Motorboys Vivell 09 Diesel Build

[LADmachining]

Hi all,

Though I would post some pictures of my current work-in-progress.

This is a replica of the Vivell 09 diesel from 1948, reproduced by the 'Motor Boys' with castings supplied by Roger Schroeder.

Construction was started on the 4th September 2009. To date, the following parts need completion:-

Connecting Rod, Piston, Rotary Valve, Fuel tank and cap, Needle valve, Prop driver, Contra piston.

Here are some 'in-progress' shots of some of the components:-

Crankcase

Cleaning up the front of the casting ready for marking out.

Casting marked out and set-up in the 4-jaw for boring and threading.

Screwcutting the case - 32tpi LH thread.

Parting-ff a plug to fit into the recess that has just been bored. This will be used when the cylinder recess is bored to ensure the deck height (distance from centre line of crank to top of casting is set correctly).

Completed plug with flat, which is a known distance from the centre of the plug.

Crankcase set-up on angle plate to bore cylinder recess.

Recess boring in progress...

Angle plate transferred to mill to drill mounting lugs and cylinder securing screws.


Cylinder

Cylinder fin cutting in progress....


More pictures to follow (if anyones interested :big....

 

[GailInNM]

Anthony, of course we are interested. Photos are always welcome here.
There are a few of us who play with compression ignition engines so a WIP on any of them is nice.

I never got around to welcoming you to HMEM, so here is your official welcome from me. wEc1

Gail in NM

 

[zeeprogrammer]

I don't remember a welcome either...so welcome!
I'm interested too! Keep the pics coming. Very nice stuff so far.

 

[LADmachining]

Hi Gail and Carl,

Thanks for the welcome.

More photos will be posted soon, once I have sorted through and uploaded them. Some don't come out that well - I am using a mobile phone to capture the pictures. Some shots look OK on the screen, not so good once uploaded to the computer.

What also suprises me is how 'rough' some of the machined surfaces look in the pictures....

Anthony

 

[zeeprogrammer]

Don't worry so much about the quality of the picture. That's secondary to seeing that a build is in progress. Yeah...the camera can be unforgiving in showing the machining. Don't worry about that either. (Course...if you look at my work..you'll understand why I say that. ;D)

 

[LADmachining]

Here are some more pictures of progress on the Vivell. Well, that's not strictly true, all of the work was done a few weeks ago, but have just got round to sorting through the photos and posting them - you get the idea.

After completion of turning operations on the cylinder, it was transferred to the mill

Transfer passages are cut into the side of the cylinder using a 1/4" end mill.

As you can see, careful work is required as there is not much metal left between the port and the outside of the cylinder.

Next, the exhaust ports are cut using a slitting saw.

This is actually a new head, as a fatal error was made when drilling the holes for the cylinder head screws. A moments inattention saw me drilling all the way through with a 2.6mm drill, rather than just lightly countersinking to prevent the tapping operation raising a burr. Why does it always happen on the last hole? ??? Rather than try and repair, I just made a new part, which actually took a lot less time than expected (about the same amount of time I spent pondering how to repair the first cylinder)

After turning in the lathe, the cylinder head is centered in the mill, and the mounting screw holes are drilled and counterbored.

The start of the fin cutting process - very slow going with a 1/16" end mill, even with Sherline mill cranked up to top speed (6000 rpm, I think).

The process nearly complete about an hour later. Lots of powdery swarf everywhere!

Crankshaft

After plain turning of the crankshaft main bearing journal, a fixture is made for offset turning of the crankpin. Here, a hole is being reamed to take the crank main journal.

A nut and spacer secures the crank in the fixture. Tailstock support is used to prevent the part shifting in the jig whilst the corners are 'knocked off' Radial cuts are taken - like a facing cut, but not winding the cross slide fully to the centre of the part, leaving an amount for finishing turning of the crankpin.

Once the interrupted cut is complete, the tailstock is withdrawn and the pin is finish turned.

Turning complete, all that remains is a little work with some wet&dry paper and a steel rule to bring the crankpin to size and ensure a nice fit in the big-end of the connecting rod.

Spinner

A scrap of steel is turned and screwcut to make a mandrel.

The spinner blank is mounted and truing cut is taken along the outside diameter.

Now the profile of the spinner is formed. It is a large, curved radius. I could have made a form tool, but a didn't have any suitable material. Instead, I used a method detailed in one of the 'Machinist's Bedside Reader' books by Guy Lautard. The part was drawn up in CAD, then the diameter calculated at intervals along the axis of the part. These dimensions were then fed into an Excel spreadsheet to calculate the depth of cut at each interval along the part (I used 0.5mm (0.020")). Once this stepped profile was formed, it was smoothed using progressively finer files and then sandpaper until smooth and polished.

The finished result.

Plenty more to follow.......

Anthony

 

[vlmarshall]

Excellent work... this thread's got my attention! :bow:

... Instead, I used a method detailed in one of the 'Machinist's Bedside Reader' books by Guy Lautard.

I was just suggesting those books to someone yesterday. I've bought all three, and they're full of useful information .

 

[LADmachining]

I was just suggesting those books to someone yesterday. I've bought all three, and they're full of useful information .

They certainly are! Despite having read them a number of times, I always seem to learn something new each time, and think to myself 'how did I miss that?'

I 'discovered' the Osborn centering method recently - I now spend a fraction of the time centering stock under the mill spindle....

I wonder when the 4th book will be published? It's been a long time coming!

 

[mklotz]

The profile of the spinner is what mathematicians term an "ogive". There are two types of ogives - tangent and secant. Both are formed as an arc of a circle the center of which is offset from the central axis of the part. For a fairly complete description of the mathematics of ogives, visit:

http://rocketguy101.jimdo.com/ogive-nose-cones/

I wrote a program (OGIVE) to produce incremental cutting charts for ogives. Because I included some exotic graphic code in this program it won't run under XP although it runs fine on older Windows operating systems.

If anyone has a genuine (i.e., not merely curiousity) interest in machining ogives, I'd be willing to excise the offending graphics and produce a version that can run under later operating systems. Contact me if you have such a need.

 

[LADmachining]

Hi Marv,

Thank you for the info. After reading the plans, I took a guess when I redrew the part in CAD to calculate the dimensions. Drew two orthagonal lines, the length of which were the same as the finished length and diameter of the spinner. Then drew an arc from each end point of the diameter line to the end of the length line, using the opposite diameter line end point as the centre of the arc. I couldn't have been far wrong, as the part looks OK... ;D

Also, a belated thank you for the utilities you provide on your site - they have come in very useful in the past.... :bow:

 

[LADmachining]

Hi everyone,

Here are some more progress shots to update you all.

After 2 attempts at trying to machine the con rod 'manually', I took to cutting a blank out by CNC. It was rounding the ends that was causing me grief. They turn out perfectly by CNC...

After about 45 mins, the program has completed, and the blank is left attached to the stock by a very thin sliver of metal that can be peeled off the blank by hand.

Turning of the cylinder lap to size, to a loose sliding fit in the cylinder bore. The lap is then drilled most of the way through, and then tapped with a 2nd M4 tap to about a 1/4 depth. The lap is parted off, and then saw cuts made along the lap to make 4 petals. An M4 screw is fitted into the tapped hole. The further the screw is wound in, the further the petals are pushed out to increase the effective diameter of the lap.

A small amount of 4 micron diamond paste is spread on a piece of HSS tool steel. The lap is then rubbed on the steel, which embeds the diamonds in the aluminium lap. The lap is then chucked in the lathe, with lots of glossy paper on the bed to catch any abrasive material, and the cylinder is stroked up and down the lap with lots of WD40. The M4 screw expands the lap as necessary to keep cutting the cylinder, until a polished finish with no machining marks is obtained. This type of lap also introduces a slight taper into the cylinder, which ensures a nice fit with the piston at TDC, to provide good compression, but a looser fit lower down to reduce friction.

The tank top O/D is turned to size on the lathe, then transferred to the mill for drilling and reaming operations. The Allen bolt forms a primitive 'Machinists Jack' to support the part.

Cross drilling the venturi for the spray bar.

The prop driver is externally turned to size, then a 'D'-bit reamer is used to cut the taper that matches with the drive collet on the crankshaft. The D-bit was cut from silver steel (drill rod) at the same time as the drive collet, to ensure the tapers match exactly. It was then machined in the mill to cut away half its diameter less 0.002", then hardened, tempered and sharpened. Feeding it in slowly with plenty of cutting oil produces a very nice finish and an exact fit for the drive collet.

The prop driver is parted off and remounted in the 3 jaw with a piece of thin aluminium shim from a drinks can to protect the finish. After facing off and counterboring, the knurling is applied.

Here is the knurling completed. The medium striaght knurl is mounted slightly above centre, and slightly angled so that the knurl cuts deeper on the outer edge of the part.

The disc valve blanked is turned in the lathe and parted off, then centred under the mill to cut the port and recess for the crankpin. Here, two holes are drilled, by co-ordinates, to demarkate the extents of the port arc.

Then, a short CNC program is used to 'join the dots'. The crankpin slot is machined manually to ensure a slop-free fit on the crankpin.

Here is the progress as of 27-10-09. Not far to go now.... Only a piston, finish the connecting rod and make the contra-piston ;D

Regards,

Anthony.

 

[LADmachining]

Another update on the Vivell build...

Lapping the piston to the bore using an aluminium ring lap charged with diamond paste. The toolmakers clamp is used to pinch the lap closed, as well as a useful handle to hold the lap.

Two pieces of round stock are slotted to accept the connecting rod. A brass bush is made and held in the tailstock chuck. The conrod is then fitted into the slots and bolted firmly into place after truing the blank for minimum run-out. A thin parting tool is then used to turn down the centre section.

After a run through the ultrasonic cleaner, the parts were arranged for this shot before being lubed and assembled. A modification was required to the OD of the disc valve, as it was found that the piston was fouling it at BDC. 10thou was taken off the disc, and all was well.

Now I just need to make a mounting for it, then it will be the moment of truth!

Anthony

 

[GailInNM]

It is nice to see it all coming together Anthony.
Looks very good.
I will be listening for the first pops>
Gail in NM

 

[LADmachining]

Thanks for the comments Gail.

The first pops may be a bit later this afternoon, once I have finished a couple of other jobs, and if the weather holds out for me... :bow:

I haven't been practicing any sort of dance for when it fires up - have I jinxed it??! :big:

In a typically understated British way, it will probably be a case of saying 'well done, old chap' to myself. If no one's looking, I may let out a little cheer. ;D

Anthony

 

[black85vette]

Amazing work! Loved some of your set ups.

As for the happy dance how about doing this one:

 

[LADmachining]

Well, the engine has not been run today. Rain stopped play, and now it is dark here. Maybe tomorrow will bring more luck.....

Gives me more time to practice the dance!!

Anthony

 

[LADmachining]

Today's news headline..... IT LIVES!!!!!

th_wav

After spending 30mins or so modifying a piece of MDF to make a suitable mount, the workmate was set-up, the fuel tank was filled, and I started to flip the prop in earnest. The compression screw was gradually increased about an 1/8th of a turn each time, until the engine started to 'pop'. Then, the intake was covered and the prop given a couple turns to draw in a good prime of fuel. Another few flips, and we have a sustained run. Woo hoo! ;D

Mounted-up prior to first run.

After the first 30 second sustained run.

During the next sustained runs.

At this point, a couple of problems come to light. It vibrates a lot - turns out this may be due to me not cutting the crankweb away at two places to balance the engine. This vibration led to the carb loosening and shaking around, which was causing fuel to shake out of the tank. Also, the needle valve was doing a happy dance and turning by itself, leading to erratic running.

The tank was temporarily secured with a cable tie, then another run was made. More successful this time, the fuel staying in the tank led to a longer run, and a chance to get some action pics and video. The needle valve was still 'wandering', but this didnt seem to have as much effect on running as it did on the previous run.

About 5 tanks were run through in total, about 2 minutes very rich running each, and 5 minutes for the engine to cool in between, so about 10 minutes running time in total. The engine is starting to loosen up nicely, and the oil coming from the exhaust is lightening-up from the very dark colour it was on the first couple of runs.

A shot of the 'mess' after the runs.

Here is a pic of the mods made to the engine a little earlier. A jam nut now secures the venturi tube to the crankcase, and a ferrule and spring should prevent the needle valve adjusting itself.

The crank will have to be removed and the crankweb cut away to improve the balance of the engine.

I have some video of the engine running, but am having trouble posting it. I guess I will have to sign up to YouTube to host it....

Anthony

 

[GailInNM]

th_wav

:bow: :bow:

Congratulations on the first runs.
Gail in NM

 

[John Rudd]

Congrats... a nice piece of work there..

 

[zeeprogrammer]

Great job Anthony and great pics. I look forward to the vid.