by Tom  Dandes


(The victim picked totally at random is a Fly Ferrari 512s. Why this car and not another is simply because it was next in line to be abused).


Here is what happens with most of us. Just imagine you are inside your local hobby store and there it is! The one car you have been waiting for all year long. And it has your name written all over it.


You see this car and imagine what it would be like to have it sliding around your track. You save your money and now the day comes that you can finally take it home. You want it to be fast, smooth, quite, no rattles and no de-slots. Just the way you imagined it would be.


You put it on the track and then a heavy dose of reality sets in. Itís a dog! Every turn it falls over like an egg stood on end. And if it does run it sounds like a blender.


Face it.Everyone of us has bought one of these and I own more than one.


Luckily there is hope because most of these problems can easily be fixed by investing a little time and effort to fix the car.



The tips Iím writing here are not new. They are ones that I have been shown by many different slot addicts over the years. They are the same tips many of us know share with others every time we go to the track.


I am not an expert and my goal here was not to reinvent the wheel. But what I wanted to do is to pick one style of car (In this case a sidewinder) and share the knowledge that applies to it in a start to finish build up. Almost all of these tips can also be applied to other sidewinders regardless of their parentage.


I keep saying tips but in reality what we do is blueprinting. Blueprinting is simply taking the car and making it the way the factory would have if they had the time and were not mass producing them.


(DISCLAIMER: If for any reason you fill these tips are wrong or you question your skills to complete them then donít do them! Take your car to someone you trust and fill comfortable with and let them fix it for you).


What we will do:


SECTION 1. Inspect the exterior: This is a detailed outside inspection of the car to find problems. (Requires pencil and paper for notes).


SECTION 2. Inspect the body interior: A complete inspection of the interior body to find problems. (Requires pencil and paper for notes, and a screwdriver to remove the body screws).


SECTION 3.Chassis inspection front and rear: Assembled chassis inspection with the body removed is to find any problems with the parts as they work together. This is done before the chassis is taken apart. (Requires pencil and paper for notes).


SECTION 4.Dissasemble and inspect: A complete chassis tear down and examination of every part. (Requires pencil and paper for notes. Tools required are: small flat tip and screwdrivers, small needle nose pliers, and pinion press/ axle remover).






Take a look at the outer body of the car. Physically touch each piece to see if there are any loose parts that may rattle or come off the car. (Note: parts that rattle can easily be mistaken for gear noise later if not found now).


Look for:


1.     Lens covers

2.     Gas caps

3.     Windshields

4.     Antennas

5.     Lights

6.     Mirrors

7.     Scoops

8.     Windshield wipers


(Rule of thumb is to check any piece that was added to the cars body).



The arrows here are showing the windshield wiper falling off and the rear engine scoop thatís not tight and rattles badly.


One tip to find body rattles is to simply hold the car with two fingers of one hand and with the other hand tap the car. Listen for the rattles. Turn the car around and do it again). Sounds stupid but youíll be surprised what you will find.

Now turn the car on its side.


Look for the following at the front of the car:


1.Push the front tires up into the fenders and roll the tires.Do they rub against the inner or outer fenders? (No)

2.Does the tire rub the head light buckets? (No)

3.Do the tires touch the inside chassis? (No)

4.If the car has stub axles do they have so much play in them that the tires tow out at the bottom and wonít sit on the car straight? (This one does).

5.Does the cars axle move from side to side with a lot of play? (Axle slop and yes)

6.Does the axle bind when turned or is it bent? (No)


Do the same to the rear making sure to check for:


1.Excessive side-to-side movement of the rear axle. (Yes)

2.Tire rub anywhere in the rear on the body or chassis of the car. (No)

3.Binding of the rear axle. (No)


In this instance there is a problem with the front axles. We have excessive clearance (slop) in the stub axles. Stub axles are small individual axles installed on each front wheel. They allow each wheel to turn separately and freely.


Many cars have stub axles. Others have one solid front axle instead. Either setup is fine providing it works correctly.But both can be a real problem when they donít.


Severe front axle slop can let the tires travel so far up into the inner wheel wells that they will rub the head light buckets or other areas of the car. This can destroy the tire by wearing a grove in it and can even melt the plastic where the tire rubs against the body.



†††††††††††††††††† (Note how tire is inside the wheel well and above the chassis)


The arrows in the above photo show the results of stub axle slop. The tires are allowed to travel up into the wheel wells until they are above the chassis. This also lets the tires tow out on the bottom making the car squat.



Here you can see in the above photo how front axle slop makes this car look as if it has broken something.




Turn the car over; remove the screws and separate the body.


These are the items to inspect on the inner body:


1.Are the body posts broken, cracked, or have stripped threads? (No)


2.Are the melted weld plastic areas of the car tight and do not allow any pieces to rattle? (And yes we have rattles).


3.Are there any signs of tire rubbing? (No)


(The front arrows show types of areas that need to be inspected. Back arrow points to the white melted plastic area that rattles).


Above is a picture of the underside of the body. As you can see here it is not in bad shape.



(Left arrows show melted post; center tab not flush to the body, and the right shows the white dot of plastic weld that was not melted correctly)


Here is the cause of the engine scoop rattle we found earlier. The plastic weld is barely melted holding the scoop on (bottom arrow). Also the black tab for this same area of the engine compartment is not flush to the body causing a rattle. Something to note here is the melted area of the body post caused at the factory during assembly (left arrow).



These parts are what fell off the car. The wiper was during the body inspection. The others when the body was removed. Not fun to put back on during a race!




Here is where it pays to be real observant to what you are looking at. Fact is simply this: The assembled chassis is the one area that is going to make or break your cars performance. You get it wrong and you will scream at the car on every corner. Get it right and you get to hear the other guy scream.


I start at one end of the car first then move on to the other end. Remember to write down all that you find so it can be fixed later.


We will start at the front of this car and hope for the best.


††††† (Left arrow shows where to look to see if there is tire rub on the chassis.

††††††††††† †††† Right arrow is showing the crack in the hole for the shipping bolt).


1.Do the tires rub on the inner chassis? (No, This can be caused by axle slop or simply no clearance between tire hub and chassis).

2.Is the chassis cracked? (Yes, The crack shown above is small but I have seen them over three inches long completely ruining the chassis. Long time storage, a brittle chassis from age, and a screw that was to tight caused this).

3.Does the guide fall out of the chassis? (No).

4. Are the brushes falling out? (No). 



††††††††† (See how guide pulls to the right, and the new flat braids)


5.Does the guide bind when turned? (No).

6.Does the guide stay straight? (No, It stays off center).

7.Are the braids groomed and in good shape? (No, New car).


††† (Bottom Arrow shows stub axle slop. Top arrow shows loose leads)


8.Do the leads fall outside of the chassis when the body is removed? (Ours does. This can be a problem in a race when trying to put the body back on!).

9.Are the leads pinched or broken? (No).

10. Are the leads attached correctly to the guide and not falling out? (Yes).

11. Does the guide stay in place and have acceptable clearance? (Yes).





1.Does the pinion gear hit the rear tire? (Yes it does, Arrow above)!

2.Does the motor shaft hit the tire? (Yes it does, Arrow above)!

3.Is there binding in the rear axle when turned? (No).


††††††††††† (Look at the left rear tire. See how it is bowed up while the other side is cupped)


4.Do the tires touch the chassis? (Oh yes, right arrow).

5.Are the tires flat? Hardly (Left arrow above).

6.Is the axle gear hitting the chassis causing it to rub and bind? (No).

7.Do the motor leads have good solder joints? (No, they are about to fall off, middle arrow below).

8.Does the rear motor shaft touch the tire? (No, Bottom arrow)

9.Is the motor loose in the motor mount? (No).

10.Are there any cracks in the motor mount? (No).

11.Does the magnet stay in place ? (Yes).

12.Are the leads kept away from moving parts? (Nope, Top right arrow).


(Bottom arrow shows how close the end of the motor shaft is to the tire. Middle one shows bad solder joints. Top left shows motor and pinion gear hitting tire. Top right shows loose motor leads.


As you can see the repairs are really starting to add up. So far I can see about two to three hours of work to get this car road ready. Luckily these are easy fixes.


Keep in mind that what was found with this car is not unique. It could have easily been any car by any manufacturer out there. So look at each one as suspect until proven different.





Using the tools described earlier we are going to take the chassis apart. We will start at the front of the car placing all parts in a container to inspect and fix later.


1.     Remove the front tires from the rims.

2.     Remove the rim and axle from the chassis by using the needle nose pliers. To do this grasp the end of the stub axle with the pliers and twist the rim off the axle with your hand. (Go slow and easy and be careful not to break the axle or twist the plastic stub axles in half).

3.     Remove the motor leads from the guide by using a small flat tip screwdriver. Simply pry up on the brass eyelets on the wires located on the guide. (Use caution here. Not all cars come with press in eyelets. Some use a pressed in braid to hold the leads in place).

4.     Remove the guide.

5.     Remove the braids form the guide.


Now we are going to move to the back of the chassis.


  1. Remove the screw at the end of the motor pod and remove the pod.
  2. Remove the magnet from the motor pod

3.      Remove the rear tires and rims from the axle by holding one tire firmly and twisting off the other slowly. The remaining tire can be removed by holding the axle gear while twisting off the remaining tire. (Use caution here as some axles have a knurled end making the rims extremely difficult to remove).

4.      Remove the axle. .

5.      Remove the bearings from the motor pod. Do this by inserting an old axle or the blank end of a 3/32 drill bit into the bearings. Prying upward will free the bearing. (Here I do not recommend using the cars axle to remove the bearings as it can easily be bent).

6.      Remove the motor from the pod using your hand to pry up on the end of the motor shaft.

7.      Remove the pinion gear from the motor using a pinion gear puller. (Was the gear tight on the shaft or could you remove it by hand? If it was not tight it can easily slip on the motor shaft).

8.      Remove the tires from the rear rims.

9.      Remove the gear from the axle using an axle press. (Before you do this check to see if the gear was only pressed partway over the knurled area of the axle. See below left arrow).


This is very common. When the gear is not pressed all the way onto the shaft it will allow the part of the raised knurled area to rest inside of the bearing and bind the shaft. This one has that problem.



This is what you should end up with. Trust me it does go back together.

Now look at the individual parts to see what needs to be done. Again start with the front and work to the back.




1.     Is the guide blade cracked or broken? (No. Replace if yes).

2.     Is the guide guidepost broken? (No. If yes replace).

3.     Are the braids in good shape? (New braids and they need groomed).

4.     Is the guide hole in the chassis cracked? (No. Can be repaired with brass tubing).

5.     Are the stub axle shafts smooth and casting nubs removed? (Yes).

6.     In the chassis, are the housings for the stub axles cracked? (No. Can be repaired with brass tubing).

7.     Are any screw holes in the chassis cracked? (No).

8.     If there is a mounting post, are the threads stripped? (No).

9.     Are any of the front rims cracked in any area? (No).

10. Do any of the front rims have plastic nubs left on them from the casting molds? (Yes, these will have to be removed as it can cause the front of the car to bounce down the track. They also cause the tire not to sit correctly on the rim).

(Arrow above shows the plastic casting nubs left over from the molds when they were made. Also note how the flat tire areas are not truly flat).


11. Are the front rims tight on the axle? (Push an axle into one of the rims. The rim should not be so loose that it will fall off the axle).




1.     Take the chassis by itself and set it inside of the body. Do the sides of the body have to be forced open for the chassis to sit flush against the body posts? (Yes. Easily corrected by sanding sides of chassis till it fits inside of the body).

2.     If the car has a flat bar magnet is it cracked or broken? (No. This one is a button magnet).

3.     Is the mounting area for the magnet cracked or broken? (No, but this can be a common problem).

4.     Roll the axle on a flat surface. Is it bent? (No, if yes replace it).

5.     Does the axle have any nicks or scratches that would cause binding in the bearings? (Yes, polishing will correct).

6.     Place the bearings on the axle one at a time. Do they slide over the shaft easily? (Keep in mind that at the knurled area of the axle there might be resistance as the bearing tries to slide over it. This is normal. But only for that or other knurled areas).

7.     Do the axle bearings rock from side to side on the axle? (No).

8.     Is the axle gear cracked in the hub area? (No, but common with plastic gears. If it is cracked replace it. CA glue does not hold forever).

9.     Are the axle gear side surfaces flat? (No. It has casting nubs that will rub against the chassis).

10. Is the axle gear bowed? (No, if yes just replace it. I have never been able to straighten one).

11. Does the gear have missing or damaged teeth? (No, if yes replace it).

12. Is the motor mount (pod) cracked or damaged? (No).

13. Look at the motor for the following: are there signs of overheating (melted plastic, insulation on leads melted, motor smells of burnt plastic)? (No, if yes toss it and get a replacement motor).

14. Does the motor turn freely? (Yes. Sounds dumb but it happens).

15. Is the motor shaft bent? (No).

16. Is the pinion gear cracked? (No. But common with plastic gears. If yes replace it).

17. Does the pinion gear have damaged or missing teeth? (No. If yes replace it. I have tried to file and lap bad teeth and it is just not worth the trouble).

18. Are there any areas in the rear of the chassis cracked or broken? (No).

19. Do any of the rear rims have plastic nubs left on them from the casting molds? (Yes they all have. This will be removed to keep the car from bouncing down the track).


20. Are any of the rear rims cracked in any area? (Yes, in the hub area of one rim. I highlighted it below with a marker).


21. Were the rear rims tight on the axle? Push the axle part way into the rim. The rim should not be so loose it will fall off the axle (One was loose because of the cracked hub).



At this point the inspection phase of the car is done.


And as you can see there are many areas that need to be fixed. But they are easy fixes. When work is completed this car will be quite, smooth and handle the way it was supposed to when you bought it.


For Part Two click here


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