Slow Monster rebuild

[350TSS]

Today was a day that started very badly but ended up sort of OK.
I started by trying to separate the split mould from the pattern for the Ignitech enclosure. Fortunately. I remembered to drill the flange between the two halves of the mould so that it would register in the same place when I come to put the Carbon fibre and epoxy resin in, 4 x 6mm holes about 50mm apart. I then trimmed the borders with a dremel (using a c40mm diamond disc cutter) so I had a thin line between two coats of black gel coat on each half of the mould to aim at with the wood chisel. Horrendous quantities of evil dust were generated and even with a top quality mask I could taste it on my tongue.
The first setback was that the pattern separated from the base. For this I blame Gorilla glue which is in my humble opinion not a patch on Evo stik exterior wood glue (blue container). Then, although I had a distinct line to aim at with the chisel, the two halves just would not separate. My only option at this point was to chisel out the wooden pattern, which was made from marine ply covered in filler and hard gloss resin. Marine ply is made with the grain on each laminate at right angles to the one below it. Wood chisels are not great at cutting across grain. The wood was coming out in thin strands looking like pulled pork but with considerably more effort required.

Two hours later some of the pattern was still inside the mould and worse the filler had de-laminated from the wooden pattern and was proving very stubborn to remove.


In all honesty, I think the pattern was too intricate and whilst I did my best to shape it so there were no parallel sides I do not think I entirely succeeded and consequently the release agent on the pattern was not slippery enough to overcome the extent of mechanical locking caused by the shape and intricate details. Eventually I got it all out and there are about 4 or 5 places that will require repair where the chisel clashed with the gel coat.
Three lessons learned here, 1) use a really strong glue to attach the base to the pattern and if necessary mechanically fix with screws; 2) do not skimp on the width of the margin for the mould separator (min 50mm I had less than 25mm for the Ignitech enclosure) you cannot lay the fibre glass accurately to the edge of the margin so you will have to cut the margin back after all the fibre glass for the mould has hardened off; and 3)ensure that the gel coat is as thick across the whole width of the separator margin as on the main body of the pattern. The reason my mould would not separate was because the gel goat was less than 100% and the voids were replaced with the polyester resin applied with the first and /or second coats used to reinforce the mould. The release agent works exceptionally well on a smooth gel coat surface but substantially less well on a corrugated gel coat surface and almost not at all when the corrugated gel coat is contaminated with polyester resin.

[350TSS]

When my poor old arthritic hands could take no more of wheedling out the marine ply ignitech pattern with a chisel I decided to have a go at the fly-screen, as with the hugger I left a good margin (75mm) and used my trusty Milwaukee jig saw (I love that tool) to trim the mould. 12 x 6mm register holes were drilled and about 6 chisels used to separate the mould. There were lots of cracking noises and quite a lot of trepidation as to the twisting force applied to the chisel to separate the mould from the pattern but in the end it was extremely satisfying. It separated with no chisel damage to the mould. Unfortunately, I will still need to do a couple of filler repairs where the gel coat either, took umbrage and refused to adhere completely to the pattern, or operator error occurred and an air inclusion was unaccountably in the gel coat.
which fallout is better

I had a look at my ETTC (estimated time to completion) on my Excel spreadsheet and despite the 3 hours overrun today getting the ignitech mould ready it has now dropped to below 250 hours – obviously it has got absolutely nothing to do with the time it will take me but satisfying progress nevertheless.
Tomorrow I hope I will have time to make the means of securing the air scoops to the frame – 12 x 40mm x 40mm x 1mm aluminium plates then drilled then shaped and bent and the gel coat on the other side of the air scoops and if I am feeling strong the separation of the hugger pattern from its mould. I have a strange feeling it will be more difficult than the fly screen because of the reverse angle half way along the bottom plane?????????????????

[350TSS]

Well it is not often I get done all I plan to do, but today was one of them. Splitting the hugger mould took a good 2 hours as did making the air scoop brackets. Gel coating the other side of the air scoops took an hour, most of that time was getting a wax seal between the pattern and the base and applying 5 coats of release agent.
The brackets fit to the washers I welded to the inside of the frame via a 5mm screw, the washers will have rubber grommets fitted and a nylon P clip will hold the wiring harness parallel to the frame tube so entirely hidden from view and no cable ties evident. The three smaller holes in the bracket are to enable the bracket to be bonded to the inside of the air scoop

[350TSS]

I started to think about the tank mould and quickly realised I had a problem, when making the pattern I had assumed that the filler bolted through the visible tank top surface. Stupid really as I only had to open the filler cap to see how it worked. The filler cap has no connection with the outer surface of the tank but rather is bolted to a recessed enclosure about 15mm below the surface. This would be impossible to incorporate into my tank pattern as it now sits.
I considered manufacturing a new plate to bolt to the top surface but this would have involved accurately cross drilling the surface plate to take the hinge pin for the cap itself.
I would also have to make up the neck that the cap locates into and seals against and this would have to be at the right height viz a viz the tank surface or the cap would not sit flush or more importantly seal. Looking at the cap itself there a number of critical dimensions measured from the tank surface, depth of mounting lugs, point of engagement of the filler cap in the neck, compressed depth of the sealing ring, depth of lip for engagement of locking latch. Manufacturing a new plate to hold the filler cap was not going to end well.
I therefore had to find a way of manufacturing the recess that I could bond into the tank after the top skin had been manufactured but before the tank base was also bonded to the tank top surface.
Scouring the garage for something suitable to make a mould from I came across a pot I keep all my chuck keys in which was exactly the same diameter as the filler cap plate.

I re-cycled some 3mm polypropylene from one of the belt cover moulds and I now have a reasonable facsimile of the original steel tank recess with a nice big flange to bond into the new CF tank when it gets made.

I cut the polypropylene with a jigsaw with a fine toothed metal cutting blade in. The polypropylene was melting with the passage of the blade then re-forming behind the blade so I had to go round each circle about 3 times before they parted company.

[350TSS]

I will obviously still have to make the filler neck with the correct position for the locking latch, I will machine this from aluminium bar 60mm dia and bond it into the new recess

[350TSS]

I picked up some titanium rear sprocket nuts on e bay. These were "seconds" with very slight defects, hardly noticeable and certainly not affecting serviceability , they were about 1/2 to 2/3rds the price of perfect ones and will save another 24g of un-sprung weight.

They will be drilled for lock wiring.

[Mr Gazza]

Originally Posted by 350TSS

This would be impossible to incorporate into my tank pattern as it now sits.

Not so.

You could make a male version of the recess on your lathe, from a piece of MDF of appropriate thickness.
This would then need to be shaped to the gentle contour of the inside of the mould, where it sits.
It could be highly finished in vitro as it were. You could then hold it in place on the bolted up mould halves with a couple of small screws from the outside. (don't forget to remove these before release!)
Then apply a small radius of plasticine round the joint.
Plasticine is great stuff for adding radii and fiddly bits inside finished moulds. Composite suppliers sell the stuff cheaply for that purpose. You can also get dumbbells to form radii of different radius
These are usually made in stainless steel and are literally just balls of differing diameter connected in pairs by a rod. They make a good enough finish on soft plasticine to pass on the finished moulding... Maybe with just a quick compounding?

You could still add internal radii on any of your existing moulds this way to aid release.

Just found an image for you and was reminded that these are used for pressing in wax fillets...Wax fillets of different radii are also available from your composite supplier..

Obviously plasticine and wax fillets are one use only and need to be cleaned off and re applied each time the mould is prepared.

[utopia]

Originally Posted by 350TSS

I picked up some titanium rear sprocket nuts on e bay.

Er .. I hesitate to mention it but .. the Dymags use bolts to mount the sprocket.
They're low-headed hex socket bolts too (thus giving about 4mm clearance on the swingarm), so probably hard to find in titanium.
To date, I've left the std bolts in. They rotate on a very small radius anyway, so they add very little inertia/gyro effect.
Nevertheless, I'd be interested to hear of any titanium replacements that you can find.

[350TSS]

Mr Gazza
The impossibility was to do with the way in which the pattern was made with a 9mm ply skeleton and dense foam under a skinning of body filler. There was no way I could break through the surface and cut out a recess without compromising the overall pattern.
Those round balls and rods look useful what are they called as I would like to buy some

Utopia - Not my dymags they have studs and nuts - mine were for an S4 not an M900 although I specified a 520 chain and sprockets

[350TSS]

Utopia I am now worried I have a clearance problem on the SA , but it can wait until I install the SA and rear wheel - better to be forewarned though

[utopia]

Originally Posted by 350TSS

Utopia - Not my dymags they have studs and nuts - mine were for an S4 not an M900 although I specified a 520 chain and sprockets

Originally Posted by 350TSS

Utopia I am now worried I have a clearance problem on the SA , but it can wait until I install the SA and rear wheel - better to be forewarned though

Hmmm ... I would have thought the rear wheel would be the same for both an S4 and an M900, both having the double sided swingarm.
(and just in case you were wondering, despite my bike being a 750, it has an M900 ally swingarm and wider, M900 rear wheel).
I suppose they may have changed the design, but I would be a little surprised at that.
Anyway, sorry to be the harbinger of worry.
I've just measured my bike and I have about 12mm clearance between the outer face of the sprocket and the inner face of the swingarm, if that helps.
That's on the original, Talon sprocket as supplied by Dymag, but my replacement Renthall looks to be the same (I had wondered if it was slightly counterbored, but no).

[Mr Gazza]

We always called them dumbbells in the trade, but I see them referred to as fillet rubbers and fillet balls here.. https://www.ecfibreglasssupplies.co....uct/wax-fillet .. Other suppliers are available.

Regardless of how you made your mouldtool for the tank, it is still easier to make an insert in the mould for the filler recess. It would have been difficult to split the mould over the recess and an untidy way to mould it with the flash line down the middle. With the recess as a separate component it will be far easier to release. Provided you remember to very gently taper the sides.
I think you will be better off machining an accurate part for this, rather than hoping that the filler will fit the Brownie bites carton. Certainly on an injection model, the filler has a peripheral O-ring that takes no prisoners when you go to fit it. and then there is a surface rubber seal which is equally precise in it's requirements to fit.

All you need is an accurate stepped disc, you can measure and add the internal radii in wax/plasticine after fixing it in the mould... those will become external radii on the moulding... Obviously.

Alternatively, you can buy "flush" fillers which actually mount to a surface (and so are slightly raised in reality) you would just need to drill a hole for the filler neck.

Fairly sure my Renthal sprocket is counterbored for the (Alloy) flange nuts.

[350TSS]

Thanks guys,
The carbie monster tank does not have a seal, the filler cap assembly simply drops into a recess in the tank and bolts to the bottom surface of the recess, so no worries about accuracy and machining grooves for "o" rings etc.
I agree that splitting the tank through the middle of the recess would be a) difficult and b) likely to lead to flash lines. The precise positioning of the mould splitting for the top surface of the tank is still "fluid", current thinking is to split it front to back rather than down the middle with the widest point of the frame the reference point at the base of the tank and the highest point of the expansion blister (as per 900SS tank) at the top.

I bought the dumb bells of e bay for £25 delivered , wish I'd known about them a few months ago, thanks anyway Mr Gazza.
As to rear wheel /sprocket/swinging arm/chain alignment I will check this when it gets put together but I cannot foresee it being a massive issue as the Chain alignment with the swinging arm is fixed , the only concern is the position of the surface the sprocket bolts to on the wheel relative to the inside of the swinging arm.

[350TSS]

After my usual 3 -4 hours fibre-glassing, I thought I would try to tidy up the filler cap, the gold painted lid was pitted and the outer ring with the machined grooves was corroded/stained. Twenty minutes with a wire brush on the outer ring and it looked worse than before I started, so, I decided to get rid of the grooves. Half an hour with a file and they were gone but there was some collateral damage on the lid so that got treated to 240 wet and dry.
Here are the before and after pictures, I am leaning towards not painting the lid but rather treating it to progressively finer wet and dry and 10 minutes on the buffer.
fallout frank horrigan
fallout ian

[Darkness]

Just be careful to keep that Elefant safe: they’re a protected species you know!