NER EE-1

[cabbage]

Well end of another Sunday at the saw... The following shot shows around 95% of the steel work for the loco. This is without a doubt the heaviest thing that I have ever built!!!



You instantly know the models that you cheerfully lug around to "shows and open days" -and those that you don't. This one is one that will rarely leave home. I have calculated an, "all up weight", of 10.3Kg -which is on the border line for one person to "rail" easily(?)

regards

ralph

[cabbage]

Domestic (and other) things have meant that there has been little time for me to play in my shed. However at the end of the week I am not displeased with the couple of evening that I have had "free"... In my by-line I write that "Everything I build was real -unfortunately..." and this part of it -is just that. Certain parts of this loco do make sense, some parts of it do not make sense, and some parts of it are simply weird.

This is one of the weird parts.

The part in the picture below I call "The Spine". It functions as the main gearbox and motor base and from this all the drive is transmitted to the wheels. It has a central steel plate with two arms from it. Silver soldered in to the central plate are two M6 greenhouse bolts with two stubs of M6 threaded bar beneath them. Silver soldered into each piece are two M3 bolts which hold the section of 20mm aluminium U section which forms the base of the gearbox.



Turning over The Spine reveals its secret. The Spine is actually a differential articulated joint. Thus during the action of cornering, it moves the central axle across the chassis.



The Spine as actually sat on one of the gears that will form the tubular "bull gear" and you can see one of the 3mm bolts that will be used to transfer power from the gear to the drive wheels via the springs.

But the most important thing that I have done this week is "square" the wheels... During the construction of the snowflake wheel (ie being heated, quenched etc) the wheels have distorted to a slight (but to me) very noticeable amount. So -quite a lot of the evening work has been spent with a "surface" (which I "inherited") and -a hammer... Having got the wheel "suitably persuaded", I then had to re-bore the axle hole in each wheel to "true". This involved putting the wheel onto an 8mm silver steel bar in the 3 jaw chuck of the lathe and gently flicking it round to see what the wobble was. Eventually at the 9mm point I could guarantee a "normal" shaft to my wheel. I now have to sleeve my bores back to 8mm, (I will just sweat in some 9mm K&S brass tube).

The next thing to do is to start building the horns and guides. I favor the "sandwich" technique rather than milling them from a solid block. My axle boxes may be slightly larger than required -but they hold a lot of grease!!!

regards

ralph

[cabbage]

I had to try something... I am glad to say that it has worked!!! One of the main problems that I have had is "How DO I fix the wheels to the axles???" The classical method of cutting a slot and ramming a tapered "key" into it only really works when you can "get at" the wheel axle interface... So, armed with my latest toy (I have finally got a compound slide -I have only been waiting 5 months for it....) I cut a 20 Degree taper on the central hub of each wheel. Then having done so I then clamped the wheel in a rotary table and elevated it to 70 Degrees. Now the taper on the hub was parallel to the bench(!) Delicate work with a 1mm then 2.5mm drill in a pillar drill (I broke three 1mm drills...) gave me an inclined hole. This hole I intend to tap to M3 -once I can find/ beg/ steal/ borrow a long Tee tap. All the Bar taps I have will turn the tap ONCE and then the arms clash with the wheel rim...

Anyway, once I have an M3 tapped hole I can then screw in an M3 Allen grub screw -this will crush the brass tube on the inside of the wheel hub and thus grip the axle very firmly.

regards

ralph

[cabbage]

Well after several evening of extreme metal dandruff... My late father often said "you have to go into some bad houses before you know you are home" and I always knew exactly what he meant. I have been turning my drivers (I have done all six) and I have started on my bogies (I have done three out of the eight). However this was not done without the development of a complete new dictionary of "words" to explain my exasperation at certain things. One of the things I have are "indexable replacement tip" lathe tools, this means when they go blunt it is a two minute job with a torx driver to turn the tip round and then carry on. And this is what I have been happily doing! But, they are not as "long" as the old tool steel tools... The shot below shows the problem. I had to saw bolts and grind them square in order to get the tool close enough to the wheel to actually cut anything. Then the face plate clashed against the traverse etc etc etc(!)

)

But in the end things prevailed and I cut my treads and flanges easily. (I don't know whether the threat to take the whole lot out into the garden and smash it to shards with a sledge hammer helped -but it did seem to co-operate after that).

Here is a very fuzzy shot of two completed driver wheels with an M10 nut and bolt for an axle.



Normally my camera work is better than this -blame the diabetic clinic for the fact that I could not focus for several hours after having my retinas photographed!!!

regards

ralph

[cabbage]

Another successful afternoon in the shed!!! All the Bogie wheels are now cut, and I have been assembling my horn blocks and guides. I don't use the technique on milling a slot in a block of brass -what I use is normally referred to as "the sandwich method". I have had my mill and lathe less than a year so I am still learning on them. However I can make sandwiches with the best of them.

The sandwich method uses three sheets of brass, two wider sections and a smaller inner section



Torch the ends with some silver solder and it never comes apart...

Once the hornblocks are finished and the semi-decorative axle boxes are fitted to them (they may be made of aluminium channel and platikard -but do hold grease).

regards

ralph

[cabbage]

Well now that I am safely back in the UK, and after a family week end at Barrow Hill Roundhouse...

I have begun assembly of the various modules that will lock together to complete the model. I knew right from the start that this was going to be one of those where it "all came together" right at the end -but the end is still some months away! I have cut and made the grease boxes for the bogie axles to run in. These are as I have said simply off cuts of aluminium channel. The bogie axles do not actually rotate the wheels sit on double ball bearings and are thus free to rotate independent of the axle. I am going to have a go at building leaf springs for it, these will probably turn out to be more decorative than functional -so I will "graft" a torsion bar to the back of the axle.

The spine has been test fitted to the chassis rails. This is held in position via four transverse bolts to a "union" (another piece of aluminium channel) which holds the vertical bolts from the spine. The union has ground down square nuts bonded to the sides -while the vertical bolts are held in place by the compression of the lateral threads. There will be a nut and washer providing the final vertical security and "fine tuning" to the position of the spine. Once that is in place it will get pumped full of epoxy putty and thus will give me a rigid mount.

I would have provided you with a few pictures but my camera is not feeling well after having been drowned in Diet Pepsi and TicTacs fountain. My son decided to take a photo that was just a little bit too close....

regards

ralph

[cabbage]

I now have one set of bogie axles(!) After suitable persuasion with a "cloth and hide", I had a length of 6mm steel bar that was straight. I duly chopped it up with a hacksaw and squared off the ends in the lathe. These axles do not rotate, but simply act as the carriers for the wheels -which sit in a double ball race.



However turning down the ends to 4mm for the first 10mm each side was good practice for the main event -the driver axles.

regards

ralph

[cabbage]

Well now that I have axles with journals on them I suppose I had better explain the process of making a grease box. This is based, (of course!), on Rhodesia Railways practice... I seal up the bottom of the Aluminium channel with some balsa then using a cotton bud mix up up some 2 hour epoxy and swab the entire inside of the thing with it. This gives me a "tanked" seal. Into the chamber thus formed I cut some felt into ribbons and dollop Castrol LM onto it. A small amount of "Milliput" seals the top of the grease box. In the morning after, "a night on the cooker", it is rock hard, and the grease has now been sopped up by the felt. The Milliput can now be ground flat and drilled for the spring mount.

I have drilled and fitted the horn stops for the bogie sides and I now have to fabricate the "leaf springs" that will disguise the coil spring hidden within them. I will admit that I have never been very good at this and on my first G3 loco simply gave up after having broken three in a row trying to make them out of lengths of ABS. This time I will use an L shaped section of brass strip with lengths of brass rod down to the 3mm loop connectors that fix the horn stops in position. The coil spring will sit between that and the top of the grease box and the false leaf spring will sit in front of it.

(This Time -It Is Going To Work)....

regards

ralph

[cabbage]

Well the Bank Holiday weekend is here! and in the glorious sprng sunshine -I have spent most of it in the shed... However while the rest of the family were "slipping, slopping and slapping" as the saying goes, I was torching away merrily. I have in the past two days used nearly 3 lengths of silver solder and lost my "cool" in the heat of the forge. The first thing that I set out to solder together was the bogie "saddles" as these are really the most important things in the contruction of the loco (honestly!). The lateral piece of angle iron was duly bolted to the piece of 3mm plate and the torch lit. The main problem with this piece was that the only real way that it wanted to "sit" was upside down. So I clamped it in the vice and cooked it and its companion. Once they had been cooled and pickled, it was out with the wire brush and on to the next stage. This involved soldering square nuts to the corners of the angle iron . So after having polished up the nut and the area of angle iron that it would sit on -it was again out with the torch. I had to use a lower melting point solder for the nuts because if I had used the same temperature as the solder -it would have come apart... At the end of two hours of work I had two saddles that were clean enough to pose for a photo. The saddles are held to the sides of the bogie frames by M6 Allen bolts



The frames were the next victim of the torch... I had planned how I was going to do this some time ago -but as the saying goes "no plan survives first contact with the enemy". I had designed in the slots were the L shaped clamps would bolt through and then G clamps would hold the frame fast to the piece of  firebrick. Well after some bench work -I had to move EVERYTHING off my work bench inorder to have enough room for the frames, I did solder the joint. However you can tell where the "nose" of the G cramp was -there is a definate "dab" mark!!! I did bothe ends then hit the next snag. Although the designed in slots had worked well  I now had to hold one frame side 9cm in the fresh air while I soldered one end and then the other. This was done by a carefully sawn piece of 3x3 screwed through the slots. and I am very relieved to say that it worked perfectly.



In the previous shot You can see that the two "trays" that hold the batteries and associated electro mechanicals have been bolted on through the slots. The L/H tray contains the power control side of the loco while the R/H has the lights and direction control system.  (Note the large relay marked STOP). You may just make out the stub of the bogie arm poking out from the rear of the tray. The arm is fixed at this point and moves across the bogie between the main chassis frames. It is the movement of this arm that will squeeze the Quantumn Tunnelling Composite and thus tell the loco that the front bogie has begun to turn into a curve. This will lower the resistance of the QTC and thus allow enough current through the relay to close it -powering up the solenoid to lift the mousetrap bar.

regards

ralph

[cabbage]

I am beginning to hate springs... I had worked out all the Trig and the Hookes Law calculations so the the springs sat perfectly in their stretched length and the forces on them were all correct. Then the manufacturer decides that they are not going to make any more of this value... Thus I have SOME of the springs that I need for the loco -the others I am going to have to scour the web for. Anyway I have enough of the correct value to "float" the bogie arm and bogie (minus wheels) in 3 Space. Thus only the weight of the wheels holds the bogies onto the track -the rest of the weight of the loco is available for traction. The flanges on the bogie wheels will pull the frame across thus transferring some sideways torque to the chassis frames. This SHOULD force the central driver axle away from the centre of the cuve thus angling to two outer axles towards the centre of the curve.



Here you see the bogie arm suspended in 3 Space by the four tensile springs. The mounting point for the connecting point is not central as when the arm moves across in its arc the line between two sets of opposing springs becomes straight and they then provide no real effort anymore. The offset from the "true" is such that the steering effect of the bogie will only be effective in curves of greater radius than 1.50m ( roughly 5 feet).

regards

ralph

[cabbage]

Well at last "the postman" has delivered something.... I know the I am on the final push to complete something when I tick off the days for my orders to arrive(!) Anyway, the first installment of gears has arrived with some of the ball races for the gearbox, and all six of the 25mm bore needle rollers for the bull gears. So, I now have three sets of nylon reduction gears in a fetching shade of red -which will have to rubbed down and painted black. The same thing will have to be done to main power gears -except they are white!!!

The next set of gears and bearings are for the bull gear and the bogies.

One of the things I am still unsure of is what to make my gearbox faces out of. I would like to use Aluminium for lightness and ease of machining -but is it too flexible in the thicknesses that I can get it?. Brass would make a lot of the work quite easy, as well as looking nice -but the price is quite high. Steel is dirt cheap -but it would be the hardest to work...

Time for me to get to bed!

regards

ralph

[cabbage]

"In the clear bright light of a young morning...." Enough of the lyrics -to work! The shot below shows the arrangement of the gears.

The motor is above (obviously!)
Step one is 20:40 -this clears the side of the motor.
Step two is 10:30 -the 30 gear providing drive to the two 16 tooth gears.
Step thee is 16:100 -the 100 tooth gear is of course the Bull Gear.



regards

ralph

[cabbage]

The best thing about enamel is that you can use it in the evening and by morning -it will have set. I normally use Hammerite (in this case Smoothrite!) for my metal work. I am now in the position that all of my chassis components are now painted with two coats -and three where it will take the most hammer...

The shot below shows the chassis with the two bogie side plates and the connecting saddle. The "spine" can be seen bent to its limits, (for illustration), in the centre of the chassis frames.



This is the chassis inverted. Clearly visible is the differential connection to the two arms of the spine. Also visible are the three sections of U channel that will form the mounts for the three gearboxes. The spine transmits the thrust through the two 8mm bolts that it is suspended from to the four 6mm bolts with captive nuts that pass through the two sides of the chassis rails. The bogie axle boxes with their "sandwich" horn blocks are easy to see in this shot.



The bogie sides are sprung and compensate in a manner that would warm the heart of one I.Driver Esq...

The last shot is perhaps the most interesting, (for me). I like for some reason to have my buffer beams made of wood and as normal the buffers are sprung. It was suggested that the draw hook should be sprung as well -so I tried it... I have to admit that I like the effect. My test traction piece, (a tin of nails and a length of string), did seem to want to move more easily with the sprung hook -so I think that this is method that I will employ for this and future locos.



regards

ralph

[cabbage]

Well a couple of weeks have passed since the last entry -this has to do with having to tend to my garden... But thanks to severe weather I have been able to spend the odd evening in my shed(!) What I have been slowly building is the "mouse trap" arrangement for the bogies. The patent taken out by Sir Vincent Raven has been applied here -but in a more modest form. The original patent described a longitudinal locking bar that held the rear bogie in place while the front was free to move. This works fine until you have to take the VERY sharp curves that I have...



I modified the patent bar into a mousetrap that held a bar that the bogie swung on. This "amplified" the bogie movement into something that I could electrically "measure".



The Quantumn Tunneling Composite (QTC) varies its resistence between 1.0M Ohms to 50 Ohms at 1Kg pressure. This gives me a 6 Volt Relay fed from a 12 Volt source that would not close until 0.3Kg of force was squeezing the QTC. Whether this would be useful in anyone else's model I have no idea -but you are welcome to use it.

The next shot shows the mouse trap bar closed on the bogie bar (the reed magnet is at end of the bogie bar).



The next shot shows the bar has lifted and the solenoid is the right of the arm -with the return spring on the left side of the arm.



The next step is to wire up the reed that will provide the "earth" connection to the relay. Once the magnet has moved away from the reed the circuit opens, the solenoid drops, and when the bogie arm returns to the straight section of track the mousetrap captures it and the system resets.



regards

ralph

[cabbage]

The shot below shows the mousetrap bar and the bogie arm with its magnet CA'ed to it. Above the magnet is the suitably angled reed switch again CA'ed to a off cut of 5mm sq pine the position of the reed is such that it cuts "off" when the bogie arm is 2mm out side of the gap in the mousetrap bar -thus the solenoid holds the bar "up" while it moves across.



Looking at the close up shot -reminds me to touch up the paintwork -when I am finished!!! The next thing on the agenda to build is the QTC cramp -early test systems resembled something out of "The Inquisition" -but I think I am finally on the right track. The early designs had it squeeze only one side -the one I am playing with at the moment is a "U" shaped frame that slides across the eccentric and thus the QTC is squeezed from both sides. This seems to give a more "repeatable" point of deflection than simply squeezing it from one side. This should enable me to accurately position the QTC and compress it so that it can detect curves great than 13 feet radius. This is the curve rate at which the bogies would have to unlock for cornering. Wider than this there would be no requirement.

regards

ralph