NER EE-1

[cabbage]

Well I have spent most of this morning sawing slices of aluminium U section and sticking squares of QTC to them. The main problem with the QTC is the fact that CA is an insulator... So, what I have had to do is delicately place them on the U section and before CA'ing them into position by dripping it around the edges I put a piece of "hook up wire" between the QTC and the aluminium. This air gap has ensured a good electrical contact(!)



There now needs to be some "delicate calibration" with a pin hammer and a 12 inch vice to make the moving part of the assembly just the right fit for the eccentric...

Once all this is done I then have the problem of getting the body to fit "nicely" over the chassis. I know it does fit -but parts of it have shifted from "true" and will have to be "persuaded" with a mouse sander and a Dremel to meet exactly as required!!!

regards

ralph

[cabbage]

I don't know how other people do it -but this is how I do it... Armed with a fresh tin of grey cellulose primer and a large expense of newspaper I rattle my tin for 2 minutes and then start puffing greyness over it. It is actually quite a satisfying experience. All the odd off cuts, bits of black or white ABS, balsa, brass steel washers (and the squadron green putty!) et all all disappear leaving a smooth (hopefully) grey shape. This then "cooks" for an hour under a couple of angle poise lamps armed with 60W heat bulbs. After a couple more coats I am happy.

The fitting session went as well as could be expected armed with my Korashu saw and a Dremel grinder I fettled the fit until it all slid on and off beautifully. I had doubts when I first tried a Korashu saw as I had never seen anything like it -it looks a small dagger with teeth. But after a few trials with it I have found it to be almost indispensable for wood work. They are after all used by Japanese wood workers for fine cuts -it leaves an almost "polished" cut.

This is what the grey primer body looks like fitted to the chassis.





Only one of the pantographs is functioning at the moment due to a "slight accident" by my son... Replacement parts are on order.

regards

ralph

[cabbage]

Well it has been a little like Christmas here over the past few days... I now have a complete set of gears for my loco and I have been able to try the one thing that I have waited for for over a year -to make a Bull gear!!! I have had the roller race bearing for over a month and the 22 mm plumbing fittings since the new year. I am very happy and relieved to say that everything has gone together perfectly in the first test assembly. (Honestly!)

The assembly procedure goes like this.

Cut a strip of 0.5 mm  ABS sheet 10 mm wide and wrap that around the boss of the 100 tooth gear. Lower the pipe fitting over the abs strip and whack it with a mallet... This ensures a perfect compression fit. Now wrap one layer of PTFE plumbing tape around the 22 mm  fitting and slide over the 25 mm internal dia roller race. What you now have is half a tube axle. It moves whizzingly around if given a finger flick -so I don't think that there is that much friction.

The next step is to drill the spider holes in the bull gear and tap them to 3 mm. I know that it would be far simpler and quicker to just drill 3 mm holes and double nut the 3 mm bolts -but it stops the torque of the Quill Drive from undoing one side of the double nut. Knowing Murphy's Law -this will be the side that it is hard to get at!!!

It may be me -but I think this could be the only Quill drive that I ever make...

regards

ralph

[cabbage]

Well another wonderfully rainy evening means more play time in the shed!!! The shot below should really be on the entry above -but I ran out of battery power (Lithiums go flat too).



The next two shots show the prototype of the Quill Drive. My version of it anyway... Rather than use Compressive springs I have opted to use Tensile springs. This has several advantages -not least that I do not have to fabricate 72 sets of spring cups... So, there are six tensile springs from the bull gear to the junctions of the tridents. The tensile springs will help stabilize the snowflake wheel.



The snowflake wheel can float vertically +/- 3mm in its tube axle -or swivel +/- 5 degrees.



I wrote above that the spine with its articulated backbone flexibility was "just plain weird" after having played with the home brew Quill Drive -it not only makes perfect sense -it is also vital!!!

regards

ralph

[cabbage]

Do you ever ask yourself -"Why do I do it that way?" I have a design habit that I use "Switch to Earth" rather than "Switch to Power". As I have written above I am having the problem that I cannot "get at" the solder tags at the back of the 2 end modules. I now have a tag that has 8 Earth connections to it... I am a firm believer in the principle of "Star Earthing", and as you will have gathered -this is how my model is wired. Normally there are just 3 or 4 connections to the Star point -but I have yet to wire in the PWAM or the lights.

I am nearly at the point where I will have to solder in an Earthing Bar to cope with the amount of connections that will be required...

I am also becoming rather concerned about the amount of waste heat that will be blown around by the motors when running. Granted that the motors have built in fans and I can stick together some ABS sheet to make some ducting from the exhaust ports of the motors -each motor is going to put 36 Watts of heat into my plastic bodied model. The sum heat is about the same as a set of curling tongs...

regards

ralph

[cabbage]

Well after another glorious summers day (of rain) and a slight amount of burn creme... I hereby present the world with the wired chassis of my loco!!! Well the control and lights side of it anyway.



The IR "key" that will unlock the power side is yet to be installed (AKA anti small inquisitive fingers device) but the parts for the modulator are in drawer waiting for "iron time".

The next task on the list is to machine up the wheels for the bogies and fit the ball races to them. THEN and only THEN will I be able to test if my maths has worked with respect to the QTC and the unlock/locking of the bogie arms...

regards

ralph

[cabbage]

The weekend's work has stopped and I am happy with the progress made -I have a bogie! The shot below shows on the left the painted and sanded wheel with its 2 ball races and one of the collets. On the right is an assembled wheel with its axles (a 6mm dia length of silver steel bar). The whole thing went together quite easily -bar the usual one of sliding the bearings to the right position and using "Green" sleeve retaining compound on them...



The next shot shows the rough assembled bogie on a length of track. You have to give it a push up and down to see how it rolls... I have tried it on my 2 curves, 7.5 feet and 11 feet radius, and it scoots along quite happily. The fact that the wheels are independant of each other means that it can take tighter corners a lot easier than a solid axle. (It also moves as smooth as silk!!!)



The last shot shows the rough assembled bogie in its position under the loco. The damaged finger IS mine -the injury is from passing down my sons skate board from its hook in the hall...



regards

ralph

[cabbage]

Well after a suitable break (to do some domestic chores) I have returned to building my loco.

The shot below shows the initial assembly of the spine



The roller bearing sit in wood pillows (made from the remains of my last shipment of rail) and the sequence of assembly (right to left) should be obvious. Hopefully before the weekend is over I should have a rolling assembly!

This is the experimental gearbox...



Yes I will admit to "borrowing" some of my son's Meccanno -but he will get it back. What I have worried about is that fact that the motor may be a little bit too powerful for the loco. It has been tested by laying the output gears across the bull gear and watching the drivers go around. Even at only 6 Volts they are whizzing merrily around...

regards

ralph

[cabbage]

I have been very busy, not that you would notice much!!! The spine with its collection of bits has been completed.



Both bogies now have wheels, with sprung axles. The mock leaf spring covers for the coil springs have yet to to be fabricated. The rolling resistance of the chassis on its bogies is unearthly... I can push the chassis along with a feather. The next shot shows the chassis and body "plonked" on top of the spine. The M3 set screws stop the chassis from sitting correctly on the spine -these will be replaced by grubs during final assembly.



regards

ralph

[cabbage]

I have traction!!! The shot below shows the "production prototype" gearbox.



Yes, I know it is made from scraps of ABS sheet and balsa, but the point is -that it actually works... I assembled it from my drawings and simply expected to use it to check for "fit" and then "fettle" the gearbox to shape with a pair of kitchen scissors. However since it was just "junk" I had to see what happened when I applied power. If it tore itself to pieces inside a few seconds -then this was expected. It went around and the loco moved -if somewhat slowly. I knew that it was very free moving, but to be totally honest, I would never have expected 20Kg of loco to be propelled at circa 1cm per second by an almost dead AAA NiMH...

So, what it will be like with two fully charged 6Volt SLAs giving it 4.5Ah at 12Volts could be -electrifying(!) There will be two motors powering it, one either end of the spine. The next step is to machine the gearbox out of the 0.6cm polycarb sheet and screw it together. The tension on the bull gear will be maintained by dynamically mounting the gearbox to the same pivot point as the pillow and then forcing it into contact with tensile springs.

This will enable the gearbox to move with the spine as it flexes and shifts when the loco corners.

regards

ralph

[Gauge3er]

Sounds like it's going to be able to pull everything out of the yard, including the tracks!

[cabbage]

Well after another Friday in the shed (tomorrow, Sunday and Monday I have been "told" I have to do the Summer House).

The polycarb gearbox!



The sides are CA'ed together and then re-enforced with 3mm setscrews into M3 tapped holes. Polycarb is not hard to work with just completely VILE....

This is the A and B gearboxes placed into position. The central gearbox is still in the aether stage. (Once everything is in position I will know how much space I have got!)



regards

ralph

[cabbage]

Well you may ask yourself -so what has he been doing with it -the answer I am afraid to to say -is not a lot!!! Work in my business is seasonal and I have had domestic priorities to deal with -and re-build my wifes summer house...

But while I have not been playing with my locos I have been busy with the speed control system. While doing my researches for the Technical Manual -I stumbled across the american company called "Dimension Engineering". They produce a series of controllers that (quite frankly) were never ever designed to run locos -but they are just perfect for the job. The two that are suitable are the Syren 10 and Syren 25 controllers. They have an on-board CPU and it can be controlled by an external CPU. In the UK they are expensive at £54, when I commented that I liked it, an american collegue commented that; "For $75 it had better be" -then I told him the UK price....

It operates in a number of "modes" from simple variable resisitor, (great for testing), to a digital serial input, (great for me!).



The device is about 70mm sq (the smaller Syren 10 lacks the big heat sinks).

When everything is finalized I will use a PIC 16 series CPU programmed in the FORTH programming language, (yes I am that type of geek....) But, while I am developing a feeling for what I can do with it I am simply messing about with a BASIC Stamp 2 CPU board. This is a cheap card populated with stuff from e-Bay -I think I spent nearly a fiver on it(?) I think the hardest thing to get was the PP3 battery, (I had to "persuade" my son to let Daddy have the last one from the family stock). The "chip" uses a PIC 16 series with an on board BASIC interpreter -it takes a massive 49 lines of code. (Remember that the Apollo Lunar Lander Computer took 14 lines of code???).



The breadboard on the left is about the size of a floppy, the blue socket is for the BASIC Stamp 2 "chip". Hiding behind the PP3 is most important button in the world -the reset!!! Each of the pins from the "chip" has a blocking resistor for "oops!" events -there are 16 of them.

I admit that I am simply playing at the moment!!! I have it raising the pantographs at startup then whistling three times. When the R/C signals fwds; it whistles twice, the lights then change to the correct code, and then the acc loop ramps it up to speed. The R/C signals slow down it dec loop slows it down, (the inertia is used to re-charge the batteries!), it stops, whistles three times. If the R/C signals reverse the lights change ends, it whistles long once. It whistles twice and then it moves off.

It is all absolutely ridiculous, (and I love it)!!!

regards

ralph

[cabbage]

Despite the fact that blood has been constantly pouring everywhere -I have been busy(!) I gashed the end of my ring finger and it has been very messy for the past two days. I finished painting the base coats of Saxony Green and Gloss Black over the body work.



The second pantograph has been repaired after its contact with my sons' Frisbee (don't ask). I have altered the method that I was going to use to hold the pantograph arms aloft. Previously I was going to use my "standard" method of dynamically bending coil springs -but a few high speed tests show that this method is fine for speeds below 1.5m S-1 thereafter it starts skipping.... So. I have gone back to basics and produced a polyharmonic system using three springs. All springs resonate at certain frequencies, thus if you get a spring tensioned to resonate at 5Hz and then tune 2 others to absorb at 5Hz -the result is perfect stability!!!



The last thing to be installed prior to power trials is the Syren25, This is sitting nicely underneath its little cover -where the power resistors would have sat in the original. It too is cooled by a fan drawing air over the fins -as was the original. In fact this little circuit board almost duplicates all the functions of the original system -it also regeneratively brakes the loco.



Everything is progressing well and it is on course to doing a quick trip to the test track (up and down the hall!!!)

regards

ralph

[IanT]

Well you've certainly been busy Ralph - and I suspect the photo doesn't put across the true size of this model. I hope you are going to bring her along to the AGM so we can have a closer look. I'd also be interested in more detail about the control electronics.

Regards,

IanT