Work continued on the pair of patterns for the Seal engine. I am now at the stage of painting to get a good finish. To help me I use two different spray colours so I can see clearly the areas I am covering. This works well and after making a few more adjustments, seen because of the paint finish, I am not to far away from finishing these patterns befre casting some to see what lessons I can learn in pattern making.

Whilst I will need to dust off the furnace I thought it would be sensible to complete all the different project patterns making best use of the furnace time. I must admit to being a little surprised at just how many different jobs on the go (or waiting for me to cast the part). These include a pen stand to display the pens I make (I hope to try a local Saturday craft fair in Brixham soon), a casting of the 3 pronged bracket to run the power feed to the milling table project (I will try first to use the metal part it will mate with before seeing if I need to make a wooden one) and a more substantial table for my Clarke bandsaw (for use when operating vertically).

I am quite happy I have the system of melting the alluminum sorted now but am not so sure about my patterns but the only way to find out is using them. We shall see. I expect to use the furnace the end of this week if I am lucky so watch this space.

When phoning Hemingway's, the supplier of Westbury's Seal castings I found out that whilst Edgar T Westbury designed the engine to work in either direction, no patterns for the 'other' way exist. So I am making a couple of patterns to cast the two parts needed. This is my first attempt to produce patterns to the quality required so it is interesting to say the least.

I have started by looking at the plans and comparing the existing castings to them. Remembering to allow for shrinkage and having the sides sloping, I made a start by tracing the outline then reversing onto wood and rubbing the reverse side, transferring the shape seen in the photo below. One the outline was done it was over to the fretsaw and cutting outside the line the basic pattern produced.

My next stage is to use filler to get the shape I want before spraying in one colour, sanding/filling then spraying in a different one to get as good a finish as I can. Of course the final test will be when they are cast.

Whilst I was at the fretsaw I also cut out some templates to make a set of pen stand patterns. So sometime next week I hope to fire up the furnace. Lots to do but its a start and its working on the Seal. Will post more tomorrow hopefully.

Well today's session I should have made at least 4 valves. In the end silly errors resulted in two being scrapped before finishing. On the plus side the work I did whilst laid down yesterday afternoon, in writing up an aide memoir for machining, worked well.

I decided after completing the first valve proper, that I would treat their manufacture in two phases. The first was to do all the turning on the lathe whilst the second is to thread the end of the valve stems 8BA. The second phase will be to face the valves off to finished size.

Based on today's work rate it will take at least another 4 sessions and some more stainless steel stock! Still more made than I had yesterday.......

And before I stopped I made good progress with the 3rd (well the second really - still with me?) by bringing the blank to overall diameter + 50 thou. Then it was centre drilled, before drilling through 0.250". The next stage was to bore out the rear recess and I am about half way there before stopping. I suspect there is only another hour or so left to do (I can't muck it up because I don't have any more 2.5" dia brass bar!) . Once I have bored the rear recess I will cut the taper for securing the flywheel to the crankshaft.

The blank will then be put onto the between centres fixture, so the work on the front of the flywheel can be concluded. One lesson learnt with the first and unsuccessful flywheel, was the benefit to be had by clearing some material before using the specially ground tool steel for creating the chord grove (see photo). I used the parting tool to depth and when changing to the profiled tool it was significantly easier to machine.

Perhaps because of the positive session today, I have changed my project priority list to next start the crankshafts. This will require some fixture work first so I can cut the very expensive HT steel bar in half (along its length), allowing two crankshafts to be produced from the one piece of steel I have.

I am still having problems with the web hosts I use in getting the main website updated. Why do support staff that are supposed to help not understand that you pay them to be experts in server support! Really wind me up!

Anyway here are a few photo's to help you understand the information above.

GLANZE BOXFORD 16MM SQ INDEXABLE PARTING LATHE TOOL    £28.95

GLANZE CLAMP TYPE INDEXABLE PARTING TOOL 12MM    £33.72

SPARE INSERT GLANZE 10 12MM PARTING TOOLS    £4.60

GLANZE 10MM INDEXABLE LATHE PARTING TOOL FOR MYFORD    £26.95

Well it was a mixed up session today with the dustpan completed (including some nice artistic paint runs - done on purpose.....honest....) with a turned tapered aluminium handle.  Then for some silly reason I thought I would melt some pistons that came my way into a bar I can turn to make the 8 pistons needed for the pair of Seal engines I am building.

I have written my guidance notes for the melting of metal and at the top, in bold is the reminder to only melt aluminium at the beginning of a session when I am at my freshest. So what did I do today? Ignored it!! Fortunately it went reasonably well but it did takes its toll. When making the mould I searched the memory banks for how to set the mould for a round bar. It has to have a parting line at the half way level. I then remembered one of myfordboy's video's where one half of the mould is set the sand removed to allow the bar to settle to its half way mark. Then I covered the bar and sand in baby talc and filled the top box.

Once the second box was completed this was then turned over and used as the base. The first box sand was removed and sifted  and with the bar and sand covered in talk the top box including the feed and exit pipes added. Once this box was completed the boxes were split and cut outs between the feed and bar mould were cut for both tubes. the boxes then put back together and the feeder and exhaust tubs added.

After adding some weight to the boxes the pour went well enough and when the mould split I have a bar to turn! So I suppose in the end it was a success. Whether the sophisticated alloy used will be of any benefit to the small engines or whether it will machine well has yet to be answered.

Still it was a nice if very short session since I am a Formula 1 fan and the first race of the season is calling a halt to the day. However I have taken the plans and my machining notes with me to refresh myself ready for some serious work next week (with a bit of luck).

I did find another error with the Westbury plans when checking over the dimensions of the flywheel. the length of the taper at the end of the crankshaft. I was checking the taper (since this was the cut I was making in the flywheel) on the plans and the length of the taper is shown as 5/32" of an inch instead of 15/32"! This error is now added to the 2 9/8" (instead of 3 7/8" it should be) as the length of the main casting.

So its good to be out in the workshop even for a short time.

Work done before on the 'practice' flywheel (ok I made a mistake.....)

The 'practice' flywheel and the turning mandrel

On one visit to my local scrap yard I was fortunate enough pick up a large diameter piece of scrapped brass. It had one problem, which I guess is why it was put into some factories scrap skip, a large cut on part of the bar, but fortunately it had enough unaffected to match the 2 ½” diameters needed for the flywheels.

Brass from my local scrap yard

The first task was to decide a machining procedure for the flywheels and after a little thought I decided that I would make a centre mark and scribe a 2 ½” diameter circle in the available space on the brass bar. This mark would be used to centre the brass  in the 4 jaw chuck by using a centre drill in the tailstock, using the pressure from the tail stock to hold the brass in position on the 4 jaw chuck.

Using the tailstock to centre the brass blank in the 4 jaw chuck

I will then face off the blank and turn the outside to a round shape before centre boring the cavity which forms the rear of the flywheel. Once this is done the blank will be removed and then use the 4 jaw chuck to hold onto the inside of the cavity, the front part of the flywheel will be turned and finished to shape. The final diameter however will not be completed until the flywheel is held on a mandrel running between centres as per Westbury’s suggestions, to get the flywheel turned accurate enough to eliminate wobble when used on the engine for real. Well that was/is the plan.

To save me some effort without producing mountains of swarf, I used the new bandsaw to cut away as much as was safe from the scrapped lump.  This blank was then taken to the 4 jaw and I decided it would be safer to reverse the jaws when holding the rough blank. They would be reversed again when the cavity is produced.

The blank was set up as per my machining plan and the first cuts made to the outside and this is where I decided that enough was enough. The next session will see the continuation of the turning of the outside until round before facing and then boring out the rear cavity of the flywheel. Look back and see the progress

Progress so far on turning the first of two flywheels for the Seal engine

Well I managed to get back into the workshop this morning and decided that I would start on the last camshaft for the Seal engine since the lathe was still set up for the cam turning fixture. With the half turned practice blank that will make nearly 4 camshafts now made. Two proper camshafts made from Stainless Steel and another made from BMS which I intend to try and harden. If it works I may use it as a comparator in one of the engines. If it doesn't work, well I will have learnt from that as well.

I am going to write a large lettered poster for the workshop saying “If it looks or feels wrong then it IS! Investigate as to why before continuing!”  I may produce a dozen copies and post them all around the workshop and maybe have it tattooed to the inside of my eyelids as well.

I did have a few set up problems with the camshaft fixture turning true. I must be learning something though because it took me less time than usual to find the culprit. My tail stock also swivels around the locking point located centrally. I couldn't see to begin with why, when I was off setting the tail stock, the live centre did not follow, indeed it was going the other way! It was only when I lent on it that it revolved! Doh.

Hopefully tomorrow I shall complete the camshaft and then I can get my lathe back.

Well another lesson learned and mystery solved. It brought to mind all the times when 'something' wasn't right and in the past I have not investigated fully. Its only since the rebuild of the Myford ML7 that I have been far more investigative with good benefits resulting. So the new motto will hopefully serve to 'help' me. Time will tell.

Today I spent quite a bit of time on working out the co-ordinates for drilling then reaming the holes in the cylinder block for the 8 valves and 4 cylinder liners. It’s critical that measurement should take place from a machined surface and I choose the right hand side face when looking at the photo of the cylinder block on the milling table. I had previously set the casting parallel to the X axis by using the two plugs centre drilled previously.

I normally use my electronic edge finder that lights to show contact, and therefore the edge (after allowance for ½ the diameter of the end) of the part being measured. However the overhang on the edge finder would not allow measurement and I do no possess any slip gauges or the like so I made use of the ‘wiggler’ set I used before buying the electronic edge finder.  It was quite nice to revisit an old friend as it were and the edge was fed into the digital readout, after allowance for the ½ diameter.

Because the cylinder block is a substantial casting and the critical nature of making sure the valves, cylinders, camshaft etc. line up, I made several movements to see that the end co-ordinates looked correct. It was during this exercise that I found the co-ordinates wouldn’t work in relation to the 4 holes already there for the pistons.

(above is supposed to be the centre of the 4th bore!)

When checking the dimensions against the other recently bought set of castings, I found yet again that my casting was significantly larger. So I decided to center the mill over the nearest cylinder hole to the datum face and confirmed the ‘extra’ distance. So after recording the measured difference in case it is needed later, I reset the DRO to zero and carried out the checks for the co-ordinates again. This time everything worked out fine and I decided to center drill the 8 valve stem holes. Then it was the turn of a 15/64” drill before reaming with a ¼” reamer.

The remainder of the session was spent adjusting the belts of the milling machine to reduce speed for boring and a start made on the first cylinder bore. However at the beginning of the next session I will make a plug of the correct size to use as a set standard for all four bores. Whilst each cylinder liner can be ‘adjusted’ to suit I would like to get them as near as possible to the correct size so I can produce the 8 cylinder liners as a batch. After all I should seek to increase my engineering skills, and accuracy is a measure of progress is it not.

Overall a good session with the many checks proving of worth, even if there was not a great deal of swarf made!

Today I managed to finish turning the second camshaft as can be seen in the photo below although I have yet to complete cleaning up the camshaft. It is only held in the chuck to allow it to be filed and sanded. It is not unsupported for turning, just using the Myford as a very expensive vice!

The second camshaft took a lot less time than the first, but I did annoyingly catch one of the lobes with a nick. I blame SWMBO who came in at a very inopportune time! I managed to keep my muttering under my breath until she left. Then I said a loud tut tut. Fortunately most of the mark was removed with further cutting but part of it is still there, and I know its still there!

Hopefully tomorrow will see an end to cam cutting for a little while, although I still have one more to make. At least I now have a pair of camshafts and that should allow me to tackle the main castingsnext , namely the cylinder blocks. Anyway here is the photo of the latest camshaft, half way through tidying up.