Metal Melter

[Kram]

Get another photo with even, centre front lighting, should be much easier to convert it.

 

[Onoff]

Get another photo with even, centre front lighting, should be much easier to convert it.

I going in a minute to get another photo if you know what I mean!

 

[Onoff]

A frrebie program would be good where you chuck in a few pictures taken from different angles and it converts it to a mesh.

 

[daedalusminos]

A frrebie program would be good where you chuck in a few pictures taken from different angles and it converts it to a mesh.

That's photogrammetry!

 

[Onoff]

Hmmm...

The head sits too low in the surround for a start. If I move it up though the horns will get lost. Maybe I need to make the image smaller and include some of the neck / body?

Shape is somewhere near but the definition is rubbish. The nose is at the same height as the face. The right nostril is just one massive, concave mess!

 

[Onoff]

My lad's been experimenting here with photogrammetry. He took about a hundred (albeit crap quality) pictures of a cat ornament. Ran it through some fancy algorithm and ended up with a printable, solid model. Proof of concept really. Need to up the quality of the photos and take from multiple angles, better lighting etc.

So photo, render, model:

Means I have to go to the pub of course and take hundreds of photos of that cow ornament...

 

[Anguz]

So what software are you using to do the cat?

 

[Onoff]

So what software are you using to do the cat?

Oh sorry, meant to say, it's Meshroom.

 

[JMS1972]

Oh sorry, meant to say, it's Meshroom.

I actually paid for a licence (!) For 3DF Zephyr photogrammetry it's excellent.

They do a free version I think.

To get good results take photos with lots of overlap e.g. every 15 degrees around an object at several heights.

 

[Onoff]

I actually paid for a licence (!) For 3DF Zephyr photogrammetry it's excellent.

They do a free version I think.

To get good results take photos with lots of overlap e.g. every 15 degrees around an object at several heights.

That's handy, I know someone with a paid for version...

 

[Onoff]

A plan is forming...Thursday afternoon, pub. Ask the landlady to bring the cow statue out into the garden for good, natural light. Place statue on the garden table, maybe on a white background. Snap away a couple of hundred photos.

Obligatory pint(s).

 

[JMS1972]

A plan is forming...Thursday afternoon, pub. Ask the landlady to bring the cow statue out into the garden for good, natural light. Place statue on the garden table, maybe on a white background. Snap away a couple of hundred photos.

Obligatory pint(s).

Shadowless lighting is best so pray for overcast conditions

 

[Kram]

Might have a go at sand today, possibly some brass.

 

[Kram]

I did a bodge on boxes, quick sand all over, 6mm dowel pins fitted. Not very level so I forced a bead of sand around the join hoping to prevent a leak, but lucky it did not try.
Made up a mold, warmed the melter and had a pour. Used 1.6 grams of ecogas16 degasser, seems to work.
I didnt plan the first mold very well, couldnt find anything better so used this square. Removed half depth of the sand islands. Theres no draft on the square so I was quite pleased to pull it out!

However it was a failure. Metal not hot enough or blocked sprue. I had to pour down the feeder

Surface finish is poo, but I think its just the sand or bad ramming. Chopped into a couple peices and very little porosity. Filed one side of square, its good under the surface, porosity looks low I need the microscope for a proper look.

Odd when filing, clogs very quick and then drags across giving huge scraches, Likely to have oxides from being pored wrongly!

I wasnt happy with it, remelted the feeder bits and some fresh, made a new mold - this took ages!

I completely removed the island and holes after the pic.

Second pour went well! Surface is much better but looks like I had loose sand in couple places.

 

[JMS1972]

I did a bodge on boxes, quick sand all over, 6mm dowel pins fitted. Not very level so I forced a bead of sand around the join hoping to prevent a leak, but lucky it did not try.
Made up a mold, warmed the melter and had a pour. Used 1.6 grams of ecogas16 degasser, seems to work.
I didnt plan the first mold very well, couldnt find anything better so used this square. Removed half depth of the sand islands. Theres no draft on the square so I was quite pleased to pull it out!
View attachment 336994
View attachment 336995
However it was a failure. Metal not hot enough or blocked sprue. I had to pour down the feeder
View attachment 336996
Surface finish is poo, but I think its just the sand or bad ramming. Chopped into a couple peices and very little porosity. Filed one side of square, its good under the surface, porosity looks low I need the microscope for a proper look.
View attachment 336997
View attachment 336998
Odd when filing, clogs very quick and then drags across giving huge scraches, Likely to have oxides from being pored wrongly!

I wasnt happy with it, remelted the feeder bits and some fresh, made a new mold - this took ages!
View attachment 336999
I completely removed the island and holes after the pic.
View attachment 337000
View attachment 337001
Second pour went well! Surface is much better but looks like I had loose sand in couple places.

Surface finish might be down to venting. Try a riser at each end of the arm and/or poke wire from the top so it almost contacts the pattern multiple times. This allows steam to escape from the void as the ally hits the damp sand.

 

[Onoff]

However it was a failure.

Consider it a bump on the road to perfection. I'm constantly hitting them. Yet to reach my destination mind.

I'm really impressed by these attempts.

Reminds me of when, as a kid in the early 70s, we found a load of "failed" 50p fakes in the River Darent at Eynsford whilst hunting crayfish. Cast from lead from memory. Presume the counterfeiters had decided to dispose of the evidence. Could have been from the houses who's gardens back onto the river. The adults we showed them to reckoned they were to have likely been used in cigarette machines etc.

 

[Seadog]

Odd when filing, clogs very quick and then drags across giving huge scraches, Likely to have oxides from being pored wrongly!

Pinning is quite common with aluminium. My thought is that the grade you have is too soft, i.e. less of an alloy, more pure aluminium.

Rubbing chalk on the file will help prevent pinning.

 

[Kram]

Im not sure what grade but it came from a 125cc bike rear calliper mount. I dipped all of my scrap in NaOH to remove the worst of the oxides. The calliper mount came out silvery where as all my engine scrap turned a nasty black, I assume from sillicon.

Vents, the first one I did add a few small risers and poked with a 1mm tungsten. The second one I forgot to do it, and the sand was wetter.

Anyone know where I can get some fine or very fine grit sand?
I saw Olfoundrymans video, he has a machine set up for grinding sand to a fine flour.
Im guessing my sand is 60-100 mesh, and something like 400-800 mesh should give a better surface.

Short clip of degassing

 

[Onoff]

Anyone know where I can get some fine or very fine grit sand?

Walsh's at Biggin Hill?

 

[Kram]

Ok, "affordable fine sand" then I asked, they only do blasting sand.