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Author Topic: Jerry C starts building a Stuart Twin Launch Engine from castings.  (Read 7204 times)

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #125 on: January 29, 2021, 08:16:16 am »

The day before yesterday  I went to my newly discovered machinery suppliers to get a 300mm brass rod, a HSS  1/4Ē tool blank, a 5/32x40tpi ME, no. 1 tap and die and a 3/16Ē taper reamer all for making the drain cocks. The guy said heíd have to order in the tap, die and reamer. Great I said. Next morning I get a phone call saying theyíre in. Wow they must have a beam me up Scotty machine. Went in, he handed them over and said $388! I nearly fainted. How much I yelped. He did a check on the paperwork and said sorry $308!  I suppose itís my own fault for not asking for a quote but seriously? I said sorry but thereís no way I can afford that. He asked me if I was a member of the Canberra model engineering club. I said my membership is pending. He said in that case I can do them for $208  I said I was sorry for any trouble caused but I couldnít take them. Really embarrassed. I only paid $57 for a full set of BA taps and dies!
 So, I decided to use 4BA instead and Iíll try and make my own reamer. The American guyís compound build that Iím copying shows them but doesnít say how he makes them but Iím guessing he machines the taper onto a mild steel rod then grinds it just over half way across at an angle then hardens it. ??? Any advice would be appreciated.
I used his microscope photos based on the size of his 5/32 ME thread to gauge the dimensions of a cock and made a pattern which I will repeat if Iíve got it near enough right.
This is my take. Itís overall protrusion from the cladding is 0.530Ē. Diameter of globe (rugby ball actually) is 0.260Ē. Is this anywhere nearly right??
















It took me 3 hours to grind that 1/4Ē HSS blank down to that size and shape. My quenching water pot actually got hot and my fingers are really sore. Iíve got a really big bench grinder with a course and fine 9Ē wheels.


Jerry C.

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #126 on: January 29, 2021, 08:32:50 am »

I forgot I made this this morning, apart from the drilling and tapping largely by hand.
Quickly, does it matter which end of the engine the reversing gear goes? If it does Iíve put it on the wrong end! I favour the reversing lever on the flywheel end.





Jerry C.

frazer heslop

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #127 on: January 29, 2021, 10:13:39 am »

Just make a tapered D bit to form the seats for the cocks. Once Ive machined the D bit I make a batch of valves whilst the compound slide is still set so that the angles of dangle match
To make the bodies I use old files softened to make form tools then re temper.Makes life a bit easier 
cheers
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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #128 on: January 29, 2021, 11:01:02 am »

Many thanks Frazer. Thatís given me something to think about. However all my files are new, even my 10 year old ones. Lol.


Jerry C.

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #129 on: January 29, 2021, 04:04:32 pm »

When I was working at machining I used to just order stuff from the supplier without worrying about the price. I soon learned once I started ordering for myself to always ask the price after the first time I ordered stuff and found out about restocking fees, sometimes half the price of the item. I used to have a buddy that was into knife making and he had a heat treating oven and was quite versed in heat treating. I would make up a part, he would heat treat and temper the parts for me.
Gerald.
 
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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #130 on: January 31, 2021, 08:22:20 am »

Iíve continued working on the drain cocks. I donít have any 8 BA nuts or hex bar to make them from so I went for M3 threads for the cock handles. I also donít have any suitable coil springs so tried s/s plain and spring washers and nuts I found if I use Loctite on the threads and apply a small amount of compression on the spring washers the cocks work well. I used a duff cock tightened into the body to have a practice at bending the handles. I rigged up my makeshift hearth and using a small pencil gas torch on the bit I want to bend. I could get the bit slightly red. The body was screwed into a round cylinder of brass immersed up to the top in a tin of water to protect the parts from unwanted heat. After everything cooled down it proved easy to put a 45į bend in the handle. I used to do similar when annealing the necks of cartridges prior to reloading.
As I have been watching the guy doing the compound engine build Iíve been using his pics to get the scale  approximately right based on the size of his BA threads. I did notice one anomaly though when he showed a pic of the nut which he described as 1/6Ē A/F which is smaller than an 8BA thread diameter??? Not a criticism mind just an observation as heís been very helpfully and informative. I suspect my attempts may be a bit larger than his, certainly a tad longer as my globes are more oblate compared to his spherical ones. Not having seen these parts in the flesh itís difficult to know one way or tother. I used 6į for the taper on my first home made taper D bit which I made from bright steel 3/16Ē rod which I hardened with heat and quenched in oil. It wouldnít cut butter and split the body apart. After this I noticed a burr on one of the cutting edges. I removed this with a file and tried again on another part  and it worked perfectly turning and cutting in either direction.
For the taper on the handle I used the same 6į but the thick end looked ridiculously thick so changed to 3į which looks much better. Two more to do and theyíre done.





Jerry C.

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #131 on: February 02, 2021, 08:13:41 am »

Iíve finished work on the drain cocks. Iíve left the threaded parts long in case I find some springs. 3/16Ē brass hex bar on the way for the nuts. Iíll start working on the connecting rod doofers  for the reversing gear. Il be using exactly the same method as the compound guy.







Jerry C.




SteamboatPhil

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #132 on: February 02, 2021, 09:24:12 pm »

Really nice work on the drain cocks Jerry, they really look the part  :-))
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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #133 on: February 05, 2021, 06:14:29 am »

Thanks Phil. I thought they could be smaller but Iím happy with them. The bends in the handles need a little attention for symmetry purposes and I rounded the ends of the handles by mistake so a little work with a file will sort that out.
Iíve been working on the two connecting rods just copying the American guys method. These have proved the most difficult of the parts Iíve made so far and also the most scary, fingers very close to sharp, spinny, liable to take charge bits. Using the vice in the milling attachment without a collet chuck means Iím also in close proximity to the chuck jaws too. However, job done and inventory of fingers tallies with what I started off with! Dressed with file and Scothbrite and Iím happy with the result.








Jerry C.

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #134 on: February 05, 2021, 06:27:25 am »

On completion of the connecting rods I made a start on the expansion links by marking out with blue and a pair of dividers. While studying the plan however I discovered mention of a 1/32Ē pin through the hole for the drag links. The fittings list mentions three 1/16Ē pins for locking the connecting rods and reversing lever to the reversing shaft but no mention of the clearly marked (if youíre lucky) 1/32Ē pin. The American guy never mentioned it either. Iím puzzled what itís purpose is meant to be???





Iíve drawn a circle round it I the plan just above the steel plate. Do you get a prize off Start if you discover it?


Jerry C.

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #135 on: February 05, 2021, 08:46:43 pm »

Jerry,
The 3/32" hole circled is for the drag links, the other 2- are for the eccentric sheaves.
The drag links need to have a plain long bolt , ( not Machine screws ) as it is a pivotal hinge as do the holes for the sheaves.


Look at the drawing Item No 5 which calls for 4- off drag links, one end to the circled hole and the other to the link lever [size=78%]on the weigh shaft.[/size]


If you don't have any long Bolts make them from 3/32" dia rod.


George.
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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #136 on: February 05, 2021, 11:41:23 pm »

I found it George. Woken by a thunderstorm during the night and it came to me. On the sheet showing parts not included in kit ďExpansion Link Pins 1/32Ē Ý pins mild steel 1/32Ē Ý WireĒ. Drilling through expansion links and 7BA bolt is going to be challenging to say the least. I suppose you just push the wires through the holes and twist them for added security. I may choose to leave this step out.





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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #137 on: February 06, 2021, 09:14:01 am »

I rigged up the gear for milling the expansion links. Bolted to a pin at the centre held in the vice. First chain drilled the slot then drilled the three holes #38 (2.6mm for me). Then milled the slot using small mole grips as a lever, followed by the top curve. Finished the rest with hacksaw, files and Dremel. It fits. Marked up for the second one. Fitted the first one on the plate and spray painted the lot. When dry marked all the way round with a scalpel.
Weíre off on our holibobs to the coast on Monday for a week as the house is being painted.











Jerry C.



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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #138 on: February 06, 2021, 01:02:16 pm »

I found it George. Woken by a thunderstorm during the night and it came to me. On the sheet showing parts not included in kit ďExpansion Link Pins 1/32Ē Ý pins mild steel 1/32Ē Ý WireĒ. Drilling through expansion links and 7BA bolt is going to be challenging to say the least. I suppose you just push the wires through the holes and twist them for added security. I may choose to leave this step out.





Jerry C.


Jerry,
There is nothing hard about making the long bolts to go thro' the holes in the drag links and the quadrant.


Take a piece of 3/32" dia rod ( wire ) and cut it to the length thro the links plus leave enough on to screw both ends 7B.A. push the rod thro the links and the Quadrant , put on a 7B.A. nut with a little Loctite 243 on 1- nut ( the outside bolt ) until the job is finished and then 243 the other one and they will never move.


Regarding the bolts 4-off for the eccentric sheaves are they not included in the kit of parts.


I am assuming that you have stock and dies for 7B.A. threads.


Have a good holiday and forget about your engine until you get back.


George.
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Mark T

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #139 on: February 06, 2021, 04:04:09 pm »

That engine is looking great Jerry and its turned into a proper engineering challenge  :-))   Have a great holiday mate - we may even let you back into the UK soon  {-)

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #140 on: February 16, 2021, 09:06:01 am »

Hollibobs over so back to work. Today, first job, take plans and fittings lists to Office Works to get them laminated. I canít think why I never did it as soon as I got the kit. Luckily theyíre all still readable so anyone buying a kit get them laminated straight out of the box.  I completed second expansion link which took about an hour. Marked up for the two expansion dies which fit nicely into the gap on the donor steel plate.


Iíll box those off tomorrow on the belt sander then move on to the draglinks.
Still no new 4 jaw chuck. Iíll give it another week then ask for a refund and order from local. This has gone on longer than any order from India or China and this is from Sydney so theyíre taking the pee now.


Jerry C.

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #141 on: February 16, 2021, 11:44:12 am »

I don't go as far as laminating plans, but I do make an "archive" set of copies. Also using an office type copy machine I make a copy of the section of a large plan sheet needed at the time.. don't have the counter/bench space for a large sheet..
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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #142 on: February 16, 2021, 11:55:13 am »

My working bench/table is a 4íx4í ALDI circular saw table. The plans were getting oily and frayed. Cost of laminating two plans and two A4 sheets of fittings only£7. Next time I buy the kit Iíll only need castings and fasteners. A big saving.
Jerry C.

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #143 on: February 16, 2021, 06:19:44 pm »

My working bench/table is a 4íx4í ALDI circular saw table. The plans were getting oily and frayed. Cost of laminating two plans and two A4 sheets of fittings only£7. Next time I buy the kit Iíll only need castings and fasteners. A big saving.
Jerry C.


Hi Jerry,
Hope that you had a good holiday break, don't get too enthusiastic in a saving as you already have the drawings and parts list of the Launch engine.


If I recall Mick Brown ( patternmaker ) when he ordered the castings for his launch engine he wanted a reduction of the cost of the drawings which they would not do as they said the package was as the listed price which included the drawings and no discount was available.


He tried this as I was going to give him my drawings of the Launch engine and reverse gear for him to use and send back when finished, Stuart may have changed their policy now as it was a long time ago when he asked, don't hold your breath. !!!!!!!!!!.


George.
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Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #144 on: February 23, 2021, 09:42:03 am »

Since the holiday Iíve been training for my second attempt at the Southern Ocean Road cycling trip that was cancelled at the last minute last year due to the virus. If all goes well we will fly down to Melbourne instead of using the train.  Three days after we finish that itís the Big Canberra Bike Ride also cancelled last year.
In between Iíve made more progress on the engine. Made the expansion dies and a few spares for the next build. No machining for these, drill, hacksaw and file. Quicker than machining.








Moved on to the drag links following the same method as in the compound build. Only problem was in the 7mm square stock. It's quality was a bit hit and miss. Milling would be great then a hard bit appeared which completely dulled the end mill. I went through nearly all of my cheap Chinese set. Finally managed to finish them with the slot drill I used to make the crosshead slides. Suffered terribly with metal splinters in hands and fingers. Must stay away from any magnetic compasses for a bit.  Everything appears to work smoothly except one position when top of strap just fouled the valve rod head but thatís a simple fix.





Next I start on the reversing lever.


Also Iíve finally given up waiting for the replacement 4 jaw chuck which the courier swears heís delivered. So itís a refund and Iíve got one from another source arriving this week.


Jerry C.

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #145 on: February 26, 2021, 04:52:18 am »


I invested $35 in a Sutton Tools 1/4Ē 4 flute end mill which made short work of these reversing levers. I shipped two 1/4x5/16 pieces of m/s bar stock in the milling vice and drilled the two holes simultaneously and carried on replacing the second bar after each operation saving set up time. Donít know why I didnít do this with other parts.  Will duplicate all the rest though.




Next will be the anchor rod. Intend making from an old tent peg, thread rod and end collar as one part and will silver solder the other collar when I assemble this group.


At last I have received my new 4 jaw chuck which I used to turn the handles of the reversing levers.


Jerry C.

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #146 on: March 31, 2021, 10:12:49 am »

Iím ok. Nothing wrong. Been on Slow Ocean Road cycling tour with Alltrails. Then final training for Big Canberra Bike Ride which was cancelled due to a ďweather bombĒ. Not once did the weather forecast say there was anything coming. And it never did. Now moving house so workshop stripped and packed up and moved in dribs  and drabs to new house in Queanbeyan NSW. In process of reassembled. Then weíve got to move everything else. Going to take a while but weíve got a ute, two trailers and two cars to do the job with. A few things will need a panel truck but may borrow one. Hope to be back in action in three weeks.
Jerry C.


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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #147 on: March 31, 2021, 03:33:10 pm »

Good luck with the move Jerry - hope you can find everything afterwards!  We will be patient until you are up and running again.   :-))

Greg

Jerry C

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #148 on: June 10, 2021, 12:28:30 pm »

House move completed, workshop rebuilt. Engine finished. I dispensed with grub screws in the eccentrics and flywheel and used industrial superglue. Timing is correct and will stay that way.
Plinth made from Blackwood and danish oiled. Drainage channels built in.   Need to source silicone o-rings to replace piston rings and Teflon coated yarn for gland packing.  On another subject I need a new toothed drive belt for mini lathe. Approx 16Ē x 3/8Ē 10 tpi . Canít find one anywhere. Can anyone help? 


 

























Iíll rig up some compressed air and start bedding in.


We get our first vaccine jab next week then 3 months till no 2 then we can see about getting home. Well spend a year on the canals to try and catch up what weíve missed by being stuck in Oz. Freezing here atm.


Jerry C
« Last Edit: June 10, 2021, 11:38:22 pm by Jerry C »
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SteamboatPhil

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Re: Jerry C starts building a Stuart Twin Launch Engine from castings.
« Reply #149 on: June 10, 2021, 07:08:56 pm »

Great you are back Jerry, the engine came out really well (love the maroon colour my grandfather always finished his engines like that) and the base just adds to it.
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