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As a child I always loved playing with my Scalextric set, but as I grew older, real cars took over. Whilst browsing the net I came across www.SlotForum.com and noticed that in my 25 year absence from the scene things had moved on a little! The two main drawbacks were the space required for a decent track and the limited possibilities of cars restricted to a single lane. There is now digital racing where cars can switch tracks and the smaller scale 1/43 and HO offers much more bang for bucks in terms of track layout.
Just been thinking up some alternative wire designs to enable lane changing. Fig 1 shows how one could work without a plate.
Wow I didn't realise it was so long since I had posted here. A lot of work on other projects, so slot cars have taken a back seat. Fortunately last week I was browsing the net and discovered MAGracing. This is a slotless car system which uses magnets to guide cars without slots. I have ordered my first car and am busy planning my first track. This really appeals to me as the tracks are really cheap to make and they look so much more realistic. Not sure what sort of track I want to build, but I see there doesn't seem to be a rally / hillclimb sort of circuit yet in existence.More to follow.
Progress is rather slow on the Keysoe Rally circuit, however I have managed to make some hills from polystyrene and plaster bandage and also cut some pools in the surface. A basic painting scheme has improved things.
The pools were achieved by jigsawing a hole, then attaching another piece of wood below the top layer. A quick dremel of the edge and some polyfiller did the trick. I might fill them up with fibreglass resin or use wood varnish for the water. I am not going to do any detailing work just yet until I am confident I have added all the features on the circuit. The lap timer is next to be installed. The SCX Citroen DS goes well on this circuit, even though its quite a long car.
There has been some progress on the Keysoe Rally circuit. I have now begun the scenery and am making good progress. The best method seems to be to use a hot glue gun as this is the quickest assembly method and is easily stong enough for what I want. First I have made a box in hardboard and plywood, then filled it with roughly broken bits of polystyrene. I used a large screwdriver dragged across the surface to randomly break the pieces to give a more natural look. I'll probably cover it with toilet paper dipped in PVA and then paint it with acrylic paint. The hope is that the scenery sections can be removed when I want to stow the track away. The edges where the rocks touch the track, I plan to cover with small bits of litchen etc.
The Hillman Imp is now finished. I am quite pleased with how it has turned out, but I can see areas where I could have done much better.
The car is painted Ford polar grey with details in acrylic paint. The door stickers are standard "Mini" self adhesive items.
The chassis has been modified a little, I added some brass bushes turned on my lathe to replace the poor nylon ones. The car is very quiet and as such I think I will call it Lil' Whisper. It drives real well and is very tail happy just as I like them.
I have now finished the circuit development for the lap timer and am now transfering the design to Veroboard (Stripboard) for the final design. In order to get the best layout on the board the use of CAD is needed. This has taken about 2 days, but hopefully its nearly done and I can get on with building the circuit. This will also assist in when the designs are release on the net.
I have taken the trouble to add two additional LED's in the design as it will give me a little flexibility should I want to add a race start proceedure later.I
There has been much progress on the Slot car front. The lap timer circuit now has an LED light and speaker to give the user news that the best lap was beaten. I have also carried out some work on improving the car sensor. I was going to sense the guide blade, but the pulsed signal time is very short and can cause missed cars. I purchased some infra red sensors and a photodiode and today I got them working with a distance between emitter and sensor of 80mm. With this I will be able to sense cars across the track similar to how rally stages are sensed in real life.
The Hillman Imp kit has arrived and is well on its way to completion. I modified the chassis to incorporate some brass bushing which I turned on my lathe. The chassis now runs very well and is the quietest car I have. The bodywork is prepped and sprayed, so its just a case of detailed paint work on the body and finishing the interior. I have ordered some basic water slide transfers to tart the body up a little, so I am hoping my first self build will be on the road soon.
The routed track has also recieved some attention. Yesterday I extended the ends by about 6 inches or so. This doesn't extend the track, but does give cars more room to tail slide and makes them less prone to fall off the end. The extra room also gives me some space to put a little scenery. Maybe a hill or building might improve the look of the track.
The Auto Art Peugeot 206 has recieved some attention. I took the body off and oiled the drive train. There is a brass bush which was a little tight, but after oiling seemed better. On the track it now runs much more quietly with better throttle reponse. This may be enough to save it from the parts bin...but I must say that a 4 wheel drive classic car does sound appealing!
I have now purchased a few more cars. The first is an Auto Art Peugeot 206 which is 4 wheel drive. Unfortunately this is very fragile and is already missing its wing mirrors and rear spoiler after a rather violent roll over. The 4 wheel drive is also not really any benefit and there is a lot of resistance in the drive train. I may break this model down and put the chassis in another car, perhaps a classic such as a Ford Anglia! The second and third cars are an Ocar Hillman Imp kit which will need to be assembled and a Scalextric classic mini off eBay. I am still awating arrival of these two.
Other work includes the assembly of a lap timer for the copper rally track. The circuit and software are complete. Its just a case of tidying up the circuit and adding a few more frills such as a led light or buzzer when the best lap time is beaten and setting up the track sensor to give reliable triggers.
I have now copper taped and wired up the routed track. I am very pleased with how it drives. Unfortunately 1/43 cars are a real dog to drive without magnets, so I have decided to put them on the back burner and convert the track to 1/32. Suprisingly they work very well on such a small track and as I am only really a fan of small cars (Hillman Imps / Ford Anglias / NSU TT etc.) they should work even better. Here is a video of the track in action.
Other news is that I have won a cheap 1/32 set on eBay. Its a small rally figure of eight with two cars. I''ll give this a test when it arrives and see if its much better than the 1/43 stuff I have.
The DCC Mini is on the track and is quite driveable due to some revised software. It appears that the DCC decoders don't like bieng overloaded with data, that or my software is not doing exactly what it should in between interrupt cycles. Anyway here is a video of the progress so far. You can see that the car is great fun and the headlights work as expected. I would still like to improve the throttle some more and may try to get the car working using a PC game controller.
The work on the DCC car is now to a point where I have run a car around the track with working lights and full throttle control. The throttle is very laggy , but I am confident that this is due to the hand controller / analog data input as the car lights work instantly when the hand controller button is pressed. There is still no lane changing, but I have recieved the Carrera Go lane change section and have begun to decypher how it works. Unfortunately as the lane changer relies on complex pulsed data to control it I think this will be more difficult than expected as it will require a custom circuit to flip and return the paddle. I'll put the lane changing on the back burner for a while whilst I sort out the throttle as without this all the other work is is of little value.
The image above shows the modified hand controller with two extra buttons and a 5 pin DIN connector linked to the circuit board. The car at the top of the picture shows the decoder and LEDS fitted. I have used large connectors as this enables me to remove the decoder easily. Its very cramped, but would be much simpler if I hard wired it and didn't have any headlight/taillight LEDs. I may revisit this wiring setup to improve things. The red track section is a standard Carrera Go double lane changer which uses two infra red detectors (see black dots just to the left of the track join.)
The hand controller is now finished, The breadboard, DIN inputs, Arduino and a short section of track has been mounted to a board and the circuit is assembled. Tonight I got all the basic functions working via Arduino firmware, that is to say motor speed control and also control of two LED lights from the switches. This now proves that the circuit is capable of controlling the slot car and some lights for lane changing etc. There is some lag in throttle control, but I believe this to be due to the hand controller rather than delay in the decoder or software. The hand controller is very poor and there are a few dead spots. As I am only putting 5v through the potentiometer which is more designed for 12 to 14v this may be the problem. I may try putting the full 14v through it then using a potential divider to pull the voltage back down to 5v for the analog input.
I have been progressing the DCC project and have made good progress in understanding the control software. The plans are to use modified micro scalextric hand controllers. I have completed one assembly and the hand controller has now two push buttons and a 5 pin DIN style lead which will plug into the breadboard via some connectors. I chose the DIN connector as MIDI cables used for connecting music keyboards are very easy to obtain and cheap.
I was looking to extend my Carrera Go track with extension set 3, but during a visit to Maplin Electronics I spotted a full Carrera Go set for £24. As this is only 3 pound dearer than what I was going to buy it seemed a no brainer to buy this. I now have some track, and the extra bonus of two hand controllers, power pack and two cars (A BMW Mini and a Fiat 500). As I really dislike the BMW Mini and all it stands for, I think this will take the place of the Porsche 911 on the operating table when I come to butchering a car with LED's and decoders. Tonight I designed and printed some brackets on my Makerbot to make the installation of the DIN connectors near the breadboard much neater. I am hoping that the breadboard circuit is robust enough that I can use it for many months as the trackside electronics. This way I can fully debug it and maybe add an LCD display and also get four cars working at once.
There has been some progress on the my first routed track. To keep it simple I modified the design so it is one continuous loop. A quick trip to B&Q revealed that they sold 12mm MDF in sheets of 1819mm x 607mm. This fits nicely into my car, so I bought one sheet. The routing went quite well an I did two passes, one 3mm deep and the next at 6mm deep. The slot is 3mm wide. Most of it was done freehand as my router is very easy to control. I only used a guide on the straight sections. A quick lick of paint and the track now looks as below. I still need to add some a strengthening frame and copper tape etc. I was quite surprised how quick it was to produce a track. This only took about 3 hours to do. I tried a car in the slot and it appeared a little tight in places, so maybe I will need to use a 4mm wide groove, but I will only really know this when I wire the track up.
Unfortunately I scrapped a decoder trying to fit it to a HO sized car. My second attempt proved troublesome and there is also no room to get any extra LEDs in. As the decoders are £15 a throw, I don't want to scrap another quickly. I think I have now abandoned trying to do this for a while, so instead I will fit one to a Carrera 1/43 car to see how it runs. To this end I have ordered a Porsche 911 which should have sufficient room to get all I want into it.
I have made good progress on the DCC control and managed to piece together all the information scattered across the net and I have now got a working circuit controlling a slot car chassis. Its all placed on a prototyping board at the moment, but it does at least prove that it can be done. Here is the video of it working. I will try and get it fitted to a chassis and maybe some headlights, but I first need to become comfortable with how the software works before I can modify it.
Plenty of parcels have arrived at Helium Frog Headquarters! The parcels include another 1/43 car (Suzuki SX4) and some sections of track which now extend my circuit across the floor and under the dining table! I also knocked up some bridge supports on my rapid prototype machine and these are much better than the Carrera ones.
Other news is that I have continued to investigate the possibility of using DCC control on slot cars and to this end I have now succeeded in using a motor driver to get a car motor going forward and backward (ie +/- 12 Volts). This is the first step to full DCC control as it basically switches between plus and minus voltages quickly to generate the binary data to the decoder. Hopefully over the weekend I may get some control via an Arduino microcontroller, then its just a case of software design to generate the signals to a decoder in the car.
I am also going to build a little routed test track to see how much work is involved. The 3mm diameter router bits also arrived today. This is the last thing I need to get going on this.
During a visit to the nearest model shop I bought a card flat pack building. Although this is OO/HO scale, it gave me the idea of making my own in 1/43 scale building for my slot cars. As luck would have it my partner has experience in the printing industry and gave me usefull information as to how these are made. I might have a go at designing a simple building on CAD to see how it looks. My Brother is a keen railway modeller so he will also give me some tips as to how to proceed with the detailing. He usually makes his buildings in plastic card, but the principle is the similar.
As you can see there are a lot of ideas here, and I am sure that some will be dropped as I simply don't have much free time, but we shall see.
Today the postman brought me a Carrera Go rally cup racing set. The scale is 1/43. The track is quite short and the cars are very difficult to keep on the road, particularly on the rough rally section. The electrics are generally a bit weak, but OK.
Where the set does score top marks is the detail of the cars. For such small models they look superb. I think that this has to be the way to go for the permanent track. This now gives me the opportunity to see if they will fit my CAD design which was originally for 1/64 cars.
Here is the basic design. A start loop at the bottom left and a single track rally layout and a loop at the top right to return the cars back down the same track to the start. This effectively doubles the length of the track in a small area. A little bit of flip flop relay circuitry will enable automatic switching of the track polarity so the cars can run continously back and forth. The circuit to do this is well established in the slot car community. This track is incredibly small at just 6ft x 3ft (similar size to a door), so I hope it is large enough to test the cars. The Carrera cars seem much more eager to come of the track, so a small compact layout should keep speeds down and be more focused on driving skill.
Over the past few weeks I have aquired a AFX HO racing set which is 1/64 scale (Similar to matchbox / hot wheels sized cars) and also have on order a 1/43 scale carrera set. In the image below is a comparison of the sizes. The Blue Marcos is a 1/32 scale slot car by a company called Fly. The Red Alpha is a static model but at 1/43 scale. The two smaller Pontiac slot cars are by AFX. They ate 1/64 scale (HO Scale). They do lack detail, but you can get a lot of track in a small area.
I have two interests here.
1) I would love a static track possibly at 1/43 scale. There is a chance I could get a decent rall track (single lane) in a small area, so i may do this. I have begun sketching a layout in CAD
2) Digital control in HO has not yet been done. As DCC control for N gauge railways is possible and the decoders would fit in these tiny cars. I am currently investigating the electronics that would be required to send signals to one of these via an arduino microcontroller.