Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: Patternmaker on January 21, 2011, 01:46:06 pm

Title: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on January 21, 2011, 01:46:06 pm
Building a Stuart Twin Launch engine from a set of castings.

I was very surprised at what materials are not included, a total of 32 parts including the crankshaft which doesn't  matter as I am going to machine from 40mm ENA1 steel. As I have a good stock of materials its not
a problem. and I got a good deal on the castings set.

In my opinion its buyer beware as because until you have bought the Castings you will not know what else is needed to build this engine.

The boiler is designed by George (ooya/2) who has kindly given me plans and his expertise how to build it.


Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: rathikrishna on January 22, 2011, 06:40:06 am
WOOW...its a great stuff...please follo..and keep posting...please...
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on January 22, 2011, 09:45:47 am
rathikrishna,
I will post pictures of each stage of machining, I am making some changes to the original design, I will use stainless steel for the 5 columns, all nuts & bolts, grub screws & brass cylinder top covers.

In between building the engine & boiler I will build the launch for it.

Mick


Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on January 22, 2011, 11:30:49 am
I'm looking forward to this Mick, good luck.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: kno3 on January 22, 2011, 05:16:26 pm
Good luck with your build. This is a beautiful engine when finished.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: rathikrishna on January 23, 2011, 05:50:19 am
OHHH...nice...and also waiting for a nice video from you...sure..? 
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on January 23, 2011, 08:47:34 am
OHHH...nice...and also waiting for a nice video from you...sure..? 

There will be a video eventually, but that's a long way off with over 100 individual parts to machine for the engine without Boiler and Feed Pump.

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: rathikrishna on January 23, 2011, 12:47:52 pm
HAPPY.... :-))THANK YOU...take your own time to finish it....
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on February 04, 2011, 02:50:48 pm
Cylinder machined, bores honed with brake wheel cylinder honing tool, Piston ring shown in left hand bore.
Crankshaft webs machined from 28mm EN1A steel brazed to silver steel main shaft.



Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: kno3 on February 04, 2011, 03:23:17 pm
Nice work. What is the piston ring made of?
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on February 04, 2011, 03:37:48 pm
Nice work. What is the piston ring made of?

The piston rings are cast iron 2 per cylinder

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on February 04, 2011, 05:30:34 pm
Beautiful Mick, well done! Are the counter-weighted webs your idea, they look fantastic? Was the piston ring turned from CI bar?

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on February 04, 2011, 05:48:37 pm
Greg,

I decided to machine the counterweighted webs although its not possible to perfectly balance the shaft with 90 deg offset but they should make a smoother running engine, the piston rings are included in the Casting set.

Mick

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on February 13, 2011, 03:06:55 pm
Sole plate & bearing caps with crankshaft fitted.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on February 22, 2011, 06:12:46 pm
Bottom cylinder covers & Slider Bracket incorporating reverse shaft.
Reverse shaft, columns & sliders made from stainless steel, not included in castings set.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 04, 2011, 03:46:36 pm
Con rods, cross heads & pistons.the cross heads have been made by filling as they would very difficult
to machine.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: J.Walpot. on March 05, 2011, 08:56:06 am
Beautiful work Mick. I wish you lots of fun building the other parts.

Regards Jan.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 05, 2011, 06:44:58 pm
Thanks Jan, have you built a Stuart Twin?

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: J.Walpot. on March 05, 2011, 07:58:09 pm
Hallo Mick.

No I didn't. I made my own designed engine for my model tug Maarten. You can find it on this forum.

Regards, Jan.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 05, 2011, 09:45:30 pm
Hello Jan, you are to be congratulated on your superb workmanship and design skills on your engine and Tug Maarten.

Regards Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 10, 2011, 04:46:22 pm
Flywheel & eccentrics, Stuarts use to cast a stub on the back of the eccentrics to hold in the chuck, my castings did not have the stubs, the only way to machine them is to manufacture a mandrel to fit the crankshaft bore in order to hold in a independent 4 jaw chuck to get the 20 degree offset from the
centre line of the crankshaft on each eccentric.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Flyerjeff on March 13, 2011, 12:58:13 am
Could I ask what equipment you are using to machine your parts?
 I have always wanted to build this engine myself but only have a Sherline lathe and Mill.
Beautiful Work!!!!!

Thanks!!!!
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on March 13, 2011, 10:45:04 am
Hi Mick,

Those eccentrics look great- I can't imagine ST are on such a cost saving drive as to not include a machining spigot anymore!

The green you've used on the flywheel is a really nice colour, what paint have you used?

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 13, 2011, 02:38:18 pm
Hi,
I have a Clarke 300M variable speed lathe with optional extras; 4 jaw independent chuck, fixed steady, travelling steady, revolving tailstock, 6” faceplate and tailstock chuck. A very good lathe, apart from
the plastic gears, they tend to strip on the keyways, I have put steel inserts in the centres of the gears which has cured the problem.
I have a Clarke CDM 10 Micro milling machine, does everything I want no complaints with this machine.

I have looked up the details of your Sherline Lathe Mill, I don't see any reason why you should not be able to build a Stuart twin on this lathe and mill.

Regards Mick

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 13, 2011, 02:41:13 pm
Hi Greg,

Yes, I must admit I was very disappointed with the casting set considering what they cost and extra materials needed as I have told Stuarts, your web site is misleading in the description of the casting set.

The paint is Japlac British racing green.

Mick



Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Flyerjeff on March 13, 2011, 04:29:04 pm
Hi,
I have a Clarke 300M variable speed lathe with optional extras; 4 jaw independent chuck, fixed steady, travelling steady, revolving tailstock, 6” faceplate and tailstock chuck. A very good lathe, apart from
the plastic gears, they tend to strip on the keyways, I have put steel inserts in the centres of the gears which has cured the problem.
I have a Clarke CDM 10 Micro milling machine, does everything I want no complaints with this machine.

I have looked up the details of your Sherline Lathe Mill, I don't see any reason why you should not be able to build a Stuart twin on this lathe and mill.

Regards Mick

Thanks for the quick reply
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on March 13, 2011, 07:49:41 pm
Hi Greg,

Yes, I must admit I was very disappointed with the casting set considering what they cost and extra materials needed as I have told Stuarts, your web site is misleading in the description of the casting set.

The paint is Japlac British racing green.

Mick

Hi Mick,

Thanks, I'm very impressed with that paint.

You'll have to let us know what they come back to you and say.

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on March 13, 2011, 08:46:43 pm
Hi Greg,

Stuarts have now changed their Engine Description, ( No bar stock materials supplied with the kit)  no help to me but at least it will let other purchasers of this casting set aware.
As I purchased from another source, a lot cheaper than Stuarts and have a good stock of materials it is not a
problem.

I do consider this casting set expensive for what you get although I must say the quality of the castings are
excellent.

Mick










Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on March 13, 2011, 09:41:03 pm
Hi Mick,

That's something I suppose, as you say no help to you. You seem to be managing just fine however :-)) Keep it up- you'll be onto the next project in no time at all, some people make me sick!

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 03, 2011, 02:33:26 pm
Cylinder block completed, quite a few changes from original design.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: kno3 on April 05, 2011, 11:00:49 am
What's the reason for the peculiar placement of the screws on the cylinder top covers?
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 05, 2011, 01:13:09 pm
What's the reason for the peculiar placement of the screws on the cylinder top covers?

Spaced as shown on the plans, they have to be in those positions to clear cylinder Exhaust ports & drain cocks, as you can see from an earlier picture they are spaced the same in the bottom cylinder covers.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 05, 2011, 02:01:15 pm
 Kno3
Another reason is that as the pistons are set at 1.25" centers and are 1" dia it only leaves a bridge of 1/4" between the bores in the cylinder so you have to cut the cylinder covers to fit and use a common bolt in the middle.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: kno3 on April 06, 2011, 11:02:16 pm
Thanks but I didn't mean the shared screw between the covers. I mean the bottom 2 (on the exhaust side) that are much closer to the shared screw than the others, those don't seem to have to clear anything below, so why aren't they placed as to be at equal distance to their neighbours?
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 07, 2011, 08:41:02 am
kno3

The cylinder casting is different on the exhaust side, if the cover bolts were equally spaced there would only be an 1/8” depth of thread in the casting, which as you know would easily strip being cast iron.

Mick

 
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: oLiV on April 07, 2011, 08:45:21 am
Hi from france, I was following this topic, and I'll try to reply as best as possible, please forgive any bad english:

I'm actually building a Twin Launch too, and I decided to make some changes to the original drawings for cosmetic reasons. one of these is to drill the top covers' holes equi-spaced (72° from each other). I've not done it yet, but I see no reason why this couldn't be done. There are also several examples on the net.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 07, 2011, 08:53:33 am
oLiv, I hope you are enjoying your build and wish you good luck.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: oLiV on April 07, 2011, 09:43:35 am
Thank you Mick.

I'm a beginner in machining, I'm actually collecting tools and learning about using them ! And trying to get familiar with imperial sizes  %%

my mill is a HBM SX1 (the same as the Clarke CMD10) and my lathe is a "big" Fartools ML350 my father owned.

Olivier
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 07, 2011, 05:31:47 pm
Hi  Oliver
I look forward to your build, please post some pics.
I also am considering a launch engine build.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: oLiV on April 08, 2011, 09:38:11 am
Ok, I'll post a new topic soon

Olivier
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 09, 2011, 07:38:23 pm
Oliver.
Is the picture you posted pf the Stuart Twin from RC groups.com built by dunc 2504 from Somerset, if so he says that he has only run it on air, nothing else since from Aug 2010.
This is the only other example I have found with equi-spaced cylinder bolts, there is a fine line between cosmetic changes and practicality.
I'm sure that if it was practical to equi-space cylinder bolts Stuarts would have done so in their original design.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: oLiV on April 09, 2011, 08:29:47 pm
Yes it's Dunc's engine. I didn't know he had never steamed it.

Another example :
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 11, 2011, 08:39:45 pm
Oliver ,
I must caution you about these bolt positions, as you say that you are a beginner to machining I would advise you to stick with the STUART drawing.
If you space the holes equally it means that on the 2- bolts in question it only leaves you 1/8" thickness of cast iron to tap into where as if you go by the drawing you will come into solid cast iron.
Now if you don't know cast iron is not the strongest material to tap into so you risk the possibility of stripping the thread if you over tighten, so I would advise that you stay with the drawing as it has a purpose more than cosmetic but of course that is entirely up to you.

George
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 17, 2011, 10:07:35 pm
Eccentric rods, Reversing quadrants and link rods
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: south steyne on April 18, 2011, 12:26:12 am
 :-)Look great my only concern would be the depth of thread on the eccentric journals but that's just my thoughts.
John
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: south steyne on April 18, 2011, 04:42:13 am
Sorry maybe I can clarify a bit better as I see by the drawing the crankshaft appears to be 1/4 in, so the thread depth for the set screw would be probably only abut 1/8th and as these eccentrics need to be tight I would think a better way would be to drill and tap into the main body of the eccentric and double set screw after you time the engine any other thoughts welcome
John
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 18, 2011, 06:43:47 am
John,
The crankshaft dia is 5/16” When the timing is set the eccentrics and flywheel will be taper pined to the crankshaft.

 
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 18, 2011, 09:18:56 am
Hi Mick,
Taper pinning the eccentric is a bad idea, once pinned it's there for ever.
If for some reason you have to look at or alter anything you are snookered and it's going to be a tricky job to drill and pin after the engine is built.
How would you hold the completed engine steady enough to drill and ream.
If the drawing calls for pinning, pin it if not leave it as there is very little strain on the eccentric sheaves on the shaft.
As the eccentric sheaves are steel there will be enough grip with a socket  grub screw.

George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: derekwarner on April 18, 2011, 12:50:48 pm
 ooyah/2...I do not necessarily agree that taper pinning is a "final solution..........& cannot be revised/altered from a timing perspective"  >>:-(

Most of the British designed mechanical gun control computer systems [pre & post WW1] had small backlash compensated gear drives that were aligned & secured by BS Standard taper pins

Some of the beauties of such fastening devices was that they required no heat......no liquid adhesives....would never vibrate loose .... :-))  but were still easily removable & easy corrected from a timing perspective simply by rotating the componet to be re-timed & re-reamed

Another positive characteristic of the tapered pin over HPGS is that diametrical clearance between mating parts is not savagely distorted  :o  which is important with high speed & balance ....Derek



Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 18, 2011, 04:40:10 pm
George,
 
This is what I meant by a tapered pin, 3mm stainless steel socket set screw, I will also use it on the worm drive for the boiler pump.
I have used this method on all my sports boats for flexi drive couplings for many years.
 
Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 18, 2011, 05:15:29 pm
Hi Mick,
That's O.K. just a use of different words, I have always used taper pins where you need to drill the shaft and ream the hole to put in the pin.

Having built several Stuart D10's and10V's all with Stevenson reverse gear a taper pin thro' the sheave and the shaft is a bad idea.
.
DEREK
Some time ago you told me that you don't build engines which is O.K. so let me explain how you adjust the timing with Stevenson reverse gear.
You need to be able to move the sheave around the shaft to get the proper timing and once it's set if you put a taper pin through thro' sheave and the shaft it's there for ever, so if by some mishap or some thing else you need to re-time the engine you are snookered.
Now what Mick calls a taper pin is actually a grub screw ( you must forgive him , he's only a wood butcher but a darned good engine builder ) and the use of the grub screw allows you to re-set the timing if required.

 I am sorry I can't  can't figure out what you mean, you have lost me, you can't compare a toy steam engine to a gun but if I ever required info on a gun or weapons you would be  "MY MAN" to keep me right.
Derek, what is HPGS ?
I can only go by facts ,either by calculation or experience and my experience knows that taper pinning a sheave to the main shaft is a bad idea.

John, there is very little strain on the eccentrics as they are only  driving the valve which is held to the cylinder face by steam pressure, all that is required is a grub screw otherwise STUART would have designed something else.
George.  
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on April 18, 2011, 07:34:05 pm
Hi Derek,

In a situation where there is plenty of 'meat' available between the two things located using a taper pin (full size engines, ordnance etc), small adjustments; ie. <10 thou, you can ream the taper out and put a larger and/or longer taper pin in.

In a model 10 thou is an awful lot of metal, as George says, at this size a taper pin is the last word, if you do it wrong you'd have to fill the taper in the shaft with braze and re-drill and taper ream it- not what you want when all you want is to rotate the sheave by .5 deg.  >>:-(

Mick,

Looking great, as always!. Thats some very nice work on the eccentrics. If I'm keeping up (would make a nice change) your next pic's should be of an assembled engine...?

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 18, 2011, 07:44:41 pm
Hi Greg,
Yes the next photos will be the assembled engine, doing a lot of jobs in the garden at the moment in this glorious weather, 24c for the last 7 days.

Any progress on your D10

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 18, 2011, 09:22:19 pm
 You can't ream a hole out bigger and move the object by .010" as you are reaming on the same center line so no gain has been made.
If you move the said object by .010" and clamp it you now have a hole that is out of line, top and bottom and the drill will break as you try to bore out the hole which then if successful you would need a very large taper pin to make a good fit on the now large hole which will be seriously larger.
If the hole has offset edges not only will the drill break but the reamer will snag and break also.
To get some adjustment you would have to redrill a hole at 90deg and ream it out for a new  pin, this is very bad practice in engineering as you would drill thro' the old hole.
If an item is to be taper pinned to a shaft the design will call for that item never to be moved.

If you take this to the launch engine which has a 5/16" main shaft it will be seriously weakened, this is why the design doesn't call for taper pins but grub screws to allow for adjustment.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on April 18, 2011, 09:46:02 pm
Hi Greg,
Yes the next photos will be the assembled engine, doing a lot of jobs in the garden at the moment in this glorious weather, 24c for the last 7 days.

Any progress on your D10

Mick

 {-) That would require spare time! Seriously, busy with my 1:1 scale dinghy at the moment, and like yourself spring brings all those wonderful pleasures such as gardening/painting etc- at least the sun is shining- though up north it's only been 12 deg.C.

I await your next installment with anticipation.

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: derekwarner on April 19, 2011, 01:57:49 pm
Guys....an alternate view on a few fundamentals in basic minature engineering

A 3.0 mm HPGS [commonly termed as a hollow pointed grub screw] according to UNBRAKO is available in a number of forms....a] knurled hollow point, b] flat face, c] hollow pointed inverse cone, d] dogs point

Any attempt to alter a previously set position with a [knurled hollow point], [hollow pointed inverse cone] or [dogs point] HPGS results on the need to redrill through the existing tapping......[naturally this action also has the clear potential to partially strip the previously established tapping  >:-o  to remove the previously established seating surface ....

An alternative to this is dissamble the components....remove the previously established in-acurate mating surface>>>>>> reassemble & start again %%

Typically here, a 3.0mm  ISO metric tapping has a 2.0mm tapping drill size...and all you are attempting is to respot  >>:-( the revised timed location on the component

Conversley my experience with #6 or #7 British Standard [HT] low dimensional tolerance [0.0005"] taper pins will enable radial adjustments in components in "minutes if not seconds" to be achieved

No holes are redrilled, simply hand re-reamed  & the new timed location secured  :-)) ....Derek

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 19, 2011, 03:29:09 pm
Derek,
I think we are talking about different things here, we started out here by Mick describing a grub screw as a taper pin which he clarified.
There is no need for a taper pin to be used on the sheave of the Stevenson reverse gear as the grub screw allows the rotation of the sheave for timing adjustment.
Mick prefers the pointed grub but I only use hollow point grubs.
If a taper pin was used it would be thro' the sheave collar and right thro' the shaft and taper reamed making adjustment impossible.
(http://s2.postimage.org/2chalpcis/D10_Build_29.jpg) (http://postimage.org/image/2chalpcis/)
In the pic of a recently built D10 with Stevenson reverse gear you can see the grub screw in the sheave which when loosened, the sheave can be rotated for timing adjustment.

(http://s2.postimage.org/2chxr87fo/D10_finished_6.jpg) (http://postimage.org/image/2chxr87fo/)

This pic is further advanced and you can see the grub screw on the sheave just behind the worm gear.

(http://s2.postimage.org/2ciealodg/Taper_pin.jpg) (http://postimage.org/image/2ciealodg/)

Here is pic of a 1/4"dia grub and a 2" taper pin.    With a 6 ba  grub screw tapped into the sheave all that is required is the grub to be loosened and the timing adjusted, I used to be able to purchase 1/8" long x 6 ba grubs but the only small size I can get now is 3/16" long.

If a taper pin is used it is impossible to alter the adjustment of a collar or any other item slid onto a shaft other than rotating the item to the setting require bore a new hole at say 45%   and re-reaming the hole, bearing in mind that to keep the object in the same position you will drill into the old hole.

So are we on the same wavelength?, after 42 years in the engineering industry  would you please describe how to say adjust a collar on a shaft by re-reaming the hole.
So not sure if we are talking about the same thing but would like to hear how it's done.
Thanks for taking the time to answer.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: derekwarner on April 20, 2011, 07:40:43 am
George......I don't want to get too far off track here  %%....but....

1. a few years back I had an issue with the Stevensen reversing gear on my JMC3H horizontal engine
2. the M2 hollow pointed grub screws were not capable of being tightened or removed  >>:-( ...& hence the reversing gear would not function
3. the answer was that the M1.1 AF in-hex of the M2 HPGS had cracked across the hex points
4. the only solution was a new weigh shaft + reversing arms...at great expense as the manufacturer accepted no responsibility for an engine that had never been commissioned
5. in addition to the new arms I installed M2 SHCS [socket head caps screws] which were capable of being tightened

So from that day on I have had a love/hate reluctance to use small HPGS...........  >>:-( <:(  Derek
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on April 20, 2011, 09:44:43 am
Hi Derek,
Very nice little engine and I now see 1- off the things that you posted about.
I like Socket head cap screws and socket grubs and use them in preference to Hex Heads when possible.
It's not a problem as you say that if you strip a tapped hole it's easy to go the next size up.

The other thing is about Taper pins and must stress that you can't move say the operating lever on the weigh shaft if it has been taper pinned to another position say  .015" and then re- ream the hole it can't be done.
A new hole must be bored with the lever in the new position and then re-reamed.
Thank's for the pics
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 20, 2011, 01:11:36 pm
My pennies worth on grub screws, I personally do not like HPGS, from past experience with these on converted petrol engines and other hardware associated with the running gear for model sports boats, that is why I use 45 deg tapered point grub screws.

Once the timing has been correctly set there should no need to alter the position of the eccentrics, with screws that I use the point marks the position on the crankshaft which can then be drilled at 45 deg to the depth of the taper which does not weaken the shaft, and will never move.

Thats my opinion but then what do I know I'm only a wood butcher!
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on April 21, 2011, 08:44:07 pm
Anyone contemplating building a Stuart Twin Launch engine check your cylinder casting exhaust port diamensions, I had a problem with mine, one port is 3/32” off centre top to bottom resulting in the slide valve not covering the exhaust port at BDC so it would be open to steam. I have had to make a larger slide Valve to compensate, and adjust the steam chest casting to accommodate it.

I contacted Stuarts about the problem in fairness they did offer to send me a new cylinder casting and slide valves which I declined because of the amount of work to machine a new cylinder and match all the other components.

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 05, 2011, 09:22:17 pm
Engine assembled, next job engine bed plate, boiler pump, oil separator, condenser, boiler and launch to fit it all
in.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on May 06, 2011, 11:05:35 am
Super job Mick, it would put a lot of professional engineers to shame.
When you see such a well made engine it only makes us try harder to compete and raise our standards.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 06, 2011, 06:41:10 pm
Thanks for your generous comment George.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 21, 2011, 12:37:44 pm
Macc Model engineering supplies unique way of cutting copper pipe, they do add a little extra length, but what a waste you loose 1/2” of each end so 12 customers equals 12” of waste, 100 customers 10ft, why not use Tube cutter, as they sell them.

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: oLiV on May 21, 2011, 02:21:43 pm
hum... a way to do it faster I guess... {:-{

Anyway, very good job, Mick ! I'm working on mine too at the time. I have 2 questions for you :

- why did you machine most parts of the Reverse links from brass instead of steel ?
- could you tell us where did you find the worm gear you have set up on the crankshaft end ?

Thanks a lot !
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 21, 2011, 07:22:43 pm
Oliver, the gears can be obtained from www.hpcgears.com
The reasons I used brass for the reverse links, appearance and less parts to rust.

How far have you got with your engine and how about posting some photos.

Mick

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: oLiV on May 21, 2011, 09:10:49 pm
Thank you for the link Mick, will be helpful  :-))

Here are some pictures of my engine. As you can see I decided to modify somewhat the Stuart drawings for the cylinders and steam chests studdings.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 22, 2011, 02:29:27 pm
Looking good Oliver, why did you decide to change the studs on the valve chest to the same as the Stuart Compound engine.
If you are going to fit a worm gear on the crankshaft for a boiler pump you need a minimum of 4cm of shaft from the end of the bearing cap with double eccentrics.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 25, 2011, 04:42:10 pm
Engine base plate & boiler pump, the pump crankshaft has 4 options for plunger stroke length.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 26, 2011, 03:30:05 pm
Suggestions required please from steam experts, I want to make a condenser that will fit on the engine
Bed plate, the maximum dia that will fit is 2” if I make 5” high this will give me a volume of 1.032 litres will
this be sufficient for this engine?

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Aeronut4 on May 26, 2011, 06:30:34 pm
I'm no expert  :} but I'd have thought that around 0.5 litre would have been more than sufficient, if you're talking about an oil separator rather than a true condenser. It looks like you've got cylinder drain cocks fitted, so there should be very little carry over of water after the engine is warmed up and they are closed.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 26, 2011, 06:41:24 pm
It's a Condenser Oil Trap

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on May 27, 2011, 09:31:51 pm
Mick,
I have an oil trap on my CERVIA which is powered by a D10, this is 35mmDia x 60mm long and is mounted above the water level on the funnel.
It drains thro' a 5/32" pipe overboard and this is sufficient for this engine.
I don't have drain valves on the engine so to get rid of the condensate I turn the prop over by hand until it clears.
I have fitted a by pass valve to the exhaust before the oil trap which allows any contaminated water to be fed overboard into a can for disposal, that's it painted red on the pic, when the engine is running clean I switch the valve over to send the exhaust up the funnel.

You will find that a slide valve engine only needs the needle valve on the displacement lubricator to be opened just a crack and when running the water drains from my trap " clean ".
Oscillating engines use much more oil than a slide valve as they are inclined to "gulp ", they do, but nobody so far has told me why, possibly because they use straight thro' lubricators without an adjusting needle.

One of the disadvantages of the drain valves is that they allow the condensate to flood the boat and with the quality of your work I am sure that this will not be acceptable to you.

You have made a super job of the launch engine, not bad for a" wood butcher" I will send you some BRASSO for your birthday.

George.

(http://s2.postimage.org/2sifko2w4/Oil_Trap_1.jpg) (http://postimage.org/image/2sifko2w4/)

(http://s2.postimage.org/2siphw5us/Oil_Trap_2.jpg) (http://postimage.org/image/2siphw5us/)

(http://s2.postimage.org/2sjcnf0ro/Oil_Trap_4.jpg) (http://postimage.org/image/2sjcnf0ro/)

(http://s2.postimage.org/2sjrj957o/Oil_Trap_5.jpg) (http://postimage.org/image/2sjrj957o/)


Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 27, 2011, 09:48:52 pm
Thank you George for your information, very helpfull.
I use T cut, I find it better than Brasso.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: flashtwo on May 27, 2011, 10:02:59 pm
Hi Mick,

I've fitted a very successful vertical 1.75 inch diameter feed heater / oil separator on the outlet of my D10 (see the "Flash steam plant control" thread

http://www.modelboatmayhem.co.uk/forum/index.php?topic=15817.100  for details ).

"Vital Byte"  will be steaming at Wicksteed this weekend.

Ian.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on May 27, 2011, 10:12:33 pm
Well well well Mick, never thought of T Cut. I will throw my Brasso out, second thought will give it to my wife to keep the coffee table polished.

You could incorporate a feed water heater in the oil  trap but the boiler that you are going to build has the facility to install a heater in the smoke box
as I have installed in my boiler.

George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on May 27, 2011, 10:28:44 pm
Thankyou George & Ian for your suggestions, it would seem that the size to fit my engine bed plate will be okay.
Just started the launch to fit it all in, bit of woodwork makes a change.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Brian Adley on June 29, 2011, 12:38:24 pm
Hi Mick,
Wouild it be possible to email the plans of the boiler to me? 
Thanks
Brian
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on June 29, 2011, 01:01:44 pm
Hi Brian,
The Boiler was designed by George Thompson (ooyah/2) I am sure if you contacted him he would be able to help you, although I have his plans I cannot send a copy without his permission. He is a very experienced
Engineer and very helpful.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 04, 2011, 02:35:56 pm
Boiler end plate, from 3mm copper.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 06, 2011, 09:15:54 am
How the boiler end plates where formed on a turned Oak plug, before machining
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 09, 2011, 05:11:11 pm
Boiler Tubes
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on October 09, 2011, 07:09:08 pm
Very tidy Mick, I'm liking it very much. Just for a sense of scale; what diameter is the combustion chamber please?

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 09, 2011, 08:29:34 pm
Greg, its 1.75in OD

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: broger on October 14, 2011, 08:12:06 pm
Hi Mick
I'm very interested in this as I will be making a Launch engine for Alaska.
Looks a lovely job, is the outside skin 3mm as well?

alan
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 14, 2011, 09:03:25 pm
Hi Alan
The boiler tube is 2mm

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 22, 2011, 05:42:49 pm
Boiler soldered, hydraulic tested to 160psi.


Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on October 23, 2011, 10:35:13 am
Is there no end to this mans talents ???
Wooden boats!!!!
Machining castings to produce a great engine, and now boiler making.
Well done Mick  Super job all around, still can't keep from looking back at WIDE AWAKE .
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on October 23, 2011, 12:28:14 pm
Hi Mick,

A beautiful job, as always! What did you use for pickling if you don't mind me asking?

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 23, 2011, 12:43:01 pm
Hi George,
Thanks for your comments and guidance on the boiler.

Greg,

I use diluted sulfuric acid.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 29, 2011, 05:52:53 pm
Gas Tank, 3” Dia  6” Long,  pressure tested to 280 psi

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: KBIO on October 29, 2011, 07:05:37 pm
Hello Patern Maker!
Shiny! :o :-))
But why two valves linked through a T ?? ok2
Regards! :-)
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on October 29, 2011, 07:15:19 pm
Hello KBIO.

Open valve No 1 to light burner when steady open valve 2 (which has a tube running to the bottom of the tank) close valve 1 the burner is then running on liquid Gas, much more efficient.

Regards Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: KBIO on October 29, 2011, 07:50:16 pm
 :-) :-))
Thanks Pattren Maker. So your are going to send your gas in liquid phase!!
Very interesting. :-))
Cheers! ok2
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on October 29, 2011, 10:02:45 pm
Hi Mick,
Remember that you need to have a vaporizer wound round the burner flame tube when burning L.P.G straight from the tank.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: KBIO on October 30, 2011, 07:28:56 am
Good morning! :-)
Like this one?! ok2
(http://img573.imageshack.us/img573/2679/bruleurwilliam.jpg) (http://imageshack.us/photo/my-images/573/bruleurwilliam.jpg/)
Regards! ;)
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on November 07, 2011, 03:28:05 pm
Boiler completed
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on November 08, 2011, 10:42:00 am
Super job Mick,
I have run out of superlatives describing your workmanship, woodwork, metal and copper work all to the highest of standard.

If you have only one layer of insulation on the inside of the fire box may I suggest that you double it up , even triple it as the flame from your burner will very quickly discolour the brass cover, the same for the smoke box but only two layers.

Well done.
George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: KBIO on November 08, 2011, 11:46:45 am
Good morning!
What can I say??  :-X
Go on Mick! We appreciate and we learn on each photo. :-))
Regards! :-)
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on November 08, 2011, 03:16:46 pm
George & KBIO,
Thanks for your comments and interest, very much appreciated.  I was beginning to wonder if its worth the time and trouble to post pictures, I'm not the type of person that gives a running commentary on my build but very willing to answer any questions or queries.

George, I have put 4mm of ceramic fibre in the fire box cover and 3mm in the smoke box cover, thanks for your invaluable help and guidance on the boiler.

Regards Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on November 08, 2011, 06:08:23 pm
Mick,
Keep posting your build, you must remember that the majority of  members buy all their bits and pieces for steam and don't  scratch build everything like you do.
It's very encouraging to see what you are doing considering that your major experience is in building things in wood and as this is your first boiler build it lets us all see what can be done when you put your mind to it.

I don't suppose that you have spent an enormous amount of money on the boiler build and the fittings , considering what it would have cost to have it made by , say by Maccsteam which for a Scotch marine return flue boiler would be up in the £1000 region all complete as you have posted.

I for one look forward to the link up with your engine and the first steam test, so keep posting, you are doing a great job.

George.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Bernhard on November 09, 2011, 07:55:32 am
 :-)) :-)) :-)) :-))
YES  what ever you are doing on the launch and boiler engine...let us Know and See it,,, :-)  ,,, and 4276 Views...
THANKS

Regards
Bernhard
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: america12mj on November 09, 2011, 09:08:20 pm
 :-))
Hy guys
a very god job Patternmaker !
a very nice boiler
i just start build the"la mouette"whit a 3x expansing, made himself, and for the boiler i want use ....COAL, it's a big challenge .
welcome on the french forum
i post my last boat
the"cap sizun"


regards :-)

America12mj
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: thelegos on November 09, 2011, 09:26:48 pm
Hi Mick,
Yourself and Ted Welding with his 'Natterer' are the two things not to miss so keep it coming if you can. Before watching you two chaps I'd never considered this type of work but that's all changing, I've got an old piece of mahogany furniture to sacrifice and have started to acquire a few good quality tools. There's even a steam plant in my ebay watch list!
Roger
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: derekwarner on November 11, 2011, 05:47:05 am
america12mj...I have seen a PICASA web page from Pascal Joubert ....is this you?  %)

It has some brillant photographic images of the build of Cap Sizun...... :-))

I think many members would be interested in you posting a new thread of your build under your name here on mayhem...... O0

regards Derek

https://picasaweb.google.com/109661643894098666352/CapSizun?authuser=0&feat=directlink&gsessionid=jCLwiwPUOf_qI0IH-b4zMA#
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: KBIO on November 11, 2011, 12:42:45 pm
Hello!
I think many members would be interested in you posting a new thread of your build under your name here on mayhem...... :-))
and then, we can stick to :
BUILDING A STUART TWIN LAUNCH ENGINE & BOILER %)
Cheers! ok2
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on November 17, 2011, 02:49:34 pm
Condenser, Lubricator & Pump Valve, not far to go now.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Martin (Admin) on November 17, 2011, 04:25:52 pm
Nice job Pattenmaker!
 That's looking annoyingly good! ok2
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on November 17, 2011, 04:35:11 pm
Hi Mick,

That's a very tidy arrangement indeed- I'm surprised with that layout you haven't utilised some waste heat in the seperator and put a coil in the feedwater pipe as an economizer.

I love the flanged brass top to the seperator, very professional, are you going to employ a small child to do all that polishing....!?

Greg
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on November 17, 2011, 06:38:53 pm
Hi Greg

No surprise, look at the boiler build for water heater, far superior than putting it through the separator where
the exhaust steam temperature is considerably lower, most suppliers of separator's use soft solder, I used silver solder.
To date I have used over 18ft of various size copper pipe, and will probably need another 3ft to finish the installation.

Mick



Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on November 17, 2011, 06:43:30 pm
Thanks Martin,
I try not to be annoying.

Mick
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: thelegos on November 17, 2011, 08:49:11 pm
Hello Mick, very very nice and thank you for continuing. Some of the comments from the experts underline the work involved in creating this engine and boat, steam is indeed a whole new world!
Roger
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: gondolier88 on November 17, 2011, 10:44:31 pm
Hi Greg

No surprise, look at the boiler build for water heater, far superior than putting it through the separator where
the exhaust steam temperature is considerably lower, most suppliers of separator's use soft solder, I used silver solder.
To date I have used over 18ft of various size copper pipe, and will probably need another 3ft to finish the installation.

Mick

Of course you have, I was surprised you would forego the effort to put in a detail like that, I stand corrected. It's almost verging on scary the amount of material that goes into a plant isn't it.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: acrowot1927 on January 18, 2012, 08:18:10 pm
[img]Hi and hello just joined this forum, I have just acquired an ML7 and a Milling machine it has been 10 years since I have used either so am very rusty. I would like to have a go at building a Stuart Twin Launch as I have the castings left to me by a dear departed friend, he bought this in 1975 I believe. with it is the casting kit in the picture below as anyone any idea what it is?
Hope I have attached the pic. correctly.
TIA


Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: ooyah/2 on January 18, 2012, 08:38:13 pm
It's a set of very early steam boiler feed pump castings, and as the water pump is an integral part of the main frame casting it's difficult to grip for machining.
George
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: acrowot1927 on January 19, 2012, 03:15:40 pm
It's a set of very early steam boiler feed pump castings, and as the water pump is an integral part of the main frame casting it's difficult to grip for machining.
George

Thanks ooyah/2, all is now clear, I think I will give this bit a miss.
Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: Patternmaker on January 19, 2012, 03:37:03 pm
I would suggest you check the port measurements on the cylinder casting before you do anything, if they are not within the drawing dimensions this will cause no end of problems with the reverse gear when adjusting the valves and eccentrics.

Mick

Title: Re: BUILDING A STUART TWIN LAUNCH ENGINE & BOILER
Post by: acrowot1927 on January 22, 2012, 12:02:41 am
I would suggest you check the port measurements on the cylinder casting before you do anything, if they are not within the drawing dimensions this will cause no end of problems with the reverse gear when adjusting the valves and eccentrics.

Mick



Thanks for the tip Mick, at the moment I do not have the drawings and most of the cylinder and the pistons have been machined by my friend and the pistons and rings fitted, the drawings are not with the castings. I am going to ring Stuart with a view to obtaining the drawings, a bit disappointed that they are not full size but as the saying goes "beggers cannot be choosers".
John