Model Railway Speed World Record

[RJS1977]

Reminds me of Michael Bentine's infamous two stage fireworks rocket (he apparently loved experimenting with fireworks - so all his neighbours went on holiday in early November every year for their own safety!). Inspired by the Apollo missions, he built a two-stage rocket, such that the explosion of the first part would ignite the second and launch it even higher.

 

Unfortunately what he forgot was that firework rockets start to dip just before they explode, with the result that the second stage was not launched upwards, but downwards - straight on to the roof of the thatched cottage next door! Bentine rang the fire brigade and gave his name. The duty officer replied "No need for any further details - we've been there enough times before!"

[Stevelewis]

Amazing!

Why are there not more people like you!

I was googling last week to see if anyone had videos of doing that

When  I   was  doing  that  sort  of  thing  Video  had  not  been invented!!

 

Reel to Reel  tape  recorders  cost  around  3 times  a  weeks  wages!

 

When  I look back to  my  early model railway days  I am sometimes  amazed at  the  development that  have  been  made over  the  years

[ejstubbs]

Fastest Railroad in the World

[bertiedog]

I talked to Michael Bentine about his love of models, at several model shows, and his ideas on safety were non existent.......I did hear separately about his model rocket work, in the days in the UK when any model rockets were banned, except fireworks. My Uncle, who had worked in the war as chemist at Woolwich Arsenal, also had a strange attitude to safety with fireworks, he taught me how to make them, and developed his own display rockets in the 1950's, and knew Michael Bentine as well.

 

Michael Bentine's own tales of his exploits with all his various projects and experiences, even in his own biography, should be tempered with the fact that he loved telling a good story.

 

His wartime work has been told in different ways by Michael in books, lectures, radio shows and stage shows, and the facts rarely tie up!!! He used his strange and wonderful imagination to develop ideas for comedy that I think he came to believe had actually happened, when in fact, the real real incidents where pretty harmless.

 

It is undeniable that he was a deep eccentric of the mainly harmless type! He certainly knew about the secret war work in London, "The Funnies", as they were called, but whether he worked for the Dept is a bit debatable, as he was invalided out of the RAF during the war, due to severe complications from an inoculation, only returning to special services towards the end of the war.

 

One thing he loved was winding people up by giving them the chance to embellish what was happening.

 

He invented characters called the Bumblies for Children's television in the late 1940's, and with a puppet maker he designed a pneumatic control for these animated figures. His story is that after a few weeks on TV he got a visit from a Government Official who was aware of Bentine's war work, and asked him how the models worked.

 

Now officialdom was a deep problem to Bentine, and he refused to say how they worked, dropping hints that a secret method was used to radio control them. The official asked if it was an official secret and Bentine delighted in leaving him with the impression that a new way of radio control had been discovered and he was using it. He never claimed this too directly, the official just got that impression.

 

It all fell apart when the next week he found himself under special branch investigation, questioned by experts from Harwell, about his control method with the puppets. He delighted in finding them so intent on proving that he was using advanced radio/microwave or even nuclear control, only to show them that it was a plastic tube with a rubber camera cable release, that he blew down to make the toy figures appear to walk!!!

 

 

I do not think such rocket use as mentioned would be any good on models, keeping it stable on a track would be near impossible.

 

The use of propellers on electric motors is easy to answer, any supplier will have suitable props to match the motors. Props are difficult to design, the available types are the best to stick to, simple blades like a fan will not work efficiently.

 

Ducted fans are another area that is best left to commercial makers, the speeds involved at the fan tip edge are considerable, and require specialist plastics to stand the stresses. Metal blades are far too heavy, and would need very accurate balancing indeed, or the lot will shatter.

 

The brushless three phase(or more) Aircraft/Helicopter Electric motors are indeed AC motors, using Tesla's design of a wave magnetic field being rotated at speed, with a magnetic armature following the wave. The rotating field is generated by a DC to AC convertor, carried in the model aircraft. Such convertors have some speed control, but are designed to maximise power to the motor, running as fast as it is able to. Lower revs are possible to save power, but it is more common to turn the power off/on in bursts to give control.

 

The same convertors are used with the Ducted fan motors, which again use brushless AC motors. They are quite cheap, as they are not complex to build.

 

You can simply add more DC to the converter till you get more power thrust out, but there are limits, the bearings, heat on the coils, and balance of the rotor, all sources of failure.

 

The brushless motors depend on the cooling effect of the air from the blades to keep things under control, as Kilowatts can be used by the motor, and if stalled, can result in a melt down at high heat, destroying the coils.

 

The best source of more information on these Aircraft motors is a model aircraft shop, specialist magazines or the net.

 

The one thing these motors are not is stepper motors, which share the principles, but use the power applied in a more controllable way in DC pulses or AC signals. They are multipole coils and are designed not for speed but rotational accuracy.

 

Stephen

[RJS1977]

 

 

Michael Bentine's own tales of his exploits with all his various projects and experiences, even in his own biography, should be tempered with the fact that he loved telling a good story.

 

 

 

The two-phase firework rocket story was told by Michael's son Richard on an episode of the radio programme "Dad Made Me Laugh" some time after Michael's death (Richard also told the story of how when Michael was dying in hospital, the family received a call from Prince Charles to ask if he could come and visit Michael. Richard explained that Michael was unconscious and unlikely to wake up, but Prince Charles said he'd like to pay his respects anyway. So the following day an RAF helicopter landed at the hospital and HRH was shown to Michael's bedside. As he arrived, Michael suddenly woke up and said "Good, everybody's here now!" and started laughing and joking with the family and HRH while the doctors and nurses tried to figure out what was going on! After about half an hour, HRH looked at his watch and said he'd better be going, When he'd gone, Michael said "I'd better go as well," went to sleep and died the next morning without having woken up!)

[bertiedog]

The two stage rockets were indeed made by Michael Bentine, he also tried multi stage, which is where it went wrong in several attempts, resulting in the house roof fire mentioned, as several charges were unignited when the rocket came down under power, and fired explosively on impact.

He drove the special effects unit at the BBC on Square World to distraction, by tinkering with the theatrical charges used for smoke effects and explosions. They loved working with him, but he would "add a little more", or alter a set up without telling them, and his producer, rather than have an argument, just had the fire officers ready when the special effects were to be used, just in case the little extras burnt out the studio.

There were several studio evacuations during the filming of the show, now sadly lost by the BBC, with only film stock inserts surviving. Square World was a true pioneer show, that later Python and the 1948 Show took inspiration from, in it's magnificent lunacy.

 

Stephen

[How about a Dictator Loco Class?]

 

 

You can simply add more DC to the converter till you get more power thrust out, but there are limits, the bearings, heat on the coils, and balance of the rotor, all sources of failure.

 

The brushless motors depend on the cooling effect of the air from the blades to keep things under control, as Kilowatts can be used by the motor, and if stalled, can result in a melt down at high heat, destroying the coils.

 

The best source of more information on these Aircraft motors is a model aircraft shop, specialist magazines or the net.

 

The one thing these motors are not is stepper motors, which share the principles, but use the power applied in a more controllable way in DC pulses or AC signals. They are multipole coils and are designed not for speed but rotational accuracy.

 

Stephen

 

 

Ah this must be why I'm not managing to alter the speed of my ex drone motors then!

It's 7.4V 2000mAh LiPo battery spins it way faster than two 16V 1000mA railway controllers wired in series. If 32V DC won't speed it up, what should I try?

Is it possible to make it rev faster than it's designed 66,000rpm?

Edited October 7, 2016 by How about a Dictator Loco Class?

[raymw]

afaik, the drone motor will be a small 3phase motor - sort of like a stepper motor with permanent magnets, small air gap, but less poles. It's speed will depend on the frequency of the pulse train, how quickly the power supply can supply the pulses (switched mode psu's can be problematical) and the voltage/impedance of the source (battery/train controller) will effect it. I guess, the impedance of the battery will be less than the controller, and the battery will be able to supply current pulses  faster at more than 2A, whereas your train controllers will respond slower to the pulse requirements, and the possible current will be much less, hence your better performance with a lower voltage battery. (the battery can supply a much higher current than 2A, the max. current  is not directly related to the 2000mAh rating, the train controllers can not supply much more than 1A.

 

I would think the way to go would be a  slower rev motor, with more power, and a bigger fan, unless you can get a motor with magnetic or air bearings, and suitable high frequency power system. I believe the esc is matched to the motor, and may well have circuitry to prevent over-current/revs. Although the circuitry is considered to be digital, in fact there will be a finite short time for the current to change, and an increase in pulse rate will not necessarily be able to increase the speed, since before maximum current for one phase is reached, the next one has to come into play. If you want a high speed motor, then a compressed gas and a small turbine (dentist drill?) is probably simpler/more reliable.

[How about a Dictator Loco Class?]

My current speed record is now up to 858.96mph! (00 gauge scale speed)

So faster than the sound barrier.

It had a fair bit more in it but only had 3metres to stop and got smashed on the first timed run.

 

These speeds are nothing as it's just a cheep test model. Over the next month I hope to have my new versatile, more extreme test bogies running. Then a multi car, articulated (APT style), chassis, with full bodywork.

I've found a good, indoor, 115m very smooth, clean, very level place to run the faster models.

It's hard to drive my wheels to 200,000 rpm+, so the EDF route seems most suited to an actual 325mph model.

But I'll continue to push all options for now.

 

On my EDF model, my thrust to weight ratio is about 4+ at the moment.

The space shuttle is only 3 in comparison. (3X more weight in thrust than vehicle weight)

And fighter jets around a T/W of 1. (same weight of thrust and aircraft)

My home made fans are now producing a better T/W ratio than purpose made R/C EDF's

Even that horrible, none ducted, bodged brass fan I pictured earlier gives 42g of thrust and a 55 to 60 mph wind behind the model, yet only weighs 4g (wires+motor+fan).

 

And the afterburner gives me 4.3x more thrust at 5 deg C.

And 3.86x more thrust at 30 deg C.

So the colder weather is helping.

 

If a one car model weighs 75g, (with a full body, two bogies, 4 electric ducted fans (EDF's) blowing into a shared tube/exhaust) giving a total of 320g of thrust, 4.26T/W;

then even a bad clumsy heavy 100g afterburner system and way more fuel than needed (butane or petrol) would increase the T/W ratio easily enough to make up for the hefty weight increase.

Producing 1,235g of thrust (on paper) giving a delightfully savage T/W ratio of 7.05 in theory.

 

The afterburner is very smooth compared to the twist actions of the EDF's. With laser aligned track on a near perfect surface I think it could be a smoother runner than many think.

Poor aerodynamics, bumps and bends in the track and an un stable design where the thrust at the rear wants to swap ends with the front are the only main reasons its likely to derail.

Top heavy models on slightly wavy track or over bad fishplates were the only times I've seen models unstable so far.

 

Thanks again for tips though. I have lots to learn!

[How about a Dictator Loco Class?]

afaik, the drone motor will be a small 3phase motor - sort of like a stepper motor with permanent magnets, small air gap, but less poles. It's speed will depend on the frequency of the pulse train, how quickly the power supply can supply the pulses (switched mode psu's can be problematical) and the voltage/impedance of the source (battery/train controller) will effect it. I guess, the impedance of the battery will be less than the controller, and the battery will be able to supply current pulses  faster at more than 2A, whereas your train controllers will respond slower to the pulse requirements, and the possible current will be much less, hence your better performance with a lower voltage battery. (the battery can supply a much higher current than 2A, the max. current  is not directly related to the 2000mAh rating, the train controllers can not supply much more than 1A.

 

I would think the way to go would be a  slower rev motor, with more power, and a bigger fan, unless you can get a motor with magnetic or air bearings, and suitable high frequency power system. I believe the esc is matched to the motor, and may well have circuitry to prevent over-current/revs. Although the circuitry is considered to be digital, in fact there will be a finite short time for the current to change, and an increase in pulse rate will not necessarily be able to increase the speed, since before maximum current for one phase is reached, the next one has to come into play. If you want a high speed motor, then a compressed gas and a small turbine (dentist drill?) is probably simpler/more reliable.

Wow thank you for that! My understanding of electronics etc is basic, so these lessons are a big help.

If just increasing volts can't speed these motors then, can current increase, raise the torque do you know please?

 

I like these motors as they are dirt cheap and pack wonderful punch.

Rob

[bertiedog]

My current speed record is now up to 858.96mph! (00 gauge scale speed)

So faster than the sound barrier.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Now......let's get this clear........you are not Peruvian by any strange twist of fate????

 

stephen

[How about a Dictator Loco Class?]

Now......let's get this clear........you are not Peruvian by any strange twist of fate????

 

stephen

 

No, why?   

[bertiedog]

No, why?   

Michael Bentine's main claim to fame was he came from Peru, or at least his father did.....

[raymw]

If you want to have it running on rails, and powered by electrickery, then I think you should look at this, (or similar) https://en.wikipedia.org/wiki/Railgun. For small scale you will not need millions of amps, and I think it would be possible to have a few power supplies connected along the length of track (with insulated sections between) to increase the terminal speed. Possibly best to have a circular track arranged like a 'wall of death' because at the speeds you will firing the projectile, you won't want to put your hands, or anything else, in front to stop it.

 

Having built it, then a simple step to remove the rails, and end up with a large coreless motor...

[How about a Dictator Loco Class?]

If you want to have it running on rails, and powered by electrickery, then I think you should look at this, (or similar) https://en.wikipedia.org/wiki/Railgun. For small scale you will not need millions of amps, and I think it would be possible to have a few power supplies connected along the length of track (with insulated sections between) to increase the terminal speed. Possibly best to have a circular track arranged like a 'wall of death' because at the speeds you will firing the projectile, you won't want to put your hands, or anything else, in front to stop it.

 

Having built it, then a simple step to remove the rails, and end up with a large coreless motor

I used to be mad on these rail guns as a kid but haven't managed to make one.

I've just tried again now with a battery and a railway controller. I tried with different strong magnets and positions and different tracks. The aluminium roller doesn't move??? What am I doing wrong please?

It does look an interesting idea. Good link. Thank you.

 

Increasing the amps made the drone motor speed up at last! I put 3 controllers in parallel and it speed increased a lot. All my other normal motors speed up mainly when given higher voltage. Eg wired in series.

 

I've now catapulted a waggon to 7.63m/s, 17.067mph, 1,297mph scale speed (average over the first 3m, peak speed would have been somewhat faster I'm sure). It was totally smooth thankfully.

 

Rob

 

My lame attempt at a rail gun. I copied the youtube advice yet nothing????

Edited October 8, 2016 by How about a Dictator Loco Class?

[RJS1977]

Michael Bentine's main claim to fame was he came from Peru, or at least his father did.....

 

When he joined Military Intelligence they had a shortage of Spanish speakers.... so they made him a liaison officer with the Polish resistance!

[How about a Dictator Loco Class?]

BLOODHOUND's aerodynamic design without a wind tunnel - CFD

https://youtu.be/PEalGZPGq3U?t=299

1:25 scale model doing 0-800mph actual speed in under 1 second!

Just remembered this video from the 1990's at Pendine Sands.

That's so fast.

[How about a Dictator Loco Class?]

Hm!

Tonights Laser tachometer tests.

 

1 Hornby's 5pole skew wound. Vs;

 

1amp(almost) Bachmann 12v controller = 14,100rpm

 

+ HM2000 12V 1st output in series = 24v = 20,500rpm

 

+HM2000 12V 2nd output in series = 36v = 25,000rpm

 

+HM200+ extension 12v in series (the HM2000 combo wasn't too big a fan of achieving this so for it's own safety I used the extension in parallel to boost the amps instead)

So 36v 2amp roughly(HM2000 alternates according to current draw and can exceed 1amp) = 25,750rpm + burnt and electricuted finger and thumb, multiple sources of burning smells(one terrible!!!& lingering still!), a medium strength headache and a now deepened desire to push to much higher voltages in the very near future!!!!

A test to destruction beckons!! (-:

 

These 5pole Hornby jobs are dirt obviously at high rpm. A good slot car motor or even a rubbish one far surpasses these revs.

The motor did speed up after about 10 seconds during each test to higher rpm for some reason?!

 

A big thank you to Vulcan Bomber electrician/all round genius Dave for the gift of the HM2000 combo and other bits and endless input!!!

 

Both our rival speed test train projects are well under development now.

 

More friendly rivals are very welcome! (-;

Edited October 29, 2016 by How about a Dictator Loco Class?

[How about a Dictator Loco Class?]

Actually I'm now thinking of running a twin engine, direct drive N gauge Wickham Trolley for a record run.

Using 2 twin output, 100,000rpm+ brushless transverse mounted motors. My N gauge Wickham's are designed for a single longitudinal mounted, geared down motor, with space for a dcc chip. But I've realised it has room for this new crazy idea! Maybe a twin motored trailer could be coupled to it, if this can somehow be added in a way that can make the thing more stable?

It's such an unstable proposition though! My magnetic suspension system will fit in without being visible but I don't know if it will help that much on this particular model?

Normally these ultra micro models require extra weight to pick the power up well. If anyone who understands high output micro capacitors has any imput on whether they will help I'd love to know please!

Crazily well laid, smooth jointed track will be needed too. Probably a cheap laser alignment tool and soldered/smoothed rail joints. I'm calculating 4,000mph (scale speed) area is achievable without burning it out maybe. Got enough spare motors to sink a battle ship thankfully.

The motor is just sat above on the third picture. I'll CAD up a smart version where the motors seamlessly slot in. And use a more detailed updated version of the Wickham with much smoother finish.

 

My actual OO speed record model exploded its gearbox and tore its strong, flexible chassis recently!!! And it was no where near it's 120,000rpm top speed at the time. So I'm going for a more conventional gear system now.

Edited February 23, 2017 by How about a Dictator Loco Class?

[The Johnster]

Nombre de Dios, QUE????????

[How about a Dictator Loco Class?]

Just done some wind tunnel and motor temperature measurements.

Without the windows to lessen drag,

It flips at just short of 5meters per second on the anemometer reading.

It only weighs around 4 grams.

And at a tachometer reading of around 75,000rpm the motor burns the finger from cold start after a mere 6 seconds.

 

With a front spoiler and a rigid coupled trailer, it's stable at 10m/s head wind now and flips at 10.3m/s

If it was actually moving I'd expect vibrations coupled with head wind, to cause derailment slightly sooner than 10m/s.

 

13m/s (29mph ish) is similar to Bolt's peak speed hit during the 100m sprint.

With a 13m/s headwind the motor ran at 75,000rpm (ish) for 15 seconds and barely got warm!

Very pleasing news to say it's a very stuffy 22.4 degrees Celsius (72.32 Fahrenheit) in my room atm!

So with a few more tweaks 13m/s looks achievable (4,292mph 1:148 scale speed) on 1cm circumference wheels.

Thus potentially outrunning Bolt and without being well over 6ft tall too!

I'll open up the radiator grill on the front of the Wickham to channel the cooling breeze in to the lower chassis.

Extra weight low down or a mini R/C helicopter gyroscope could improve stability further. As long as everything is hidden!

As Bachmann somehow struggled and failed to put one motor into their OO model it's nice to prove a point.

[How about a Dictator Loco Class?]

Nombre de Dios, QUE????????

Dear Johnster, I don't speak French (if that's what it is)?

If you were wanting to get where I dug those numbers from, my last message should explain a bit.

Thanks.

[The Johnster]

It's cod Spanish. Dictator, and a bit tongue in cheek; In the name of god, why???

[How about a Dictator Loco Class?]

It's cod Spanish. Dictator, and a bit tongue in cheek; In the name of god, why???

Ok Jonster my Spanish friend, I'll try explain;

 

Because I'm still a bit immature for my age. I'm on the boarder line in my life, where I still sometimes have enthusiasm for having a laugh.

I'm not bright enough to design real high speed trains, F1 cars or Jets. So putting the basics of those fields into action in silly cheap projects is as near to that fun as I'll get.

 

Occasionally I'll post update snippets on rmweb, in the vein hope that I might not be alone in the universe. There may just be someone out there who's a little like me to talk to. It's rubbish in life when you have things that you're really passionate about but there's nobody on earth to discuss it with who's on your wavelength.

 

Then after working on a few thousand serious models a year for over 14 years, I welcome a fun break from the norm once in a while.

As usual, even though it's 3:12 on a Sunday morning atm, I'm still 76 miles from home, working killer hours weathering huge never ending batches of locos and rolling stock. I do enough standard normal stuff to go mad. Surely it's not a sin to have a mess around and be different once in a while?

Edited February 26, 2017 by How about a Dictator Loco Class?

[njee20]

The bigger question for me is why are you awake at 2:40, weathering stock 76 miles from home? Have you been taken hostage and held by TMC to weather at gunpoint?!