- Thread starter Onoff
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Onoff
In the land of the unfinished project I am King!
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See here
Vacuum chamber and plastic for lid?
I will be trying to build one this week. For the lid, Chinese vac chambers seem to be 12mm acrylic, like this but much smaller. https://www.amazon.co.uk/VEVOR-Degassing-Stainless-Silicones-Extraction/dp/B09GVVRYK4 Theres a plastic shop near me that has small offcuts of 12-20mm thick acrylic...
www.mig-welding.co.uk
Kram
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Well the nose hair removal was bloody brilliant, but starting to grow back 
Casting, havent fired it up since before Onoff's visit
but, having got vac chamber just about working, couple of improvements to do tomorrow, the plan is to get the plaster, and a cow casting done early this week.
Casting, havent fired it up since before Onoff's visit
but, having got vac chamber just about working, couple of improvements to do tomorrow, the plan is to get the plaster, and a cow casting done early this week.
Kram
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Made some progress, couple of posts in SYHMT..
Plaster
Burnout
And the cast
This was Wednesdays attempt. Neither brass or plaster was hot enough to flow nicely. The plaster had not got into the text properly either - "The" at the top completely missing and the C for cattle.
Next attempt I will have the mould without any runners, then it will be open and I can check it after burn out. I'll do the runners in sand with the cow face up. I might push a spare outer ring into the sand and make it double thickness (to be sanded or turned off) to help the brass flow.
The main problem was as it started to rain, I turned the heat up, split slag, popped the element and had to pour early.
Plaster
Stuff you have made today
I'd expect them to dry out and crack, not ideal for working with food? :dontknow: You lot are a tough crowd to please. :D
www.mig-welding.co.uk
Stuff you have made today
What’s the benefit of nitrogen over normal air? Better cut quality for aluminium and stainless. How much better I have no idea as I have never used it.
www.mig-welding.co.uk
Stuff you have made today
Back at this place so grabbed some pics. Aged well over the last 12 months. Aged well or well aged?
www.mig-welding.co.uk
This was Wednesdays attempt. Neither brass or plaster was hot enough to flow nicely. The plaster had not got into the text properly either - "The" at the top completely missing and the C for cattle.
Next attempt I will have the mould without any runners, then it will be open and I can check it after burn out. I'll do the runners in sand with the cow face up. I might push a spare outer ring into the sand and make it double thickness (to be sanded or turned off) to help the brass flow.
The main problem was as it started to rain, I turned the heat up, split slag, popped the element and had to pour early.
Onoff
In the land of the unfinished project I am King!
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Not sure how I missed the plaster and casting posts? Duly liked anyway!
Do you think the PLA is burning out completely or would wax be better?
Kram
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Im happy with the burnout but next time I'll start at 180-200c and try to retrieve the molten plastic to avoid smoke before going hotter.
Worked out the main problem - the text is too deep for the brass thickness, and the thin section is sucking heat out of the brass.
Problems solved, I'll try another attempt this week!
Worked out the main problem - the text is too deep for the brass thickness, and the thin section is sucking heat out of the brass.
Problems solved, I'll try another attempt this week!
Onoff
In the land of the unfinished project I am King!
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Can always print a couple with a thicker base here and pop in the post?
Btw, are you intending to melt down the first attempt or keep it?
Kram
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I wasnt planning to melt it, plenty of brass left.
The base thickness I can do that easily enough.
Also there is a bump/print swirl/wart on the cows nose, is that intended? as it came out exactly in the brass. Im quite pleased its catching the details.
The base thickness I can do that easily enough.
Also there is a bump/print swirl/wart on the cows nose, is that intended? as it came out exactly in the brass. Im quite pleased its catching the details.
Onoff
In the land of the unfinished project I am King!
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Plenty of clean brass still here. I'm about to weigh in a load of assorted "dirty"brass as an aside.
Both the landlady and her daughter were impressed with the cow detail on the first one when I popped in Thursday night. Here the original ornament on the left and one of the very early meshes from the photogrammetry experiments:
Leave the nose as is imo, it points to it's origins, the 3D printing etc.
Looking in "the box of cows" here and the base thickness looks just about right as is, akin to the real things. How thick were you thinking to make it? As a little historical titbit, they moved away from casting to stamping the brasses at one time. Ostensibly to save on the weight the poor horses had to carry, it also cost less and was easier to mass produce.
It doesn't really matter tbh but just because it's you, I'm quite prepared to go back up the pub a little later and double check...
Kram
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About double. Do you want the back to be the as-cast finish, or can I turn/sand it to the original thickness?
I've been delegated to do DIY today, moving heaters and decorating. Hope to mess about with furnace tomorrow.
Onoff
In the land of the unfinished project I am King!
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That'll work. As cast is good. I love the idea that every cast is unique. Tbh I've just made an investigative trip up there and the backs are about as thin as the 3D prints. See below:
OK, I couldn't be ar5ed moving as I was comfy!
Onoff
In the land of the unfinished project I am King!
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That is a nice find! How big is it? Will it be used for the intended purpose or melting stuff?
Big. I reckon she'll flog it on tbh
Kram
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Big is good 
I stripped my burnt element out, Im half tempted to make the V2 pot next instead of just swapping element. Both the spares I have are the right length for V2. The old pot is cracked into segments like a pizza but they are actually resonably secure.
Do you think yours would fit the v2 pot, about 200mm diameter? It may help to fire it properly
2 element failures have been spilling slag, rather than burning them out. One was overheating from excess clay..
You can see why it failed, big puddle of brass down there, but it popped in two places. Didnt see the first but second made a nice blue glow.
I stripped my burnt element out, Im half tempted to make the V2 pot next instead of just swapping element. Both the spares I have are the right length for V2. The old pot is cracked into segments like a pizza but they are actually resonably secure.
Do you think yours would fit the v2 pot, about 200mm diameter? It may help to fire it properly
2 element failures have been spilling slag, rather than burning them out. One was overheating from excess clay..
You can see why it failed, big puddle of brass down there, but it popped in two places. Didnt see the first but second made a nice blue glow.
Onoff
In the land of the unfinished project I am King!
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You misunderstand. It's not mine. I imagine she will sell it on as soon as she can.
Onoff
In the land of the unfinished project I am King!
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Erm...you might want to rephrase that...
