Having problems posting phots so here is the text, will try and post photos.
Hi here is an update of a post that Shane did quite some time ago with information from myself and information that I received directly from the late and great Salvatore from NSR.
Shane has dropped out of slot cars and spends most of his spare time plating Dad’s taxi for his kids sporting endeavors.
The basis for the post was for the 2012 Scale Model Nationals in Adelaide several years ago and based on a Classic 917 build. Some of the models will have been updated however the basic setups will be the same. These methods also work for the Sidewinder, Inline and Angle Winders setups. Also note that these notes are for non-magnet setups.
Just as a quick note my Mosler won its class at the Scale Model Nationals driven by Sammy (I gave him the wrong car dam).
Ensure chassis and motor cradle is flat and straight. If not use the Sloit.it boiling water technique to straighten the chassis and cradle.
You will need a steel plate with plenty of magnets.
Hold down with plenty of magnets. We place the bearings in after to ensure the rear end to sit square and flat.
When the motor is pushed in it will flex the pod.
Another little trick is to file off retaining tabs on both the motor pos and the axle holders so that the motor/bearings drop in without distorting the motor pod. Note this works best if you use a new pod. Also note that this requires the motor and bearings to be glued in as the last step, if you do not want to use glue in these items do not do this, however the car will always be faster on a timber track with these items glued in.
If the pod is not true and square always use the dummy motor to let the boiling water do its magic with help of the magnets, it will bring the cradle into the dead flat position. When the dummy motor is removed the cradle is flat and when the race motor is inserted the cradle should remain flat.
Us the boiling water first so you can go on with other stages of the build. Normally leave the chassis and pod in the water to cool down for 8 hrs. or so. We have also found that the NSR pods and chassis have more of a memory than do the Sloi.it’s so you my need to repeat this step.
Running in the motor
Start by oiling each end of the bearings, start at 1.5-volt x 3 minutes at a time and adding a drop of boost on the commutator.
Work up to 12 volts then switch the positive and negative around and do it again. Now there are a lot of ways to run in motors this is the technique that we use. Also, the latest batch of NSR motors 25k Kings don’t appear to need much running in if any.
Name your poison, your selection of tyres will vary considerably on you track, club or competition type so we can not be definitive here. NSR puts out several types of tyres, Supergrip, Ultragrip, Extreme, grip levels get higher as move towards the Extremes will say that from my experience with the Extremes (on the tracks that I run on is that you will get the fastest 10 – 12 laps you have ever run then the tyres will go off, over heat and pickup dust and marbles and the lap time will go off. We tend to use Ultragrips mostly unless we run on a gooed track where we use sponge tyres. MJK make great tyres and are the tyre of choice for some club and competitions.
I will say though from the racing that I have done dry track or gooed track the sponge tyres will yield fastest times.
We also treat our rubber tyres using NSR tyre treatment oil of CRC 226 which I prefer (Our club requires the tyres to be cleaned with shelite prior to being placed onto the non-gooed tracks). I don’t want to get into the pros and cons of this this is what we do your track/club/competition may be different.
If you are using NSR rubber tyres give the area of the rim where the tyre seats and the tyre bead a rub with sandpaper to assist with the adhesion of the glue. Place the tyre into the rim then use a small timber block to seat the tyre square (one side of the timber block has a hole drilled into it to take the wheel hub) Using a tooth/dental pick carefully place super glue around the rim one side at a time, giving the tyre a slight squeeze to let the glue seep into the bead.
No gluing will be required if using the glued and trued from NSR foam tyres. First picture just a light touch to make sure true.
Picture 2 showing the removal of the edge on the tyre giving it a nice rounding. A square edge on high grip tracks, cars with a weight of 100 grams can cause shutter in the rear end. Also on the 917 rear end the wheel arches can be close to the tyre. Rounding of the edge can avoid missing the wheel arches too. When you get to the stage of cradle tension and how loose to have your body, these factors also can contribute to things rubbing and touching.
Motor and Cradle
Gear mesh is important so dry fit the motor, axle and gears and test the gear mesh, you do not want it to be too tight or have too much gear lash so this is the time to test. If it is too tight file out front of the pod until you get a good mesh do it incrementally so that you don’t over do it. If it’s too loose file out the rear end side of the pod and put a little pressure on the motor towards the rear whilst gluing in, You can also use grinding past if the mesh is too tight once you have glues it al in to run in the gears. One trick you can try if you use a plastic spur gear is to apply a little heat in the form of a lighter flame whilst the gears at running at high speed you can hear the sound pitch change and the noise smooth out, but be careful it takes some practice to get the technique right and not melt the gear too much or other plastic parts. Metal gears are the preferred option though.
First glue the motor, little bit of a file to make sure glue holds well.
Glue in the motor in sitting flat on a set up block making sure everything is flat. After this it’s time for the axle and bearing.
The picture above shows the insertion of the axle bearings by pushing down on the axel and rocking from side to side, back and forth. By doing this it gives the axel its free slide. Hard to put in words but you feel the freedom of movement. A little trick that the 1:24 car builders use if the axle is too tight is to lightly sand the axle in a drill with wet and dry sand paper to reduce friction, be careful not to over do it as going too far can cause vibration which we need to avoid.
Next measure with Vernier’s from the top of axle both sides to ensure the axel runs true before gluing in the bearings. If they are not carefully file out the bottom of the bearing holder that is high until it matches the lower side. Slow and steady or you will be chasing the set up.
Now all bearings are glued and run true. Gluing is an essential must for 1:32 scale builds as it:-
stop the rear end from popping out,
reduce vibration in cornering,
eliminate shudder on acceleration.
Minimise friction as far as possible. Now bearings set the axle now falls through when placed on its side.
Now time for assembly. This photo shows how flat everything is, look at the cradle how flat it sits on the chassis. The red pod to black chassis no daylight.
Setting up the chassis pod screws is something you will need to test for your situation. You can just use the supplied screws or use a spring suspension setup. Generally, start with the screws tight test then loosen to get the best setup for your track. We have found that having the front screw tighter than the rears two yields the best setup. If using the sprung pod setup start with the hard springs varying the screw tension test ten try the medium and soft springs, once again test record test until you optimize the setup for your car and track.
Next photo shows the .05 washers either side on the axel to reduce the area of the surface that contacts the bearing surface face wheel hub and gear. These little 1% incremental changes can give you a racers edge.
Also if you rules allow (and track clearance requirements) you may consider roller bearings or eccentric bearings (where the axle bore is offset allowing you to raise the axle up thus lowering the motor pod, but take care to ensure that both eccentric bearings are set to the same height).
The next photo shows the difference in surface area of the gear hub vs spacer which would be running against bearing. Small surface area of the spacer bronze color, gear hub black, big difference!
The classic NSR cars come with the treaded tyres, we tend to true the fronts and take the tyre down to when you know longer see the tread. Don't over true or front wheels will not touch the setup board.
The following picture below shows the hardening up the fronts up with super glue. This way rolling it through the glue gives even flow.
Several coats are put on then trued again on a truer, use wet and dry sandpaper by hand on the truer smooth off the superglue and finish with a wet rag at high speed on the truer to polish to tyre surface to a high gloss.
The Front End
NSR do little washers to assist with the front wheel track width.
Another little trick is to use washers in the inside of the axle holder, get the ride height to the required distance and then glue on the spacers, this can sometimes help but you need to test as it may not add any performance advantage (the theory is that if the car is running on just three point two rear wheels and the guide the car my lift the outside rear tyre on cornering reducing traction). Test test test.
Note. Now we can run the foam wheels and tyres, YOU MUST ADD .5 MM OR 1 MM SPACERS ON REAR AXEL
before rear wheels go on.
Reason the new wheels come with are a small hub and will hit on the chassis.
Picture below shows minimum wheel starting width.
For our national rules we can run weight, we always start with my testing without weight, cradle done up so no movement, body loose.
Next depends on condition of track, if lacking grip I work on cradle adjusting half a turn at a time until happy. That’s to loosen for cradle movement.
If plenty of grip cradle will remain done up. Remember do not over tighten as it can twist the chassis and have the body loose. I remember reading a review of the Italian NSR championships several years ago and one of the competitors noted that he was surprised how loose the winning NSR team ran the body.
With the body it is good practice to dry fit the body checking to ensure that there is no flashing or body parts catching the chassis it should be nice and loose. Long metric screws are preferred with a section of non-threaded shaft. Ensure that the chassis screw holes allow the screw to move smoothly without and restrictions or rubbing (motor pod and chassis body screw holders).
If weight needed this was the winning formula at the 2012 nationals. Stainless steel weight plate wire cut to perfection.
I arranged to have several laser cut inserts made for the NSR motor pods, these have been copied by many now. With these cars its important to have the weight in the pod nowhere else unless the car runs out in the corners (understeer) where a little weight behind the guide mat help.
We have found that the Slot.it timber track guide is a good alternative to the NSR guides however sometimes you may need to round off the bottom front corner a little.
It is also critical to adjust the guide depth by adjusting the guide screw to get the guide at the appropriate depth.
The finished 917.
Hope this helps