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

[Pikey]

Well its been a while!

 

Mobile excavator, might have been worth a topic all by itself, but I've nearly finished it now so its too late for that.

 

https://www.shapeways.com/product/ALGKTDDJE/mobilbagger-1-87-rc?li=shareProduct

 

I'd been meaning to tackle one of these for years, but the control methods I'd previously seen were somewhat clumsy, and it was only when this kit arrived on the scene that I finally decided to take the plunge. I've put together kits before (the Das87 4WD LandRover you may have seen on Luke Towan's youtube channel) but they always seem to have brass components which never fit together properly without hours of work, so I was a little worried that this might just be a load of money wasted. And it is a LOAD of money: the kit looks like its £53 on Shapeways, but you have to buy an additional 38t gear which is another £6, then VAT is added, plus processing and extortionate shipping costs, so in the end it comes out at about £100. Then you need £120 worth of motors, gears and bearings. Then you need a receiver and 2 separate ESCs (another £75) plus some other stuff like a steering axle, battery, servo, flashing LED light. And you need to buy the model to convert as well, which in my case was £45 by itself.

 

So total cost runs to something like £350 😬

 

Mind you, it is a very good kit, with useful instructions, albeit in German, so still takes a bit of lateral thinking to understand what to do even after it's been translated. Even better now you can get it printed in the self-coloured tan resin rather than mine which was clear and needed to be primed and painted, and on the last bit of the digger arm the paint has really suffered just with handling it to install the bucket motor transmission.

 

I've enjoyed making it, and while it definitely is NOT for beginners, it is perfectly attainable if you're really careful and patient. I'll post a video of it working shortly, but for now here are a few build pics:

 

Drive motor and steering axle:

 

 

Slew motor on top of completed chassis:

 

 

Slew motor/base inserted into model:

 

 

RX and one of the ESCs installed:

 

both ESCs, cab with flashing light and battery installed:

 

 

Digger arm with rotating cylinders:

 

 

The finished article:

 

[Giles]

It looks nicely designed.....!

 

I have found that my go-to 6mm 100rpm gearmotors have completely disappeared from everywhere, and there are many fewer of the remaining ratios available as well. Its certaiworth stocking up if you haven't already!

[otherplanet]

That's an impressive kit and build. Well done. I have seen it on shapeways. But it's not my era. Is this one all gears, worms and lead screws.  Or does it have any of the functions powered by winch driven fishing line? I've seen that type of drive on a number of the excavators on YouTube and I'm interested to know what the subtleties of implementation they might use.

But the direct drive via lead screws looks more robust

 

 

[Pikey]

The arm is all 4mm motors with screws on, driving an intermediate shaft with a z12 and another screw, driving the output shaft which has another z12 and the cylinder on the end. The cylinder rotates and there’s an M1 nut in the end which drives up and down a threaded rod to produce the motion. It’s a good design, everything’s nicely hidden

 

 

[Pikey]

Video as promised, excuse my slightly ponderous driving I'm not quite used to it yet:

 

 

[Pikey]

I've got A Remote Depot out in preparation for Redditch show this weekend, so I thought I'd film a proper video with it in the correct location.

 

I also had two of the controls reversed (had the main arm on the left stick and the dipper on the right stick, which is the wrong way round) - needed to look back over an old GoPro video I took when we hired a mini digger to see how the controls should be, and now that I've swapped them over it feels so much more intuitive to operate 🙂

 

 

[Pikey]

Barring a few minor issues, the digger worked very well for two days at Redditch exhibition, and we won 'Best Layout' as voted for by the public as well, which was nice 😀

 

We did get a lot of weird radio gremlins, whereby models would become non-responsive for anything from 1 to maybe 15 seconds - continuing with whatever functions were operating at the time, so continuing to drive when the throttle is released, for example (!) The problem did appear to be worse when both Jumper T-Pro controllers were switched on, but the bus I've just finished seemed to do it all the time and other models appeared unaffected. Has anyone else experienced this?

[Giles]

Interesting.... no.... please let us know if you have any answers. Do you transmit on 10mW or 30mW setting?

Have you always used these transmitters? 

[otherplanet]

Do you have the selects function enabled (intentionally or otherwise)

And if so, is the transmitter setup for it too.

There is a mode, at least on some receiver's, where the reciever will continue with whatever it was doing when selecta is changed to another 'notch', until it switches back. I think deltang referred to it as cruise control or something similar.

So if the selecta is drifting off the relevant output setting you could loose control.

Not sure why that would interact differently with multiple transmitters though.

 

Either way. Congratulations on winning best layout.

 

 

[AY Mod]

On 14/09/2023 at 16:36, Pikey said:

I've got A Remote Depot out in preparation for Redditch show this weekend, so I thought I'd film a proper video with it in the correct location.

 

I also had two of the controls reversed (had the main arm on the left stick and the dipper on the right stick, which is the wrong way round) - needed to look back over an old GoPro video I took when we hired a mini digger to see how the controls should be, and now that I've swapped them over it feels so much more intuitive to operate 🙂

 

 

 

That's stunning. Everything was so rock steady I though the Cat was mounted on the board until seeing the last seconds.

[Jon Harbour]

Just awesome. Thoroughly deserved Best Layout.

[StephenF]

Spectacular, beautifully done 👌. 

Hope you get the glitch sorted … 

[Pikey]

22 hours ago, otherplanet said:

Do you have the selecta function enabled (intentionally or otherwise)

 

I don't think that's what's happening. When the model becomes unresponsive, the led on the receiver is on, and I think its supposed to flash when it's told to be inactive via the selecta function. But it's a good idea, I'll check anyway.

[RANGERS]

That is something truly spectacular, though I’m not sure which shows the greatest touch of genius; the engineering that created it, or the skill in driving it. 

[Pikey]

Very kind comments, but anyone who can drive a digger can drive one of these - the controls are exactly the same. :-)

 

At the same show, we also premiered my conversion of an Oxford Diecast car transporter, which can deliver up to 8 of the Turbo Racing minis (we only have 3). My ultimate plan is to convert various Land Rover / Range Rover models, and deliver up to probably 6 of them to the JLR dealership on the layout. The Evoque on the lower deck at the front of the truck is glued in place, partially as I didn't think it was worth motorising the additional piece of floor I'd need to access this position, and also because it meant I could use a bigger battery which is being hidden behind the cab.

 

Its operation is not quite prototypical, as real ones can lower the front of the upper deck as well. I have compromised by fixing this point and only being able to lower the rear part, as it makes the mechanism far simpler - a motor winds in a fishing line which pulls the front bit of the upper deck downwards, gravity pulls the deck down when you wind the line out. The rear ramps are simply mounted to a nut and constrained so they can't rotate, a motor turns the threaded rod which makes the ramps move. The rest is just normal driving motor mounted underneath, and steering servo mounted inside the cab with the receiver. It has no lights for now (Oxford's Scania cab moulding has painted bits for lights rather than actual light lenses, so they wouldn't look amazing), but when I get the Land Rovers done I might include hazard lights for when I park it on the road, getting in everyone's way like the real ones do 🙂

 

Other improvements I made included cutting off the quite poor moulded wheel holders and made new ones of these out of 0.4mm brass, and I've also cut off the handrails which were massively thick and looked silly - these have been replaced with much finer wire.

 

 

[Pikey]

Giles and otherplanet - I've worked out (well, found out, almost by accident) what was wrong. All of my other models have the protocol set to:

Type: DSM

Subtype: 2 1F

Status: V1.3.3.0 AETR

Ch. Range: 1-6

 

The problem ones which showed weird behaviour (two buses and the truck I'm doing for Manchester Model Railway Club) had this set to channels 1-12. As soon as I changed this setting to 1-6 the models respond as normal!

Edited September 27, 2023 by Pikey

[Giles]

Good to know....! 

[Phil Bullock]

Saw this at Redditch ….. absolutely brilliant!!!

[Jon Harbour]

The engineering involved in this is just tremendous. Such a cool layout to see. 

[Nigelcliffe]

13 hours ago, Pikey said:

.....

 

At the same show, we also premiered my conversion of an Oxford Diecast car transporter, which can deliver up to 8 of the Turbo Racing minis (we only have 3). ....

 

Is anyone else thinking could use the inside of a 7 inch drain pipe, and humming "The Self Preservation Society"....  

 

 

 

 

[PhilJ W]

1 hour ago, Nigelcliffe said:

Is anyone else thinking could use the inside of a 7 inch drain pipe, and humming "The Self Preservation Society"....  

To be to scale (00 1/76) a 2" pipe would be more appropriate.

[37114]

Brilliant stuff, I saw this at Cheltenham last year and was really impressed.

[Jon Harbour]

They never quite got one to manage the complete "barrel roll" though - the stunt men wrote off several minis trying though!

 

I so wanted to post an image of that, but conscious of coypyright!

[otherplanet]

17 hours ago, Pikey said:

Very kind comments, but anyone who can drive a digger can drive one of these - the controls are exactly the same. :-)

 

At the same show, we also premiered my conversion of an Oxford Diecast car transporter, which can deliver up to 8 of the Turbo Racing minis (we only have 3). My ultimate plan is to convert various Land Rover / Range Rover models, and deliver up to probably 6 of them to the JLR dealership on the layout. The Evoque on the lower deck at the front of the truck is glued in place, partially as I didn't think it was worth motorising the additional piece of floor I'd need to access this position, and also because it meant I could use a bigger battery which is being hidden behind the cab.

 

Its operation is not quite prototypical, as real ones can lower the front of the upper deck as well. I have compromised by fixing this point and only being able to lower the rear part, as it makes the mechanism far simpler - a motor winds in a fishing line which pulls the front bit of the upper deck downwards, gravity pulls the deck down when you wind the line out. The rear ramps are simply mounted to a nut and constrained so they can't rotate, a motor turns the threaded rod which makes the ramps move. The rest is just normal driving motor mounted underneath, and steering servo mounted inside the cab with the receiver. It has no lights for now (Oxford's Scania cab moulding has painted bits for lights rather than actual light lenses, so they wouldn't look amazing), but when I get the Land Rovers done I might include hazard lights for when I park it on the road, getting in everyone's way like the real ones do 🙂

 

Other improvements I made included cutting off the quite poor moulded wheel holders and made new ones of these out of 0.4mm brass, and I've also cut off the handrails which were massively thick and looked silly - these have been replaced with much finer wire.

 

 

That's really nice work. Hats off to you.

 

And we'll done for finding that problem on the buses. That is a good trip to keep an eye out for.

 

 

[Pikey]

38 minutes ago, 37114 said:

Brilliant stuff, I saw this at Cheltenham last year and was really impressed.

Actually you saw the previous version of the layout - we completely built a new one from scratch over the winter 🙂