemQQptZUK_Trains_Railway_Models?hash=item414b16c728

Nick

[Rob.Wilson]

Hi Nick

yep i had the name wrong  ,thats the company ,,,,,,,,,,,The Great Northern Steam Company,,,,,,,,,,,,  sorry 

Have you made the  burner for the engine ?


Regards Rob

[jim]

i'm paying a lot of attention to this now i've decided i'm building one of these.

i so look forward to your "its a runner" post

[NickG]

Unfortunately not Rob! Distinct lack of shop time - I chose to do something different tonight - played badminton and caught up with a mate at the pub. I do think about this engine about 80% of the time at the moment though which is quite annoying! I might make a start tomorrow and Fri night and hopefully on Saturday morning I should get a good chunk of time to myself as the wife and kids are off to see grandad and grandma without me! 

So fingers crossed by the end of the weekend, the engine should be 'finished' and I should know what action I need to take to get it running!

Nick

[bogstandard]

Be very careful Jim with these types of engines, as Nick is finding out, they can be a soul destroyer, and with only a slight push, could put you off making model engines for life.

This one that Nick has made deviates a lot from the normal practice for this type of engine, so if you really wanted to make a flame licker as a starter project, I personally would start with one of the more common designs, with the sucky in bit on the end of the cylinder head.

I have been having a bit of a discussion with Nick, and have come to the conclusion that the way to go with these engines is a change of fuel. I actually knocked up a basic gas burner for mine, and the engine ran lovely with it, unfortunately my burner design wasn't 'clean' enough, and the engine got choked with unburned deposits and needed to be cleaned out between runs.

Then I found these,

http://www.jerry-howell.com/Propane.html

Having purchased the plans, they look fairly easy to make, a couple of D-bits to make the venturi and the rest seems to be very straight forwards

To make the jets for the above, even though Jerry sells them in an American Imperial size, I want to make them in metric or English Imperial, then I have still to construct a very high speed drill. I have all the bits to make it, and is a very similar design to Jerry's

http://www.jerry-howell.com/Micro-DP.html

Only mine will be air powered, as that seems to be the best way for me to reach the speeds required for 'stable' drilling. Over 60K rpm should give enough centrifugal speed to the drill bit to enable fairly rough handling and feed of the drill without breakage. Just to see the sizes of drills that are needed, look at the pic below. The big one is about 1mm diameter, the one at the opposite end is the size required to drill the jet, 0.15mm.

This isn't meant to detract from Nicks post, just as an add on to give an insight into what can be done if you want to pursue it.

John

[NickG]

I would concur with John on this one Jim. It looks a simple design, that's what attracted me to it but with hindsight, I think the simplicity gives it less control and means things need to be more tightly controlled. Last night i was actually looking at the poppin versions with a sliding valve operated by  a cam. Although this initially seems a little more comlpex, I think it is a much more proven design.

John,

Those burner's sound excellent but I think are beyond my capabilities. As you pointed out, you need the specialist drill too.

Nick

[NickG]

Hi all,

I know this has gone a bit quiet but I haven’t given up on it! If I’m honest, I am a bit disappointed that it didn’t run and I couldn’t even detect it trying to run. It passes I think the tests on Jan Ridders problem solving page. If anything I’ve done is a bit marginal, I think it was the cylinder and piston tolerances.

I haven’t done nothing on it, I spent a few nights messing around trying to get it to run but nothing. Then I thought, just finish the thing off and then try to troubleshoot. So I started by finishing the aluminium base off.
New Project Started!
I sanded it with the bosch mouse sander then got a stick with some wet & dry and rubbed it back and forth a bit. Then I did the same with some white spirit which gives a sort of matt sheen to it. I could really go to town polishing it but it takes ages to get the machining marks out completely so this’ll do for me. I haven’t put polish anywhere near it, just a quick rub with some wet & dry and oil seems to give a nice finish in my opinion. I decided not to put an edge around it as I’d probably spoil it if I didn’t take care in clocking it square on the milling table.

After this, I could then make the base from some brown stuff. This needed little counter bores for the screws underneath the alloy base. I was wondering which way to go to fasten it down. At first I thought, could make some nice hex bolts and bolt from top. Then I thought I could keep them hidden like the rest of the engine, but then I found some 0 BA screws with nuts so decided to drill through the lot and leave the nuts on top as a sort of feature. This meant giving my nuts a bit of a polish so to speak!
New Project Started!
Again, this was sanded with the mouse and oiled with teak oil. I did put an edge around this with a countersink in the milling machine. It worked ok but it was a mess on getting it clocked straight.

Then I decided to re-do the crank pin. As discussed before with Bogs, it’s better to retain the big end with a set clearance to stop it wondering. So I made this from stainless:
New Project Started!
Along with a little bronze spacer. This is the first time I’ve ever knurled anything since uni. The set of knurls I have are sort of sprung and you turn a screw which makes them closer together (need a pic!). I didn’t really know how much to tighten it so I went easy, but then of course you can’t go back and do it again incase it goes in a different place and mashes it up so the knurl isn’t very deep! I should have pointed out that it's a 2p coin in the photo! Not sure why I put it that way around!

I then assembled the engine together.  Here are some pics, looking much better on its real base!
New Project Started!
New Project Started!
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Hope it doesn’t stay in here for the rest of it’s life! :
New Project Started!

The base was needed as it was wobbling about when trying to flick the flywheel over. Now it’s very stable so it will give me a better chance when I try to get it to run in anger!

Almost forgot to mention that I re-lapped the bore and made a better fitting piston and valve. How much better remains to be seen though! I also took the opportunity to extend the spigot on the piston slightly as I noticed my port wasn’t opening quite fully – not sure why, I must have calculated something wrong.

All I need to do now is the burner, then I am hoping my little tweaks and improvements are enough to get some life out of the thing. If not, I’m a touch puzzled. The only real thing I can think of is that I may have to revisit the cylinder and pistons again. I have a sneaky feeling that when I lapped it, it may have taken a bit of parallelism & circularity out of the bore. I think I have some adjustable reamers which may correct that, then make new piston and valve again.
There are another couple of suggestions with regards to the mass of my piston and valve as they aren’t hollowed out and the only other things that are different are the flywheel and con rod length. If anything the conrod length should improve things though and the flywheel should be ok, it should be better and don’t think it’s any heavier. If things such as the mass of the piston affect it’s running, it is, as I thought a marginal design.

Here is a little video flicking it over by hand, sorry about the lighting!
New Project Started!

So, hopefully will get started on the burner tomorrow, and by the weekend, fingers crossed I’ll have some good news. But I’m not holding my breath, could be back to the drawing board I think!

Nick

[sbwhart]

Looking good on the base Nick 

Your little tweaks I'm sure will get it running.

Stew

[Darren]

That is a very neat looking build you have there Nick, you certainly are making a finished job of it 

Be nice to see it running though 

[NickG]

To be honest, I'm pretty gutted it doesn't run. I haven't put as much care and attention into anything before, and I think it's a good improvement on all of my other builds. Maybe it's a step to far too early.

I still have options though. If it doesn't run now, hopefully I can get things nice and true and parallel with the adjustable reamer and plenty of oil, the only issue is the wall is getting pretty thin now, so if that doesn't work it'll need sleeving but still all is not lost.

If that doesn't work I'll be stuck for ideas and it would mean certain features of the engine that shouldn't be critical to it running, in fact are ... at which point I'll try making the poppin flame licker! There are a lot more examples of that running, infact that is one of the first engines I used to just stare at, mesmorised at exhibitions and steam fairs when I was a teenager! I have seen tiny flame lickers in the past that run really well and should only have a fraction of the power of this comparatively large one, unless this isn't a particularly efficient design.

Nick

ps I have also seen another design but never seen one working. I actually thought of this myself but then when was doing some research realised that somebody had infact already thought of it! 

It's a very simple idea so probably a lot of people have pondered it. Imagine an oscillating engine or wobbler but with the exhaust port not drilled. On the down stroke it sucks a flame in through the inlet port and once it gets to bottom dead centre the port is closed - it is effectively sealed. Gases cool down causing the under-pressure and atmosphere pushes the biston back to TDC. The only issues I see here are that the seal relies on a pushing the faces together which would cause a bit of friction., and  the timing is implicit in the design. Although by drilling the port in the right place you might be able to tweak the overlap etc.  This could be worth experimenting with but is a bit of a journey into the unknown and likely to make me even more  and 

When I first set my workshop back up a few years ago, a guy on CNC zone posted a pic of such an engine and one of his own which was unusual too (see attached)

[NickG]

Got a bit done on the burner last night! Took me ages for some reason, I didn't have the metal to hand, then I couldn't decide how to do it! I will post pics of progress later on tonight. Got the bottom of the burner done. Out for a team building thing tonight, 10 pin bowling and a few drinks so doubt I'll get in the garage until Saturday night now. But this weekend should see the burner finished off. Then it'll be testing the engine and probably deciding what I need to re-work.

Nick

[NickG]

Made more progress last night and finished the burner for the engine, which completes the last piece of the engine – but unfortunately not the last piece of the puzzle :o(  More on that in a bit though!

Here’s how I did the burner:
I had a bit of copper tube in mind, only slight annoyance is it had some sort of plating on it. Turned up a nylon bung to fit the tube as I quickly realised I was just going to crush it in the chuck.
New Project Started!

Faced off to length:
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I have about a foot of 1 ¼” ish cast gunmetal, have no idea where it came from but I decided to use that for top and bottom:
Facing and putting register on:
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Parting off:
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Good fit:
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Ready for soft soldering, I just used some electrical solder and some of that soft solder paste stuff which acts as a good flux:
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After a little cleaning up:
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Facing off due to parting pip:
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Here it is with the bottom soldered in place and a bit of polishing. I haven’t fully got the plating off but it’ll do!
New Project Started!

Turning the top was pretty much the same as the bottom; just put this pic in to show the weird difference in surface finish part way across the cut. Must be something to do with the way it’s been cast.
New Project Started!

I drilled an air hole then a hole angled at 22.5 degrees. I was worried I wouldn’t get close enough to the cylinder with the wick if not. I then turned a stainless steel bush and loctited it in before a bit more polishing. The fit of the cap is a tiny bit tight really, well, it’s just there’s not much to grip to get it off! A pain when it’s ½ full as you tend to spill meths! I was originally planning on putting a little knurled knob on it but couldn’t be bothered!
New Project Started!

Pic of it on engine base:
New Project Started!

I tried to run it again tonight unsuccessfully. I did find out a few things though. On mine, it seems some sort of lubrication is going to be essential. Without it, the meths I’m using puts a nasty deposit on it pretty quickly, jamming it up. But with oil present, it doesn’t build up.

I’m not sure why it won’t run but have been in contact with Jan ridders who is going to do some experiments on valve timing and let me know the outcome. I just can’t get much out of it at all. The most promising results were when I slackened the rear collar off – this means that when the valve shuts, the suction pulls it further into the cylinder. I then almost get a sort of power stroke if the flywheel has enough momentum to carry it over – however, at that point the valve gets a bit tight in the bore so I clearly have clearance issues. If I take a little off it to avoid it being tight, it’ll probably not be sufficiently air tight. I think I may need to ream the cylinder bore out and make new piston and valve.
Also, at the same time, because the valve got stuck, me spinning the flywheel loosened it on the crankshaft and because I’ve stupidly put the grub screw somewhere I can’t get at, It’ll have to come to bits to tighten back on. In doing this though, I found another possible issue. When the flywheel was loose, I moved the conrod manually with the flame present and if I quickly put it past bdc, I felt a definite power stroke trying to pull it back. So I’m thinking of trying an experimental aluminium flywheel as I fear my big dia. Cast iron jobbie might have too high moment of inertia.

Another thing I noticed whilst studying the pictures, tips etc on Jan’s site was that his wick is about 2 x the diameter of mine. So maybe the width of flame needs to be much bigger. Not sure if I have scope in my burner to go quite that big so would need to re-make the lid.
Sorry if all that is difficult to understand. I find myself rambling when things aren’t going to plan! When I looked at the design of the engine, I didn’t think there were many variables as they were inherent in the design – how wrong was I! Still, hopefully I’ll get there one day.

Disappointing but lots of things to try. I just need to do them in a logical order.

Nick