I have done no castings but watched many videos, it looks like an additional (sprue?) at the top(s) of the casting would allow the melt to displace the gases without having to run back through the melt. You can also watch the behavior of the aluminum in the vent to check for gas and cold melt. The melted plastic would also tend to float on top of the Al and be displaced. I must try reading Gingery.
What you need to do to improve your lost foam casting is to make your entry pour through a plaster funnel which allows you to pour at a much faster rate, the funnel shape and being above the sand will cause a needed hydraulic effect. Also making vents from plaster tube attached to the foam pattern will allow trapped gas to leave at a faster rate than trying to dissipate through the sand. Overall.......parts are looking good!
If you install a copper disk under the clamp bolt that secures the protractor head, it will prevent the shaft from being marred and dented by the bolt. This will make it possible to continue making fine adjustments to the angle without the tightening of the bolt drastically changing the angle because it finds a previous dent.
nice work! you can save yourself a bit of time with the plaster coat by using unmixed drywall compound...mix 1/3 to 1/2 with fine dry sand then add enough water so that ya end up with the consistency of thin pancake batter...then just dip your prepped styrofoam parts give them a few minutes to start to dry then dip again....give em time to dry completely then put them in the sand box...kinda a cross between shell casting and lost foam with a superior surface finish...youll get a better finish but prob wont save much time with a small single cast but if ya have a couple parts its a life saver....you can do the same thing with the plaster but with a thin coat the drywall compound should be a bit tougher
Excellent! the four jaw chuck for the lathe would help you alot should you choose to continue the gingery projects. Have you considered using a different foam, something finer maybe, seems like you get alot of surface defects...
+Ramiro M molded EPS is the industry standard for smoothest surface finish. I wont make enough patterns to justify investing >$10k on the EPS molds. XPS may create smoother surfaces but if i need a smooth finish I can just add a few mm for a machining allowance. The non cosmetic surface defect are caused by poor degassing. I will fix this eventually, but the logistics in my temporary shop space of adding an argon tank is infeasible. I am machining an adapter for an off-the-shelf 3 jaw chuck this week FYI.
I know ALL about time issue's...to save some time you can tap right in the drill press...get a spring loaded tap follower...and you will tap straighter holes...
Don't know how this would work on foam, but alcohol breaks the surface bond of hot glue. It comes off like it was never there. Just pour a little alcohol on and seperate.
Hey Cressel, Great videos I love the amount of details you include on these projects. Sorry if you have answered this in a previous video, but during the video, @9:15 you use a large (concrete?) area - called it a surface plate as a reference surface to "Level" the work piece. I was wondering if you could talk more about the surface plate - where you got it or how you made it - Was it designed to be a tool as a reference surface or did you re-purpose something that had a nice clean flat face to it? take care. Thanks, John
I link to the surface plate I bought on my website: makercise.com/tools The best video I have made related to the surface plate and its use is part 9 of the lathe project series playlist: th-cam.com/video/kINjfcl3GAw/w-d-xo.html
+Karl Månsson not really. Check out the video on facing the ram. For the reasons detailed in that video, even a measurable several degrees of out of square will not have a perceptible effect on the angle.
Yes, but EPS causes problems not present in aluminum casting. There are specially developed resins used to mitigate those problems. I am not sure obtaining those resins is feasible for a hobby foundry. When I get to cast iron, I'll let you know.
I love how you show both successes and failures. Very interesting series. Thanks for all of the hard work.
You are making wonderful progress! Sorry for repeating any previous comments, I jumped in.
Great stuff, it's very cool to see the shaper coming together!
Awesome work, it's coming along nicely. Cheers Peter
Awesome work buddy. Really coming together now.
Best matt.
I have done no castings but watched many videos, it looks like an additional (sprue?) at the top(s) of the casting would allow the melt to displace the gases without having to run back through the melt. You can also watch the behavior of the aluminum in the vent to check for gas and cold melt. The melted plastic would also tend to float on top of the Al and be displaced. I must try reading Gingery.
Cheers for the awesome videos Cressel! i dont miss a single one :)
Thanks for the video.
What you need to do to improve your lost foam casting is to make your entry pour through a plaster funnel which allows you to pour at a much faster rate, the funnel shape and being above the sand will cause a needed hydraulic effect. Also making vents from plaster tube attached to the foam pattern will allow trapped gas to leave at a faster rate than trying to dissipate through the sand. Overall.......parts are looking good!
If you install a copper disk under the clamp bolt that secures the protractor head, it will prevent the shaft from being marred and dented by the bolt. This will make it possible to continue making fine adjustments to the angle without the tightening of the bolt drastically changing the angle because it finds a previous dent.
Ooooh. I like that idea.
Fantastic
Love the videos!!!
impressive! as always :)
nice work! you can save yourself a bit of time with the plaster coat by using unmixed drywall compound...mix 1/3 to 1/2 with fine dry sand then add enough water so that ya end up with the consistency of thin pancake batter...then just dip your prepped styrofoam parts give them a few minutes to start to dry then dip again....give em time to dry completely then put them in the sand box...kinda a cross between shell casting and lost foam with a superior surface finish...youll get a better finish but prob wont save much time with a small single cast but if ya have a couple parts its a life saver....you can do the same thing with the plaster but with a thin coat the drywall compound should be a bit tougher
Excellent! the four jaw chuck for the lathe would help you alot should you choose to continue the gingery projects. Have you considered using a different foam, something finer maybe, seems like you get alot of surface defects...
+Ramiro M molded EPS is the industry standard for smoothest surface finish. I wont make enough patterns to justify investing >$10k on the EPS molds. XPS may create smoother surfaces but if i need a smooth finish I can just add a few mm for a machining allowance. The non cosmetic surface defect are caused by poor degassing. I will fix this eventually, but the logistics in my temporary shop space of adding an argon tank is infeasible. I am machining an adapter for an off-the-shelf 3 jaw chuck this week FYI.
where did you get the angle finder on the rotating head ?
You will do well.
I use lost foam. Pink or blue foam. Then cast in green sand
I know ALL about time issue's...to save some time you can tap right in the drill press...get a spring loaded tap follower...and you will tap straighter holes...
Hi. Btw this is missing from the playlist if I’m not mistaken.
Thanks very much. Fixed.
Don't know how this would work on foam, but alcohol breaks the surface bond of hot glue. It comes off like it was never there. Just pour a little alcohol on and seperate.
Hey Cressel, Great videos I love the amount of details you include on these projects. Sorry if you have answered this in a previous video, but during the video, @9:15 you use a large (concrete?) area - called it a surface plate as a reference surface to "Level" the work piece. I was wondering if you could talk more about the surface plate - where you got it or how you made it - Was it designed to be a tool as a reference surface or did you re-purpose something that had a nice clean flat face to it? take care.
Thanks,
John
I link to the surface plate I bought on my website: makercise.com/tools
The best video I have made related to the surface plate and its use is part 9 of the lathe project series playlist: th-cam.com/video/kINjfcl3GAw/w-d-xo.html
Awesome! thanks man.
What kind of aluminum do you use for casting and where did you obtain it?
th-cam.com/video/Y6ypconbEjU/w-d-xo.html
After scraping, you know that the surface is flat. But the really important aspect would be having it square with the ram, no?
+Karl Månsson not really. Check out the video on facing the ram. For the reasons detailed in that video, even a measurable several degrees of out of square will not have a perceptible effect on the angle.
Can you use lost foam to cast with cast iron?
Yes, but EPS causes problems not present in aluminum casting. There are specially developed resins used to mitigate those problems. I am not sure obtaining those resins is feasible for a hobby foundry. When I get to cast iron, I'll let you know.
I'm 92nd viewer yay~