This was a real pita to mold. It took several attempts, eventually I added a little more water to the sand, and pushed 3" nails into the centers of the high spots to hold things together.
Sunday, June 12, 2022
Casting aluminium wheels from melted down aluminium wheels
Monday, June 6, 2022
3rd time lucky
This was cast with a length of steel rod embedded in it. I used a smaller length to make up the drag.
Sunday, June 5, 2022
Casting the gingery lathe Face plate
I cast the face plate.
Sunday, May 29, 2022
Pullies and lead screw
https://youtube.com/shorts/6r-MS5sE5aU
I've replaced another 3d printer pulley with a cast one, and also added the apron for the cross slide. The cross slide moves about 0.2 mm for each rotation of the lathe l.
The 3d pullies were starting to fail where the bolt was placed to tighten them on to the spindles.
Shaking out, still no biscuit
Saturday, May 28, 2022
Close, but no biscuit
Shrinkage
I forgot to add a riser, whatever cools last tends to shrink, particularly if it's thick.
Next times I'll add a big riser.
The riser has to cool after the part so that it can keep feeding in liquid metal as the part cools and shrinks.
Monday, May 23, 2022
A boring jig
Once you have a hole, you set the depth of cut by eye, then measure the diameter.
Then you can use this jig, with a set of feeler gauges to expand the hole by a set amount. Touch the floating bolt off the blade, back it off till you can fit the feeler gauge with a hint of friction, loosen the cutter, and move it forward to the bolt, tighten up and off you go.
Pretty rough and ready, but with practice you can get a hole bored to within 0.1mm, or about 4/1000" of an inch.
Sunday, May 22, 2022
A little less breakout on the mold
That came out pretty well, especially compared to the previous result below..
Drag, cope and hat
Ok, it's not called hat by anyone else, apparently it's called an upset. I don't have a proper molding bench, so as the cope fills up, sand spills everywhere, add an extra frame, and I can fill the cope and ram it down with a lot less mess.
You can see the over-centre latches that hold the cope and drag together, a lot easier than trying to balance weights on the sand to stop the hydrostatic pressure lifting the cope.
Thursday, May 19, 2022
A few metal casting channels,
In no particular order, if you want to learn to cast aluminium, there's so much information here:
- https://www.youtube.com/c/Grunblau
- https://www.youtube.com/c/PwnFunction
- https://www.youtube.com/c/TroyeWelch/videos
- https://www.youtube.com/c/swdweeb/videos
- https://www.youtube.com/c/VegOilGuy
- https://www.youtube.com/channel/UC90RoN_IjSRF18jAG0HIA6g
- https://www.youtube.com/c/myfordboy
A stepped pulley cast from a 3d print
Monday, May 16, 2022
It fits
A little boring on the mill with a home.made boring tool. This would be so much easier on a lathe, once the lathe is finished.
Sunday, May 15, 2022
A file can fix a multitude of sins..
Here's how it turned out after a gentle application of a file....
Ok, perhaps quite a bit of filing. But aluminium is soft...
Lessons learned
Aggressive rapping can break smaller sand features. It seems better to do a lot more rapping with a lighter bar
I think I will try making up a template to sit on the sand around the pattern and hold it in place as I pull up the pattern, not sure how this will go.
I was so concerned about the metal post I was casting around, I forgot to preheat the muffin tray for left over metal ingots. Lucky it's been warm, no condensation to bite me. 😳
I'm getting a better feel for how much water my sand needs, I suspect this varies by sand, and it's very much a feel thing. The sand should still be possible to sieve, but not as easy to sieve as dry sand.
Nothing a file can't fix
Here you can see the core piece.
Pouring pullies
That's hot. Just one mold to pour. From heat on to pour is about 12 minutes.
Saturday, May 14, 2022
3rd attempt at pulley mold came out okish
A 3d printed core box and the core
A little protection from splashes?
Overlapping leather, perhaps if there's a splash, this will help reduce the damage?
Hopefully I won't get to test it.