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Radio controlled road vehicles on Upper Benllech

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Very entertaining.

 

I don't think I ever saw a real one (in Dublin) but I had a Dinky model and I am amazed to see how closely they reproduced the coupling system.

 

...R

They were fairly ubiquitous in the UK. I think the film clains 10,000 tractors and 30,000 trailers in BR ownership alone. which is pretty astonishing really.

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Hi Geoff,

 

I broke off this thread to watch your videos on YouTube via my tv and was most impressed with the Keil Kraft bus conversion definitely my sort of vehicle/ time period.

 

As a complete Luddite regarding this type of modelling may I ask what you use to control the vehicles ie handheld device or some such thing?

 

Regards

Grahame

Edited by bgman
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Various little bits of progress came together last night.

having finished cleaning up the SLA's.

I have built up the steering knuckles, using my favourite crankpins.

 

post-25615-0-76527600-1496170905_thumb.jpg

I am evolving this design with each generation. This time:

I squeeze the large screw in the vice to flatten the threads. I align this, to the two notches, which will make sense in a moment.

I then file off the top and bottom of the big thread to create a rectangular profile.

Next the kingpin hole is markup and drilled through the filed faces. I aim for a drill angle of 10° which allows for some slop in the bearings to result in the 5° target camber. The unused tip of the thread can then be cut off with a fine saw.

Finally, the link arm is bent up from wire, a loop at one end, and a sharp bend at the knuckle end. This is then soldered to the side of the knuckle, with the tip of the bent end fitted into the notch of the crank pin.

 

This gives the basic knuckle.

one side also needs to be connected to the servo. The model T actually pushes sideways rather than front to back to actuate the steering, but for the model I need a longitudinal actuator. So on the right hand side I added an extra link arm to the front of the knuckle. I wasn't sure about how this would look but, now its built, it looks a little like the speedo mechanism, so I am hoping that once painted it will look OK.

post-25615-0-86713200-1496170920_thumb.jpg

 

Once both knuckles were made, I fitted them onto the axle with temporary kingpins and bent up the parrallel link to fit.

 

After a few photos, I then put everything together and fitted then to the front grill.

post-25615-0-75745900-1496170948_thumb.jpg

 

I'm pretty happy with how this all looks. At least prior to painting.

The stub axles look droopy, but this is with gravity pulling them down, where as in use, the weight of the vehicle will push them upwards.

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Hi Geoff,

I broke off this thread to watch your videos on YouTube via my tv and was most impressed with the Keil Kraft bus conversion definitely my sort of vehicle/ time period.

As a complete Luddite regarding this type of modelling may I ask what you use to control the vehicles ie handheld device or some such thing?

Regards

Grahame

Glad you enjoyed the videos. Thank you.

Originally, to control the vehicles, I bought an off the shelf parkzone transmitter, that provides 4 channels on 2 sticks. however, i subsequently used the deltang TX2 transmitter modules to build a couple of smaller handsets which better suit the scale of the vehicles.

post-25615-0-89277400-1496174844_thumb.jpg

The one on the left uses a case bought from RS components, where as the one on the right uses a 3d printed case.

both provide steering and throttle on the one stick, (a Play station 2 replacement joystick).The big one also has 2 push buttons and a rocker, whilst the little one has a single push button for headlights.

Both can be used one handed, leaving the other hand free to weald an uncoupler, or otherwise be useful.

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I squeeze the large screw in the vice to flatten the threads. I align this, to the two notches, which will make sense in a moment.

That looks really great. However I am a little confused. Am I correct to think that the "large screw" is not the screw shown in the picture?

 

...R

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That looks really great. However I am a little confused. Am I correct to think that the "large screw" is not the screw shown in the picture?

 

...R

My apologies. A very poor description on my behalf.

by large screw, I was referring to the large end of the Romford Crank pin.

 

Hopefully this will make more sense:

 

post-25615-0-69335900-1496260954_thumb.jpg

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Thanks. I had not made the connection between "crank pin" and locomotive wheel - probably very stupid of me on this website.

 

...R

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I've spent the last couple of modelling sessions focusing on wireing up the chassis. My aim is to make the 'active' part, ie the chassis motors reciever etc into a self contained unit that I can slot in and out for servicing. Leaving only an umbilical for the lights. 

Everything within that unit is wired now, although there is some rework as I made a couple of mistakes (Such as wiring the battery and charger sockets the other way round from my usual standard).  But it does all work! The servo swivels and the axle drives, all under the control of the Receiver. I choose the Deltang Rx63 for this build. Its bigger than the Rx45 and 43's that I usually use. But following the discussions on other threads (one of Gile's I think)  I wanted to try out the new added features such as the servo slow.

As you can see, with the charger and battery sockets on the end of the chassis block, the lengths all work out OK.but if I was building a standard model T delivery van for example, things would be much more constrained.

post-25615-0-39793400-1498289033_thumb.jpg

In the picture you can see the chassis, with the Rx on top to the year, the sockets are tucked underneath to the right. The servo controller pcb sits on its side at the front centre,whilst the on off switch is the silver rectangle on the lower right.

The wire is single core tracing wire, which holds its shape, except the servo leads, which are the original.

The battery will need its wires replacing to make it more compact, but are left long for now to make other work easier.

The next step is to fit this assembly to the front chassis and connect the servo to the steering. It should then be possible to drive it around and test the speeds etc.

 

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The Rx63 uses the same Atmel Atmega 328 as an Arduino Uno and it is possible to load your own programs onto it. Some time back I figured out how to interface with the Cypress wireless.

 

...R

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Did you manage to find a small servo-slow? I found a small one in China that simply didnt function (unlike the large ones)...... so that one just went in the bin!

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I havent found an independent servo slow. But the Rx63 claims to have an adjustable one built into its settings. So once the vehicle is running I intend to delve further into them and give it a go. The servo pcb in the picture is that cannibalised from the original donor servo.

Robin, I am intrigued by the thought of adding to the programming

 What features are you thinking to customize into it?

The most valuable to me would be to read the output of the servo pot directly and then contol the servo motor directly from an H bridge on the receiver. Edward has already asked David Theunissen of Deltang if this is possible, but apparently they dont have the analogue in and David doubts the processor has the spare capacity. In this Rx63 there is the added flaw that the is only the one H bridge which is already in use for propulsion.

However the new Rx47 is only about 1mm longer with plenty of outputs and claims to run the same v6 software.

If it works ok, then being able to flush the servo slow back to an RX45 or 43 might be valuable as they are both still significantly smaller. But the way your comment is written it sounds like that uses a different processor?

One other feature I would like is old style combined indicator and driving lights. On the Austin K8 I am told, original equipment would be to have the driving lights and brake lights flash as turn indicators. Which means when they are on at night, they have to flash off. 

Actually, original equipment when they were launched was for the driver to stick his arm out the window, but thats a future project.

 

Any other thoughts or inspirations out there for extra features to add to software?

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It would be great if there was a (simple) tweak to the receivers to slow the servos....

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Robin, I am intrigued by the thought of adding to the programming

 What features are you thinking to customize into it?

Just to be clear, I was not talking about customizing David Theunisson's code - he has not published it. I replaced the code completely with my own code. David did help with a detailed schematic for his hardware.

 

I programmed a separate Deltang unit to act as a base-station connected to my PC so that I could build a program on my PC to control my trains. The one base unit could control several locos.

 

Not all of the Atmega 328 I/O pins are accessible on the small Deltang PCB and it is a long time since I did anything with so I don't remember the details. From looking at some diagrams I made back then I think there are spare accessible digital and analog I/O pins. I am reluctant to post my diagram in case it is out of date and someone accidentally destroys their Deltang unit.

 

I'm not sure what advantage there would be in trying to bypass the control system on a servo. With suitable Arduino code you can make a servo move in very small steps.

 

...R

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I missunderstood you. Interesting use of integrating with a Pc, 

My desire to bypass the servo controller is size. How small, neat and compact can I get all the gubbins. Whilst this T van is the smallest I have sone so far, I aspire to smaller. 

Which doesnt necessarily mean smaller prototype, rather than; less space to hide things. Unfortunately, pre 1914 motorised vehicles were very limited on fairings, covers & bodywork. 

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My desire to bypass the servo controller is size.

If you have the knowledge and skill to make another surface-mount h-bridge like is on the Deltang module ...

I know how to program an Atmega 328 but I have neither the knowledge nor skill to make the h-bridge :)

 

I guess David Theunisson would probably give you the knowledge in the form of the parts list and schematic.

 

Maybe a more practical approach is to take the servo apart and mount the electronics away from the motor and gears. Put the electronics where you do have space.

 

...R

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Progress is slowing again, so I'll share this video now, rather than waiting until the bodywork is complete. 

 

 

This is the first running trial, it is nice and slow and I am very happy with the steering lock, although its a little asymetric at the moment. There is too much slop in the front axle,  which I had suspected, it will need some radius arms to keep things better aligned. For reference, its running on a piece of A3 paper.

I havent tried playing with any of the settings yet.

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So, following some suitable inspriration at Uckfield last weekend.

I have been making some progress in the background, although it tends to average only about an hour per week.

The body is mostly complete now, with the front chassis and rear van sections joined, extra detail in the cab to add pedals etc. The headlights and tail light are wired up and installed. (surface mount LEDs).

And almost everything has at least 2 coats of paint.

post-25615-0-18834700-1508932034_thumb.jpg

The mechanism has also been tidied up, with the battery assembled and the necessary bracing to retain the motor assembly into the body.

 

post-25615-0-86326900-1508932768_thumb.jpg

Painting of the driver is also progressing.

1 bit of wiring left before the mechanism can go back in, and then the wheels can go on.

 

 

Picked up a bargain at the show, in the form of this little taxi. conveniently it almost fits the model T chassis, and would only need the axle moving slightly forward to keep it entirely in the passenger cabin. A future project for the box of ideas on the shelf.

post-25615-0-22361800-1508932391_thumb.jpg

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Oh yes. I've had my eye on that since they were on preview. The civilian version was available for sometime before WW1 so it suits my target timescale well. But thankyou for sharing, I am always on the look out for decent Edwardian motor vehicles, but it is a very under represented topic matter. I hope the 3D chassis will fit, but might need rearranging to make it longer and lower. I am not sure how to make usable wire wheels that it should really have, although this guy seems to have a way for static ones at least.

 

I am torn between one of these as the next model, or a subsidy truck from WD models. http://www.wdmodels.com/page5.htm.

I quite fancy the Dennis, there is a restored version that comes to the local Bedfordshire steam rally.

 

However, I must try to resist the temptation to start a new vehicle or I will never start the layout.

 

Speaking of wheels, the T has gained its boots.post-25615-0-33566800-1509182290_thumb.jpg

It took a bit of work to get the steering link and the radius arms right and the servo needed some fettling as it was sticking. I cleared a burr from the final worm. But something else keeps sticking I think it's the first worm on the motor, the shaft of which has a little free play and I think it gets pushed against the motor body. I will give it some oil, but if that doesn't work then I'll have to take the chassis off again. Unfortunately all that took some testing, so I only managed to drive about 30cm after fitting the rear wheels before the battery went flat. Still some painting to finish.

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Well so much for the enthusiasm, immediately countered by a nasty attack of real life to distract me away from the models.

 

Never mind, progress has continued.

 

Most of the detailing is now completed, headlights and tail lights painted and lensed, repainting largely finished, driver added and everything fettled underneath.

 

At some point I need to find a supplier that can create custom decals including white, and then create a job lot for all the vehicles so far.

This van will belong to a successful plumber, transporting equipment and deliveries to jobs, particularly new builds and retro fitting plumbing to wealthy houses. The long overhang enables the carrying of these new fangled 'plumbed in baths'. You may note in the picture the lengths of lead piping carried on the outside. I found a photo some time back that provided the inspiration behind this concept. The plumber in question had a fleet of vans lined up side by side.

 

post-25615-0-52740100-1512570739_thumb.jpg

 

The servo slow function works particularly well, although takes a little getting used to. It proved easy to program once the allocation of channels to steering and lights has been completed. But it only needs to be used on the first notch. set to anything above that, the movement can get painfully slow and your are left waiting for the steering to catch up even when driving carefully. On maximum setting it literally takes seconds, which could have some value as an actuator, but was unusable for steering.

 

The lights are wired through 10K ohm surface mount resistors soldered directly to the deltang PCB, this reduces the LEDs to a less over the top glow, although I suspect still a little too bight. But its hard to turn them down much more. They are also too white, the search for 'warm' white LED's in the suitable package size proved unsuccessful when I was shopping for them. So I experimented with adding some coloured filters, but just ended up with lurid yellow, which felt even worse. My search will continue for future vehicles.

In the mean time, they work quite well for an atmospheric shot.

post-25615-0-46560000-1512571539_thumb.jpg

 

Video to come soon, just knocking together a film set of download and print kits to give a background / context.

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Simply marvellous! I'm very much looking forward to the video. I hadn't realised until you said that some of the Deltangs had a built-in servo slow - I shall have to get one and try it....... Of course the other thing one may be able to do (how many servo slows has it got?) would be to put an ADD board onto the servo output and take the drive from that (as I did with my crane winch motors) but with a servo slow attached, would it control accelatration? or would it only act as a brutal speed limiter.....?

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Hoorah, The video is finished.

 

It took a lot longer than I had planned, not least because I have had to find and then start a new job.

I also make no apologies for getting enjoyably distracted by building a series of download and print kits from Model Railway Scenery and from Scalescenes.

I made up a set of low relief buildings plus a simple baseboard of road / paved surfaces which can then be configured to represent different aspects of a scene for filming. Long term I hope to add a few more buildings, but whilst it may end up looking like a simple diorama, it is specifically intended to be a film set. Allowing different scenes to be created and buildings to be moved to allow the camera into position.

 

 

 

Overall I'm very happy with the result.

I hope you enjoy it.

 

 

Oh, and note the 'servo slow' demonstration about 1:40

I have to say, that whilst it looks great, it is a pig to drive.

Unlike a real vehicle, you have no feedback of where the steering is. You have to watch the position of the wheels, from a scale 100yards away! Unless you are very gentle with the steering input (and the throttle) things can get out of hand very quickly. For comparison, I also filmed the Atkinson driving around the same set. I rarely had to retake shots of that due to crashes, but the T often required multiple attempts, although I was much better by the end of filming.

I think the servo slow needs to be twice or even four times as fast, but this was the fastest setting on the Deltang.

I am thinking about building a new transmitter soon, I may try some experiments with a multi turn resistor and a steering wheel as an alternate steering input.

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Fabulous as usual.

 

In the comparison of the response of the steering the Model T seems to have a lag. That could make control more difficult rather than easier.

 

Out of curiosity, what space is available for a receiver - W x L x H in mm?

 

And have you any interest in writing your own program for the receiver?

 

...R

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