Whilst not up to doing any machining I thought I would take the opportunity to draw up a better dimension aide memoir. I did however manage to reverse the set up ready for the next  session.

In this, and future posts, I am adding links to where I source my tooling (new or second hand) in response to the many enquires I get as to where I bought a particular item. So the links will take you to suppliers or auction sites relative to the item highlighted and hopefully help readers directly.

Crankshaft.

After quite a bit of work on laptop the produced a set of dimensions were transferred to my master build notebook and also the white board alongside the Milling machine. I first tried using my dividing head to hold the blank for machining but because that  meant using a chuck I decided that my Vertex Rotary Table would be easier. It also meant using my as yet un-used, tail-stock, as the first method of securing the blank. I took good care to make sure the blank was level in both planes and then added an angle plate with vertical flat bar to secure part of the blank with an engineers clamp. Finally, a small jack was secured under the blank allowing a very stiff fix to take place.

Once the top side was completed the bar was revolved 180 deg. and the remainder of the blank milled to shape. This was then transferred to the lathe for the next stage in the process of producing the two crankshafts.

Quite a bit of time was spent setting up the lathe. I decided to tackle the turning by fixing a driving dog (to be made up) to the face plate. Using a new large centre at the head stock end and a live centre at the tail stock meant a smooth turn could be achieved. The final task was to ensure the tail stock and head stock were in line before turning the whole face plate one complete revolution to ensure nothing caught.

I have a Glanze replaceable carbide tipped parting tool and thought I would try to use the parting tool to machine the crankshaft. The carbide insert hadn't been changed for some time but I thought it would be best to turn all down before finishing cuts would be made using a brand new insert.

The surface finish gained so far shows promise for final cuts. So far I have turned one end to just become round before turning down the three different sizes required of that end. So far , so good.................

Not sure it was needed but I 'normalised' the steel blanks

I knew I shouldn't have gone out to the workshop, feeling a little under the weather after being brutalised by my younger brother Stephen (he maliciously tripped me up  when I was already wobbling - my life is spent being 'wobbly' all the time). However he also suffered some damage to his ribs, from laughing so much!!!

I have to make excuses for a very poor couple of hours at the milling machine somehow. Those who have been following the build of a pair of Westbury Seals here (or on my main website) will know I made a fixture for making the con rods and that the methodology for machining was in development. Well the radius turning for the ends worked well, and I shall keep that, but profiling the rest of the con rod didn't achieve either consistent, or satisfactory results, so it is going to be left until after the crankshafts now.

Another reason to stop is the revelation (to me after 4 years or so) that always using my scrap box (I call it recycling to be politically correct) for all my parts is not really the way to go for critical parts. Hugh, my nearest model engineering neighbour, supplied me with a link to his metals supplier. So I am going to order some aluminium flat, with known properties for the con-rods. That allows me to put them to one side, waiting for the metal to arrive (smart excuse eh!). I am simplifying my procedures as well. Milling to shape using 'normal' techniques is the best way to go only using my fixture to radius the small end and mill the indentation in the centre of the con rod body.

I tried to be to clever really, and use the rotary table in the same way I made the 4 chess knights. So when the correct stock arrives, at a known grade, and closer size, I am sure it won't take long to get them done.

Now over the the crankshafts. I got myself tied up in a knot over the requirement of HT steel for the crankshafts as described in Westbury's article and plans. This brought no end of trouble in cutting a bar of  HT steel in half (again being to clever for my own good  bought a bar of sufficient diameter to get two cranks from). In the end I went back to Hemingway's site (supply plans and a kit of castings as well as bar stock) and ordered two crankshaft blanks from them.

They arrived quickly enough and I put them to one side to concentrate on the con rods, however as you know from above this has now changed. A couple of years ago now I machined a piece of flat steel bar and was amazed when releasing it from its clamps, to see it bend like a banana! HMEM (the forum I use) members explained how cold rolled steel (that was what I was using at the time) had so many stresses when rolled that before use the metal should be 'normalised'. This is achieved by heating it to a cherry red colour, then letting it cool naturally, so releasing all the stress. Whether the steel as bought was normalised or not, ( knowing my recent luck, or rubbish working....) being bent like a banana,  is not good for an engine.

Since I had never carried out the simple procedure before, it seemed sensible to heat it up so that's what I did. Whether my cherry was dark enough I don't know, but its been done. So when I next go out to my home from heaven I will face off the ends of both bars so they are square, then drill 3 holes for the lathe centres to run in. One for the two central end shafts and the others for each throw.

I never seem to learn that the body is a better teller of  my potential workmanship than my head!

I set everything up last night ready to make a start on cutting the 1.5" diameter round bar of high tensile steel, in half. I was full of hope that with the carbide tipped saw blade that cuts wood and metal, this would be a successful. However two issues quickly arose, firstly the width of cut was increasing beyond the width of the blade, and secondly, it was very brutal and I suppose to a degree I chickened out!

So I decided to see whether a 4" slitting saw with side cutting teeth would do the job. I hadn't tried this previously due to how to hold the work and secondly, all the handle work on the mill. These issues were resolved because the power feed was working well and I now had a method to hold the work (the use of tapped holes in one end to secure plates too). Well it worked to a degree, after adding additional table clamps to stop some lateral movement. However it was again very slow going and I was not convinced that this would be successful in a reasonable amount of time (and blades!!).

So I have decided to approach the problem in a different way. 1, search out a local engineering firm to see if they can help cut the bar. 2, research whether the need for High Tensile steel is still valid bearing on mind how much materials have changed over the last 63 years since Westbury designed the Seal. and finally 3, look to take on another element of the build such as con rods or pistons while I sort out 1 and 2 above.

So if you can be of any help then please email me.

Pleased to get out into the workshop and carry on with the Seal build. Today I spent my time boring out the previously made  valve guide blanks. Once this was completed I reamed all the guides 3/32" to match the valves and decided to press all the guides and cylinder liners into place. Before pressing them home using the Myford face plate and tailstock, I checked the depth of recess and the amount of clearance on the cylinder liner or valve guide. Then I measured how proud they were so ensuring they were pressed fully home.

The next task will be to face the block off to size (allowing 5 thou for the base to be cleaned up) so I spent my last time setting the block on mill ready for tomorrow. I did a test running the new power feed and am wondering whether the control of speed has a wide enough range...... Will see the next time....

Yesterday I managed to make the tappets for one engine (8 in all) and they are now awaiting my first attempt at case hardening. To speed up their production I made a tube out of stainless steel to fit over the slot drill I was using. The method worked fine and it didn't take too long to make. However, today I only managed a short time in the workshop and looked at how to cut the chamber in the valve guides with the radius required at there base. I did try and make a special tool out of some drill rod (as the Americans call it) but whilst they worked to a degree I wasn't happy.

That's when my memory kicked in and I remembered the ball nose cutters I have and one was in the correct size of 0.250". A quick check of the radius showed it to be near enough so my previously turned valve guide was mounted in the chuck and when considering how to get to depth the second part of my memory decided to wake up. I have a clamp that I attach to the tailstock and then use a DTI, secured to a small magnetic base, to rest against the clamp so ensuring complete accuracy with depth. Why I didn't use it yesterday for the tappets I do not know!!!

I did not use the ball nose milling cutter directly on the valve guide but drilled it out first just undersized and using the cutter to clean up and cut the bottom radius.

Another plan issue showed itself yesterday when completing the two camshaft bushes. Neither the article or the plans show the angle of the oil holes required in both bushes.  Nor does it give the diameter of the hole.

My solution was to use the new digital angle ruler bought from Axminster tools on the plan (see photo). This gave a reading of 33 degrees and measuring the plan showed the hole size o be 1/16".  I had a bit of a blonde moment however when working out how best to drill the hole and its chamfered entrance. I thought the best was would be to use my Proxxon drill and stand. So I set the head over to 33 degrees and yes I know you will know but when depressing the stand of course it goes only directly up and down!

Blushing I got out my angle vice and after setting the digital angle meter to zero on the base of the drill stand, I adjusted the vice to the required angle and form then on it was simple.

The next session should see most of the valve guides for this first engine completed. After that as soon as the 1.8mm drills arrive I can complete the two nuts required for each valve before carrying out a new experience for me, case hardening the tappets and nuts. I will cover the experience in a separate section of the website as I have had some advice from a member of the forum I use.

If you don't know it then I can highly recommend the Home Model Engine Machinist forum, especially if you are a novice as they are both approachable and knowledgeable.

As always here are a few photo's that may help explain my ramblings.....

I managed a short session today and managed to nearly complete the first engines 8 valves. There only remains 4 valves to be finished to overall size then cut a slot in each face. When these 8 are done I will then make the corresponding valve guides. I am undecided whether to follow this by drilling and tapping the top stud holes followed by inserting the cylinders, valve guides and facing off.

My reason for being in two minds is an itch to work on the Fowler tender, but the valves and guides have to be completed first. Watch this space.

The reason for buying a replacement bandsaw was to increase the capabilities for metal cutting in my home workshop. My 'old' Warco bandsaw was bought 3 or 4 years ago and to a budget. However, with increasing experience comes greater knowledge. My local source of metal is a scrap yard which means I have all sorts of sizes of cast off's from local industries.

One prime example is a 'lump' of brass that has a part saw cut through the better part of one side. Now I have the new Clarke Bandsaw I can at last cut off sections of the brass lump which I will use to make the two flywheels needed for the Seal 15cc 4 cylinder, petrol engines I am making at the moment.

Once this job has been completed I will put the bandsaw into its vertical position, attach the table and attempt to cut the special steel bar bought for the crankshafts. It is tough steel so I have bought a bi-metal bandsaw blade (has HSS teeth) and see how it performs. A job that the old bandsaw could not tackle (not that this one has yet!). Time will tell.

Seal Cylinder Liners - Session 1 09-01-2009

Well a start has been made at last on the pair of Seal Engines I started this time last year! There are 8 cylinder liners to be made and they are turned from cast iron. I was soon reminded on how dirty cast iron is to work. Fortunately I remembered enough to protect the lathe as much as possible from the swarf.

The first cylinder is 3 thou oversize so its piston will have to match, that is of course unless I remake it in the end. My excuse for the oversize is the new honing methodology I am trying. It comes expensively from industry but its performance is exceptional and quick!!!!

The allowance I made of 2 thou undersize first time before honing proved to be insufficient! The second one came in 1 thou over when honed which was within the tolerance I set myself. Now the lesson has been learnt the others should come out the same, but I suspect I will need to make more than the 8 (already one down out of two!!!).

Edgar T Westbury, the engines designer, recommends painting the cylinder liner with paint or varnish when pressing home and for the liner NOT to be a tight fit. I will wait until later before making up my mind what, if any, sealant I shall use.