Using car body filler I then filled the lexan canopy striking off excess filler level with the top surface of the mould.

Once hardened I was able to take the cast out of the mould.

I repeated the process for the other side of the canopy.

To help with designing decals I put one half of the cast on my flatbed scanner and scanned it at 100%.

I then transfered this to AutoCAD and traced the outline (shown in Yellow).

I cut out the AutoCAD trace to check for dimensional accuracy (shown on the left cast).

The finished canopy needs to be 12mm wider than the JMD version, I used some pieces of plastruct to get the right width then joined both halves of the canopy together with more car body filler.

The task of shaping using rough files and production paper then gets underway. The top surface was made rounder than the original and the front sharper.

I used anything to hand to give me basic shapes, I wanted an air scoop at the front so used a portion of an AA battery box to give me the basic shape.

The canopy needs to be wider where the maingear is situated. I found some plastic door handles that where the correct curvature I wanted and used a portion as the basis of the fairing shape required.

The rear of the canopy was trimmed off to the shape I wanted then its a matter of shaping, filling, rubbing down until happy with the shape and surface.

Once I was happy with the shape I applied several coats of acrylic primer rubbing down in between coats and applying filler if required.

It is important that the 'plug' as this is called is as perfect as possible, any defects will show in the mould and transfer to the finished canopy.

After priming I applied several coats of gloss paint, black is best as it shows defects clearly.

This stage is done purely to look for defects and correct.

Next task is to cut the plug in half and mount it on to a baseboard to cast the mould against. I used some MDF and stuck the plug down using car body filler.

Once trimmed I again primed both halves of the plug and baseboards.

It is important to note here that there cannot be any undercuts in the model otherwise the mould will not release.

The entire plug and baseboard is now finished with gloss.

After 24hrs I polished this to a high gloss with car body wax.

Having completed the plug/model it is treated with two coats of PVA release agent, this will release the mould from the plug once it has set.

Casting in glassfibre is completed in two stages, the first stage is the application of a gelcoat which forms the finished face of the mould/cast, after this has set a polyester resin is applied intio which is brushed chopped strand matting.

It is important to mix the resins in accordance with the manufacturers instructions, to wait the correct period of time before applying the polyester resin to the gelcoat and also to ensure that there are no air bubbles present anywhere in the cast ensuring that the matting is fully wetted with resin. It is also important to wait the correct length of time before removing casts from moulds etc.

As Glassfibre products are irritants it is important to wear the correct saftey clothing.

Prepare all materials well before mixing any resin, you should have mixing containers (I use plastic cups) resin and hardener at hand, strips of chopped strand mat (for this size mould I use 75 x 25mm and 50 x 20mm strips of 163gm matting) sufficient to cover the mould in two / three layers, acetone solution for cleaning and 20mm paint brushes for application.

Once the PVA release agent has dried a thin layer of gelcoat is applied to a thickness of 3mm covering the entire plug and a good portion of the baseboard. Brush this in to ensure no air bubbles are trapped within the gelcoat.

Leave this to set fully.

Next stage is to brush in a layer of polyester resin followed by layers of chop strand mat.

Cover the entire surface of the mould, reinforce strategic areas with more layers if necessary. On larger moulds strips of timber can be added.

After 24hrs the mould can be released.

This is done by first trimming down to within 20mm of the edge of the plug with a Dremel cutter.

The entire mould and plug is then immersed in hot water and allowed to soak. This removes the PVA release agent and allows water to seep into the junction between mould and plug.

Use an old kitchen knife (nothing sharper or you may damage the mould) to work around the edge of the mould slowly applying pressure until it is released.

Polish the mould well with car body wax in preparation for casting

Casting a canopy uses the same principle.

Apply only 1mm or less of gelcoat, apply as little polyester resin as possible and reinforce using glassfibre 'tissue' preferably in a single layer. The idea is to have sufficient strength but maintain light weight.

After 20 min use a sharp blade to trim off the excess material around the top edge of the mould, if done correctly the material should cut easily (dont do this too early or too late!) and will save work later with a dremel.

After a couple of hours with a small canopy the cast can be removed. I prefer to do this at this stage whilst the resins are stil green as it is easier to remove, however there is a risk of distortion on a large cast so use caution.

Use the same principal as before using hot water for removal.

Next stage is to trim the canopy and fit it to the heli. This can actually be quite tricky and takes a fair amount of looking at!

This picture shows how the canopy is held in place, use one half of the canopy to mark where the carbon mount is to be positioned and drill the corresponding hole.

Then tape both halves of the canopy together, push the carbon mount through the half previously drilled, square the canopy and mark the hole required, check the fitting.

Both halves can now be joined together.

Tape the halves together accurately with masking tape then from inside apply resin and a strip of matting.

When set the masking tape is removed and the canopy rubbed down and prepped for painting.

This canopy has an air scoop at the front (in theory to cool the lipo but perhaps not!) which is cut out as can just be seen.

Next is a couple of coats of primer rubbed down in between with 600 wet and dry paper looking fro any defects.

Followed by a couple of coats of base colour.

I made some decals using wateslide inket decals which are applied to the base coat.

The Canopy can then be finished with several coats of clear.

Having made the mould it is very easy and very cheap to make further canopies, see some more examples I have made below.