NMBROOK

No Mark,most of this is original footage filmed by the Australian crew that was never used in the DVD.These have been posted by Modelsworld.ru,Russia's modeling forum.There are literally hundreds of other tutorial videos covering plastic modelling,armour etc.
 
Happy New Year
 
Nigel

No Mark,most of this is original footage filmed by the Australian crew that was never used in the DVD.These have been posted by Modelsworld.ru,Russia's modeling forum.There are literally hundreds of other tutorial videos covering plastic modelling,armour etc.
 
Happy New Year
 
Nigel

I felt the need to post some pics to celebrate the completion of the gundeck 'treenailing'.The aft section still needs sanding smooth and I will then apply a coat of thinned poly to protect the deck during future work.A rough count up shows well in excess of 3000 fixings Some sanity has been retained thanks to the music of Vangelis and Hans Zimmer
 
Kind Regards
 
Nigel

This was the sequence for the top end shaping.
 
the first shots showing the rotational shaping in the lathe using the chuck as a vice while moving the cutter back and forth.
 

 

 

 

 
Next using a rat tail file to finish off the shape
 

 
after filing but before final clean up.
 

 
ready to assemble
 

 
Michael

Thank you Ed, Tom, Carl, Bob and Row for your kind comments and to all those who liked the last few entries.
 
I think I could make one of these small stop cocks now in my sleep. I have gone through a number of failures with silver soldering handles mainly because I was using the wrong approach to setting them up to solder.
 
The following sequence shows most of the steps and elements in the stop cocks.
`
First picture shows some 1 inch tapered clock pins cut to length prepared for soldering
 

 
This  one shows the box of tapered steel clock and watchmaking pins that that match the tapered broaches, I decided to use them instead of threading the rotating part and using springs and nuts. 
 

 
The hole through the centre was bored after the threading was done, with a number 59 drill, I used paint thinner as a lubricant, normally I do not use lubricant when machining brass but with these small diameters and threading it helps.
 

 
A finger tip as requested behind the main body of the valve
 

 
Drilling through the body for the steel tapered part. I found it helped to make up a couple of holding jigs with some hex brass rods.
 

 
Using a full pin to test the depth of cut with the taper broach of the valve body
 

 
In the palm of my hand for scale
 

 
The new stopcock on the left with the old one on the right. I Like the shape of the longer handle better and it is also easier to turn, as I am sure they are in full size as well
 

 
Another couple of overall comparison shots for scale
 

 

 
I have all the parts now to make a pair of stop cocks like the new one, plus all of the steps figured out for soldering and final assembly. I think it is also time to finish shaping the top part of the head.
 
Michael
 
 

Built another priming cup and stopcock, it is getting closer still needs some refining.
 

 

 
michael

Jack, Row, Mark, Steve, Matt, Denis and Carl, thanks for the encouragement.
Thanks to all for the likes.
 
I took a break from the drive train today and fabricated the Valve caps these are there to allow the valves to be removed from the head because on the full size engine the head was a single casting. because of the small size of my model I have built the head in two parts. I haven't fully resolved how I will join them yet.
 
The two outside caps which line up with the inlet ports are also set up as priming ports with a couple of little cups above the stop cocks that are threaded into them. like these on the top

 
So I had a bit of fun having a go at making a stop cock to fit into the top.
Looking down into the open valve.
 

 
Now closed
 

 
From the side
 

 

 
The valve cap is threaded 8x36 into the head these were made from some 3/16th rod from Home Depot (nice hard brass)
The valve body is machined up from some 1/8 hex stock, I have a fair bit of it left over from a commercial job 20 years ago (it was a special order locally and I had to buy 16 feet of it) it is also a nice free machining hard brass.
 
The steel insert is a mystery steel (salvaged rods from a library card catalogue system filing cabinet) it seem to machine freely and is 1/8th in diameter.
 
The threads on the valve body is 1x72 with a # 59 drill hole through the length. The cross hole was 1/16 then tapered with the largest clock making tapered broach. the steel was tapered to match on the lathe and threaded 0x80 for the retaining spring and nut. the handle end was shaped with needle files while still on the lathe then heated in a pin vice and bent with some flat pliers.
 
Once the steel was shaped I set it into the brass body put it back into the lathe and drilled through the steel with the handle in the open position using the same #59 drill from the opposite end. It looks a bit crude and now that I know I can make one this small I will set up and make a pair that are a bit closer looking to the ones on the 1:1 engines
 
Michael

Steve, Carl thanks for your thoughts , and thanks you to all who added a like.
 
Carl the real engine is actually quite a small one.
 
 
Steve, My plan is to have it as a slow running engine am thinking that I will weight the flywheel with some lead in the outer area to give it more mass.
 
My silver soldering was a great success..... not so with the clean up
 

 
look at the upper right hand con rod bearing!
 

 
Yup made the classic mistake of beginning to cut out the wrong piece
 
I went ahead and cleaned it up because after letting the universe know what a silly move it was with a little colourful language, I wanted to see how the shaft fit and can also use it as a placeholder to test fit the con-rods and pistons knowing that I do have to build a new one.
 

 
I was pleased that it did not warp and and my method of setting up the parts and pre-placing the solder by wrapping very fine strips around the shafts outside of the actual bearing surfaces worked very well. I turned up some sacrificial pins that were the same diameter as the spaces between the plates to hold things in line. after cleaning it up and placing it into the bearings the shaft spun nicely between my fingers.
 

 

 
Next on to the con rods and Pistons.
 
Michael
 
 

Row and Carl
This is a picture looking inside the crankcase of the 3hp buffalo just like the one in Skipjack
 

 
I have modeled my crankshaft after this one.
 
Michael

This afternoon after getting the shop warmed up a bit from 3 degrees to 13 degrees C I worked on the parts for the crankshaft.
 
First I thinned down a piece of 1/8th gauge-plate to .094 then drilled and reamed 8 holes to 1/8th diameter.
 

 
Next I cut the piece into the four plates for the sides of the con rod bearings part of the crankshaft, I used a new blade in the jewelers saw.
 

 
A 1/8th set of dowels were slipped through the holes and the group were clamped in the vice and filed to shape.
 

 
Then polished up with 400, 600, and 1200 wet and dry sandpaper., I like it when I can get a reflective surface, then I know it is pretty smooth.
 

 

 
The sides of the plates will get polished Tuesday or Wednesday. Tomorrow is errand day in the big city.
 
I turned up the .344" long 1/8 inch diameter shafts for the big ends of the con rods and did a dry assemble to see how the whole lot looks.
 

 

 
I will silver solder the lot together then cut off the parts of the main shaft that are not needed. "The proof will be in the pudding" as they say, so crossing my fingers for a clean soldering job.
 
Michael
 
 
 
 

"From my hot rodding days, it might... maybe... hope... be easier to fabricate it."
 
Mark this is the option that I have decided upon, When I have more experience I would like to have a go at machining one from solid.
 
"we are all spellbound. This hardly seems possible by human hands and tools at this scale"
 
Mark As I am working I often muse to myself how would a watchmaker tackle this fabrication, and then look at some of the amazing work they do and am humbled by their skill.
 
Joe, and all Thank you for following along and your kind comments.
 
"but I would have thought that at the scale your working at fabricating would probably be quicker - from what I've seen of the processes the machining option looks to be long and tedious without cnc lathe control."
 
Row, I have read a couple of tutorials on the model engine forum about machining the crankshaft and there is a fair bit of preparatory jig making to set up for the offsets and keeping it all inline, You are correct in suggesting that fabrication is faster, not that speed is a concern.
 
"I had almost forgotten the size of this until you mentioned the 1/8 shaft."
 
Ed, this is something that continually trips me when working on the drawings because it all looks so large on the screen
 
"Machining like that is something I only dream about"
Bob, funny you should mention this, because I have been waking up with immediate thoughts about how to do the next task, sort of solving it in my sleep.
 
"Never throw any stuff out, "It might come in useful...""
 
Druxey the only concern with having this mindset is one almost needs a warehouse to store all this stuff I have to argue with myself all the time "really do you need to keep this?"..... Yes because I might need it one day!"
 
"will you have to adjust the compression ratio for scale?"
 
Mark, I honestly have no Idea, I am basically flying by the seat of my pants on this one. I suppose that the only way I will know is when I give it a spin and she fires up. I would be able to make some adjustment with the length of the valve caps in the top of the cylinder head.
 
Thanks to all those who added a like the previous posts.
 
Suppers ready so I will add some pics of the crankshaft after supper.
 
Michael
 

Thanks for all the likes today.
 
I reached a milestone today and got the main bearings roughed in.
 
First I machined up the keeper blocks. and some studs.
 

 

 
Assembled them in order to ream them for the 1/8th shaft.
 

 
I thought it best to use the hand reamer rather than setting it up in the mill for the machine reamer.
 

 
After thinning down the area on the upper crankcase it all went together quite nicely. and the shaft rotates easily.
 

 
I am still deciding whether to fabricate the crankshaft or machine it from solid bar, either way it will be tricky.
 
Michael
 
 

Hi Steve
the extra length serves as a housing for the reversing clutch for the prop. like this one on the old marine site
 

 
 
Thanks for all the likes
 
Michael

Ed hopefully the next set of pictures will clarify my description. Mark well it is not a complete machine job there is some soldering however I did not want to anneal the brass that has the bearings braces so opted for soft solder which will be more than adequate for the oil pan.
 
The first picture shows the material being removes that will become the hollow areas'some parts were machined by the numbers and the bulk was just milled away by eyeballing it.
 

 
Next the 1/32 thick sheet was annealed and curved over a steel bar.
 

 
It took a while to get it fitted cleanly, the flat area on the middle bearing wall is to allow the oil to pass through to equalize both chambers.
 

 
The next picture shows the assembled parts cleaned up a bit getting ready to do the soldering.
 

 
Resting the upper part of the crankcase to see the overall scope of the whole engine.
 

 
In the next picture you can see the central cross member.
 

 

 
There is still a fair bit of cleaning up to do but I am generally pleased with the progress.
 
Again thanks to all who have looked in and pressed the like button.
 
Michael
 
 

Set up the table of offsets to machine the curved inner surface of the oil pan, and after two hours of cranking the block back and forth the shape slowly emerged. I lowered the cutter .010" for each pass.  Next I will cut away the negative areas where the cranks will rotate and either side of the bottom of the crankcase then flip it over to finish off the bearing recesses. then a brass shell will get soldered onto the cross members, creating the hollow shape.
 

 
I made it this way because I was stumped as to how to get the inside shapes of the oil pan, I suppose I could have set up a boring bar and scooped out the recesses the only issue with doing it that way was being able to have an opening underneath the central bearing beam to allow the oil to move about in the bottom and equalize rather than being isolated to each recess. the other advantage to making it this way is is that I will be confident that the wall thickness will be consistent.
 
Thanks for the likes.
 
Michael
 
 

Thanks for all the likes and encouraging comments.
 
I had to make another cutter to make the recesses in the main flanges
 

 
I have already drilled the holes to accept the camshaft bearings they are larger because I need to be able to clear the raised cams.
 

 
An overall shot of the progress to date.
 

 
A close up of the new cutter, I needed a long reach with a small diameter cutting edge to fit next to the body of the case. it is hardened drill rod the diameter at the cutting face is .086" The bolt holes are .060 and the case it tapped ready for the 0x80 bolts.
 

 
Michael

Omega, here is a drawing showing the cross section of the engine and the camshaft with the valve in the open and closed positions.
 

valve train.pdf
 
Bob thanks for the compliment, one of the difficulties of working with the small sizes is that when drawing they are as big as the screen and it is a constant effort to remember the real size as I am drawing.  when an area looks about right and then I realize that the dimension might be only 1/64th I have to do some rethinking.
 
Michael 

After doing a few experiments with the valve stem springs and keeper, I have increased the diameter of the valve-stem to .060" inches leaving the narrow section for the keeper at .046"
 
This was one of the early tests using the .046 stem the spring is .078 in diameter and the wire is .011. the keeper was a bit fiddly. I can safely increase the stem diameter and still maintain the .078 diameter springs the length of the springs are ..259" presently I am learning how to wind them so that there is a double coil at each end with the wider spaced turns in between. I have found that it is better to make them this way rather than winding a length then stretching it out to form the compression spring.
 

 
The crank case is progressing well at this time also. there is a fair bit of hand filing to finish up the corners because I do not have the requisite end mills to do all this work on the milling machine.
 

 
this next picture shows the flats on the sides of the liners slipped through the top of the upper part of the crankcase.
 

 
that's it for now.
 
Michael

Si, thanks for the kind words, Denis I like your new avatar, The song "Imagine" is my favourite song of the last century.
 
I started working on the crankcase it is cut from a block of brass that a friend gave me, it was given to him by somebody who melted down a bunch of odd bits of brass. it is hard and fine grained. The block was about 5 inches long and 3 wide and about 1 3/8 thick looked like it was cast in a mini bread pan. The brass cut nicely in the cut off saw.
 

 
This is the progress on the flats that will slot unto the crankcase hole. this will ensure that the sleeves remain seated, this is because I am not familiar with the differential expansion of the brass and stainless when the engine warms up. I doubt that there will be any problems so this is just to keep my mind at ease.
 

 
Michael

Thanks for all the likes, and to Row ,Mark, Druxey, and Andy thank you for your kind remarks they are very encouraging.
 
Began working on the new head part today but first I needed to make a couple of tools to help with some of the tasks.
 
first one was an end mill that was .155 in diameter and with a .015 radius at the cutting edge this was to ensure that the combustion cavity had a bit of a cove rather than a sharp corner.
 

 
a test cut
 

 
 
The second one was to make a collar for the 6 x .05mm tap so that I could tap in line accurately without taking the drill chuck out. It is just a disk of 1/2 inch aluminum with a couple of grub screws at right angles I ground a couple of 1/16th flats at the threaded end of the tap then I could use the drill chuck as the guide by releasing the tap from finger tight this way the drilled hole and the tapping are able to be accomplished without moving the work.
 

 
Then a lot of fiddly settings to shape the cavities.
 

 

 

 

 

 
next comes a lot of filing to finalize the shape.
 
Michael

TAKE... ME... TO... YOUR... LEADER
 
Sorry I couldn't resist, I just showed this to Jude and she said hey it looks like a face then in a robotic voice said "take me to your leader" I laughed out loud.
 
Just a bit more fetling and then I can move on to the next piece. I need to add a couple of relive grooves so that the jacket clears the valve springs, I will use an .093" end mill. lay the block on the top face and centre the end mill over the valve guide holes and just take a whisker off down to the holes.
 
Bob thanks for your very kind comment.
 
Thanks also for all the likes.
 
Michael

Denis ,Row, Dan, Carl, thanks for looking in and for the kind words. 
 
I am beginning to wonder about this engine business.
 
The three cylinder blocks so far!
 

 
The one in the middle was the first one I was getting more dissatisfied by the hour, because the little break through into the water jacket area was nagging at me all the time. It was actually the second of the things that was bugging me and the top part had its own error I realized the oval water area was too long. also I decided that the bottom mounting lugs needed to be an integral part instead of part of a plate that was going to be fitted to the bottom somehow?
 
So I started over and was merrily milling down into the water jacket area when saw the cutter making it way down the outside of the jacket....... yup I set the cuts on the mill from the wrong side of the block after working the outside dimensions.
 
you can see the clean little slot on the one in the back, right down the middle.
 
The one in the front is version number three, according to folk lore it should be lucky.
 

 
The most tricky part was drilling the inlet and exhaust holes (still a bit gun-shy after the first mistake) I had to set the block up with a compound angle, for each hole the inlet ones on the outside and the exhaust ones in the middle. Now the hand work filing the surface shapes is under way. I also increased the size of the valve heads to .125 from .093 inches. The bore of the cylinders is reduced to 5/16 from 3/8ths in order to get more space for water circulation.
 

 
Carl in answer to your question why brass instead of iron, it is because brass is easier to work and I have the material. I have noticed that some of the engines on the engine website are brass and they seem to run fine as long as there is a steel or iron liner and an aluminum piston. this is the route that I am following.
 
Michael
 
 

Thank you all for the likes.
Brian, Jack, Mark  thanks for the kind comments.
Ed the more I think about laminating the ribbands the more I like the idea.
 
I discovered that at this small scale there is little room for error. When I removed the support plugs today after finishing the shaping and a few more holes for the water inlet and inspection hole in the front side, I saw that the port holes had in fact penetrated the wall of the water jacket. the space inside the jacket is large enough that I decided to add a plate that will get sweated in place.
 
the first picture shows the two crescent shaped holes from the port drill breaking through the wall.
 

 
The sleeve insert is machined from some  hard 3/4 brass rod the wall thickness was .020"  I sliced off two rings then cut those further to just fit enough that the curve is slightly greater than half the diameter inside. By doing it this way they are snug enough that they do not fall out.
 

 
The next picture shows the inspection hole which still need cleaning up and the cylinder liner positioned to show the water circulation cavity. I will make the base plate before the liners are finalized. It has occurred to me that I will need a pretty good filter system to keep any debris out of the water system.
 

 
The next photo shows the top of the cylinder with the head removed the holes still need to be reamed 13/32 for the stainless liners. I am still contemplating making these two parts able to be separated I think I have enough space to add some small long bolts up through the water jacked that way they would be hidden.
 

 

 
I think I need a break from metalwork and do a little whittling of the boxwood stem and sternpost.
 
Michael
 
 

Thank you for all the likes, And Bob and Steve for your comments, its been a long couple of days fiddling with some finicky numbers, I had to make a couple of small modifications to my Mill Drill so that I could use some dial verniers as read out dials for the table travel. I had already set up the depth one a few years ago and because I have slip dials on the mill I have been able to manage up until now . However machining these tiny dimensions with a centre Zero was challenging to say the least. so now I can clip in the vernier and use it as a poor mans DRO (digital read out, only this is an Analog read out )
First I cut a piece of 1 inch square brass and then re cut it to 1.375 x 1 x .625 inches the first task was to bore the main holes to form the inside of the water jacket shell these are .625 diameter and almost 5/8 deep. then bored the holes that will mate with the combustion chamber in the top piece. After the big hole were machined I flipped it over to reduce some of the metal and then machines the small holes for the valves and water passages to the top part of the head.
Next I made a couple of support keepers out of some 3/4 diameter brass rod to fill the bore holes and reduced the diameter at the top to use as location stubs for the top part this also allowed me to thread some 10 - 32 cap screws through the spark plug holes  to hold the whole shebang together. after the inlet and exhaust ports were machined which seemed to take forever, I was finally able to get on with some finish filing.
 
 

 
I like to have a ground safe edge on some of the files it really helps to keep things square
 

 
The parts are beginning to look like the top of the engine.
 

 
The valve rods will be fabricated from some largish sewing needles these are .046 inches in diameter which works perfectly, they obviously need some work yet.
 

 
Time for a break.
 
Michael

I have been doing some research into the whole engine building aspect of this little launch. I made the top part of the engine this evening it still need a bit more work to add the top plat to seal in the water cavity the spark plugs will thread through the plate into the main body thereby allowing water to circulate around the part that goes through the cavity.
 
This drawing shows the section through the engine and sections through the cylinder head.
 

 
Buffalo 3HP sheet 1.pdf
 
this is the top part of the head
 

 
Buffalo 3HP sheet 2.pdf
 
And the brass part I made today
 

 

 

 
Michael