Member postings for Four stroke Fred

It's surprising what a coat of paint does to a model! Only a few small bits to make and then have to "time" the cam shafts and ignition on the engine. With a bit of luck the engine should be going in the not too distant future and when it does the video camera will be at the ready to record the moment. It's taken about three years of work, drawn over 260 sheets of drawings and had a great time doing it. Next model will probably be the 67 cc "V" 8 which I started some time ago - did the main castings but then managed to get side tracked on the tractor.

George.

Not so much "what have I been doing today" but what I have been doing over the last ten days. Having stripped, cleaned and painted all the bits of the tractor I have now assembled it. There are still a few small jobs to do such as making the plug caps, fuel taps, the external oil tank (fits in part of the box) and I still have to time the cam shafts and ignition. After three years the end is now in sight.I hope there are not too many problems in getting the engine to run and when it does I will have the video camera at hand to record the historic event!

George.

The model has now been painted with the exception of the engine as this will be dealt with as a separate unit. It's a bit demoralising when one has to take a model apart to clean and paint each of the many parts! I used an etch primer and then had the green and red paints mixed to match the colour in the photographs. The paint proved to be the most costly part of the model but having spent that amount of time on construction it was worth it. The engine still requires piston rings to be made and then it will be stripped, washed and reassembled with all the timing set. I do expect there will be some teething problems and I am a little concerned that the compression will be low ( due to the shape of the combustion chamber). After about three years I am looking forward to finishing the model.

George.

Yesterday I stripped the Saunderson & Mills tractor ready to paint and today I did make a start. Fortunately the humidity was down and the air was quite still. As I don't have a spray painting bay the painted parts were hung out to dry on an improvised "washing line" and some were left to dry on o plank of wood. All was going well until a cheeky Willie Wagtail decided the painted back axle would make a good perch!

I did a colour match from the photographs and had the paint mixed at a local car spares retail outlet - it cost $37 per can and I will have to get two more tomorrow! It's amazing what difference a coat of paint makes and I am looking forward to seeing the assembled the chassis. I still have some work to complete on the engine but will do that while the chassis paint cures.

George.

I have now reached the stage of making all the small details relating to the governor,carburettor and ignition system. The magneto is a "dummy" as it houses the Hall effect transistor and trigger mechanism. The aluminium part on the vertical shaft has now been replaced with a distributor that has been made from an insulating material. It is difficult to scale the sparks as they are prone to jump to the nearest metallic part! The link from the governor to the throttle still has to be made. The longer of the two levers controls the advance / retard and the other is attached to the governor/ throttle.

George. P

Today I finished making the magneto for the Saunderson & Mills tractor. It is actually a dummy as the the innards work a Hall effect transistor but it does have an advance and retard worked by a lever. The body is cast in aluminium and the horizontal shaft runs in two small ball races and carries the slotted disc to "drive" the transistor.The lever is connected to the governor control via cone clutches. This allows both the lever to the governor and the ignition to be moved together and independently. The drive to the magneto is taken by bevel gears from the vertical shaft and now runs at engine speed.

George.

Good Day HobbyNut,

The Lister con rod looks good as does the rest of the engine. Keep up the good work.

George.

Today I have been working on the drive to the magneto and distributor of the Saunderson & Mills tractor. This area also contains the governor and all the controls - still some work to do as they all have to line up and work. The two levers are for the advance / retard and governor and are linked with friction clutches with spring pressure. The photo looks as though the engine has been painted with a hammer finish paint. This is the effect of taking a photo quite late in the afternoon light! It looks as though the project is near the end but it will take quite some time to detail all the parts, have the engine running and then paint the model. I hope to complete the tractor by Christmas.

George.

What did I do today?. I have been working on the carburettor for the tractor and decided to make the float from a plastic. It was made like an inverted thimble with a pressed on base and a thin walled aluminium tube through the centre all being held together with Loctite .The total weight was 2 grms. The first test in water saw it float with about 3mm above the water level. Next try it in petrol - Oh dear it went straight to the bottom of the test tank - all to do with density! I have now decided to use the "chicken feed" system using 3/32" copper tube from a fridge for both petrol and air pipes. At least the day was not wasted as I made up the float chamber and feed. This unit is fabricated from nine parts silver soldered together. Back in the shed tomorrow to finish the carburettor unit.

George.

Jason what a great collection of castings for the IC engine must have been your lucky day. This weekend I have been making the carburettor for the tractor. It's not the usual type of carby as it has a built in "snifter' valve, a heater to vaporise the paraffin ( a dummy on the model) and throttle vane. I have yet to make the float chamber and float and then attach it to the main body. Both manifolds will have to be given the treatment to make them look like castings - a case of elbow grease and emery cloth! The left hand side of the engine will be quite busy as it has yet to have the points,distributor and magneto fitted. As it has been raining all day and the workshop has been the best place to be. We need the rain as most of Queensland had been drought declared and also I have just planted up the veg garden.

George.

Yesterday I made and fitted the I exhaust manifold and silencer to the engine of the Saunderson & Mills tractor.This has started to fill in some of the gaps around the engine and makes it more interesting to look at . Today I used the CAD drawing program to design the inlet manifold and carburettor. This is quite a complex unit and it has to line up with both the governor, exhaust manifold and control systems. I intend to first make this unit out of wood to check that it will line up as some of the clearances are small. Looks like another busy day tomorrow!

George.. Today I

This week the clutch has been made and fitted to the tractor. There is still some work to be done including adding the friction material to the face of the cone clutch. The bracket on the side of the chassis rail is fabricated from eight pieces of steel silver soldered together.. The flywheel,cone clutch and pulley are made from cast iron with the view that the weight will encourage a slow running engine.

At last I have managed to get both words and picture on the same page- wonders will never cease!!

George

1. This week I have made and fitted the cone clutch. The flywheel,clutch plate and the pulley are all made from cast iron and the contact faces of the clutch have yet to be faced with friction material. I intend to try cork but have the option of the type of material used in car clutches as an option. The clutch is attached to the pulley and as pressure is applied to the clutch pedal and a series of levers, pressure pads push the pulley out causing the clutch to disengage. The clutch will be very much "on" or "off" as there is very little movement between engage or disengage. There is still some machining to be carried out on the pulley. The bracket on the side of the frame is fabricated and made from eight pieces of steel silver soldered together!
2. George.
4. 

Good Day Jason,

Just had a look at the video of your I.C. engine. It looks and runs beautifully - congratulations on a job well done. What I the capacity is it ? Did you have access to the original full size engine and what did you do in the way of castings.

George.

Had a good day today as I ran FAB 2, the all fabricated 15cc engine, and also started to machine the cast iron flywheel for the tractor. As it is winter here in Australia the cold start (7C) to the mornings reminds of my workshop in the UK (Newhaven). Cold metal,cold chucks and cold fingers! I still have problems adding photographs to forum -can get photograph or typed script but have difficulty with both. Must be a combination of thickness and age!

George Punter,

Bundaberg.

Edited By Four stroke Fred on 21/07/2014 10:18:16

What have I been doing ,not so much today but over the last couple of weeks while waiting for the flywheel of the Saunderson and Mills tractor to be cast in iron. The photo shows the results of my efforts ( if it's not on here look at the album). It is a 15cc OHV air cooled engine designed for the beginner or school student. It does not use any castings and all the materials can obtained from local suppliers . A commercial carby is being used for tests but will later be replaced. The tube which acts as a sump for the crankshaft is also used to keep both vertical plates in the correct position when being assembled. The gears are module 1 and are 20/40 teeth. The ignition is by coil and points (ex lawn mower) and the engine has a single cam that operates in exhaust valve ,the inlet being automatic. Tomorrow I will finalise the drawings and fire it up for the first time.

George.

Edited By JasonB on 13/07/2014 10:21:37

Oops for "cod rod" read connecting rod - some thing to do with big fingers on small keyboard.We may have lost the footy but the sky is still blue and the sun shines. Spent part of the day coming to terms with Windows 8.1 on the new computer.

George

Mid winter and today it was 26C high and 13C at night. Still wearing shorts and short sleeved shirt in the workshop that's why I love living in Queensland. Had a good day in the workshop, cast the two pistons for the model tractor and fitted the cod rods. Next step is the manifold systems and I governor . Plenty to think about and plenty to do!

George.

Having had a good couple of days in the workshop "we" decided it would be a good idea to take some time off and have a picnic up in the mountains - part of the Great Divide. Drove 120 Klms inland to the old mining town of Mount Perry. Great weather, great views and a great day. Back in the shed tomorrow finishing the tappets for the tractor.

As regards to the bees , a friend of mine lost 106 of 130 hives in last years floods in Queensland. The water came up so quick that the bees drowned.

George.

Edited By JasonB on 25/05/2014 12:31:28