#4938920
"Yet another trap build?!" I hear you cry. Well, yes, yes it is. There will be photos, lots of them.

Since there doesn't appear to be any build threads for Ben's kits I thought I'd do one myself. After reading some of the amazing build threads on here (shout out to bromie, damster117, Filandrius, noslliT, barison82, mburkit and a few others) I was inspired to take Ben's kit a step further, and upgrade a lot of parts where possible. It's not modelled on any one trap, more a general homage to the GB1 traps.

Trap Parts list

Trap & cartridge - Benofkent
Aluminium trap side plates, bargraph plate, cartridge front plate, battery box cover, cartridge base, rails, side rods and handle - Click Metal
Trap Vector plate - Charlesworth Dynamics
Raytheon pointer knob and skirt - eBay (I Frankensteined an MS91528-1P2B pointer knob together with the skirt from an MS91528-1F2B round knob)
Heathkit knob - user gbmichael
CAL-R MC250 resistor - eBay (maybe someone on here, seller asked me if they were for GB props rather than "proper" usage)
Cartridge rectangular side vents - Wickes
Cartridge round side vent - eBay
Front knob KN500A - RS Components
Front knob KU4025B - user gbmichael
Front slider knobs - RS Components (not 100% happy with the side of these, but couldn't find anything closer to the dimensions I wanted)
Male Foster 22-2 Connector - Radwell
M3 x 6mm countersunk socket screws - Westfield Fasteners (for side vents, cartridge base and side of trap body)
M3 x 8mm countersunk slotted screws - Westfield Fasteners (for track rails)
1/8" and 1/4" potentiometers - Farnell
Imperial socket cap and button cap screws - Modelfixings.co.uk
Flat toggle switch - Farnell ( think I might replace this with the correct Alcoswitch, as it'll cost about the same as getting a finishing nut anyway)
D-sub male / female - Farnell

On to the build!

There was some of the usual clean up, priming, sanding, priming, sanding of any 3D kit. You know the drill, I won't bore you with that.

Out of the box Ben's trap has a removeable cartridge, happy days. But, I wanted to do a rail system, and add side vents. Adding rails would cause the cartridge to sit too high in the trap body, and look a bit weird. The cartridge is also quite a snug fit in terms of width, so adding vents was a no-go. So I did what any sensible person would do and took a razor saw to the cartridge to reduce the height by about 5mm, and the width by 3mm.

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Glued the two halves back together, and whacked on some P38 body filler to fill the gaps where my cut wasn't quite parallel.

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After sanding back the filler

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The front of the cartridge also sat flush with the edge of the main trap body, with the door mounting lugs being flush to the back end of the cart, which didn't look quite right to me (maybe it's accurate to GB2? I dunno), so I glued some 4mm styrene sheet onto the back of the cart to lengthen it a bit. This will also give me the added bonus of being able to add the welds onto the door lugs. Should also mention I wanted to include a d-sub, so I chopped out some of the back of the 3D print to mount it through.

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Before clean up. The top nearside corner got cut slightly wonky, so I had to build that back up with filler later on.

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Lots of careful marking up for the d-sub and I chain drilled out the hole for it.

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About an hour of careful filing, testing, filing, more filing, even more filing and I had a pretty snug fit for the d-sub! Hurrah.

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Quick test fit of the doors. I replaced the M3 bolts in Ben's kit with #6 hex head bolts from modelfixings.co.uk too. As I'd narrowed the trap body there was some sanding of the doors to get them to fit nicely, they had quite a noticeable gap previously, so I need to consult some reference photos and possibly make them a little narrower still.

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As I mentioned before, I want vents on the cartridge body, so following damster117's lead I got some soffit strip from Wickes and cut them down to size, filled the unwanted gaps with more body filler, countersunk some holes in the corners and had some nice side vents. I didn't have quite enough space in the trap body to do a double layer like damster did, so they're glued to 0.5mm styrene sheet to make them a bit thicker. Looking at one of the reference photos it does look like the vent cut outs might not be quite the depth of the whole vent anyway, although that might be a trick of the light in the photo? The eagle eyed among you might notice they don't have the right number of vent slots, because I made the cartridge height shorter they came right up to the very edge if they did, so I reduced them by one. +100 geek points if anyone ever calls me out for it! For reference, they're all mounted with M3 countersink screws, and I've got the circular one on the way from eBay as a 33mm diameter / 1.5mm thickness aluminium disc for something like £1.50.

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Where possible I wanted to use aluminium too, as painting 3D prints to look like real metal sucks, and the real deal will gradually weather nicely if it's painted. I was a bit nervy about getting a large sheet of 2mm aluminium and being able to cut it accurately/straight enough, so I got all the aluminium parts cut to custom sizes from Click Metal, and despite them stating they have a +/-2mm tolerance the parts I got were pretty much spot on!

Added the front plate, again with #6 screws from modelfixings.co.uk. It's very slightly too narrow, so I may yet replace it if it keeps bugging me. Still need to drill mounting holes for the front knobs too, and planning on mounting them on potentiometers so they turn.

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Then added the bargraph plate, with more #6 screws. The bottom two were slightly off where they should be, but I think I can probably live with it for now.

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Some drilling and much filing later, I had a pretty perfect fit for one of Spongeface's beautiful bargraph bezels! Still need to drill a hole for the LED to the right of the bargraph, but until I know what size I'll be using I'm going leave that.

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Now I'm waiting on a new smaller countersink drill bit to arrive tomorrow so I can drill the aluminium base plate and mount it with countersunk screws. Having a removeable base plate also means when I work out the way forward on electronics I can easily get in to add them in. Then I need to decide on where the front knobs will go, and get the mounting holes for those drilled out too, after which I can think about paint!
Couture, cristovalc, kahuna900 and 2 others liked this
#4940044
Plenty of progress to report since my last update!

Smaller countersink bit arrived, so I got the replacement aluminium base of the cart on. I had to add in some bits for four of the screws to go into, as the walls weren't thick enough to screw into, just used some more 4mm styrene cut into squares and glued in so they sat flush with the body of the cart. Drilled and tapped them, and they hold fine!

Some of the countersinks were a bit wonky, I later found that you don't countersink aluminium at the same speed as you drill holes in it, in fact the total opposite! I was drilling the pilot holes at 2500 RPM, but doing the countersinks at more like 250 RPM and got a lot less deformation of the countersink. It's really apparent on the second photo below. This got mostly sorted later on, as I had to countersink the screws a little bit more so they didn't catch on the rails, so that was fortuitous!

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Then set about getting the rail on the bottom of the cartridge as well. I followed Bromie's dimensions for the rails, 25mm and 35mm width rails, using 1.5mm thick aluminium. All mounted together with M3 slotted countersink screws, and nuts on the inside of the cartridge just to make sure they don't work loose at all.

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I got fed up of everything being in primer at this point, so decided to get some paint on the cartridge at least so I felt like things were a bit more "finished". Behold, the cartridge with paint and most of the screws in! Doors weren't painted at this point, so I didn't bother attaching them. The circular one is 1.5mm thick aluminium from eBay, and after a quick google I found how to draw an equilateral triangle in a circle, so I had the holes nice and evenly spaced.

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Still debating whether to lengthen the right hand vent on this side to better match the screen used traps. It's a bit of a pain in the arse, so I'm erring towards not bothering. Sorry detail geeks!

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Added the welds on the door mounting posts at some point too, definitely like the look of extending the body a bit so these can be added. I think I'll add on the aluminum bracket on the top at some point soon too. I also got the d-sub mounted in. I think I might apply some epoxy glue on the back of the d-sub, as the screws are barely long enough to get into the mounting holes on it and it might eventually work loose.

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Final thing I did on the cartridge at this point was get the front plate mounted. At this point it really came to life! The two round knobs are on 1/4" potentiometers, which are mounted into holes in the cart body itself, I forgot to take any photos of that so you'll just have to imagine it. The sliders are both mounted on 2mm x 18mm spring pins. I think I saw someone else mention them somewhere on here, and I wanted these to move as well so have it a try and they're great. Drilled a 2mm hole through the front plate and into the cart body, then hammered them in (cue lots of nervousness that the joint where I cut the cart in half wasn't going to break!) leaving about 8mm sticking out, enlarged the hole on the back of the sliders to 2mm and then hammered those on and bingo! I have sliders than turn as well. I know the decals on the front aren't GB1 accurate, but I'm still thinking I might add some of Mack's Factory's dry rubs as they look awesome in my opinion. You can just see the bargraph plate peeking over the top too, I attached that at this point as well. You can just see the seam where I joined the two halves in this photo too, but I can live with that. It's less noticeable in person.

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At this point I couldn't do much more on the cartridge, so I started concentrating on the trap body itself. That'll be a post for later though, as I need to go cook Thai green curry for dinner!
kahuna900, mike_waclo, RedSpecial and 3 others liked this
#4940383
Onto the main body of the trap now!

I've not modded this nearly as much as the cartridge, so this was a bit "easier" to do. First thing was following a few other's lead I countersunk holes for screws just below the bottom edge of where the side plates sit. They're purely cosmetic, but a nice little detail. There's one above the top corner as well, which shows a little more once the side plates are on.

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Ben's kit has these big holes in the back wall of the trap, I guess to run electronics through if it's a static trap? There were some very shallow channels either side too, that had a counterpart on the back of the cartridge, to help align to the two, but they were covered over now, so these weren't needed either. They all needed to go though!

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I filled the holes with some more 4mm styrene, and then liberally applied Isopon P38 filler to create a flat back for the male half of the d-sub to mount into. I filled both the round holes too, as I'm mounting the battery box a different way than Ben intended, and the top one was bang where the d-sub needed to be anyway. It was a bit of a bugger to get into the corners to sand it, but it turned out ok in the end.

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Next step was to get the other half of the rails in, as I wouldn't know exactly where to mount the d-sub until I'd done this. Following Bromie and damster117's builds pretty closely I settled on a small gap at the front, as that seems to be pretty accurate to the screen used traps. I had the same issue that the screws need to be countersunk pretty deep to make sure they don't catch at all (that's what the arrows in Sharpie are, the holes that needed to be deeper). I had to put a slight countersink in the middle layer of the rails so that the screws would sit deep enough, so bear that in mind if you use 1.5mm (1/16") thick aluminium for a rail system.

In the first photo above you can see that Ben's kit has a void in the floor of the trap (for batteries/electronics), which caused a slight problem as all bar one of my screws went through into that, so had nothing to bite into to hold the rails in place! I've used a piece of scrap wood I had that was almost exactly the right depth to fill the hole, with a piece of 1mm styrene sheet glued on to make it flush with the bottom of the rails. It's a pretty snug fit, so once the rails are screwed in place it won't come out. I've drilled holes in the block so I can access the nuts on the screws for the wheel blocks too, should I ever need to remove those.

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Once these were in I did a dry fit of the rails. Took quite a bit of adjustment on the rails to get them to be a smooth fit, but nothing that disassembling them and some gentle work with a file and some fine sandpaper didn't fix. I'm hoping they still work as well after painting!

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With some careful measuring I worked out where the male d-sub needed to be mounted, and following the same method as the female part got that attached. The screws don't sit flush, so I subsequently enlarged the holes on the d-sub, which had the annoying impact of separating the two metal halves! Fortunately they glued back together ok with some contact adhesive, and the enlarged holes allowed the screws to sit further in.

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They joined up perfectly first try! Hurrah! Big relief, as I had visions of them not lining up and having to use loads of filler to fill the hole, and recut it.

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Somewhere during this I mounted the potentiometers for the Raytheon pointer knob, and the Heathkit knob as I wanted both of those to rotate as well. Both are a 1/4" shaft, but the Heathkit is a D shape, so I had to file that shaft down to fit. I worked out where they needed to be set by attaching Ben's 3D printed side plates and marking where the hole for the knobs was, and then used that as the centre point for the hole for the potentiometer. Drilled corner holes, then used a keyhole saw to cut out the square shape, and then filed it to shape until the potentiometer's fitted nicely. Got them sat in place, and then slapped some more P38 filler on the back of them, and made sure they were held in place until that set, then sanded it smooth. From the inside of the trap you wouldn't know I'd cut a bloody great hole (about 23mm square) in the side, and the outside is hidden under the side plates so doesn't matter too much.

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At this point I also refilled the holes along the bottom edge as they weren't quite close enough to the edge for my liking, and then re-drilling them. I made the countersinks a bit smaller too, as some of the previous ones were a bit too large.

Next job was the battery box, not much to write home about on this one. I replaced the cover with 2mm aluminium as well, and rounded the top edges of the box off, as well as filing some grooves into the corners to give the impression of it being folded aluminium sheet (saw someone else do this in one of the other build threads - can't recall who but thanks for the idea!). I've used button head screws to attach the lid, rather than the socket cap screws Ben supplied. Got the Linrose indicator from Charlesworth Dynamics, and may yet swap out the toggle switch for the correct Alcoswitch model so I have the right mounting nut. Go big or go home, right? Welds were added with Milliput, and then tapped the hole for the Foster connector so it screwed in nicely.

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I've attached the battery box from inside the trap, which whilst not screen accurate allows me to easily remove it if I need to get access to the back of the d-sub or the switch / Linrose light when I sort electronics. I've got two countersunk screws above and below the d-sub, and they will also serve to hole the handle in place when I get that sorted too.

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That brings me about up to the photos I've uploaded so far, so more updates will be later this week!
#4942613
Bit of a gap in updates, but I've got a lot done since the last post, so on we go!

I ended up not quite liking how the d-sub sat in the back of the main trap body, and the areas I'd filled were a bugger to get perfectly smooth, particularly in the corners. To counter this I added a sheet of styrene over the whole thing, cutting a hole for the d-sub to sit in so the whole thing sat flush to the face. I also enlarged the mounting holes in the d-sub so the countersink screws would sit a bit more flush as well. This had the unintended side effect of splitting the two metal halves of the d-sub plate. Disaster! Luckily they glued back together ok with some epoxy glue, so it wasn't a write off. I also had to tweak the rails slightly, as they needed to accommodate this extra depth, so I had to trim them down by a couple of mm. I forgot to take any photos of this part, so just imagine all of this!

I took a slight diversion back to the cartridge at this point too. After a bit of sanding I got the doors closing nicely, and then applied two layers of 3/4" yellow electrical tape to the doors. I used some other build threads to determine the angle of the tape (note 20 year old protractor in the background!) and carefully applied, with another temporary layer in between them to act as a spacer so they were all equally spaced. I did both doors together so the lines between them were spot on. End result was this...

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Pretty sexy, right? At this point it felt like I had a real ghost trap on my hands!

I've made my own aluminium handle, although I've yet to get the two parts welded together. Same technique damster117 used, chain drilled the square tube and then filed it down to fit. I've not worked out how I'm going to cap the ends off yet either. The blowtorch I have doesn't get hot enough to melt the aluminium solder I bought, which is a pain. I've ended up using Ben's 3D printed handle for now until I can sort that though.

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I was now pretty much ready for paint, on the main body of the trap and the rails. I used Hycote matt black, for reference. I rounded off the rails on the bottom of the cartridge so they would go into the trap rails a bit more easily too. I think I also tweaked the countersunk holes a bit more as the screws were catching a bit, this also meant they were rounded better after my initial effort was a bit crap.

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Next was time to get the aluminium side plates mounted up. I used Ben's 3D printed side plates as templates for where the holes needed to go before I'd painted the trap body.

When I drilled the holes in the vector plate they all blew out the sides, even using a pillar drill and getting them as centred as I could. I used M3 screws and the heads are 4.5mm diameter, so unavoidable unfortunately. Maybe in hindsight I should have used M2.5 screws? C'est la vie.

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This side plate needed polishing up later on, as even sanding with 2000 grit sandpaper left it looking really dull compared to the ones I didn't sand. You can see my frankensteined Raytheon pointer knob here too, I taped off and sprayed the white line on it as well, which has come out ok I think.

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Next job was the side rods. I wanted aluminium ones so they'll weather naturally, so again following damster117's lead I made my own using 1/2" diameter aluminium rod. The GBFans store also made me realise Ben's were the shorter GB2 style, so I made mine 3 1/4" long as it's a GB1 trap. I put them into my pillar drill (13mm chuck luckily, so just over 1/2"), and then filed them down with the drill on at a fairly high speed to get the bevel I wanted. Then measured that up and recreated it on the other three ends, before polishing the whole thing up with 600 grit sandpaper while I was in the drill. I slipped with the file a couple of times, and left some gouges in the rods, so this helped get rid of those too, and should be hidden almost completely when I paint them.

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Next thing was mounting the rods to the side plates. I was going to use spring pins for this originally, but decided against that in the end so I could in theory swap the rods out more easily if I ever needed to, and decided to use M3 hex head screws. Again using Ben's side plates as a starter I drilled holes in the side plates, and then drilled larger shallow holes for the screw heads to sit in in the side of the trap. I used a little hand drill for this so I could control the depth more easily, an electric drill can catch in the plastic and run away too easily.

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The finished holes, slightly enlarged with a Dremel afterwards. They're hidden under the side plates so didn't need to be beautiful.

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I could then measure up the holes on the side rods to align with these, and get those drilled and tapped. Word of advice kids, measure twice, drill once :roll: I cocked up and drilled the first set offset, so the rod didn't sit where it should when mounted. Irrititating! Fortunately the holes are totally hidden when it's attached so I could re-drill them in the right place.

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Attached to the side plate! I started polishing up one end of the plate too - it looked markedly better, although still needed more work later on. I still need to paint them up, but the weather have been rubbish since I got some paint. I'm going to use Tamiya TS-49 Bright Red for this.

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I could finally assemble everything at this point, and get stickers on. Turns out Mack's Factory pack stickers have sufficient spares to do the two red danger labels, so I used those as they're bloody lovely. I also used a Mack's dry rub for the white arrow next to the heathkit knob. This all really brought the trap to life at this point.

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You can see where I dropped the battery box (twice) and bounced it off my garage floor and chipped the paint on the battery box cover. I'm calling it "natural weathering", rather than "I'm a clumsy idiot".
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You can see how much better the side plate looked once I properly polished it up with some metal polish too.
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I also weighed it at this point, as it was feeling pretty damn heavy. Not sure this will be a belt hanger, especially as this is without any electronics, or the pedal! This is about 3lbs 11oz for anyone who doesn't use kilos.

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So that about brings me up to date. Next steps are paint the side rods and reattach them, put together one of Spongeface's bargraph bezels and get that mounted temporarily until I put electronics in, and get the handle welded up and replace the 3D printed one. I'm going to need to think about the handle mounting bolts too, as I realised they weren't square when I put the temp handle in, so were a complete bugger to get holes at the right orientation through the handle shaft. It's ended up with the battery box not quite sitting flush as a result. I might replace the toggle switch with the correct Alco one so the mounting nut is right.

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RedSpecial liked this
#4942877
damster117 wrote: December 2nd, 2020, 4:20 am Some nice work there! I like the pots in the side plates idea! What size tap did you use for the foster connector?
Thanks! I've seen people allude to pots for the knobs, but didn't come across any detail of how they did it. Pretty easy to do and adds a nice extra little level of detail. Not sure if I mentioned previously but all the knobs on the front plate rotate as well, the sliders are just on spring pins, and the round knobs on more pots.

I used a 1/8" NPT tap, I bought a cheap-ish set of imperial taps and dies on Amazon as none of the GB greeblies seem to be metric sizes, so I figured they'll get used again on my pack etc.
#4942937
I’ve got the front knobs set up as potentiometers with the spring pins for the others already, these are going to be functional controlling my smoke setup. The side ones though I hadn’t considered fitting them to, only problem with that on my trap is that side plates are not as thick as yours to conceal the depth of the pot base.

Cheers for the info on the tap. Bought all my parts so long ago I’d forgetter the thread size of the fosters!
tobycj liked this
#4943114
The pots I used for the Heathkit and Raytheon pointers were these. I cut off the metal cover and the legs, and trimmed down some of the thread on the shaft so the knobs would sit flush to the side plates. Basically I was looking for slimline with a 1/$" shaft and these seemed to fit the bill. You could probably grind down some of the plastic casing a bit more too I think.

What are you building for your brother? If it's got half as much care gone into as your trap he's a lucky lad!
#4968211
l3w1sb159 wrote: March 22nd, 2022, 7:21 am Could I ask what size square and round tube you used for your aluminium handle?
I used 3/4" 16swg square tube (90mm long), and 3/4" 16swg round tube (133mm long). Both from clickmetal, and cost less than £7. A friend at work welded them for me since I last updated this, but I've yet to install a latch in it.

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