Page C3 March 1936 NEWNES PRACTICAL MECHANICS 332
The Problems Solved for You
In the design here presented the problems have been solved for you. Our £20 car complies with all of the legal requirements, and it is technically sound. Inlater articles dealing with its construction I shall show you photographs of the various stages, and photographs of the car under test. Additionally, we shall sell detailed blueprints and an anouncement will be made when they are ready. All of the constructional details, however, including dimensioned drawings will be given in this series, thus enabling the reader to build the car. The blueprints will be issued to those who are unaccustomed to laying out the various parts from scale drawings.
A Driving Licence
Another question which will arise, in the mind of the reader who is under 17 years of age (the minimum age for which a driving licence for a car-owner is issued), is whether he is entitled to drive this three-wheeler within the meaning of the Act. Anyone over 16 years of age may drive a motor cycle, so the age limit is 16 years. If you are over 17 years, you will apply for a car.driving licence in the ordinary way. If you have not held a driving licence before, it will be necessary for you to Pass the driving test; for details of this you must apply to the local County Council Offices, when a provisional driving licence will he issued to you. You will have to carry the "L " plate and be accompanied by an experienced driver. As, however, the latter can easily be accommodated pillion-passenger fashion, there is no difficulty here, although I recommend the beginner to teach himself to drive in private grounds. No doubt permission can be obtained locally for this.
Driving the Car
You will find that you will be able to drive the car within about five minutes, after you have become familiar with the operations of starting the engine, accelerating, changing gear, and braking. Actually it it's much easier to drive than a motor cycle. I shall confine my remarks this month to a general description of the design, so that the reader can collect together the necessary material. An inspection of the plan and side elevation, Figs. 1 and 2, indicate the racy lines of the body. The engine is mounted behind the driver's seat and the, gearbox, of course, behind the engine. You will require any good secondhand motorcycle engine of the type and power previously named, and a three-speed gearbox capable of transmitting the power of the selected engine. For example, you must not fit a gearbox from a 250 c.c. engine, if you are using a 350 c.c. engine, although it will be in order for you to use a gearbox which has been used in conjunction with a 350 c.c. engine on a 250 c.c. engine.
The gearbox must be of the countershaft type with an integral clutch, and later I shall show how to calculate the size of sprocket required on the rear wheel in order to obtain, the correct gear ratio. You will also require a silencer of the type fitted to 7 h.p. cars if you desire the engine to be extremely silent, otherwise the ordinary motor-cycle style of silencer will suit. I cannot, for obvious reasons, prepare designs suitable for all of the engines available, but as the only thing which is affected is the method of mounting, the reader will experience no difficulty in obviating this. The kickstarter will, of course, need to he extended by means of a piece of tube so that it protrudes outside the body. It will then he carried a starting handle, and placed under the cushion of the driving seat when the car is started. The wheels are of the light motorcycle type, having internal expanding brakes operated from a quick pedal, whilst the chassis and body consist of ash members and three-ply respectively.
The Car Controls Car
Controls are used, that is to say, there are the usual three pedals, namely (from right to left facing the front of the car), accelerator, brake, and clutch. The steering wheel is centrally disposed, since this is a monocar and not intended. for passenger carrying owing to the low power. The radiator in front is, of course, a dummy; it is made by overlaying pieces of three-ply wood and picking it out in a different colour to that of the body colour. Two doors are fitted so that entry to the driving seat can he effected from either of the near or off side. A motor-cycle sidecar hood is used, whilst the mudguards are of the motor-cycle type.These have the advantage that they move with the wheels and thus do not throw mud when locked over as does an ordinary car.
The windscreen is one of the Auster aerotype as fitted to small aeroplanes and some sidecars, whilst the steering wheel is of the Bluemel type. The tool-box, number-plate and tail-lamp are combined. Ackerman steering is used, enabling the car to be turned within a very sharp radius since the wheel base is only 5 ft. in
. The overall length being only 9 ft., the car may thus he comfortably stored in the space normally required for a cycle and sidecar. The total weight of the vehicle will be not more than 280 lb.
I have estimated that the total cost of the material will be approximately £18, and if the reader happens to strike bargains in his purchase of the various parts, it can be made for less than £10. For this particular car 1 have selected the Blackburn 350 c.c. side-valve engine, but, of course, the reader will endeavour to obtain from the sources mentioned a second-hand car engine and gearbox.
Just a word about the petrol consumption; it will work out, with a 350 c.c. engine, at 65 miles per gallon at least, whilst the oil consumption should be in the neighbourhood of 2,000 miles to the gallon. I shall, of course, be pleased to answer any questions which readers care to me provided they enclose the Query Coupon and a stamped and address ed envelope. these queries should be confined to the present design, and I make the offer so that who are able to follow the present illustrations and who wish to proceed with the work in advance of publication of the scale drawings next be able to do so.
I want make it clear, however, that I cannot, for obvious reasons, undertake to vary the design to suit individual needs. For example, some readers perhaps prefer to make a four-wheeler; 1 cannot undertake to prepare the many special diagrams which would be necessary to enable them to do so.
I shall he quite willing to advise readers regarding suitable engines, gearboxes and materials; to advise them on the lighting question and passing the driving tests. I shall also be pleased to indicate sources of supply for the various parts.
Here I would advise the reader to study the advertisement columns of papers like the Practical Motorist (3d. every Friday), particularly the Classified Advertisements. They may thus be able to pick up reliable second-hand gearboxes quite cheaply. A word of warning is necessary, however : make quite sure that any engine you purchase locally is in good condition, for it is just possible that some of the parts have been sold as spares, and the engine is therefore not complete. If the manufacture has been discontinued, you may experience difficulty obtaining replacements and they will thus have to be specially made which can be quite costly!
The Second Article on this Remarkable Car, Specially Designed for Readers of Practical Mechanics, will appear next month. Order your copy now !