Slot Cars Adelaide
Hi There is quite a bit of interest in the Clone of the old Monogram 1/24 ( not the 1/28 ) Speedway Midget
EJ Hobbies make a complete kit -
I have included details of sizes for those who love to scratch build
It would be worth thinking about the kits though as everything needed to build is in the kit
If the class starts it would be pointer motors only - same as the sprint cars.
For those wanting to get lazer cut & make here is the chassis & sizes as I measured them
A body can be bought from " Big Donkey " web site.
There is also a Revell Kit static body which is about 0.5mm narrower than the EJ's Body. The kit includes a trailer for the midget.
It is squeze on the ej chassis at the front so if making the chassis for this body
I suggest making it about 16.5 mm wide at the front axle bracket.
Here is the link Revell Midget Link
Wheel Base is 76mm - center to center measurement
Width is 19mm for the rear axle bracket and the front motor mount bracket - over all , the chassis flat width is relieved to 17.6 mm between those brackets ,
After the motor bracket mount to the front is 17.6 mm all the way including the front axle brackets .
The Revell 1/24 midget kit Body is slightly narrower than EJ's body so it may be best to go 17mm or less at the front for the front section,
The chassis base is 73.2 long - not counting the guide tongue.
Overall for front to rear axle bracket extreme length is 83mm.
The Oillite bearing holes are 4.5 mm
The rear axle bracket is 15.4mm wide at the base . The front axle bracket is 12.2 & the motor mount bracket is 11.3 at the base
25mm between the rear axle bracket to the Motor mount bracket
10mm between the motor bracket and the front axle bracket
45mm between the front & rear axle brackets
9 mm from under the chassis to the bearing hole center of both front & rear axle brackets .
4mm from under the chassis to the motor bracket hole .
Rear motor bracket is 16 mm high from under the chassis.
The motor shaft center is 8.3mm above the bottom of the chassis and is a 6mm hole for the motor bearing .
The 2 motor mount screw holes are 10mm apart & central to the motor shaft . They are 2mm holes
The guide hole center is 8 mm in front of the front axle center line. The tongue is about 10.4mm wide at the chassis base .
The body mount screw elongated hole center id 9.2mm behind the center line of the front axle .
The guide post hole is 4.7mm
The front motor bracket is 17.5 mm overall width - to fit inside the chassis at the mounting bracket
It is 11mm wide across the bracket .
The motor bearing loop is 10mm wide . The bearing hole is 6 mm diameter. The bearing hole id 7.5 mm above the underside of the bracket .
The chassis screw holes are 3mm above the underside of the bracket .
Well I think that is all you need to draw up planes or even make the chassis .
If not ask me for more details. - The brass plate is 0.8mm thick for the chassis & the bracket .
Measurements herewith -
Revell body is quite thin and can be stretched a little – but not noticed out of shape -
inside at rear axle could fit 17.5 mm and it is the same all the way to front axle as it has a parallel bottom pan,
but some of this pan would need to be used to maintain appearance – if chassis was up a little, 17 mm would be OK I think.
Wheel base of plastic bits is only 72 mm but there is a fitting with two slots that takes rear axle and spring behind – this could
cut and faired to allow a slight increase to 76 mm. The gap without the extra bit is 13 mm wide – plenty of room, you could go to 80 mm – not quite scale
but there is only about 2 mm diff between the 1/25 and 1/24 scales.
Rear wheel from plastic kit is 23.5 mm outside diam and 8 mm wide.
Old Monogram body could take 22 mm at rear axle, 20 mm at middle and 16.6 at front axle – virtually a straight taper.
Wheelbase could be anything from 75 mm to 82 mm, again with a 12 mm wide opening at the rear axle area.
Rear tyre from the kit is 21.5 x 9.25, fronts are smaller, as are the fronts on the Revell, but only slightly.
Group N tyres on the hub measure 25 x 10.5 – compare this with EJ’s for size, and we should get some thing that looks OK.
EJ’s does look a tiny bit larger – after this weekend perhaps we could put the three(even four with Big Donkey’s) plus some wheels and make a decision.
The Monogram wheels do look a little small alongside the body and I cannot remember which standard Scalex chassis was stipulated way back at Port Adelaide.
My son is a mechanical engineer and he suggested laser cutting chassis after visiting Lobethal and then coming around to raid my boxes with grandson, Little Max.
So I will check with him and see if he has any contacts or any suggestions.
Hope this helps.