Yūrakuchō

[cteno4]

Now you are back up there Joe, glad tom kicked your butt back in gear there, this is looking like your old work again!

 

jeff

[Kamome442]

Sometimes you just need a push.

[Kamome442]

I have printed some of the lenses in clear resin ready to make up the first light. All the parts a stupidly small so no doubt the first few attempts will be a little sketchy until I get a technique down.

 

Here is first lense (actually the second, the first one is with the carpet people now) getting its test fit ahead of construction.

 

[Kamome442]

First attempt complete. I had no expectation that would look good and I wasn't disappointed!

This is pretty much just a pathfinder for working out how to construct them going forward.

In all fairness it is not that bad but can be better.

 

The biggest issue I had was the height of the LED barely fits the recess of the grey housing. When I was gluing it place I was trying to hold the housing straight and hold down the LED with a cocktail stick while holding a torch to cure the glue. An extra pair of hands would have been nice. I added the clear lens as the last step but as the LED was sticking out partially I had to drill out the back of the lens. 

For the next attempt I will print a new lens with a small recess and glue the LED into this first. Then I can glue the whole uint into the housing more easily.  

 

[Kamome442]

My Adventures in Light Continue

 

I have found a technique that works works well for one of the street lights and I am going to spend the the day making up the 5 I need for the layout. 

For this shot I just held the light in-front of the arches as I still have to connect the negative wire to the base of the pole before I can install it properly. 

 

Once I have them all made up I will take a better picture and maybe one next to the lights they are replacing.

What can I say, you leave the room for one minute then come back to find all your street lights are wearing tinfoil hats! Never underestimate the power of social media folks 🤔

 

One of the biggest problems I was having was the light shining through the top of the cover. Seeing as they are so fine (the wall thickness is around 0.2mm) it was unavoidable. I tried several combinations of silver and black paint both inside and out but still the light got through. The only solution I could find was to cover the top half of the light in tinfoil. The downside was the amount of reflection makes it hard to take a clear picture.

 

Explicit Content Warning

 

I thought it might be useful to show you a picture a light without its top on.

 

If I have a superpower I think it could possibly be snapping wires off small LED's, I have realised over the past week that I am quite adept breaking down small components into their constituent parts. Therefore the first thing I do is add a little dab of UV resin over the contacts on the LED, it just helps to protect everything while I am stripping and bending the wires.

 

I cut the negative wire to about 1cm from the LED and slide the protective coating off with a scalpel blade to leave the bare wire. I then wrap this around the positive wire so that it acts like a tiny spring. The positive wire runs through the middle of the brass tube (I am using 0.6mm OD, 0.4mm ID), I have filed the top of the tube at 45 degrees this helps the wire to sit nicely where it is bent over the top and give a small surface to glue the cover directly to the pole. I gently hold the negative wire back with a cocktail stick with putting the 90 degree bend in the positive wire. When the negative wire is released it pushes up against the brass tube turning the pole into the return. A quick dab of resin at the top of the pole holds everything in place. 

 

Once placed upside-down into the cover I drip resin into the front half using a pin until the LED is covered and the resin is flush with the top of the cover and cure it slowly with a UV torch (have burnt out two LEDs by curing the resin too quickly, well what's a couple more inhabitants in the ever growing LED graveyard). I fill the back half the the cover with conductive wire glue this helps to stop light escaping in the wrong place and ensures the negative wire and pole have a really good connection.

 

Bonus Content

 

I have also been quietly working on miniature paper lanterns going through several prototypes to find something that works. I started with the simplest design, these are 2mm spheres (to represent a 30cm lantern).

 

I originally planned to used fibre optics fed back to one LED to try and cut down on the amount of casualties wiring however the best result I ever got was a clear resin ball with a small glowing dot in the middle. I then moved to an LED in each lantern. The print on the left has the basic shape with recess in the top, I fill the recess with resin then push an LED into the middle and cure.

 

Originally I used a clear resin for the first attempt however LED was so bright it lit half the street and seeing as there will be 94 these side by side I moved over to using white resin instead. It was cheaper than buying everyone sunglasses to view the layout. With all the different shapes and sizes there are a total of 214 lanterns on the first phase of the layout so it just as well they are super easy to make. For the collar at the top and bottom I was going to use brass tube until I knew how many I needed. I will probably use round styrene strip cut into little pieces and painted black.

 

Joe

Edited November 12, 2021 by Kamome442

[Kamome442]

A Welcome Surprise

 

I normally get an e-mail when the etches are ready with a tracking number. For whatever reason I did not get any notification so it came as a very welcome surprise this morning when they arrived in the post. Here are some of the goodies included on this etch:

Firstly I have enough shop fronts to complete the arches on one board. Windows for the centre and the recessed grilles for either side.

 

Lattice style brackets for the more decorative streetlights.

 

The housings for the floor mounted uplighter's that illuminate the arches.

 

I also received a small second etched sheet in 0.1mm brass. This mainly has test parts for an idea I want to try out, more on that at a later date. It did also include several etched fire hydrant signs. I only need one for the alley however they are terrifying delicate so having a few spares around for when I inevitably squash one isn't a bad thing!

 

I now have tons of the missing pieces, I needed so I can get on with some serious modelling.

 

 

[Kamome442]

A Quick Update and Some Questions

 

While I have spent most of the last week gluing small pieces of etched metal to my fingers, I did find the time to attach some the of the said pieces to each other.

I am putting the shop fronts together so that I can get them ready for painting and glazing. To get a nice level of depth I have etched the C channel details separately to build up a layered effect. 

Etched parts on the sprue (left) and the finished frames (right):

 

There are 20 parts to a standard shop and 23 parts to a shop with a door. I am about half way through now so I should be able to test fit them on their bases this week.

 

Preparing my next LED challenge

 

I recently did a little hunting around the interwebs for the dimensions of traffic lights and pedestrian crossings. Now that I am finding my feet with using 0405 LEDs I have decided to have a go at making some working lights. This will not be for a long time as I really need to focus on getting something running however there are a set of lights under the bridges. I therefore needed to draw everything up before I glue the bridges down to make sure I leave enough room for running wires under the pavement.

Here is the progress so far, I am going to etch these so that I can get a nice crisp outline on the crossing signs. For the lights themselves I am considering fixing each LED into brass tube with resin to prevent any light bleed. 

 

Question/Advice: One of the things I really want to capture is the bluish turquoise colour of a Japanese green light. I figure its history might make for a nice paragraph on the information boards in front of the layout. Before I do any experimentation I though it would be a good idea to ask if anyone here has tried to create this effect themselves. The only thing I could think of is using a blue LED with a green tinted resin or a green LED with blue tinted resin?!

 

My guide to making new friends

 

Ok so this one is again a project for way down the line but like with the traffic lights I would need to prep some parts now. Certainly in the UK sound fitted trains are becoming more and more popular at exhibitions. I personally don't have much interest in this however the speakers are reasonably priced and conveniently small and there is a memory of Japan that I would love to capture. That being the wide range of pips and tunes played at stations and crossings.

 

I thought it could be a fun way to make friends on the circuit when your neighbours are running their sound fitted Gresley engines. To turn up and say I see your chuffing sound and raise you half a dozen speakers playing chirps, beeps, catchy jingles and birdsong on repeat for the next 5 hours, your welcome!

 

Question/Advice: So can ask if this is even possible? I assume it would be a case for finding the right sound files (I am guessing in a certain format) and assigning them to a speaker through some piece of wizardry? These would need also to be timed with the lights and/or trains moving on the layout, which sounds complicated just writing out let alone doing. Assuming it possible all really need to worry about right now is leaving a space under the arches for the speaker and any other electronic gubbins needed to make it work.

 

As with the not green, green lights, I thought it would make for some really interesting talking point for display boards. How much thought has been put into the infrastructure to help people move around a sprawling congested city. Such using a female voice to announce Yamanote trains and a male voice for Keihin services or the bird song played  to help passengers with limited vision navigate the station independently.

 

If it can be done I might even go as far as including an off switch should I see another exhibitor develop a nervous twitch or reach for a blunt instrument.

Joe

 

 

Edited November 21, 2021 by Kamome442

[disturbman]

It should be possible, probably if you run it from an Arduino. The most problematic issue is where to insert/hide the speaker without killing the quality of the sound. You can buy all the elements: Arduino, cables, amplifier, and speaker cone independently. I would run tests as soon as possible, before the layout is too advanced and you cannot change where the speaker is placed.

 

Perhaps a simpler possibility would be to use a small Bluetooth speaker. There are a lot of small ones that have a pretty good sound, they also some times have a female jack port where you could plug in your player/Arduino.

Personally, I think a more interesting effect would be to play a long soundscape recording from a nearby street or from the corridors inside the station, rather than focusing on the railways operation side, if you have the space for it. Repetitive sound can become very annoying, very quickly when played in short loops or at high frequency.

What is this about birdsongs being played to help passengers with limited vision navigate the station?

[Kamome442]

That is great advice dusturbman, thank you. I hadn't even considered using a Bluetooth speaker. I agree about experimenting with the placement of speakers. I actually have quite a lot space to play with seeing as the front of the arch is covered with a relatively flat facade. I will also be keeping the back of the arches open for maintenance. There is actually a recessed area on the bridge supports where the guttering is channeled down from the track, this is only about 2cm from crossing so I could easily drill out the resin to get a clear sound.

 

I like the idea of a more widespread soundscape too, I will have to see if I can find any recordings in the area. Either way I am aware it would become very annoying so I want it to be barely audible. Along the lines of you read about it then lean in close to hear the sounds.

 

As for the birdsong, there are dedicated speakers mounted above platform exits on many of the stations. All they play is a recording of birds tweeting, I believe every 30 seconds or so. For visually impaired passengers to locate escalators and stairs etc you just follow the bird song. I only became aware of this from a post on this forum but is was a long time ago and I can't remember which thread it was on.

I did find this recording for what it sounds like, StationSE even included a picture of the speaker:

 

Source: StationSE youtube channel

 

That along with the extensive use of Tactiles it utterly puts stations in the UK to shame, I quite like the idea of giving it some recognition. I notice they didn't go for crows, I assume it not a bird that is that common in Tokyo so as not to attract bunch of them and confuse people. 

[disturbman]

If you already have a Bluetooth speaker at hand, I really like the small JBL GOs even though they could be too big for your purpose, you could play @Spydarman's walk around Shibuya Crossing: https://www.youtube.com/watch?v=Qcn93F-FOag. It would give you a good idea of how a soundscape could sound on the layout.

And thanks for the explanation, I had no idea JR East used this. It reminds of the work of James Webb, a South African sound artist. He has a series of works where he uses a hidden loudspeaker to play the song of foreign species of birds within specific locations. I'm assuming they do the same to guide people, using local species of bird could render these speakers useless.

Edited November 21, 2021 by disturbman
typo

[cteno4]

Joe,

 

soundscapes can be fun but they also take a lot of work at times to get right and they are very dependent on the space the layout is in and ambient noises in the room. I’ve done some small audio stuff in exhibits and it can get messy fast. Worked with a really professional soundscape guy on one exhibit to see if we could do something wild but the space (old Carnegie library with huge barrel vault ceilings) made tuning the sound scape really really difficult and we had to give up on it as it would have been really expensive to try and so so chance of hitting a home run. All that being said it’s still a great dimension in a scene to play with and see what you can do. Luckily there are some inexpensive ways to try this.
 

At shows you have big spaces to loose the sounds in and lots of ambient noises to contend with, at home things can be much more under control. N scale trains also make a ton of wheel/rail noise as well (amazing how quiet it gets at the end of a show or with a wreck and all the trains are stopped). Over the years I tried a few times playing with some sounds on the lab layout and it worked ok, but I realized it was something I couldn’t probably not get too complex with in many of our display places and the old layout with usually 4 good size trains running at once making a lot of racket. I have better hopes on Ttrak modules as they usually are fewer and smaller trains (way less wheel/rail noise) and the focused small scene will get the visitor right up to it and more tuned to audio mixing with the visual scene.

 

I’ve messed with a few little Bluetooth speakers for fun’s stuff like making Goji roar remotely and surprise people whe they are looking at Goji (fun game to get them trying to figure out what is triggering the roar and they of course think it’s motion sensor and when two people are there it’s fun to set it off only for one of them and drive the other person crazy!). It’s also a good way to just experiment. They are a good way to experiment by plinking a speaker somewhere and playing sounds from your phone. Drawback for installed use is its difficult to select different speakers if more than one is on the layout and even small ones are a bit bulky to hide.

 

I’ve had fun with these little micro MP3 players. They are tiny, like the size of a postage stamp and totally self contained player. Just hook 3.2-5v to then and small speaker. You can then wire the pin outs to just repeat play sound files on the micro sd card or have push buttons to fire different sounds or just new sound played every time you push a button. You can wire buttons up to also turn volume up or down. No programming to do just some wiring switches to the pin outs and wiring on the power and speaker to the pins. You could even use some simple circuits to fire a sound with motion or light change. You can get them on ebay or aliexpress for a buck or two. I made these up to put in knit stuff toys my wife makes for our grand nephews, adds a cool new dimension to the stuffed animal!

 

https://www.amazon.com/gp/product/B07JGWMPTF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

With small like 1-2” speakers they can sound tinny and whimpy just out by themselves, but if you mount them in a little resonance chamber they can really sound pretty good even with the only 0.5w output. This is what they do with sound decoder speakers to make them sing better, especially in n scale. I used a 1.4” circular speaker in the humpback whale my wife made and made a resonance chamber out of a 1.5” dia X 2.5” long plastic jar and wow was it sound and the humpback vocalizations were really in great fidelity! It’s on the project list to play with these on Ttrak modules next.

 

you do need to find source files and that can be tough for some. But lots of sources for some things like station announcements. for audio editing you can use free programs like audacity or garage band to space sounds out to right timing and adjust relative volumes of different sounds in the same audio file as well.

 

maybe instead of trying to embed speakers into the pieces you could have some like 1-1.5” holes precut thru the baseboard with plugs in them you could later remove and put a little speaker/resonance chamber in/onto. 
 

Other route is t9 use arduino, but that quickly gets more complex and programming involved. Love these little chip MP3 players as super simple, cheap, but versatile and self contained.
 

cheers

 

jeff

[Kamome442]

@disturbman Thank you for putting me onto James Webb, an interesting character, I really enjoyed reading about some of his projects. I will certainly have a play around with soundscapes, Spydarman's Shibuya video certainly has some great ambient sounds, it would be great for running tests. 

 

@cteno4 Wow Jeff, that was really informative thank you for taking the time to share your experiences. I certainly want to create an immersive and educational experience for anyone who views the layout. I would like to include an element of sound in that, if it is possible. Having precut holes that are plugged but could later be removed is an interesting idea. Creating a resonance chamber to amplify the sound is a great idea. It may well be that this something I save for a future project and plan it in from the beginning or could even take the form of a button on an information board to play a sample from a speaker separate to the layout.

 

You make a very good point about the acoustics of an exhibition space, I assume even fluctuation in the number of people throughout the day would have an impact on the experience. For now I have a pretty long list of things to complete, that take priority and adding to that list right now would be crazy. From the outset I have tried to create voids and hidden spaces as a failsafe. I think once I am somewhere nearer completion it might well be something I try to play around with.

[disturbman]

45 minutes ago, Kamome442 said:

Thank you for putting me onto James Webb, an interesting character, I really enjoyed reading about some of his projects.

My pleasure, James is a lovely person and a wonderful artist; one of my favourite.

 

45 minutes ago, Kamome442 said:

You make a very good point about the acoustics of an exhibition space, I assume even fluctuation in the number of people throughout the day would have an impact on the experience.

It would if there is great variations, bodies “absorb” sounds and people usually are noisy. It can be quite difficult to set a sound level in public settings as the loudness of a space constantly varies; it can make a preset change from overwhelming to inaudible.

[cteno4]

Yeah it’s super dynamic in exhibit spaces. Hard enough when it’s one of our static museum exhibits and we can control things some, but even then changes in body numbers cna have big effects along with their own ambient noise that make! Bodies are very good sound absorbers, but the make their own noises as well. Open space as well like high ceilings can suck up sound by scattering it more widely. Ceiling, floor, and wall surfaces can work as reflectors or absorbers depending on their composition. 
 

Doesn’t mean don’t do it, just means it requires experimenting some for get the best effect you can and find where it just doesn’t come off well or even becomes annoying or when effects interfere too much with each other.

 

things like station announcements work well on a random loop as even if drowned out by trains when coming thru they give a nice effect when you do catch one. Smaller sounds are harder. I tried a dog barking on the old club layout thinking it would be fun to randomly go off (it was from a famous sound scape done in San Francisco in the huge atrium of city hall that had random sounds of everyday happening all over for a few minutes then silent for a while and wild to watch the usual hustle and bustle come to a complete stop when the sounds started up!) but sadly the 4 train lines really drowned it out unless right there and making it louder just sounded off. Of course Goji roar can be loud! Experiment and see what you can come up with with your setup.

 

there are some fancier sound boxes you can do for the really tiny speakers and smaller spaces, but in experimenting with the 1-1.5” speakers for the stuffed animals I was surprise how the little plastic jar did so well and simple. I was worried I might have to ad an amplifier circuit in the stuffed animal as the speaker is basically in the middle of a big pillow (the humpback was almost 3’ long and meant to be a big reading pillow). At full volume it was up at parental annoyance volume w.o an amplifier.

 

yeah if you can make access points to as many void spots as possible it will help with places to put speakers and such later.

 

you are spot on these are perfect for the little info panel push the button to make something happen. Really huge bang for the buck if they simple action drives home the point of the panel. You can drive these with little MP3 players with a 18650 lipo battery. Just put the graphic in a thin box plex frame and you can hide the whole thing in the frame.

 

The thing I’ve been churning on is how to have a button in front of a Ttrak module for someone to push for an animation or audio effect. Many times there is no table space in front of the module and you don’t want folks poking the front of the modules even if a very sensitive switch as you know a few will really poke it hard!

anyhow very fun little boards to play with and no programming needed. Figure 4.4 on this doc (you can ignore a lot of the digital interface stuff in this doc) will show you how to do simple wiring for 2 buttons to play 2 different sounds and 2 buttons that will let you increase/decrease volum (long hold) or cycle thru all the sound files on the micro sd card.

 

https://www.electronics-lab.com/wp-content/uploads/2017/06/DFPlayer-Mini-Manual.pdf

 

You can even see in fig 4.5 you can wire a bunch of switches onto pin 12 and 13 with different value resistors in series on the push buttons to control play, volume, looping, or individual play for up to 14 sounds. Could do this for a poor man’s sound effects box.

 

jeff

 

[cteno4]

Btw talking about the ambient audio in a space, the california pizza kitchen has a background music system that dynamically fills in to the restaurant chatter to keep the overall decibel level constant at the level that is not so annoyingly loud you want to walk right out, but loud enough to make the place always seem hopping but just loud enough that you want to leave once your meal is eaten and not stay chatting for a long time for max table turnover for the place. 
 

Talk about the wrong use of an audioscape!

 

jeff

[Kamome442]

There is certainly a lot to think about and don't worry @cteno4 you have in no way dampened my enthusiasm for try to experiment with ways to create a dynamic experience when viewing the layout. It seems opening the 'sound' can of worms is probably a bigger project than building the actual layout! I do not want to do anything to cheapen all the hard work I have put into everything so far. It is likely something I try out once I am further down the road.

 

21 hours ago, cteno4 said:

you are spot on these are perfect for the little info panel push the button to make something happen. Really huge bang for the buck if they simple action drives home the point of the panel. You can drive these with little MP3 players with a 18650 lipo battery. Just put the graphic in a thin box plex frame and you can hide the whole thing in the frame.

 

I totally agree that this would give the panels more purpose and sounds like could be a little easier to set up. It would also add an element of interactivity, who doesn't like the odd button to push! Whenever I decide to revisit the idea I will certainly reread these posts, hopefully it will help to avoid one or two beginner mistakes! 

 

On a slightly different note I decided to tack a shop front together with some masking tape, I just wanted to get a rough idea of its shape before setting it up on its base (yeah right! really I just wanted to play with my latest toy ☺️).

I am really quite pleased with the final look.

 

I have three complete now and one more to go. Once these are done I also have to detail the bigger store to go inside the sunken entrance.

 

Once of my favourite details is the little lock at the bottom of the sliding door, not that it will be visible once it is in place😶 And no the door will not be working!

Joe

[Drunkenclam]

That's a shame. I'm sure it could move with a solenoid or hidden magnet underneath. Then you just need a 1cm tall person to walk through it:D

[JR East]

1 hour ago, Drunkenclam said:

That's a shame. I'm sure it could move with a solenoid or hidden magnet underneath. Then you just need a 1cm tall person to walk through it 😄

I would suggest also a 1 mm dog in motion  😆

for @Kamome442 I'm sure it'll be a piece of cake !!

 

I really admire this incredible work. 

JM

[Kamome442]

@Drunkenclam Not this time sadly, if only I had considered it earlier.

There is a similar unit on the next board with an Irish pub interestingly called 'Little GANG'. Maybe I could make a drunken office worker that falls out when the door opens.

 

@JR East Would a 1mm dog in the handbag of a moving person still count as in motion?!

 

1 hour ago, JR East said:

I really admire this incredible work. 

 

You are too kind, thank you.

[Spydarman]

On 11/23/2021 at 5:33 AM, Kamome442 said:

@disturbman Thank you for putting me onto James Webb, an interesting character, I really enjoyed reading about some of his projects. I will certainly have a play around with soundscapes, Spydarman's Shibuya video certainly has some great ambient sounds, it would be great for running tests. 

 

@cteno4 Wow Jeff, that was really informative thank you for taking the time to share your experiences. I certainly want to create an immersive and educational experience for anyone who views the layout. I would like to include an element of sound in that, if it is possible. Having precut holes that are plugged but could later be removed is an interesting idea. Creating a resonance chamber to amplify the sound is a great idea. It may well be that this something I save for a future project and plan it in from the beginning or could even take the form of a button on an information board to play a sample from a speaker separate to the layout.

 

You make a very good point about the acoustics of an exhibition space, I assume even fluctuation in the number of people throughout the day would have an impact on the experience. For now I have a pretty long list of things to complete, that take priority and adding to that list right now would be crazy. From the outset I have tried to create voids and hidden spaces as a failsafe. I think once I am somewhere nearer completion it might well be something I try to play around with.

I hope my video(s) can be of service to you!

[Kamome442]

4 hours ago, Spydarman said:

I hope my video(s) can be of service to you!

 

Hi Spydarman, 

 

Thank you, they certainly will be. I have already watched parts of your Yamanote Line video, frame by frame, to fine tune some details around one of the bridges. It is always great to find a high quality video taken on a sunny day. I subscribed to your channel as I am sure I will keep coming back there in the future. 

I look forward to seeing where your next ASMR adventure takes you!

 

Joe

[Kamome442]

I got a couple of bits done on the layout today. Here is the first test print of a shop front, hot off the printer. There are a few minor tweaks that need to be made such as the position of the floor lights. Once I am happy everything fits nicely and made a few corrections I can print up a batch of them.

 

I finally got around to cutting a hole for the sunken entrance.

 

The little toadstool looking thing is one of the hidden mounting points I mentioned in the post, on page 10, about designing the boards. Essentially it is to give the option of mounting a decorative front edge to the layout. I will need to cut this back before adding the lowered floor.

 

I have also started work on more of the shop fronts to get them ready for etching. At the north end they are a little more decorative, with a nice metal arch above the entrance and metal louvres on either side to hide the AC equipment. The outer edge of the metal arch is illuminated, I am going to try and recreate this with EL wire.

 

To try and keep track of the parts being etched and their position on the layout I have started to record them on this handy plan.

 

It includes the type of light for each location and details about the which units are occupied and by who, this will be needed once I start making the signage to go out front.

I may post refreshed images of this in the future to help keep everyone up to date. 

Joe

 

[Kamome442]

I completed the first test print of the sunken arch. The final print will be in sections so that can get to the inside for fitting handrails, lights and painting etc. I find it easier to have a physical model, I can pick up and look around to work where to hide joins than looking at a 3D model on a screen.

View from inside the arch (left) looking into the arch from the street side (right).

The final model will also extend back another 70mm or so.

 

Today I received my parcel from China with another 100 LED's. Now I can to make up all the lights along the alley. For a layout that that wasn't going to have any lighting there now seems to be no shortage of LED's to fit. Here are the positions for each light on the board I am working on.

 

I am also pretty much done with drawing up the arches at the north end. I should be able to get the etches ordered this weekend.

 

Joe

[Kamome442]

I Made a Thing

 

I did elude to having some test items on my most recent etches, I finally got around to assembling one of these today.

This is my Mk3 fence making jig (ignore the bobbin, that just what the elastic is supplied on):

 

To be honest the picture makes it look way more interesting than it actually is. Essentially is just two outer frames that give the spacing to run the elastic. 6 threaded bolts are (crudely) fixed on one frame. Smaller plates slot over the bolts to act as spacers, basically you lay the elastic over the jig add a plate on each side and repeat. Once enough layers have been added the second outer plate is added and whole jig is compressed with hex nuts. I have found holding the bobbin on a bold tread prevents accidental unraveling of the elastic when not in use.

[cteno4]

Wow, now that’s  jig!

 

jeff