Plasser-Theurer General Purpose Crane

[ColletArrow]

Warning: long post ahead! Go and get your cuppa first...

This thread was supposed to be my 3-stage WIP-story and entry for the BMR OcTRAINber 2019 Technic Challenge. I was ecstatic when the theme was announced, trains+technic is exactly what I like building. Unfortunately, life conspired against me, and I have no access to my bricks this month. I can still enter the contest, but with an unpublished 3.5-year-old version of the model, rather than a new one as I would have liked. This also means the pictures and videos are far from ideal, since they were only taken for a personal record rather than a contest entry. Nevertheless, here we go.

My subject: the British Railways Plasser Theurer "General Purpose Crane" GPC72. A fairly simple, robust and versatile self-propelled maintenance crane, they were often used for track laying. They could be coupled up and work in tandem to replace large track panels on double track lines, or work over one end lifting individual rails and components. For a whole host of prototype photos, visit Paul Bartlett's amazing site: https://paulbartlett.zenfolio.com/plassercrane

My model V1 was built in March 2015. I had only recently acquired Power Functions components, and decided to have a go at building a decent, functioning rail crane. The result looks a bit of a mess, but worked rather well and proved the concept worked in LEGO.

The two switches were used to operate the two m-motors, mounted side-by-side under the chassis. The nearest one is clearly connected directly to the winch spool, whilst the far one operated a gear train to slew the superstructure. The boom was raised and lowered manually, using the mini linear actuator - I'd ran out of motors and space by this point, and the switches meant this was never going to be a fully remote-controlled model anyway.

Of course, it was a bit of a cheat. Power, propulsion, and speed control of the functions was provided by a "PF wagon". I could have built it into a Class 08... but I didn't. Overall, the crane worked surprisingly well and was great to play simulate operations with, but it just looked a bit... odd. I wasn't really satisfied with messy cables and the PF wagon either.

Therefore, a year later, V2 was built. The functionality and controls remained exactly the same, but everything from the mechanism to the aesthetics was rebuilt from the ground up. And she looks much better for it!

Slightly longer buffer-to-buffer and adhering to my now-standard 7w (perfect for British models), there's more space to fit everything in. The battery box is mounted sideways under the front bonnet, which makes it slightly too blocky for the prototype but it looks good enough. The motors are in similar positions to before, and the switches have moved to the rear bonnet. The IR receiver was the one component I didn't bother to hide, but the real thing has a fair amount of clutter above deck too so I wasn't too bothered.

The boom is only red because I didn't have a yellow one when I took these photos! Use of this part over standard bricks allowed me to include boom extension as a manual function.

Eventually I got a yellow boom, and replaced the over-sized pulleys with twice as many smaller ones. Note that the battery box had also been stolen for something else by this point!

Annoyingly, these sub-standard photos and unpolished model must be my entry for "OcTRAINber - The Technic Challenge", since it's the latest model I've built and filmed. So here it is.

But that doesn't mean this model doesn't stop there! I've been building several digital versions since 2016, culminating in V3 - the ultimate. This was what I'd hoped to get home, build and enter for the contest, but it's not going to happen until at least Christmas now. 

With cleaner (if blockier) lines, stronger motor mountings and another complete redesign for the superstructure, she's better than ever. I pondered fitting in a micro motor to control the boom remotely, but it didn't sit well, would prevent unlimited 360-degree rotation, and I can't find many sold in the UK. I did make sure this design allows easy replacement of the switches with an IR receiver though, and vice-versa.

If some of the part choices seem a little odd, it's because I'm planning to build it from my existing collection of bricks - I hope to build this latest model, if there's time over Christmas.

Until then, more photos and V3's LDD file are available at https://bricksafe.com/pages/Collet22/general-purpose-crane. Happy building! 

Edited October 23, 2019 by ColletArrow
Video added

[Roadmonkeytj]

I love it cant wait to see it finished! The revisions and changes are great ... I actually was (am) building a rail crane as well only much larger lol but i feel ya on life getting in the way ... I just worked out the boom gearing this morning lol so saddly mine will not be competing.  Thanks for sharing ... Great minds think alike

[LEGO Train 12 Volts]

Super! Beautiful version! 

[Paperinik77pk]

I love it!!! Thumbs up!

[ColletArrow]

On 10/23/2019 at 9:28 PM, ColletArrow said:

I hope to build this latest model, if there's time over Christmas.

Christmas, yeah, that happened didn't it...

Suddenly, I found myself with plenty of unused time, and not much to do in it. Let's get this thing built then...

First up was the technic core of the model. This features two M-motors; one for the slewing and the other for the winch.

This was followed by the rest of the chassis; the battery box sits on it's side over the train motor front bogie, whilst the rear bonnet houses a pair of switches to control the m-motors. The undisguised IR receiver on the deck controls the train motor on one output, and the switches on the other to limit the motor speeds.

The motors have also had cowling built around the gearbox. The various brackets are to keep the PF cables roughly in place!

Finally the superstructure was built, and she's finished. Since the WIP photos above, I have decided that the switches were too inconvenient, and swapped them out for a secondary IR receiver. I also slightly rearranged the rotation mechanism to eliminate some wobble, streamlined the winch cable path to eliminate friction, and added some bracing around the superstructure to stop it tilting forwards.

The gear on the side controls mini LA that elevates the boom. It's still manual, but with a little gearing-up so it's not too slow to operate. The boom can be extended by hand, too. The black grille on the side near the front is the battery box switch; theoretically you can see the green light through it, but since the primary IR receiver is completely exposed it's much easier to see the light on that instead.

I'm very happy with this angle; the rear of the superstructure barely hangs out, and I love the cab window for some reason. The cheese slopes on the rear bonnet are knock-off LEGO equivalents that are 1 brick tall rather than 2/3; somehow, the superstructure still clears them (by 1mm in a few places!), and can therefore rotate indefinitely. 

 

But she's a little plain on her own; since the vehicle is self-propelled it needed a wagon to tow along. After (too) much deliberation I settled on a short-wheelbase open wagon, with hinged side doors. I can't think of any BR prototypes where the entire side can be dropped like this, but it's just the right length to carry spare rails or other odds and ends.

And then because this is 1970s British Railways, if this is going out for a run then it needs a brake van. So I rebuilt my trusty 20T brake van into Civil Engineers (commonly known as 'Dutch') livery, and it looks pretty smart too.

Only, by this point I've used up all my standard axle assemblies and couplings. Therefore, the van runs on technic bricks and axles concealed by the running boards, and the buffers are in fact small train wheels mounted backwards. Be honest - did you spot that's what they were?

Overall, I think the little works train looks a treat all together. 

At this point, I want to link a video. I carefully shot and edited one, but didn't count on the home WiFi being so poor that it would take many hours to upload, and finding a time when no-one else is trying to use it for work is difficult. So that may have to wait until October, when I'm back at Uni with faster and less stressed WiFi!

**EDIT 8th July 2020 - Upgraded home WiFi means the video is finally here!**

**Back to the original post**

In the mean time, I've linked my bricksafe folders. These contain more photos and the as-built LDD file, if you're bored and want to dig deeper into this model! If anyone intends to try building this model from the LDD, I would recommend ignoring the instructions it generates (they're nearly always impossible to follow), and use the WIP photos here as a guide to the build order.

The crane, including previous iterations and the LDD file:  https://bricksafe.com/pages/Collet22/general-purpose-crane
The rolling stock: https://bricksafe.com/pages/Collet22/rolling-stock

Thanks for reading, and well done if you understood all of my ramblings!

Edited July 8, 2020 by ColletArrow
Added video

[Phil B]

Excellent work! Love how you did the motors under the carriage, and how you detailed the build process.

Could you mount the main IR receiver face-down instead of straight up? So with the channel switch lying flat on the train base? It would require some serious SNOT work, but might make it look like a bit of machinery or just some structural support, and make it less of a stand-out?

[zephyr1934]

Amazing work! And lots of great details (both detailing and accessory cars)

[bogieman]

Love integrating the technic parts into the train world. Great work, between your work and Feuer Zug's tamper, we see a great assortment of track machinery.

Dave

[Feuer Zug]

Great work. All versions are good, but to see the upgrade process and accomplishments is wonderful.

[ColletArrow]

On 5/8/2020 at 1:51 PM, Phil B said:

Excellent work! Love how you did the motors under the carriage, and how you detailed the build process.

Could you mount the main IR receiver face-down instead of straight up? So with the channel switch lying flat on the train base? It would require some serious SNOT work, but might make it look like a bit of machinery or just some structural support, and make it less of a stand-out?

 

An interesting idea, so I had to try it out... 

First of all, the cable from the secondary IR receiver is pretty short; partly because it's far away, and partly because it broke once and was repaired. Lifting off the receiver exposes this mess:

The short cable forces the receiver to point forwards, so the lens is against the battery box rather than out in the open. Snot-wise it's not that tricky; a couple of jumper plates on the deck interface with the technic holes on the front of the receiver, and an extra 1x4 snot brick holds it in from behind. 

After the cable was crammed in fitted neatly, I decorated it up. I also took the opportunity to tidy the deck with some grille walkways and general clutter. 

Still fairly receiver-like, but miles better than it was! It's a lower profile and the cables are far neater. 

The IR signal doesn't seem terrible; you have to be a little more careful with aiming the controller at the lens, but since it's only controlling travel, the one function I don't use that much, it's not that inconvenient. Thanks for the tip!

23 hours ago, zephyr1934 said:

Amazing work! And lots of great details (both detailing and accessory cars)

Thank you! I'm very happy with how the wagons turned out, I think they complement the crane nicely. 

22 hours ago, bogieman said:

Love integrating the technic parts into the train world. Great work, between your work and Feuer Zug's tamper, we see a great assortment of track machinery.

Dave

Thanks! I always enjoy trying to make my models work realistically, and trains are usually big enough I can fit power functions in too. And I should admit it was seeing @Feuer Zug's machinery that reminded me I needed to post this, I took the photos about a month ago!

2 hours ago, Feuer Zug said:

Great work. All versions are good, but to see the upgrade process and accomplishments is wonderful.

Thanks! This model really shows my progress with integrating Power Functions into models. The first was very slap-dash, but the latest is much neater! Its worth noting I was happy with every version at the time I built it, but when I built the next one the older ones seem terrible to me! I'm also glad I moved away from the standard cab window I used on the first two, it was far too limiting. 

Edited May 9, 2020 by ColletArrow
Mobile formatting issues

[Phil B]

4 hours ago, ColletArrow said:

 

An interesting idea, so I had to try it out... 

<snip>

After the cable was crammed in fitted neatly, I decorated it up. I also took the opportunity to tidy the deck with some grille walkways and general clutter. 

Still fairly receiver-like, but miles better than it was! It's a lower profile and the cables are far neater. 

The IR signal doesn't seem terrible; you have to be a little more careful with aiming the controller at the lens, but since it's only controlling travel, the one function I don't use that much, it's not that inconvenient. Thanks for the tip!

That looks awesome! You could even consider adding a "Y" shaped crane arm support in there. since it's pretty close to the boom anyways. Excellent model!

One more suggestion: perhaps you can use trans-black 1x2 bricks next to the receiver to allow for better signal reception? Looks like you have LBG 1x2 bricks there now.

Edited May 9, 2020 by Phil B

[ColletArrow]

Always evolving... 

Since this crane has been built for about 3 months, it's time to rebuild it! Nothing lasts long around here. 

I've taken out most of the PF (battery box, train motor etc), in order to build a separate loco. What remains on board are the two m-motors, and a receiver - which has just had a 9V battery clip wired into the connector. This will hopefully provide compact, lightweight power to operate the crane, whilst propulsion will be provided by a loco. 

The smaller power source should enable the model to look more like the prototype:

(image source: https://images.hattons.co.uk/products/H4-GPC-002_3455119_Qty1_cat1.jpg) 

So far, the original bogies have been replaced with shorter ones, and the rear bonnet shortened since it doesn't contain a receiver anymore. All the movement is also now a lot smoother, since there are fewer PF cables all over the place. 

To be continued! 

[ColletArrow]

This model is now looking much tidier, with reasonably accurate deck equipment. The main box was built up around the IR receiver, which has been set sideways between the technic frames to keep a low profile. The signal remains responsive, provided you're on the correct side of the crane!

However, I decided to take the PP3-cabled receiver out of this model, in order to use it in a small loco (more on that soon). This model therefore doesn't contain it's own power source; instead, the cable from the IR receiver is stored in the smaller deck box, which can be opened and pulled out to attach the connector to an external battery box. I've decorated said battery box to look vaguely like a transformer/equipment box.

One negative of these downgrades is that the model is notably less stable now; partially due to being much lighter overall, and partially due to using 2x2 turntables for the bogies - they really need some tiles either side to support. On the other hand, the mechanism

More pictures and the LDD file ("Rail Maintenance GPC72 V4") can be found in the bricksafe folder: https://bricksafe.com/pages/Collet22/general-purpose-crane#

Edited July 3, 2020 by ColletArrow
Image correction

[ColletArrow]

It's finally crane-video time! This is the video for Version 3, the most recent fully-PF-equipped model, and shows the crane running and operating. I've also added this video to the first post about this version.

The slightly-downgraded Version 4 can be seen being hauled around the track in the video I uploaded recently for the 7760-inspired shunter.

I think this upload just about wraps us the story of this model. As is usually the way with my models, Version 4 will probably be dismantled in a few months when I want to use the motors or train wheels for something else more exciting. And then, further into the future, maybe Version 5...