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METAL CASTING WORK


krow113

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Hi Steve, put me down for a couple of sets !!!

great work on the moulds & I look forward to the first casts....

Now, a set for the Manx Norton & the Ducati 750S would do nicely, no rush

Mark D

Edited by Fazer
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Thanks for the continued input BK , Mark & vtrips.

Good advice indeed , however I had mounted and boxed everything already , adding the 2 gates at the top of each hub for good measure. I would hate to fuss around any more at this point. It will be possible to cut into the mould if the suggested gate becomes mandatory.

Thanks for the input for sure though.

The Manx kit is a def possibilty , love Nortons. I do have some kits in the lineup, but lets see how this goes first. Still finishing the Gotha prop for casting as well.

IMG_0256_zps1w8pwr7l.jpg

This will be the trickiest piece to cast. The face is flat so I can pour the silicone up to the face to start. Prolly mount with blades at 10,2,7 and 4? o'clock.This has yet to be done so any input can be implemented.

And actually looking at this post for a minute I can see this is a real problem to solve.

Edited by krow113
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Thanks for the continued input BK , Mark & vtrips.

Good advice indeed , however I had mounted and boxed everything already , adding the 2 gates at the top of each hub for good measure. I would hate to fuss around any more at this point. It will be possible to cut into the mould if the suggested gate becomes mandatory.

Thanks for the input for sure though.

The Manx kit is a def possibilty , love Nortons. I do have some kits in the lineup, but lets see how this goes first. Still finishing the Gotha prop for casting as well.

IMG_0256_zps1w8pwr7l.jpg

This will be the trickiest piece to cast. The face is flat so I can pour the silicone up to the face to start. Prolly mount with blades at 10,2,7 and 4? o'clock.This has yet to be done so any input can be implemented.

And actually looking at this post for a minute I can see this is a real problem to solve.

I'd hope they would be at 10,1,4 and 7 o'clock (just kidding!)

Not sure how I'd handle this one? Be almost tempted to spin cast with the prop horizontal and pour from the top centre of the prop hub. You'd need vents up and away at the tips regardless of technique. That metal will really want to trap air and cool travelling down those prop blades!

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The Manx kit is a def possibilty , love Nortons. I do have some kits in the lineup, .......

I've dithered about getting an Italeri/Protar Manx Norton,

but the availability of your castings would be the decider for me !

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Gotha prop; orientation sounds fine. I would have an independent air gate from near each blade tip and a wide V pouring gate to the centre hub

I would embed a bit of ply wood in the silicon rubber on each half so the mould cannot be squeezed too narrow when its clamped up.

>> a thin layer of silcon rubber/ply/silicon r./prop

You could go either vertically X, or horizontally, with air gates coming from the prop tips at right angles L

Yup, you could always cut an air gate between the hubs after the mould is made. I use a wood carvers U chisel on one half of the mould only when making extra air gates.

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The prop will be difficult.

Staring at it I cant figure out the mould process without the silicone wrapping around the blade 'trapping it. The prop will have to be vertical,and I might have to pour all atb once , cutting the master out after curing.

BK Thanks , not sure what you mean about the plywood , and clamping would be lightly as well , I would imagine , in order to avoid deforming the mould.

Gates will be at the tips for sure and the big V for the pour gate sounds good , I had some golf tee's around here...

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I've dithered about getting an Italeri/Protar Manx Norton,

but the availability of your castings would be the decider for me !

I'll move in this direction , but have limited casting experience. Let me get the procedure streamlined , then I would be comfortable selling items. I have built custom signs and a lot of other special order items for over 25 years, so selling isnt a prob.

I have the kit and the wheels stop me dead whenever I look at them. That middle rim seam, cant abide that...the limits of injection moulding show up in bike kits for sure!

Still , lucky to have manufacturers willing to produce classic bike kits.

4 items would be in a wheel set , spokes, rim , hub and nipples , rim locks and air valves could be included as well. Instructions and diagrams too.

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Either embed the prop in plasticine, or use plasticine to build up one side of the blades till they are level.

Pour the mould rubber to cover one half,

Then for the other half, remove the plasticine wedges along the prop blades, then make the second half of the mould.

The plasticine wedges will stop the mould rubber running under the blades trapping them.

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BK's solution is prolly the way to go, I had thought of 'dams' to get the master done. I went ahead and attached gates and .005" plastic card dams just need to heat and curve the last bit of card up to the gates at the end of each blade , be gentle....:

IMG_0282_zpsvbjd3sbj.jpg

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You'll have problems getting it out of a horizontal mould unless those gates are perfectly parallel and straight sided.

Put the gates at right angles to the way they are now; parallel to the surface of the prop.

Place as an X; Air gates from the lower blades being longer than the top two blades

Pour the mould in two halves, with the prop mostly in one half.

Clamp the two halves together; Turn vertically to pour the w/m in

Removal is easier as the pouring and air gates are not enclosed by the rubber.

If I get time today I'll mock one up with a 1/72 prop I want to cast in w/m and photo it.

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Thanks BK - gonna do it horizontal already there with the master. |I'll try to get it finished today. Dams are at 90 degrees to the blade , I can 'see' how this will go now...

IMG_0282_zpsvbjd3sbj.jpg

Edited by krow113
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  • 4 weeks later...

Ongoing , life gets in the way , made the mould box and got the prop into final stages:

IMG_0356_zps7awjxnje.jpg

And just about ready. One can see what will be attempted during the first half of the mould:

IMG_0364_zpshboxy7qm.jpg

Edited by krow113
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  • 2 weeks later...

YOU cant wait!?

Long time coming.

Thanks Mark.

To be clear these rims will fit the tires from this kit:

10001.jpg

The only knobby tires I could find easily in 1/8 scale.. Another reason turning in a lathe would be problematic.

I have a sign to finish this week, after that I'll have enough time to finish these.

Edited by krow113
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  • 2 weeks later...

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