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This chassis has been designed as a highly competitive and low cost alternative to strap motored Formula cars. As with all Formula One cars there are challenges to be met in terms ensuring sufficient strength in various parts of it’s design, however, follow the instructions and you will have a car which is strong, great fun to race and will get you in a competitive position in almost any F1 race.
You will need a Dremel fitted with a cut off disk, Acid Flux, a reasonable soldering iron, a decent soldering block / chassis jig, a roll of JK silver solder and some piano wire and tube as described.
1) Separate all component parts, ensue all surfaces to be soldered are clean and free from laser burn. Gently remove any material which compromises component fit.
2) Fabricate parts for the centre pivot of the chassis from 3/32” od. tube and 16g (0.062”) piano wire. Solder piano wire and tube solid into rear section of chassis (in front of the motor box) and tubes only into front section, this allows the centre section to pivot.
3) Drop the front axle support into it’s location slot in the centre section, ensure it fits flush with the top surface of centre section and solder in. Follow this with the guide tongue spacer plate and guide tongue, using a couple of short pieces of 0.025” wire in the locator holes to centre the assembly. Ensure that the entire assembly is flat and neatly sweated together.
4) Locate pillar blocks and pillar block brace and solder in place, followed by the Motor mount bracket.
5) Cut and trim front of brass pan sections to your required dimension according to whatever rules your racing class demands (this varies according to which country you are in and what rules you race to).
6) The pan hangers front and rear are fabricated from 0.025” piano wire. For the fronts bend a right angle and solder as shown. The rear pan hangers should be bent as shown in a “U” shape and introduced through the holes from the back of the motor mount bracket (see picture below). Solder a short piece of 1/16” square section tube (with recessed cuts to clear the wire), over the wires on the pans. This will act as an additional brace for the wire. Ensure pans shuffle back and forward smoothly.
7) The body mounts are fabricated from two components ;- K&S 1/16” square tube and K&S 1/16” OD round tube. The square tube is used as a spacer to increase the height of the pin tube on the pan and make body mounting easier and locate the pins slightly higher to add strength to body mounting. Solder a length of square tube to a length of the round tube and then solder this assembly to the pans as shown. Locate the front mounts just behind the front pan hanger as shown below (this will add strength). Locate rear mounts according to your requirements as shown.
So now we have a nicely pivoting centre section complete with two floating brass pans. Now it’s time to fit the additional downstop bar across the centre section and pans.
8) Solder 2 short lengths of 1/16” square tube to the pans, parallel to the centre section as shown. Bend a “U” section of 0.025” piano wire to the correct width to span the centre section and insert into the two tubes. Once the “U” section is bent, carefully bend the cross piece of the “U” to clear the centre pivot of the chassis. The “U” should now slide neatly into the 2 square tubes and also just clear the centre pivot tube. Cut 2 pieces of 3/32” square section tube and a length of 0.046 piano wire. Set the tubes and piano wire across the chassis and mark the position for the 2 tubes. Remove the piano wire and solder the downstop tubes to the chassis. You now have to solder the piano wire to the “U” wire. The easiest way to do this is ensure the pans are flat on the soldering block and tape them down with masking tape so they will not move, then insert the piano wire bar. You will note that this is a loose fit in the tubes. It needs to locate so the wire is touching the top inside surface of the tube, so use some shim between the wire and the pans to achieve this. When all looks right, solder the piano wire to the cross section of the “U”.
Once you have done this. Take the entire assembly off the soldering block and ensure the the pans shuffle back and forth and that the pan downstops that you have just fabricated are working correctly and preventing the pans from drooping.
And now the front axle!
9) Make your choice of front wheels. Put the chassis back on the block with a 0.020” shim under the centre section (this will fix you front ride height clearance, so if your rules require more or less clearance at the front end, use the correct size shim for your requirements). Put the wheels onto the front axle and offer it up to the front axle mount. The axle and axle mount should be neatly bound together using wire (shunt wire is good for this) prior to soldering. Cut 2 small squares of 16g brass (offcut from chassis pans) and solder these under the centre of the fronts axle onto both sides of the centre section and then solder 2 pieces of brass shim over the top of the axle on to these brass squares (as shown below). This procedure will add strength to the front axle assembly. Fit front wheels.
10. Scrub entire chassis with household cleaner and an old tooth brush to remove all traces of flux and crud. Ensure chassis is
( a) flat, (b) pans and upstops are working and all sharp edges have been removed. Fit your choice of rear bearings.
11) Motor selection is down to personal choice and local rules. The example here has an RJR Hornet motor, fitted with Quad magnets. Gearing is 8/32. The chassis will take either Proslot or the new RJR motor cans without any modification to the motor can. Ensure when installing motor that the motor shaft is in line with the rear axle to ensure gear mesh (use an F1 allignment tool). It is an idea to fit a “Nerf tube” behind the gear on the rear axle to ensure gear mesh in a wall shot (set up gear mesh, measure distance between gear and bearing and cut tube to suit).
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