Ghostbusters GB1 Semi-Hero Ghost Trap WIP

Having been an RPF member for some years it occurred to me I've never posted a build thread here. With that in mind I thought I'd share a build I've got going on GBFans here too It's a copy and paste so if anything is unclear I can explain my GBfans references if they don't make sense.

I love Ghostbusters and always wanted to get all the busting-gear but I thought it best to start small and work up, so I decided to build a trap first. I chose the excellent Nick-a-Tron V2 kit as the basis for my build.

I want to do something different to a straight build by incorporating the cartridge release mechanism as used on the GB1 hero prop, which as far as I know hasn't been tried on a resin trap kit before- making this build a kind of semi-hero in a similar vein to the GB2 proton packs. I'll also be fitting a hyperdyne servo and light kit.

The first thing I plan to do is install a track system like the GB1 hero has. The problem is the base of the nick-a-tron kit needs to be cut down to allow for the extra depth... oh well here goes!



A bit of P38 filler to fix the odd hiccup from the cutting down process!



Not too bad once sanded down



Cut the track from aluminium strips. Only sizes I could find but hopefully a close enough approximation. Then a trial fit together to see how she looks!



The top of the cartridge was then glued in place with epoxy resin, then once that was set solid I filled the gaps around the seam with P38 car body filler leaving me with this:



As this is going to be a hero trap I need to think about cable routing as I assemble the kit. I started by marking out where the front indicator block will go, and from that where to cut a slot for the bargraph cabling





Then it was onto the indicator block itself. I drilled through at the angle I wanted



Then opened it up with the Dremel



I think that should do the trick



Now onto the rear of the cartridge to open up space for the D-sub connector.






I've decided to try to include as many of the little details from the Propbay Hero pictures as I can, in this case namely the side plate fixing bolts.

I noticed in the propbay images that there are five screws running along the bottom of each side plate, countersunk VERY close to the edge.



They're not that visible, but as i'm doing a hero build I thought they should be present. It was a bit daunting but i've drilled as near to the edge of each plate as I dared and i'm quite pleased with how it turned out.







I've also added the screw above the metal side plates. It's not in 100% accurate position fore/aft due to differences in proportion between the real prop and the trap kit but I think I have the height about right



Time to bolt down the tracks. I think there's too much of a gap between the front of the trap and the rails. Measure twice...



In order to fit the release mechanism for the cartridge the resin handle post on the nick-a-tron kit needs to be replaced, as I felt it would be too weak to support the weight of the trap with the metal tracks fitted if I cut a slot in it. I wanted an aluminium one but money is a bit tight so I thought i'd try to make my own!

I started with a piece of aluminium box section and copied the curve from the resin handle post onto it, then chain-drilled the shape out.



Then I ground it out smooth with a dremel





My plan was to epoxy the resin handle in place and simply drill through it to put the release catch in but...



I soon realised that it would be difficult to drill out the resin for the return spring which would be needed to operate the catch. I decided to make an aluminium one to replace it. As I can't weld I was going to epoxy it in place but I was worried about the strength of the handle with the heavy weight of the trap. My brother came to the rescue with a bright idea- as neither of us can weld he suggested an alloy repair product which can be "welded" with only a propane torch.

Here's the result:

As I've mentioned the plan is to install electronics in the trap which I've kind of been dreading as access to the trap cartridge interior is a bit tight. It'd be like trying to install servos and boards through a letterbox! I took a look at the hero trap again and you can see the trap cartridge has a separate base:



This got me thinking.. If I do a similar thing on my build I can use the base as a "motherboard" to install my hyperdyne boards, servos and smoke with plenty of access allowing neater installation of cabling etc. Then I can simply install the cartridge outer over the top of the completed assembly. That's the plan anyway! So it's chopping time again which left me with this:



In a continuing theme on this build, I'll be replacing the base with aluminium



Yeah I know the screws probably aren't accurate, but we've never seen the bottom of the screen used cartridge (which is probably welded anyway) and it helps to have the accurate look of a separate base, not to mention saving me scraped knuckles during the electronics phase later!



Just go to round those base corners off and that's the base done until i'm ready for electronics. I've made and fitted the retaining catch to the cartridge. It's not 100% accurate ( it isn't a bent piece of metal plate) but I had an off cut lying around that I thought I'd use so it's recycling really



Just to give me a break from all this metal work I had a go at doing fake welds on the battery box.
First attempt:


Second attempt!



I rounded off the sharp corners of the cartridge base and started work on the cosmetic plating. Here's my work in progress front plate. I've decided to have a go at recreating the shear cut look of the hero trap by filing the edges at an angle.

The trap plating has been test fitted, and I spent about 30 mins per plate trying to get the edges looking right. The plates still need final finishing but it's starting to look like a ghost trap at last!





I'm also adding the side details to the cartridge. I started with the discs, a knightmare to mark out but easy to make once I'd worked out how. I think the vents may be more difficult but I'm up for a challenge!



Next up it's the wheels! wheee! Did a bit more chopping



Made some wheel bearings and axles



and voila! A rolling chassis!

Hole made in handle and opened up into a slot with jewellers files for the cartridge release lever



Slots all cut for now. I think they may need to be made longer but i'd rather take too little out than too much at this stage until i've made the final catch to go in there.



Prototype release catch



I've also made a new battery box cover as I sanded the resin one too thin on one end- oops. I've also rounded off the top corners of the battery box and used a file to put slots at the corners to try give the impression it's folded metal.



Now..the accepted wisdom is that the original trap was painted satin black.. but I've been experimenting with different finishes for the trap, and I think i've made a bit of a discovery. I don't think the hero trap was painted at all! I think it was treated with this stuff:



I've decided to use this on the tracks as it oxidises the alloy rather than coating it, adding zero thickness which will allow the tracks to run as smoothly as before treatment On my test piece i've notice it has the same slightly patchy, almost translucent quality as the finish on the Hero. Also it doesn't take so well on the edges if you do a relatively quick coat, which also appears to match the hero trap:





See what I mean?




Quick update- new battery cover drilled and finished today. As I had to make a new one anyway I thought I'd make some changes. I made this cover slightly smaller than the original, and I've moved the light, switch and bolt locations to look more accurate.

Quick clean up after drilling



then drilled holes for the bolts into the battery box



and used these threaded inserts for durability





Time to try the alu black on a larger plate




Looks pretty rough so it's about right!

Things have not gone according to plan! I've had alignment issues caused by the base being out of square, which pretty much meant I couldn't get a functioning trap until it was rectified. That's the trouble when you add perfectly square metal parts to a resin kit, things don't always line up as before. The only way to fix the base was to take it all apart and machine it square.

This made the base too short so I had to build it back up with styrene.



And then I started down a slippery slope. I wasn't entirely happy with the way the cartridge stuck out more since I put a metal bottom on it, so I thought why not add a bit more styrene to lengthen the base further. I'd need to move the tracks a little I thought to myself but it was worth it as I had the filler out and they weren't quite right before anyway.



Now, this made the bottom layer of tracks too short. That's ok, I thought i'll just redo the bottom layer.



Then my OCD took hold. Basically even with chopped-down base depth the cartridge sat too high in the trap for my liking. (see pic below)



So, after much deliberation, I decided to redo all my previous work on the tracks. My first tracks we're too thick, the wrong widths (I just used whatever my local DIY place had), and were held with screws that were far too big! By switching to thinner metal tracks I could reduce the height a little and improve screen accuracy at the same time! so I started playing about with different thicknesses and bolt sizes. See how oversized the previous heads were? New size bolt is fitted on the left track for comparison:



After poring over reference pics I settled on new sizes. Ladies and gentlemen, may I present hero tracks MKII- Lower and longer with wider upper tracks!



and GB1 hero for comparison



I'm pretty happy with it and it's improved the cartridge appearance quite a bit.



That's all the stuff you've kind of already seen before out of the way it's on to new stuff. After disastrous attempts to make my own aluminium vents, which I won't show you to protect your vision, I stumbled across a cheat. DIY Soffit vents!

They require a fair bit of chopping and layering up before they're thick enough to work with though



Rough first attempt



Should look the part once finished off





Now, onto the bargraph. This bit was fun!



The plate cutout isn't big enough for the more accurate bargraph so I filed it out larger.



Finished bargraph with added 3mm white LED in lieu of inaccurate yellow standard Hyperdyne one. You can also see the extra seam detailing i've added to the lip of the cartridge opening to mirror the hero in this pic.

Wow some incredible dedication to accuracy there. Definitely going to be keeping an eye on this build!

VioletSun said:

Wow some incredible dedication to accuracy there. Definitely going to be keeping an eye on this build!

Click to expand...

Thanks

Had a bit of a setback....



Dropped the back plate on a concrete paving slab with the handle attached. Aluminum 1, resin 0. Tried to rebuild it with epoxy resin and milliput but it's just not strong enough. Working on a fix now. Aluminium may be added! ( just a side note - you can see here I've reshaped the trap side plates to more closely resemble the propbay hero trap, and also the filled holes where I've shifted everything back.

I also cut the rear of the side plates down a little as they looked more like the GB2 trap before.



Ok so Here's my repair progress so far:

Trimmed repair piece down from a piece of square tube with fibreglass cutting disc (nearly worn out they're usually bigger!)



Started cutout for release catch. Will extend and clean this up with jewellers files later



So here it is welded to the handle and bolted in place. I'm not sure what I think of it as it has added thickness to the back plate, which now doesn't look right, and a join at the front to deal with.



I'm also left with a redundant hole in the handle. I could attempt to fill this in with brazing rod, but I'm worried about heating this close to the handle welds. I could just use filler but that stops me using aluminum black as I'd planned.

Yep, you've got some real hands on skills there. You should be proud of that.
Very time consuming but more satisfaction at the end of the build.
No 3D printing here.....
Thanks for posting
Nice job!

.

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Very clean work! Looking forward to seeing more!

Sean

Awesome fabrication skills!

Thanks for the lovely comments people I do have some more build progress to copy from my GBfans thread to bring this post up to date... Stand by!

Solid work! Excellent fake welds by the way

Next up I wanted to replace the resin doors which came with the trap kit. There's nothing really wrong with them they just lack the pocket machining on the back. After working on ways to achieve this, I ended up getting some custom made in Aluminium.

Myself, Barison82 and CPU64 on Gbfans were in discussion for some time as to the correct details and spacings for these doors, but we got there in the end! Chris (CPU64) made a couple of sets of these for our Nick-a-tron kits and we couldn't be more pleased. Here they are alongside my first two 3d printed attempts at solving the problem!



Basically I printed test versions of Count Spatulas 3D doors and modified them to fit Nicks kit (both off center and straight versions), neither of which look quite right when compared to CPU64's when viewed from the rear. The offset on the final doors we have is somewhere between the two, giving us more accurate spacings around the pocket machining on the back.

CPU's done an amazing job of them Here's some pics of the doors offered up to the trap- I've just thrown all the bits together with tape for the moment but it gives you an idea of how they'll look anyway.





I started to fit the doors, which are a bit fiddly to get right for a first time trap builder. One bolt mounting hole ended up in the right place but the other one drifted off and I've had to fill it in to re-do it.

While I had the milliput out I've done a few other things on the to-do list at the same time:

Added a bit more to the door lug "welds" as I wasn't totally happy with them





Filled in the unwanted extra vent holes in my cartridge vents



and.... Started to make another new vent in light of a new detail I've just noticed. For the RH side of the cartridge I went with a mirror image of the well-known with an inverted metal disc but it seems that I'll have to change it as the real thing has another vent there!

It's different to the other vents in that the slots seem to run longitudinally



Ok I'd better make one then. I didn't show how I made my other vents in much detail so I thought I would this time in case anyone else wants to add them to their builds.

You start with some soffit vent strip from a DIY store. Mark your vents out and score along the lines carefully with a sharp knife and a steel rule 3-4 times



turn the strip over and using some side cutters snip through the channels on the back level with the scored lines



Then bend the strips back and forth a few times along the scored lines to snap the strip into sections leaving you with this



Now we want to remove the plastic channels from the back. As before, score with a knife a few times near the base of the channels



and snap off



This will leave a couple of ridges to file off



one nearly done



then give it a light sand



You need to do this to two sections of soffit to make each vent as we will be layering them up



Sand the rear of one section and the front of the other with course sandpaper to provide a key for the glue. Then get yourself some 5 min epoxy, clear sellotape/scotch tape and some clamps if you have them (tape will do if not)



Apply glue to one surface only and tape/clamp together



Leave until glue has set to full strength then sand the edges flat and smooth



After this it will need shaping with a jewellers file and sanding smooth ready for paint which I will do next time.

propmaster2000 said:

No 3D printing here.....

Click to expand...

I do have some 3D printing going on- The bar graph is 3D printed but it's the only 3d printed part to make the cut so far :lol

- - - Updated - - -

Sundowner said:

Solid work! Excellent fake welds by the way

Click to expand...

Thanks! They took a bit of practice but I've told it's an essential skill to acquire for Ghostbusters prop building

propmaster2000 said:

3D printed bargraph?
.

Click to expand...

Yeah it's a replica of the incandescent bar graph used in the hero thrower and trap in GB1. It's basically a 3D printed frame with layers of tint and a printed graphic to replicate the contacts visible in the incandescent original part. It's made by Spongeface on GBfans and is usually used in pack builds but I thought it belonged in a trap build too.

propmaster2000 said:

Are you going to have a working, lighted bargraph as well as motorized doors?

Click to expand...

I certainly am I'm fitting the Hyperdyne light kit with the optional servo control board to operate the doors, it will also smoke using a modified e-cig and pump system.

Completed cartridge vents started last time

Filed the edges square both along and across the edge- the gap between the layers won't be visible once painted.



Rounded the corners off with a file



Filed the bevel around the edge



Opposite side vents mounted!



and doors are now in place



I've made a rudimentary smoke system to experiment with. I'm going to borrow an idea I saw in another trap build thread and have functional front knobs, controlling the amount of smoke and airflow. I started on the knobs today, took ages to get the placement how I wanted them. Once I'd drilled the plate I screwed it back on and used it to mark and drill the hole locations for the knobs.



The outer square ones will have fixed pins and won't turn. I've just epoxied in steel spring pins for these. The larger holes will accommodate the shafts of switching potentiometers which will turn on/adjust the smoke



The pots are quite large but they are the only ones I could get hold of that also switch. I'm going to mount these to a cut down PCB board screwed to the back of the cartridge inner corner "posts". I had to Dremel and file this area out to flatten it out enough to fit the board.





Something like this



"Smoke control board" fitted! (Please excuse the mess in the background!)



Pot shafts trimmed down ready for knob fitting

That is awesome, great fabrication work and love the progress shots!

Thanks I like to post the work in progress so people can see how it was done. As we're a forum of builders I think it's just as important to show HOW you made it as WHAT you made! I hate those threads that just show you the finished item without any of the build!