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G1 Omega Supreme, the definitive repair guide Part 2 of 5 – The ON/OFF switch

If your Omega Supreme is still completely not working (no noise/motion/lights/nothing) and the battery connections check out okay with a multi-meter, the next most likely culprit is the on/off switch itself.

From the outside of the toy, the on/off switch looks like a “real” switch. However, when you open it up, you realize it is pretty cheesy. Disassembling the upper part of the toy to get to the switch is a little difficult. There are many small pieces to keep track of, and getting them all aligned again is a little tricky. Pay attention as you take it apart, and take your time. From what I can tell, the parts really all only go together one way.

First, you must pop off the face cover. Some of these are tighter than others. I used a plastic “spoon” on this one, however a screw driver could be used. Just be careful and avoid scratching the plastic.

Next, remove the screw holding the two halves of the head together.

The small bulb in the middle is the light that lights up in the face. The white ring with the lobes is the track that makes the red canon go up and down as the head rotates. Remove this ring, as well as the lower half of the head. You can not separate the two halves of the lower compartment without removing the head.

There are two screws that hold the lower compartment together (I failed to get pictures of them. Once once you remove them, the compartment will split.

All of the wiring will stay with one half of the housing. All of the gears will stay in the other.

This is a useful reference picture of how the gears should all sit relative to each other.

The red and green wires appear to just be soldered to brass rivets through a piece of stiff cardboard.

To disassemble the switch, you’ll have to bend all 4 tabs back to a straight position and slide the sheetmetal housing out of the cardboard slots.

The red plastic switch slider holds a small folded piece of brass. If the toy has sat for a very long time, corrosion builds up on the rivets and the brass slider. A light sanding with fine sand paper will easily bring both back to a shine. This should be enough to fix the contact issue.

You can reassemble the switch, and use a multi-meter to check continuity through the green and yellow wires.

The tabs and slots of the switch housing are not all the same length, so the switch itself will only reassemble one way.

Putting all of this back together can be a little awkward. The large red “chest” piece or “neck cover” that is spring loaded can be a bit tough. Just be patient. The best way I have found to do this is to lay the half with the gears in it flat on the work bench, and bring the half with the wiring in it down from above. You will have t pinch that large red piece to keep it in position and line up the other side for reassembly. It may take a few tries, but isn’t too bad.

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G1 Omega Supreme, the definitive repair guide Post 1 of 5

G1 Omega Supreme is an iconic 80’s toy. It really is a marvel of engineering. It is as if someone took a kinematics textbook and decided to make a toy that used as many concepts as possible from the book in one toy. However, cost pressures being what they are, the quality of the materials used in the construction of these toys is questionable at best. There are many more broken and/or incomplete Omega Supreme figures out there than there are complete working examples, which is a shame.

The most common root causes of a broken Omega Supreme are:

  • Corrosion on the battery terminals
  • Bad contact in the on/off switch
  • Broken “hubs” in the walking mechanism
  • Missing “shields” which hold the legs together

I’ve come up with solutions for all of these items, and my intent over a few posts is to share what I’ve learned. The first step to repairing your Omega Supreme is usually disassembling the tank and checking out the battery tabs. In this example, the corrosion was visible from the outside of the toy (looking into the open battery box).

To compete this repair, you will need a small Phillips head screw driver, a multi-meter, and a soldering iron (with supplies). Let’s start with disassembly.

First, you will need to remove these two screws from both sides, and set aside the yellow covers.

Then, remove the four screws in the bottom of the tank.

With those screws out, it should be easy to separate the top cover assembly of the tank from the remainder. This top cover assembly contains the battery box.

This view is from inside the top cover assembly, and the picture was taken after my repair. You can clearly see the rivets in these two battery contacts. In this case, the one on the right was corroded, and no contact was being made from the brass outer tabe to the copper inner tab.

To resolve this, I simply soldered a piece of wire between the brass piece and the copper piece. This was enough to regain contact for the batteries.

Once you are done soldering, recheck continuity with the multi-meter to ensure the repair is sound. You can also pop batteries into the holder and measure for voltage on the inside tabs to verify the repair. Re-assemble the tank, and the repair is complete.

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On Wheels and Tires Part 5 of ?

Hopefully this is the last post about tire making I write for a very very long time! Coming full circle, the simplest solution is to pour tires one at a time into an open top mold. I simply decided to print a two piece mold with separate halves for the rolling diameter and the wheel diameter.

There are simple provisions to clamp the two halves together with a screw in two of the corners.

Here is the rolling diameter mold:

Here is the Wheel Diameter mold:

I made the molds all interchangeable, however you have to have a pair for each tire width.

Based on my earlier research, I concluded I only needed to worry about wheel diameters equating to 13″, 15″, and 18″. Similarly, I only needed worry about tire rolling diameters of 22″, 24″, and 28″. From the standpoint of tire widths, it didn’t make sense to make a tire narrower than 5mm or wider than 8mm. I decided 1mm width increments was enough.

I made 8 sets of these molds in different diameters and widths. I proceeded to cast a few sets of all of the combinations of tires possible with the molds I had made. I now have a library of 20 Shore tires of easily 400 tires. All of these were yielded from a 2 pound trial size kit of Smooth On Vytaflex 20. I failed to get pictures of this process, so no glamour shots of this system.

The key to success regardless of the mold design selected is producing a large number of molds and being able to pour many tires in each sitting. The Urethane spoils quickly once the containers are opened. It has a 16 hour cure time, so you can only pour into a given mold about once per day as a practical matter. Two pounds is about 900 grams. If you are only pouring 10 or 15 grams at a time, and can only cycle the mold once a day at best, they urethane will go bad long before you can use it all.

The pot life is relatively short, just a few minutes, so I found that working in batches of 20 to 30 grams at a time was ideal. For mixing such small amounts, I used a high precision digital scale that reads out into the 1/10th gram. The urethane can be mixed in equal volume or equal weight, but in such small volumes, it is difficult to eyeball the volume accurately enough. I found disposable 1 ounce medicine cups to be ideal for this sort of work. Something like these on Amazon. For stirring, I used cocktail toothpicks, available at the grocery store.

In a single sitting, I’d mix 6 to 8 20 gram batches and pour 80 to 110 tires. Once I hit critical mass on the molds, I effectively used more of the Urethane in two week period than I had used in the previous two months. I was fighting with the Urethane at the end, as it was trying to go bad on me as I was working through the final pours. I had some curing issues with some tires towards the end of the run because of it.

Files for all of the flat open top molds can be found HERE.

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On Wheels and Tires – Part 4 of?

Hopefully all of the electrons I’m expending documenting all of the ways I can think of to cast tires will help someone else along the way. After the success of the “fixed width” mold, I decided to try a similar approach to make “tubes of tires” that I could cut to whatever width I needed.

I simplified the inner mandrel to just have printed cylinders of different sizes that slip fit over 4mm brass tubing. In order to cast different wheel sizes (tire ID’s) I just need to print different sizes of cylinders. I settled on 1mm undersize for the tire to get some “stretch” over the wheel at installation.

I made outer molds that correspond to a 22″ rolling diameter, a 24″ rolling diameter, and a 28″ rolling diameter. I oversized the cast parts by about 1mm on the OD to give room to true them.

The mandrels and outer molds are interchangeable.

I experimented with cutting them to width freehand but the results weren’t good. I needed a fixture to assist.

By swapping out the indexing block, I can cut different widths. I made blocks for 4mm to 7mm wide tires.

The mandrel just slips into place, and is retained by the plunger on the left.

The mandrel is rotated by hand, and the pressure on the blade is also applied by hand. It is a bit tedious, but the results are good.

I stopped cutting midway and pulled off the tires to show the process.

Overall, this process is pretty effective. Pouring the tires is relatively quick, as you are pouring around 10 at a time. It takes a few runs to get used to eyeballing how much Urethane to pour into the outer mold before putting in the mandrel. Inserting the end of the mandrel into the guide in the bottom of the mold is blind operation and can take a few attempts to land.

Cutting the tires to width, even with the fixture I designed is slow and difficult. The Shore 20 compound is so soft, it wants to stretch and bend instead of cut. Still, with a little time on the truer, they all come out very good in the end.

The files needed to print your own molds and mandrels may be found HERE.

The files needed to print your own tire cutter may be found HERE.

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On Wheels and Tires – Part 3 (Improved Foundation)

After a lot of thinking about how to avoid the silicone mold cost, I concluded the least expensive way out was to find a way to 3D print the molds. After thinking through many options, I decided to try something a little different.

I call this the “fixed width” design, as due to the inner diameter geometry, you have to match the inner mandrel and outer molds.

The lowest part of the mandrel has a taper and a shoulder to set the position in the mold. The mold is comprised of two halves. The are indexed by short lengths of 4mm aluminum tubing. The mandrel pieces are also on a 4mm aluminum shaft.

The process is to pour the urethane into the open mold, around 3/4 full, then plunge the mandrel in.

Once cured, the mold is spit, and the mandrel comes out with all of the tires bonded together. They must be cut to width.

The outer molds have ridges in them to mark where the tires need to be cut. These grooves are enough that the tires can be cut to width with just a razor.

As the tires come off, you can pull the mandrel parts off one at a time to ease removal.

One pour yields 8 tires:

The zip files for these molds are available here –

Click for for zip file of STL’s

This exercise proved to me that I could pour tires directly into printed molds. They require some cleanup but are definitely usable.

The downside of this design, is that you’d have to print a unique set of outer molds and inner mandrels for each combination of Diameter and Tire width that you want to produce. This isn’t insurmountable by any means, as filament is cheap.

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OpenSlotCar – Foundation Design – Wheels and Tires

Based on what I learned on the Monaco, i rethought my wheel and tire design. I still wanted geometry that would retain the tire onto the wheel in a turn. I also wanted the tires to be easier to make in a silicone mold.

I also decided to just thread a setscrew into the plastic wheel and hope for the best.

I used the tried and true process of making siicone molds from “positives” of tires, and then pouring Urethane. I use Smooth-On Vytaflex 20 for the Urethane. I’ve used several different Smooth-On Silicone products for mold making and all have worked well.

The grey parts in the right of this picture are just tires printed in PLA plastic. I glue them to the bottom of this container with purple glue stick. You can see rings where I’ve done this.

From there, mix and pour the silicone per the instructions and pour into the container. Submerge the tires by about 1/4″.

Here are some examples of several different molds I’ve done. Early on, I wasn’t using mold release compound, and although the tires weren’t difficult to remove, after half a dozen or so cycles, the molds started taking damage.

The bright red parts in this picture are the first 20 shore tires I produced.

This method works well enough. The tires come out pretty good, however as with any car, you still need to go across a tire truer in some form to really bring them in. The files to print these positives of the tires and these wheels are in the currently available zip file for the Foundation Design.

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OpenSlotCar – The Beginning – Tires

My initial design for wheels and tires had many problems. In order to reduce the number of parts, my original plan was to thread the axles themselves and screw the wheels on to the axle. I purchased left hand thread and right hand thread dies to do this.

I practice,, threading the axles tended to bend them, or at a minimum make them less straight. Of course this is a problem. I also had a lot of trouble with marring the axles trying to hold them while putting on the threads. I did get a test car put together this way, but one of the sources of vibration in the car was clearly the bent axle.

The final issue I discovered was that since you are counting on the wheels to help set the gear mesh, the fact that the wheels are getting “tightened” onto the axle while running causes binding.

My initial tire design was based on the tires on Carrera Go cars. The wheel has a “rib” around the middle and the tires have small “flanges” that fill that rib. The intent of this geometry is to keep the tire on the wheel in the turns.

These small side flanges are difficult to cast in a silicone mold. It can be done, but it isn’t as easy as I would like. The undercut in the mold is severe, making filling the flange and removing the tire both difficult. mold life was a bit of an issue.

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OpenSlotCar – The Foundation Design

After working through the Dodge Monaco, I decided to refocus the project on making a no-mag car that could be FDM printed and would actually be fast. I also set out the goal of coming up with something that could be made for a total cost of about $4 (excluding decals and paint). Obviously, you need a little bit of economy of scale to get the per unit cost down to $4. However, if you were making 20 or 30 of these, I believe you could get down to around this price point.

I’ve always liked the Group C JaguarXJR-9. I decided if I was going to make a custom car, it would have to be one of these.

With this price point in mind, and based on the issues I had with the King Crown Gears in the Monaco, I redesigned the chassis and drivetrain around 2mm components. This allowed me to get ball bearings very inexpensively, as well as allowed me to use crown gears that I can buy in bulk in China for a few cents each.

This is the very first version of the chassis. The axles are both 2mm shaft. You can see the wheels have a wide deep recess in the middle (where the setscrews are).

The frame and body have provisions for 4 screws. I typically just use two on the diagonal to secure the body (with a little bit of rattle).

This version still has de-soldering braid for the pickups and screws to secure. I ditched this in the next iteration and just run the motor wires through the guide flag. Here is the fully assembled chassis. I added several mount points to the rails to allow attaching magnets and lead weights. The loose pieces next to the car are plastic versions of the lead weights (just to check space claim/fit)

The magnet that is in the middle of the car works really well. It provides enough extra downforce to mask a lot of performance problems. I tried finding a way to tuck a pair of very small magnets towards the rear of the car (they are near the crown gear). There just wasn’t room to tuck them in.

I entered a pair of these cars into a Pro No-Mag proxy race. They ended up getting a DNQ primarily because I didn’t clue the tires to the wheels. The track they were on in the proxy race is much larger (and much faster) than my home track. Issues with the tires coming off the wheels didn’t show up in my testing.

Stickers on the Jaguar were from a 1/43 model kit. Paint and stickers really bring things to life. The other paint scheme is my personal paint scheme I use on all of my cars. I guess that makes it a fantasy livery.

All of the stl’s as well as a text file with sourcing information and other tips and tricks can be found here:

http://www.lightsout-industries.com/wp-content/uploads/2019/11/Export_20191013_OpenSlotCar_V00.zip

I have done a lot of work on wheels and tires since I made these cars. Stay tuned, as I plan on writing up something on what I believe to be the best overall strategy for making wheels and tires.

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OpenSlotCar – The Beginning

For a while now, I’ve been working on a project I’ve been calling the Open Slot Car. This project really began as a response to the terrible quality of Carrera Go!!! slot cars. I purchased a Carrera Go set for my son and I to play with a few years ago, and while the track system is quite nice, the cars themselves had many problems. Also, in general, there is much less selection of cars in 1/43 scale than in other scales.

So, I thought it would be fun to design a 3D printable chassis and bodies to enable people to build cars that run better than the Go cars, and be inexpensive to make.

The first car I wanted was a 1974 Dodge Monaco. I found some dimensions and pictures from the internet and set about creating this iconic car.

I learned many things in the design of this car. Number one is that modelling car bodies in regular MCAD is quite difficult. Number two, is that you have to be really careful with how you set up the models so that you can shell them out in order to keep the weight down.

Here is a body off shot. I tested many ideas about flag/pickup design as well as evaluated different options for the front axle. This initial flag design didn’t work very well.

I started off using de-soldering braid I had ordered from McMaster. I ordered braid with no-flux, per the suggestions of others. I thought the little screws pinning them in place was a good idea, but the screws ended up damaging the braid, and I had trouble getting a reliable connection.

For this first iteration, I tried to use as many “commonly available” slot racing parts from other scales as I could. The smallest Parma King Crown Gear I could find was still a bit to tall for what I was trying to do here. That also drove me to use 1/8″ axles, bearings, etc. I had a lot of trouble with the gear “high centering” the car on the track when in motion, causing terrible handling.

You can also see that this car uses a 130 can motor. These are so inexpensive and so common, I really wanted to make these work. However, after trying several different motors, I concluded that for 1/43 scale it is worth the trouble to track down a smaller 030 can motor.

I went into this project with the intent of making my own tires. I wanted a wheel/tire design that would make it easy to change/replace tires (no glue required). I also wanted the tires to be easy to cast. The Wheel/Tire geometry I came up with met those goals to a point. On home track, at relatively low voltages and speeds they work fine. If you take care in the process of mold making, you can produce wheels and tires that don’t require a truer (at least for low speeds and home track use). however, in the end I’ve concluded you really need a tire truer to get any real performance out of these parts. The FDM printed wheels are a little rough, the tires are a little rough, and the truer does a lot to correct these issues. I also tested two different hardness of Urethane, with the softer 20 shore being a clear winner.

If you’ve read this far, you should also be aware that I decided early on that I wanted to be able to run with no-magnet. I did design and test a few different magnets and holders on this chassis. Indeed, adding enough magnet would make it run, but I prefer no-mag racing and wanted to find a way to sort an FEM printed car to the point it could run with no magnet.

This car ended up not running very well for a variety of reasons. However, I used this car to test many different materials/parts/concepts and it served its purpose quite well. I still don’t have a 1974 Dodge Monaco in my fleet, but that day may be coming soon.

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Vehicle Voltron Fist – Complete

Well, it took me two iterations with Shapeways, but I finally got the part to fit just right!

On the first pass, I printed the fist as a solid, using the same models I had printed on my FDM printer.  The Shapeways fist is much more solid, and the printed fist was much heavier than the original.  It didn’t fire very well from the spring loaded launcher.

So, I broke the model up into three parts, and shelled out most of the material.

This didn’t change the cost much, due to the way Shapeways calculates things, but the finished fist is within about 1 gram of an original fist.

The fits are all “size on size” so some filing is required to get them together.

Here are some assembly shots:

 

And finally a happy Voltron!

 

Of course, the bright white fist doesn’t look right, so I went about painting it.  I just used Vallejo Acrylic model paint and hand brushed it on.  I put on 3 layers of primer, and attempted some sanding (this didn’t really work, which is a well known issue with SLS Nylon parts).  I then applied two coats of black paint, then did a little masking to put on the red stripe.

I left the part that inserts into the arm unpainted, as I was worried about interfering with the fit or bits of paint rubbing off and gumming up the mechanism.

 

That is Voltron’s happy face, trust me.

If you need a replacement part like this one, here is the Shapeways link:

https://www.shapeways.com/product/SDZS9S2JU/replacement-fist-for-vehicle-force-voltron?optionId=125379915