Scrapyard grappler grab crane - Scratchbuilt & modified kit

Have any questions or tips and advice on how to build those bits that don't come ready made.
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0121modeller
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Scrapyard grappler grab crane - Scratchbuilt & modified kit

Postby 0121modeller » Fri Jan 13, 2012 7:51 pm

As a part of a main theme on my forthcoming new model railway project, I recently found some photo's that I'd taken last year of my initial starting to build a scratchbuilt scrapyard crane for my project, the photo's in this post will include those all important "how I made this" tutorials that I like to post, I've only just re-discovered these photo's finding them buried amongst my other modelling photo's :D

We start with the claws
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Evergreen styrene #236 (12.7mm round tube) & evergreen #155 1.5mm x 2.5mm (strip) were used here for the claws.
2 sections of #236 were cut approx 3mm wide, then both were cut exactly in half. Then I think I used Evergreen strip #155 (1.5mm x 2.5mm) wrapping it around the outside of a tinlet of paint, then wrapped around a marker pen as to gain a curved profile (long curved piece of styrene seen in photo) , once a decent curve was achieved I overlayed this on one of the #236 claws marking with a pencil where to cut, cut the #155 strip into smaller lengths & put these curled up inside the recess of a paint tinlet lid as shown below...

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I left the #155 strips for a few hours curled up, then fixed each of these to the outerside of each #236
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I used Evergreen #4501 embossed tile , 8 of square tile sections cut as shown , then I drilled a 1mm hole in the centres & cut off 2 corners on each piece.
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Attatching the above on using plastic weld , allow to fully dry , then the tips of all 4 claws tapered down with a file , not fileing too much & ensureing each claw is alike.
The tube section in the centre (plastruct TBFS8) will be the main holding for the 4 claws as shown in my next post...
Last edited by 0121modeller on Fri Oct 18, 2013 2:22 am, edited 4 times in total.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby 0121modeller » Fri Jan 13, 2012 8:48 pm

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I cut 4 plastruct (or evergreen, I forget which I used) tubes for the hydraulic piston housings, 1mm aluminium rods were cut to size & inserted
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My appologies for not being more specific here about exactly "what & how" regarding these photo's, as its been a while, so "what, how & why" are out of my memory, but I'm hopeing you get the general idea from my brief text & photo's for what I've started here..., however, a lot of scratchbuilding is down to trial & error as I found out- mistakes & mis-judgements/ wasted time & materials will often be encountered, my recycling drawers of bodged but re-usuable bits & pieces is now overflowing !
What you can see that I've done so far on this part of the crane is a fairly good representation I reckon :D .

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A 1mm hole is drilled as to enable the claw assembly to the main arm, hydraulic pipes to the 4 pistons to be added, I think that may be the next stage.

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This 1:87 diecast model (possibly by Motorart) is possibly a little underscale, so rather than risk butchering this model as to replace the scooper bucket with my scratchbuilt claws assembly, I've decided to take on scratchbuilding the whole wheelbase & body out of mostly styrene, the diecast model will be a perfect guide for scratchbuilding this, so the Motorart diecast model is better left in tact.

To be continued....
Last edited by 0121modeller on Wed Feb 22, 2012 6:09 pm, edited 1 time in total.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby Bufferstop » Fri Jan 13, 2012 9:10 pm

Some seriously good modelling there Dave. You obviously have a very steady hand and a good eye for the detail. I'm sure I'd struggle to get the four claws to be the same length.
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Re: Scratchbuild project - Scrapyard claw armed crane

Postby jus » Sat Jan 14, 2012 10:54 am

I'll be watching with interest here. That's some serious modelling skills already on show. I so wish i had the patience and the steady hands to get anywhere close.
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Re: Scratchbuild project - Scrapyard claw armed crane

Postby 0121modeller » Tue Feb 07, 2012 7:43 pm

Thanks Jus & John :)

I drove over to deepest west Dudley today, guided by my loopy daft old satnav as to get me from Erdington B'ham to Modellers Mecca in Kingswinford Dudley (Pronounced; Dudlaay).

But my satnav's route took me out of the way & via some industrial roads that just by chance had something I'd being seeking photograpic information for my scratchbuilding project :D Scrapyards with claw cranes !

I visited 2 yards & I must say after requesting permission they were really friendly & very interested in the modelling cause of my requested photo's.
The drivers of both yard cranes were very helpfull poseing their vehicle in various positions for me as follows ;
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Scratchbuilding plans for something based on the above will start tommorow.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby Bufferstop » Tue Feb 07, 2012 11:51 pm

What? No Iron Fairies. Always got stuck behind one of them when I ventured into that territory. It's a great area for rough and ready industrial space fillers. Sat in my car one day waiting for the guy from the borough surveyors office to tun up and after looking at it for about ten minutes I realised the railings around the top of a fence were sections of Decauville 60cm portable track. It looks just like 1950s Hornby tinplate O gauge rails. The gates were locked and there was something fierce prowling the other side so I couldn't tell if there was any other contractors stuff in there.
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Re: Scratchbuild project - Scrapyard claw armed crane

Postby SouthernBoy » Wed Feb 08, 2012 9:23 pm

Most impressive... looking through your series of 'how to' pictures it all looks quite straightforward: But in reality I'm sure it took some thought and patience ... so double-top marks from me :)

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby cmeonthemove » Wed Feb 08, 2012 10:04 pm

Brilliant work on the grab assembly Dave. When you take photos of a scratchbuild it always looks so simple but it's anything but! Look forward to seeing the rest of the machine develop (and hats off to you for scratchbuilding something like this in 1/76!).

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby 0121modeller » Sat Feb 11, 2012 12:55 am

Cheers Mark & Chris :)
After printing out some referance photo's I decided to make a start on the chassis. I rumaged through my spare parts drawers for suitable items I could use, things like suitably sized wheels & axle widths, steering wheel & a componant from lego technic which I modified to suit its purpose, the item from lego will feature in the next post.
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Above; Luckily, the wheels & tyres came off the axle enableing me to have double tyres alround.
The steering wheel was salvaged from a Lesney diecast forklift with in-complete forks, the seat was from another lesney diecast suitable only for spares, & the wheels, tyres & axle sets from 1/87 diecast models from Siku, Wiking, etc.

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The diecast excavator also in the photo is from Motorart, its 1/87 scale but in my opinion quite acceptabe for 1/76 scale as the railworker stands next to it. This diecast vehicle will be an ideal guide as to build, the model I'm building will be ever-so slightly longer & wider so making it closer to 1/76 scale, as shown by my scale converter rule, my scratchbuilt model will be approximately 15ft long.
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Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby 0121modeller » Sat Feb 11, 2012 1:53 am

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The gear cog was used as a cutting guide for a spaceing plate cut to size using Evergreen #4516 , the plate(s) will be attatched to the one side of gear cog.
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You'll see there's also a black gear cog from a Lima 47, I considered using this instead of the lego componant, but the Lima gear cog is a little too small & thin, possibly lima Bo-Bo loco's have larger gears would be suited if doubled, though I reckon this lima cog may be suited for an N gauge scratchbuild project of an excavator, grabcrane or similar ? worth a thought for maticulus master modellers N gauge..., cmeon Chris, SB Mark & you too Zunnan :D
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& the round plate fixed into place using EMA Plastic Weld solvent, the lego I think is a differnt compound of plastic than the styrene, lego is more like that other Plastruct that is either ABS or Butyrate, anyway, in this case a solvent such as Revel Contacta or Humbrol Precision Poly wont fuse these together, so use either EMA Plastic Weld or De-luxe Plastic magic.
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The underside spacing plates were also cut easily using Evergreen #4516 . I needed something circular to draw round for a guide to cutting & fileing, I had'nt got a 5p coin or similar to hand, so I used that gear cog from a caniblized class 47 project.

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Using a 3mm drill by thumb & finger rotation, I carefully drilled through the styrene spacer plates, this hole will be the option for the upper body rotation pivot shaft...

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Unwanted excess from lego cog cut off with sprue cutters, the other side already done, I then filed the one side of cog down to 2/3 thickness as shown in a photo below..,

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Then the smaller plates fused on for the underside of gear cog...

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Oops :oops: , I forgot to mention, I filed the one face of the lego gear cog to 2/3 of the size as shown, (obviously before those styrene plates on the RH side were fixed on).

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The item is now proprtionally sized for my scratchbuilt grab-jawed scrapyard crane.
To be continued in a day or two.
Last edited by 0121modeller on Sat Feb 11, 2012 2:33 am, edited 4 times in total.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby Tiago&Nats » Sat Feb 11, 2012 2:02 am

very interesting build mate. you sure it will all fit the 1:76 scale???

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Re: Scratchbuild project - Scrapyard claw armed crane

Postby 0121modeller » Sat Feb 11, 2012 2:50 am

That large gear cog you mean ?
Yes, It'll be there-abouts 1/76 scale, the motorart diecast excavator is 1/87 so a little underscale, so adding 3mm or 4mm to my scratchbuilt wheelbase length & increased size to other dimensions & features in proportion should look a fair representation in 1/76 scale. The real vehicles (excavator shown & photo's of grabcrane) share similar dimensions regarding chassis/wheelbase, outrigger/stabilizering feet & other upper body features (excluding the grabclaw feature).

Also,the diecast excavator model does'nt show the large gear/cog mechanism that rotates upper body, but the orange grabcrane in my previous posts clearly shows this design feature (unlike the more modern looking red grabcrane in my other photo's posted) , I'll be baseing my model on the orange crane version, or a sort of hybrid version of the two :D

Dave.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: END OF DAYS 2012- Scrapyard claw grab crane

Postby 0121modeller » Tue Feb 14, 2012 1:53 am

Small update;
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Back to my modelling bench as to continue... those 2 clear plastic trays seen at the rear lower work surface are various offcuts of styrene strip, rod, profile, sheet, etc from Evergreen & Plastruct, I'm trying to use whatever I can from these trays rather than use full length componants.

It was now I relized just how complex this project would be, I rarely plan stuff on paper, prefering to build as I go in various stages, the finished model will hopefully turn out to look reasonably accurate & I'm determined to see this through especially now I've started this thread, & I have more projects in the pipeline , scratchbuilt PXA scrapwagons next, but that should be easy compared to building this scrapyard grab crane !

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I had to give more thought about the size of the wheelbase toal area, Various embossed sheet styrene from evergreen I find ideal for this sort of thing, as, cutting accurate rightangles is easy, just lightly score the recess to required size & Bob's your uncle !.

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The louvre vents for the engine compartment are from Dornaplas, I just needed to remove some excess flashing between louvres with a fibreglass pencil.

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Positioning of the wheels & their axles, they'll screwed on as dismantling will be neccesary whilst building other parts, also being able to dismantle something makes repair & modifications/rectifications so much easier :D

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The wheels & axles were placed temporary, I may need to re-position those axles, another piece of styrene was tacked in place (no photo due to upload issue) to keep those axles & wheels moving sideways, also (no photo) a hole was drilled in the underside centre for a tiny screw to retain the gear cog.

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Other assembled componants awaiting fitment,

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Cab body panels were made, scale size of cab being 3ft wide x 5ft length x 6ft high approx

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Crane cab body half built, the floor, roof, some interior & exteral fittings needed.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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Re: END OF DAYS 2012- Scrapyard claw grab crane

Postby 0121modeller » Mon Feb 27, 2012 8:46 am

Appologies for delayed update,
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On to the making of the what I think is known as the outriggers & support feet.
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Duplicate componants of varius styrene strip & profile were cut to what I consider to be a fairly accurate 4mm=ft scale scale size based on my photo's of the real thing...,
The positioning of legs & feet was decided, & lightly tacked together with a spot of Revel Contacta, i say only lightly as I may decide to tweek the postition of those legs or the option to have the legs pivoted as shown in one of the photo's below.

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A 1.2mm hole was drilled,

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A view of both componants assembled,

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A 1.2mm rod was inserted, with the pivot rivots exposed after cutting as seen below;

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Able to pivot, the option for upturned feet is shown,

to be continued.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342

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0121modeller
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Re: END OF DAYS 2012- Scrapyard claw grab crane

Postby 0121modeller » Sat Mar 03, 2012 10:52 pm

Small update on progression;
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The stabilizing outrigger feet assemblies were modified as so they could be removed or put in place held by tiny screws.

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Next, the upper rear body, on one of the real examples the end profile is curved (see my photos in a few posts back)
Some 1mm / 40 thou plasticard was cut a to 1mm oversize for the width, cut to required height & then this was wrapped around a suitable former, held in place with a "P" clip & this was dipped in a cup of fairly hot water for a minuit.
Top & botton pieces were marked for cutting...
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& both fixed on as shown above, I fitted a central support (top to bottom at the green mark) as to re-enforce the curve...
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I then filled both sides of divided curved recess with a product known as Liquid Gravity by De-luxe materials, then secured it all in with a 1.5mm thick backing plate fused on using Revell Contacta.

With regards the rest of upper body, the engine compartment area & cab already built (but not fitted on), I'm about to begin working on the crane main lifting arms assembly, I reckon this'll be the most difficult part, as to get every componant to as near as possible to scale size & then all the other componants assembled together to look just right proportionally.
Will update this project again in a few days.
Scratchbuilding 4mm scale JXA scrapwagons ; - viewtopic.php?f=6&t=37620
Scratchbuilt & kit built grappler claw cranes ; - viewtopic.php?f=6&t=36342


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