J P Models - more radio controlled vehicles in 1:76 scale

[Pikey 327]

I've called the topic just 'J P Models' as I intend to describe all of the models in one place rather than start a new topic for each one. You might also be interested to like and follow 'J P Models' on Facebook

 

The latest model I'll be attempting is a working Hiab crane on a flatbed lorry! The story so far is that I picked up a bunch of cheap Cararama box lorries in a garish red and blue 'Knights of Old' colourscheme, and after some chopping about they now look like this:

 

 

Technically they're 1:80 rather than 1:76, so ever so slightly smaller than they should be, but close enough for that not to matter. The cranes are made by Herpa and are 1:87 but again this is close enough. The cranes are pretty amazing really for what they cost - fully articulated in every way that the real thing would be. And that's the plan - to have the lorry and the crane fully radio controlled, including the extending boom! This will need 4 separate motors to control the crane, plus another one to drive the wheels and a servo to steer. I'm also planning on having the full complement of lights, and a flashing orange beacon.

 

 

 

 

[Robin2 252]

These seem to be your other Threads on similar stuff - just so I can find them easily.  All wonderful, by the way
 
1:76 tipper lorry
A Remote Depot

 

...R

[Pikey 327]

Happy New Year

 

So lets have some content, showing what I've been working on over the last couple of weeks. First is a slight deviation from the goal of a working crane lorry, courtesy of my old Scania crane lorry with the working ramps - which has pretty much been in its box ever since I built it because it never really drove very well without a load on the back. So I thought I'd recycle it, as I had several uses for the components. I used the bed with the working ramps, the flashing orange beacon and the receiver, to create a beavertail lorry on the Mercedes chassis - and the flatbed from the Mercedes plus the rear wheels from the Scania to make a drawbar trailer. Got all that?

 

Here I am testing it with a hastily-put-together loading ramp and my Network Rail Land Rover Defender:

 

 

then I had steering axles and the proper 7mm German motor/gearbox left over, so I used them to finally finish the Scania fire engine I'd had for a while:

 

 

I've also made another Transit van, this time in the instantly recognisable DPD livery, excellently reproduced by Shedring Hobbies:

 

Edited January 3 by Pikey

[Pikey 327]

And here's an annotated photo showing the underside of the beavertail lorry

Edited January 3 by Pikey

[Pikey 327]

One more - Transit dropside bringing a wood chipper to the yard, and collecting a load of sand.

 

 

After I 'boosted' this video on my Facebook page, the most frequent comment was that the truck would be overloaded with that much sand. Out of interest, its about 3g of sand, which translates to about 1.3T in real life, which I guess would be slightly over the mgw (?) anyway - it has prompted me to install a weighbridge at the depot, and I plan on using the new Train Tech info screens to show (simulate) the weight of the trucks coming in and leaving the depot

[boxbrownie 907]

Amazingly clever stuff.

[otherplanet 178]

You have been busy!

I just saw the YouTube clips and came looking for the article.

Very nice work in all cases. I like the operating ramps, though perhaps you need a working tail hook release :-).

Have you seen the weighbridge on one of of the German Ho truck layouts on youtube. It measures the weight of loaded trucks and also shows the scale conversion weight.

[PhilJ W 38,072]

The Cararama Mercedes Actros is actually 1/74 scale. They also do one in 1/80 scale that is often claimed to be 1/87.

[Pikey 327]

I have seen the working weighbridge, yes. Probably not too difficult in all honesty, but I prefer mechanical challenges rather than electrical ones, so I probably wont bother going to that extent.

 

I have built a more permanent access ramp, so I can now load and unload properly. For now, I've found I can back the trailer against a wall and hitch/unhitch it using the truck ramps, but ultimately I'd like to put another receiver on the trailer with just a single servo or motor driven strut to jack the back up - then I can leave the trailer anywhere. The Land Rover seems to be the only vehicle that can handle the reverse from the truck bed onto the trailer, so I can load that onto the truck, reverse it onto the trailer, then load a second vehicle onto the truck bed and depart.

 

Apologies for the lack of video quality, the compression when uploaded to Facebook is crippling!

[Stubby47 20,109]

Can I ask what sort of RC controller are you using - does it need to have lots of extra buttons to control the different servos/motors/vehicles ?

Stu

[Pikey 327]

I use an Orange Tx6i, which is as far as I know the cheapest DSM2/DSMX compatible transmitter you can get. It addresses the individual vehicles separately, a bit like DCC. It has 6 channels, 4 on the sticks as normal, plus 2 switches.

 

I also use a 10 channel Jumper T8SG which is a bit more expensive, but comes in 'car mode' which has both sticks centre-sprung and also has lots of programmable features. I use this for the loader.

[Pikey 327]

Loading up the two vehicles  

 

[rockershovel 3,038]

One more - Transit dropside bringing a wood chipper to the yard, and collecting a load of sand.

 

https://youtu.be/GepeEv0vuc4

 

After I 'boosted' this video on my Facebook page, the most frequent comment was that the truck would be overloaded with that much sand. Out of interest, its about 3g of sand, which translates to about 1.3T in real life, which I guess would be slightly over the mgw (?) anyway - it has prompted me to install a weighbridge at the depot, and I plan on using the new Train Tech info screens to show (simulate) the weight of the trucks coming in and leaving the depot https://www.rmweb.co.uk/community/uploads/emoticons/default_smile3.gif

Most impressed with the working loader shovel!

[Pikey 327]

Working on an Eddie Stobart Volvo FH lorry cab at the weekend, with a couple of new battery sizes. The cabs seem to be just the wrong size to fit any battery inside, so I resorted to cutting the back off the cab and sticking the battery in its place. I'll paint this white and stick the air intake back on and it'll look passable for a part of the lorry that will be at least partly hidden.

 

 

 

I'm going to upgrade both of my other lorry cabs with a proper servo like in this one. Linear servos are fine for the smaller vehicles, but I find they cant handle the weight bearing on the front wheels when used on a lorry.  

[Pikey 327]

Here's the finished truck being tested. I think the battery is disguised well enough:

 

[TechnicArrow 256]

If you hadn't shown us, I wouldn't have known the battery was even there! Hidden in plain sight, a neat job.

I've been a silent admirer of your miniature marvels for a while now, but I'm very intrigued by your proposed working HIAB project. I'd love to see it done; it seems even more of a challenge than your front loader, but perhaps more "playable" when complete. How do you intend to achieve it; motors "below deck" pulling on wires, tiny motors built into the arm, or something else?

I'm considering getting one of those Herpa cranes for a different project; would one fit well on a OO gauge open wagon?

 

Edit to add:

 

I stumbled across this video last night, proving it has been done.

It left me confused as to how it worked for a long time, until a little digging in the comments of the creator's various videos reveals all:

The piston it's self made with alloy micro tubes, all the moves are made with 1/700 geared motors to recoil a fishing line(like a winch). To make the inverse travel, I use springs.

 

It's a genius idea. I'm interested in how you plan to get yours moving!

Edited January 21 by TechnicArrow

[Pikey 327]

It was that video that made me want to do mine

 

He has 3 G700 motors for the crane (one of which I think was planned to extend/contract the boom but isnt used because that would be too many motors for a single receiver) which are lined up under the bed pulling fishing wire through the rams, plus one vertically in the back of the cab which turns a cog to rotate the crane. As above, tiny springs push the crane arms apart. I'm going to try elastic around the back of the arms first, as I dont know where to get such tiny springs from at the moment.

 

Herpa do a Palfinger and a Hiab, the one in the video is the Palfinger. I've seen both and I think the Palfinger is the more suitable of the two, and its also cheaper (although they come in a pack of two, so more expensive overall but cheaper per unit)

[TechnicArrow 256]

I thought the cranes were the other way around - it seems to me that he's used the bulkier HIAB (in red, even though they're more commonly available in black), wheras the cheaper Palfinger (common in orangeish-red) looks a bit too spindly to withstand being motorised.

I've found the video with the underside shot as well as the in-progress shots, it's all fantastic work and I can't wait to see your attempt.

As for the springs, I'm not sure about the diameter required, but might a pen spring be useful? The springs from a 4-colour biro-type pen are smaller than a regular pen at around 3.5mm OD, but they might still be too large. Alternatively, a little amazon digging turned up these 2mm OD ones: https://www.amazon.co.uk/sourcingmap-0-3mmx2mmx15mm-Stainless-Compression-Springs/dp/B076LZ7XHR/ref=sr_1_3?ie=UTF8&qid=1548083864&sr=8-3&keywords=2mm+diameter+springs. Again, might be a bit large, but perhaps they could be put on the outside (the visibly moving section) of the ram instead of concealed within; it depends how much of the look you want to preserve. And if you can make it work with elastic instead of buying parts, then why not.

Anyway, I should reassemble my pens, I need to use them for the revision I'm supposed to be doing!

[Pikey 327]

I've upgraded my tipper cab with the facility to attach different trailers, via a tiny 2-pin connector which conveys the pair of wires to the second motor. On the tipper, this is the motor that tips the trailer up and down, but it also means I can connect other trailers with moving parts to the same cab unit without building up a tractor unit for each trailer. Next on the list is a low-loader with raising and lowering ramps.

 

 

 

Edited January 23 by Pikey

[otherplanet 178]

Try Lee springs. https://www.leespring.com/uk_index.asp

We use them at work all the time. You can get very small diameter (sub 2mm) and your choice of spring rates forces.

[Pikey 327]

Very useful, thanks

 

Last night I finished the low loader trailer (which originally came with the Eddie Stobart Volvo FH cab), which plugs into the same port as detailed above. Really easy to do in all honesty - 10 minutes with the Dremel and it was ready to go. Hardest part was pulling the original pins out of the ramps.

 

The ramps are glued to 3mm dia tube, glued to 2mm dia tube which pivots in the 2mm dia holes in the end of the trailer. In truth I could have just glued the ramps direct to the 2mm dia tube, but there would have been a bit of a bump to get onto the deck. A G700 motor is mounted underneath the deck, turning the ramps via an S15 worm and a Z19 cog. This is the same basic mechanism as operates the ramps on my beavertail truck. Route the wires and solder on a 2 pin connector. Just needs a bit of green paint to hide the brass now. Photo sequence below:

 

 

 

 

 

 

 

 

 

[TechnicArrow 256]

"Simple" yet effective! I'm imagining the Ford Transit tipper, sitting on the Beavertail truck, sitting on the Stobart low-loader... 

For another trailer project, would a container hook-loader be possible? I'm not sure they're all that common as articulated truck trailers, but it's another trailer with a single powered function that came to mind.

[PhilJ W 38,072]

"Simple" yet effective! I'm imagining the Ford Transit tipper, sitting on the Beavertail truck, sitting on the Stobart low-loader... 

For another trailer project, would a container hook-loader be possible? I'm not sure they're all that common as articulated truck trailers, but it's another trailer with a single powered function that came to mind.

Cararama produced a working Mercedes hook loader model, a bit underscale for 1/76 but ideal for a lighter chassis (7:5 tonne).

[Pikey 327]

Here's a quick test of the low loader in action:

 

[Pikey 327]

So i finally got hold of one of the new Train Tech Smart Screens, and I've made a weighbridge! So now the trucks can be weighed before and after depositing their load in the ballast bins. The video was shot before I'd finished the weighbridge itself, just to demonstrate the display, which is a remarkable little thing:

 

 

To model the actual weighbridge itself, I just painted a red rectangle on the ground, and outlined it with a concrete colour. Add an ANPR camera and a handrail, job done. Marvellous