canoe21

I have got the gearbox to the point where I can now move on to the driving portion of this engine namely the pistons and associated gubbins.
 

 

 

 
First I needed to machine up some blank pistons these are .311" (7.89mm) in diameter and .372" (9.52mm) high
 
these were then set into a fixture to drill the wrist pin holes and to machine the squarish hole inside.
 

 

 
they are fiddly little things to work with, popping the O ring on is easy getting the ring off is another story.
 

 

 
they slide up and down nicely in the cylinder head.
 

 
 
Merry Christmas everyone
 
michael

Thanks for the likes.
 
I used a trick I employed when filing up connecting rods on my model steam locomotive, and that is to use a hardened button as a filing guide.
 

 

 

 
The top of the handle ended up being hand filed I had originally intended to turn it in the lathe by holding the lever in the four jaw chuck, it caught and bent so after straightening it I used needle files sandpaper and steel wool to clean it up.
 

 
Michael

Greg, Mark, Carl and Mark thanks for your encouraging comments about my work, and again to all who have appreciated it quietly.
 
Moving forward to the control of the clutch I have started to make the forward reverse lever. This lever will need to have some ability to be adjusted.To give just the right amount of pressure to the clutch spring. The geometry of the fulcrum points is critical.
 
The strength of the coil spring is also one of the items that might need a few reworks to get right as well. The whole physics of springs and their construction is no doubt a science, but from my practical point of reference, a trial and error method will have to suffice. So I will see if it works.
 
I rummaged through the scrap box until I found the right bit of brass to cut the lever out of. I used the vernier height gauge to lay out the shape, then pre-drilled all the holes while it was rectangular this makes it much easier to get them square to each other.
 

 
the cutting was done with a fine blade in the jewelers saw. I have already started to file the surfaces to the final shape.
 

 
The keeper rods are now set into the gearbox these were turned up from some free machining 1/8th inch hex stock, at first I left the heads as a hex bolt but they were too big and interfered with the pressure collar. so turned them into cheesehead screws. the spring was wound from some .020 music wire, I used the number drill series of drills as the arbor to find the correct size to finish up with a 3/16th internal bore the third attempt produced the correct diameter, it was a number 21 drill.
 

 
The lower pivot point to which the lever connect to will be mounted on the back wall of the oil pan below the prop shaft, and will be able to be threaded forwards and backwards to give the adjustment.
 

 
There will be a connecting link from the lever to the clamp on top of the clamp ring.
 
Michael
 
 

Ed, and Jack, thank you for your kind comments. and for all who added likes.
 
I had to make a new band clamp because the tabs were not wide enough to bolt it to the pan. the new one was machined from a solid ring and then a lot of fiddling and filing to get it to spring just right.
 

 

 
I also whipped up a flywheel because it is tough on my fingertips turning the 1/8th shaft all the time to test stuff.
 

 

 
Today I worked on the clutch, it was a bit of a design build affair following the general principles, the gearbox and clutch will be underneath the cover so only the top of the linkage and the lever will need to be as accurate as possible to keep the appearance of the engine looking as the full size engine.
 
I abandoned the cap screw hex and made a hex broach from a 3/16 allen key. first I heated it up and let it cool slowly to take the hardness out of it, then cut a taper on one end of the hex. Next I added the beveled slots to create the cutting faces. I ended up making a second one because I forgot to temper the first one after re hardening it, it cut the first hex through about a half inch length of brass stock, and then I tried a longer piece of brass and it shattered into three.
 

 
Pushing the second one with the vice rather than using the hammer which is how I managed to wreck the first one.
 

 
At the back end of the broach I reduced the diameter before it was hardened so that I could part off the disks one at a time, as the broach was forced through, each time the broach reached the end I put it back in the lathe parted off another disc
 

 
Next I turned a few discs of mild steel off a blank that had been pre drilled for the keeper rods. the steel discs are 5/8 diameter and .020 thick the brass plates are 5/16 diameter and .040 thick. the steel discs will be fixed to the gearbox and rotate about the hex the hex will be pinned to the prop shaft and the brass plated will spin with the hex
 
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Here they are test fitted for size, the wide brass collar is also keyed to the prop shaft and will be the pushing element to squeeze the plates together.
 

 
Time for bed
 
Michael
 
 

Remco, Steve, Joe, and Row thanks for your very kind remarks. Thanks to all who pressed the like button as well.
 
I finished up the clamp ring today and made the actuating lever to open and close the ring, it is quite tiny but was manageable. in order to get the widths that I wanted quickly I spun up a disc on the lathe, bored out the centre hole on the lathe then stood up the rod with the disc still attached in the vice on the mill and offset the other hole .156" then took it back to the lathe and parted it off then used the jewelers saw to cut out the crank.
 

 
Then cleaned it up with some files, then polished it up to a rouge finish and beveled the hub to create the cam.
 

 
Here it is set in position with the spring loaded bolt in the open position the width of the flanges at the bolt are .290"
 

 
And here with the lever in the closed position the width of the flange at the bolt is .250" locking the gearbox casing.
 

 
This is how it works
 
next the rear cam locking collar.
 
Michael
 

Thanks everyone for the comments and Likes.
Its been a long couple of days working on the gearboxes, yes I ended up redoing the casing a couple of times over, I also opted to redo the inner stuff as well. Although the micro gears worked they were not as smooth as I wanted. I ended up using some 48DP "pinion wire" it is actually 10 tooth brass pinion, and is exactly 1/4 inch in diameter. this way I was able to go by the numbers and make the proper distances for the gears to mesh'
 

 
Like this Video
 
In order for the gearbox to be able to lock so that the prop rotates forward there is a clutch that is splined, I have been wracking my brains working at finding a way to make a small spline. This morning as I woke up it hit me.
 

 
Yup the trusty old allen head cap screw has a negative hex to accept the hex key, I matched up a 5/16 cap screw with some 1/4 inch hex brass. the steel collar will revolve in the base of the forward/reverse lever and will move about 1/64 to clamp the prop shaft to the gearbox causing the forward motion. the hex part will be pinned to the prop shaft, and a loose clamping collar will be inserted between the hex collar and the casing of the gearbox, when the lever is pulled back the hex collar will move forward clamping the case and loose collar hence locking the case to the prop-shaft
 

 

 
The revers is accomplished by clamping the gearbox inside a steel band which was made from some steel rings turned up and silver soldered together. As the gearbox is clamped the splined collar also releases the loose clamping collar allowing the gears inside to impart the reverse
 

 
The rings were machined to shape using the mill and the lathe.
 

 

 

 
When I cut the slot on the top of the band it automatically sprung to a smaller diameter which works in my favour because in order to open the band a wedge has to slide forward, this wedge is connected to the forward reverse lever.
 
It is getting there.
 
Michael
 
 
 
 
 
 

Thanks for the likes .
 
I did make the casing today and fitted the gears inside.
 
the gear for the prop through the end that will be shaped with the cone recess.
 

 
The casing with the pinions and the drive gear which will be pinned to the crankshaft.
 

 
The cone end with the pinions dropped in and the gears lined up for the casing to slip over.
 

 
All dry assembled I also spotted three holes for some 0x80 bolts to ensure the casing and cone stay together and do not move relative to each other.
 

 

 
I did check the reverse by rotating the prop to see that it actually worked to this stage. still a long way to go to get it all mounted and working in situ.
 
It did work though so I am pleased about that.
 
Michael

Mark, Steve, Ed, and Denis thanks for your comments, and for all the likes.
 
Denis the picture shows the few parts that I am using just placed to get a sense of if they would work. I have since been working on the design of the reverse mechanism, for reasons of scale practicality, and to maintain some sanity I am working with the two pinions and the two spur gears and drawing a gearbox that will work.
 
The entire gearbox is covered with a protective shield (no doubt to prevent feet or clothing from getting snagged) on the full sized boat. So I am working with some drawings from the day showing how these gearboxes worked, and fitting in the gears that I have to make the mechanism work. 
 
The originals used a series of clutch plates and the forward /reverse lever either caused the outer casing to be rigid hence letting the internal planetary gearing to impart a revers motion to the prop shaft, or they clamped the prop shaft and casing together causing the whole body to revolve giving a forward motion. The vertical position of the lever caused a neutral position for the prop.
 
Here is a drawing of the progress of this design so far, I have re-machined the pinions already the shafts were pretty hard and it was nerve wracking to say the least.
today I am going to make the outer casing this will be brass. this will allow the gears to seat in brass giving a quasi bearing, similar to an old clock where the gears are steel and the clock plates brass.
 

 
revers gearbox.pdf
 
As I say this is a drawing in progress and is a bit of a design build as far as the internals are concerned my goal is to have the external appearance to match the picture of the engine in the real boat.
 
Michael
 
   

Thanks for all the likes and nice remarks.
 
I did finish up the head today.
 

 

 
It was starting to bug me. I used needle files then 400 wet and dry 600 wet and dry 1200 wet and dry then red rouge on some swede side of a leather polishing stick.
 
Michael

Steve the hole through the steel rotating part of the valve is .041 in diameter it is a number 59 drill the locating pin with the washer is also a taper pin and keeps the main part in place. they will work as real priming cups.
 
Dan , yes it is me, and thanks for the compliment
 
John, Thanks for the kind remark The handles on these valve are really no smaller than a large belay pin at .25" long they would be a foot at 1/48 scale and 18 inches at 1/64
 

 
I like the one on the right better than the one on the left so will replace the handle on the left one tomorrow.
 

 
Some of the metalwork that I see being done on many of the ship build logs is much smaller that this engine.
 
 
And thanks for the likes
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
 
 
 
 

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
 
 

Thanks to all the builders who pushed the like button.
 
Denis, I am learning a lot about engines myself at the moment.
 
Steve yes I am going to make the reverse mechanism as well.
 
Today this morning I was drawing up the feed-water pump, I ended up finding a good internal design in one of my old Model Engineer mags page 1265 October 1981 for a 3 1`/2 inch gauge Stanier 8F. I will need to make it smaller but the design will fit into the pipes that are on the prototype buffalo which pumps off the camshaft like this one on the Old Marine engine site
 
I worked on the pan today and roughed out the half round bottoms for the crankshaft and drilled and tapped all the 0x80 holes for the studs.
 

 
I looked at all my stashes of steel wire and rods looking for some .060 to make the steel 0x80 studs from. I could not find any that was exactly .060"
I then came across a most unlikely source, the re-bar ties left over from building the house just happened to be .060 the stuff threaded up a treat. had to make a small open ended wrench to get to the valve side because of the overhang.
 

 
Did a test fit of the crankcase and pan and water-jacket, it all slipped together nicely. It has really helped with the accuracy of cutting and drilling to set up the dial calipers on the mill, and working from  a 0 centre 
 
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