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11 hours ago, Ben Gardebroek said:

Again a fantastic model Ian.  Very high at my at my own wish list. May I ask why you used a resin model and not a Britains model? 

Thanks Ben, Britains models are getting expensive and hard to find so I've started casting parts. I can also modify the skid unit easily by shortening it and making minor changes, then re-cast that skid unit to get a 3 cylinder version for example. So now I don't have to keep modifying an original skid unit every time I want to make a 3 cylinder Ford, I just pour resin into the mould.

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1 hour ago, Janval said:

Looks really good, Ian! How do you go about making those castings? Do you order them by drawing, or do you make it yourself?

Thanks Jan, I have to make moulds from silicone rubber and fill them with resin to get the parts, some moulds are simple one part moulds that are just filled to the top but others are more complex two part moulds that can be separated to cast parts like wheels and bonnets. It's a bit of a black art, I've had lots of trial and error moments making parts but it's worth the effort to be able to make parts over and over without making each part from scratch!

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how easy do you find it casting wheels and tyres ian, i have tried a few times now for mf 1200 wheels, and they just never seem to come out right,normally  the  inside deforms so hard to mount them, i also tried casting the tyres in black rubber, but again after 3 different moulds made, i always seem to have one side thats just no good 

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3 minutes ago, Tractorman810 said:

how easy do you find it casting wheels and tyres ian, i have tried a few times now for mf 1200 wheels, and they just never seem to come out right,normally  the  inside deforms so hard to mount them, i also tried casting the tyres in black rubber, but again after 3 different moulds made, i always seem to have one side thats just no good 

Tyres are the worst! I've been casting tyres in one part moulds with the tyre laid flat on it's side, the mould is closed over so I hopefully get both side walls cast without too much cleaning up afterwards. The wall nearest the top of the mould always has imperfections so I make lefts and rights with the good sides always facing out on the model. Some tyres trap more air bubbles probably because of their shape so I'm trying a two part mould and filling it in the centre of the tread. This will leave an imperfection on the tread which will have to be at the bottom of the wheel when glued to the model. Bloody nightmare! Haven't tried rubber at all, I'm hearing lots of stories about the tyres reacting with the rims years later just like old Britains wheels and tyres, but not sure if this is the case with resin rims.

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Don't know if you've come across this Ian but its how I've been casting rubber tyres. http://www.farmtoysforum.com/forum/topic/24307-comprehensive-guide-to-casting-wheels/#comment-591948

Again I have the issue of one side being bubbly but only very slightly now with my latest truck tyre moulds. Only tried ag tyres a couple of times with a set Britain's Dunlops. Main issue was air bubbles catching in the lugs on the top side of the wheel which was noticeable from front on as well as the back side. Hope its of interest.

IMG_20170808_152701.thumb.jpg.cf8a76fe0df693a3095c02012534d99f.jpg

IMG_20170808_152710.thumb.jpg.8f8c6a38e0b58bec810e96bc46eca27f.jpg

 

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12 minutes ago, Stabliofarmer said:

Very envious of your casts aswell, are you using a pressure pot as theres not an airbubble in site on that skid

Hi James, that's exactly what I'm getting in your pics but I think I may have solved it this morning with a two part mould and filling the tyre upright through the tread. Good tyre walls on both sides and just a minor clean up where the sprue connects. Seems to fill right to the edges of the grips.

I've tried everything to get a nice clean cast James, I resorted to moulding the skid units in two halves, both one part moulds, then fill them up to level. I then go in with a cocktail stick and tease out all the bubbles where they usually collect, I find I have to do this with most casts to ensure a bubble free part. Then pop out the two halves, sand the flat sides down and glue them together and re-drill any cab mounts or axle holes. It's all very trial and error and I wish I knew all the secrets!

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31 minutes ago, Stabliofarmer said:

Very envious of your casts aswell, are you using a pressure pot as theres not an airbubble in site on that skid

This is how I've been casting tyres, with varied results, and the new two part mould which seems to have solved the problem.

DSC_0879.thumb.JPG.6d447a880bcb41b24a7e20bcfc45f19d.JPGDSC_0880.thumb.JPG.085a21c26c86c037a88bb8b6d0027daf.JPG

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Top notch as always ian  what with johns ih worldwide tractor these creations are putting new life into this site  

You should see my resin wheels they look like the inner walls exploded ha  thats what i lack wheels too  theyre to expensive even on ebay  pour as you like seems the best policy and havent the fords ihs deeres and browns just escalated  in value the last 2 years 

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Interesting, I suspect the greater viscosity of rubber would stop it working within your new style tyre mould but for resin it looks perfect. If the pour hole only went as deep as the top of the lugs would this stop the need to hide that part if the tyre at the bottom as no tread detail would be effected? Ie only the area highlighted in red would be visible if you looked down the mould.

1517059501163-1562229037.thumb.jpg.60b3fe43110df31d5a96da1bc57ace06.jpg

Regarding your skid unit there is a technique explained here that may speed up your process slightly. http://www.hirstarts.com/casting/plastic.html

They use a glass pane from a photo frame and lay it over the back of the mould. This would reduce your post mould processing removing the need for sanding etc. Also an interesting detail about spraying the flat side with mould release to remove surface bubbles, though I think the bubbles you are talking about are ones caught in the mould around detailed components? A cocktail stick is the only method i've seen for stopping this other than pressure casting

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1 minute ago, IH885XLMAN said:

Top notch as always ian  what with johns ih worldwide tractor these creations are putting new life into this site  

You should see my resin wheels they look like the inner walls exploded ha  thats what i lack wheels too  theyre to expensive even on ebay  pour as you like seems the best policy and havent the fords ihs deeres and browns just escalated  in value the last 2 years 

Thank you, I hope I can contribute something towards this hobby, lots of great creations on here and I don't think I've seen the half of them yet :)

Yes it's exactly what has pushed me to go this direction, I've seen bubble cab Ford 7600s and 6600s go for nearly £70 on ebay, and the 7000s and 5000s going at £40 and upwards. Hope Britains decide to reissue these models, they are always going to be popular.

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2 minutes ago, Stabliofarmer said:

Interesting, I suspect the greater viscosity of rubber would stop it working within your new style tyre mould but for resin it looks perfect. If the pour hole only went as deep as the top of the lugs would this stop the need to hide that part if the tyre at the bottom as no tread detail would be effected? Ie only the area highlighted in red would be visible if you looked down the mould.

1517059501163-1562229037.thumb.jpg.60b3fe43110df31d5a96da1bc57ace06.jpg

Regarding your skid unit there is a technique explained here that may speed up your process slightly. http://www.hirstarts.com/casting/plastic.html

They use a glass pane from a photo frame and lay it over the back of the mould. This would reduce your post mould processing removing the need for sanding etc. Also an interesting detail about spraying the flat side with mould release to remove surface bubbles, though I think the bubbles you are talking about are ones caught in the mould around detailed components? A cocktail stick is the only method i've seen for stopping this other than pressure casting

Yes James, that's the idea, and yes I'm sure it would be more difficult pouring rubber into the mould successfully. I think this method really minimizes the chances of a bad looking tyre with a lot less clean up afterwards. I build my models with fixed wheels so the rough part will always be touching the ground. Casting under pressure would be the answer. I also decided to make my mould join along the edge of the grips to avoid having to form the clay tightly around the centre of the tread, which takes ages! I need to be able to make these moulds quickly with good results.

That's a great tip with the glass, I might give that a go ;)

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Apologies for heading off topic once more but what method are you using for clamping the mould together? ive tried the elastic band method but found it to squeeze and disfuigure the mould, even with wooden plates as supports I find parts cast thinner than they should. 

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4 minutes ago, Stabliofarmer said:

Apologies for heading off topic once more but what method are you using for clamping the mould together? ive tried the elastic band method but found it to squeeze and disfuigure the mould, even with wooden plates as supports I find parts cast thinner than they should. 

No problem, I'm as much in the dark about this process as everyone else! I do use the elastic band and plate method and haven't had any problems. I think if your mould is bulkier it helps to keep things in shape, and of course the dimples for registration. I make my 2 part moulds using lego bricks as walls, they are reusable and can be built in any size quickly. Also because I've made the walls from lego, I use lego as plates for either side of the mould as they are the exact same size. It's just more efficient for a process that already takes up a lot of time.

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11 minutes ago, catkom3 said:

Yeah that would be ideal, I'm using a silicone rubber that degasses as it sets so haven't had much trouble in that area. It also helps to pour the silicone from a height in a thin strand as it takes out the air bubbles too.

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