Component Fabrication: Perspex Spur and Pinion Gear Covers

Posted: April 20, 2015 in Component Fabrication
Tags: , ,

This custom made Perspex spur and pinion gear cover is designed for the Team Associated RC18T and is intended to shield and protect the spur and pinion gears from loose debris, sand and rocks which can cause gear mesh problems and damaged gears. The process of construction can be applied to other projects requiring a similar component.

Years ago a manufacturer called ‘Driven Productions’ used to make a plastic spur gear protector for the RC18T. In hindsight I should have purchased one or two when I had the chance as they are currently no longer available. This was a great idea and Team Associated should of thought about this when they designed the RC18T. The exposed nature of the spur and pinion gear made it particularly susceptible to gear mesh issues from small rocks and sand when running on anything except asphalt. Even then a small grain of sand can easily lodge between the gears and can cause a common issue of ‘clicking gears’ which can result in the transmission to jam and damage your gears or worse, damage your expensive motor.

This custom Perspex spur and pinion gear cover is designed as two individual covers which completely seals the exposed areas surrounding the spur and pinion gears and being clear allows for easy visualisation of the spur and pinion gears. The left cover (Battery side) is intended to be installed on the chassis before the rear gearbox housing is installed. It is only removable after the rear gearbox is removed. The right cover (Motor side) is designed to be easily removable even when the surrounding gearbox and chassis components are fitted. This allows for cleaning and servicing the spur and pinion gears.

Each cover is made of 3 to 4 separate pieces of Perspex cut to size from a sheet. When joining Perspex pieces together you must use the appropriate acrylic adhesive otherwise you may not achieve a strong bond. For bonding Perspex, I use a clear, water-thin solvent acrylic cement applied using a very fine needle applicator. For the covers being made here, only 1 to 3 small drops of this solvent cement is required to form a very strong bond. The key to a strong, clean and clear Perspex join is making sure that the joining edge is completely flat and square and the edge surface to be very smooth with no file marks or scratches. I use 1200grit silicone carbide wet & dry abrasive paper to prepare this edge surface. The two pieces to be joined must be accurately positioned together and the small drops of cement to be applied to the join seam in a way that allows for the cement to flow between the two pieces. Bonding will be instantaneous as the solvent cement will chemically weld the Perspex together. You may be able to use normal cyanoacrylate adhesive ie; superglue, tire glue, however joins will not be clear and the surrounding Perspex will cloud and your component will look messy and unsatisfactory.

PART 1: MOTOR SIDE COVER (REMOVABLE)

Part 1 of this fabrication involves cutting all the required Perspex pieces and assembling the motor side cover.

Parts & Materials Used:

2.0mm thick clear Perspex sheet
2.0mm posterboard
0.25 – 0.5mm posterboard
Painters masking tape
Weld-On SciGrip Clear, Water-thin solvent acrylic cement
Silicone Carbide abrasive paper (various grit)
Polishing compounds

PART 2: BATTERY SIDE COVER

Part 2 of this fabrication involves assembling the battery side cover and surface finishing.

Parts & Materials Used:

2.0mm thick clear Perspex sheet
2.0mm posterboard
0.25 – 0.5mm posterboard
Painters masking tape
Weld-On SciGrip Clear, Water-thin solvent acrylic cement
Silicone Carbide abrasive paper (various grit)
Polishing compounds

PART 3: MODIFICATION OF CHASSIS AND INSTALLATION OF COVERS

Part 3 of this fabrication involves installation and final shaping.

Parts & Materials Used:

Part 1: Motor side cover (Removable)
Part 2: Battery side cover
x3 3Racing titanium countersunk hex screws (M2 x 8mm)
Painters masking tape
Silicone Carbide abrasive paper (various grit)
Polishing compounds

Thank you for checking out this article. I hope it helps readers with some ideas on their next build. If you have questions or need some advice on a particular stage feel free to write a comment below and I will answer them.

Cheers. RC-Christo

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Comments
  1. scott says:

    I have a mini rival would like some also. Do you they would work on a HR chassis?

    Liked by 1 person

    • RC-Christo says:

      Hi Scott,

      Sorry for the late reply.
      As far as I know the Mini Rival ‘stock’ chassis is the same as the RC18T ‘stock’ chassis which those custom covers are designed for.

      You mentioned a ‘HR’ chassis – Are you referring to the ‘Hot Racing’ fiber upgraded chassis? – If so my custom covers are not designed for that chassis.

      If you were to build those covers yourself you could use a similar design and geometry as my custom covers but you would have to modify the design to allow for mounting on the ‘HR’ fiber chassis plate.

      Cheers,
      C

      Like

  2. Rooster Reagan says:

    my god man, im thoroughly impressed with your fabrications… glad to see someone else in the world is as OCD about fabbing as i am LOL. but seriously well done, can’t wait to look around this site more, hope you don’t mind if i borrow some of these ideas….

    Liked by 1 person

    • RC-Christo says:

      Hey Rooster.

      Thank you again mate for your kind words! 🙂

      lol…Great to see another OCD individual obsessed about fabs! – Thanks mate, I think you would agree…It is so hugely rewarding to make something from scratch and result in exactly what you imagined.

      That build you have been reading has so many more articles & photos that I have yet to upload. I think you would really enjoy reading them. I just have to find the time – Work has been insanely hectic and have been travelling a lot.

      No probs mate, I hope some of my ideas help you to create some of your own OCD fabs!

      Cheers,
      C

      Like

  3. Please 3d print some. I love my mini rival but can’t drive it off road without destroying gears. Not much fun in the dirt.

    Like

  4. Tyler says:

    Hey man if u ever make another one I’d buy it lol but nice work have to attempt this one day
    .

    Liked by 1 person

    • RC-Christo says:

      Hey Tyler,

      Thanks mate. Actually after I made those clear Perspex cover prototypes I drew up that cover design in CAD so that I could use the drawing file for 3D printers or CNC if I decided to make more covers. If I do make more I will let you know.

      You should have a go at making one, just takes a bit of patience and planning.

      Cheers.

      Like

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