Hi all. Following up on some comments by viewers that the carbide cutters on the face mill are at the wrong angle, I had another look, and have to agree. Totally. So don't bother copying this great piece of engineering. These are situations where you wonder just how the hell you did that, BUT, when the pain subsides, grit your teeth and have another go. Stay tuned for more on this setback. Cheers. Rob
xynudu Steve Ramsey (Woodworking for Mere Moortals) once mounted his circular saw blade backwards in one of his clips m) it just happens. At first I thought it was the wrong alloy, there are some which don't mill too well.
There is a trick where you can do this to cut sheet metal. I tried it and it works,but not great, noisy,and rough, and eventually it tears the carbide teeth off. Like most people I have accidentally run the lathe in reverse and wondered why it wasn't cutting very well. LOL. Rob
Wow, now that I have seen you use custom made facing tool and mount a vice perpendicular, the sky is the limit on what i think I can do. Good on you for those adaptions and thank you for sharing!
Hi Rob, about those big bubbles (voids) in your aluminium block. (Later you have cast much better billets so you must have found some solutions) On the top face you have this big crater. This top face remained liquid the longest because it was only air cooled. All other faces were cooled by the steel (or sand) mold and solidified and shrunk first drawing more liquid metal behind it creating that crater and big voids. One remedy could be preheating the steel mold before casting or use a higher cast temperature so that the excess heat will heat up the mold sufficiently to get the mold above alu melting temp. And you could additionally use your gas burner to heat the top surface to keep it liquid so it has more time to flow and fill the shrinkage of the solidified metal. (That way they keep the gold bullions shiny all around when casting gold.) Use a fuel rich yellow not blue flame in order not to oxidize the metal surface unnecessarily. If you have more or less equally distributed pin head voids then this is hydrogen out-gassing. This can be reduced by bubbling argon gas through the molten metal in the crucible. Hook up a hose and metal tube to your TiG argon gas tank and stick it in the crucible and bubble it lightly. (Dont blow the melt in your face!) The often demonstrated sodium carbonate tablets make bubbles too but do not remove the hydrogen. Waste of time.
Hi Rol, Thanks for the info. I think one of the main things is not to overheat the melt. I've noticed that if you keep the temperature lower it doesn't gas as much. I have tried using degasers and while they can work, a lot depends on the alloy type and the temperature. I now preheat the mold, which as you suggest is a good idea. Also fast cool down is not a good idea. Overall the grade of alloy has a big bearing on pinholes. Some gas badly and others hardly gas at all. The Toyota wheel rims are good but don't machine as well as some softer alloys. It's hit and miss. Cheers Rob
cast wheel rims are an interesting raw material for your remelting. The cast wheel rims are heat treated after casting. To get the good mechanical properties and free machining back you better heat treat your billets after casting too. If I remember right you have to quench it at 500 degC down to RT and then hold it at a not so terribly high temperature (~250 degC) for a few hours. I think the holding can be done in a kitchen oven. The properties only appear after a few days. For quenching you could throw the whole mold in water shortly after casting and then put it in a oven at 250degC for a few hours. To get the exact figures an alloy datasheet could help.
Hey Rob. Those big bubbles on the top are strange. I sometimes get small ones but not that big. I knew you would not have to mill too deep to get rid of them. Also you are right in saying the temp at the time of pouring affects things. I too get great results without degassing and fluxes. Nice little lump of ally you have there, and the price.... Well the price is unbeatable :) You should have a go at casting vee pulley blanks that incorporate a hub. Multi step pulleys are also achievable. I started with a round biscuit tin and a small tin can and some setup jiggery, but the problem was it was a pita to setup and only good for one go, then had to be destroyed to get it out. Now I have some wood split patterns. The wood pattern can be pushed into and packed around the surface of a mix of fireclay and sharp sand in a container, or used as intended in a 2 part casting flask. Casting model 'engine' parts eh?... You have got my attention :) Paul
djpaulk The bubbles were a bit unexpected. Maybe some dross went in. The rest was excellent. Making pulleys would be easy using a built up lost foam blank - glued up polyurethane with a plaster covering, surrounded by sand. That method will be my next experiment. Rob
xynudu Yeah, probably a bit of dross.. Nothing to worry about. When I consider the price, I can deal with a few imperfections. My wallet hinges get a bit stuck when it has to open to pay a metal supplier for large lumps of ally. Cool idea, lost foam... That's a thought that never occurred to me... The patterns will be one offs but would be cheap and way easy to make. Well I will be looking forward to see how you go with that for sure! I think they shape the foam with a red hot cutting wire? Anyhow, sounds interesting. Paul
They work OK, but not as good as a dedicated milling machine, as the mill slide/carriage will try to cant back under load. You may have to compensate for that. I try to brace the mills slide with the tailstock where possible. Makes a big difference. Cheers Rob
Hello, I think these holes originate when the outer part of the block is solidifying and the core is still liquid. Because the inner part still shrinks it pulls hard enough on the surface to break small holes in it and sucks air pockets in that form the holes. If my theory is right cooling the block slower should fix the problem.
Nice concept, however it just puts limits on the lathe compared to using a mill.... A hand ground slot drill with small 45 deg corners and quick hands would have you squared up while you were setting up the lathe...and putting it back to a lathe.. Good filming I have to mention Tim
Rob, Thanks for another machining of your pour video. Did you figure out what caused the holes on the top? Perhaps air trapped at the end of the pour? Anyway, thanks for sharing an interesting video! There doesn't seem to be anything you can't do with your little Chinese lathe! Have a good one! Dave
Well Jay Gauthier, and ardvarkkkkk1, I agree with you fully! the inserts are "plowing" badly.. when the inserts are turned to a horizontal position you can plainly see they are off center by over an inch which would cause the noise, vibration, plowing, and poor finish. A little more milling to your milling Head Rob to turn the inserts inline "flat" with center will do the trick! Just offering an opinion
xynudu Sorry dude, but I'll agree with rigger1, Jay & others.... whether they be mill inserts, turning inserts or whatever, they should not be used as hammers, which is what I see from here. Do yourself a favor - take 20 minutes (at the most) and throw together a simple fly cutter ( NOT fly hammer) and use hss on aluminum. You just might surprise yourself. No offence meant, just saying.
2harrynipples Yes, you are all correct. I finally got around to looking at this again, and the cutters are definitely at the wrong angle for the arc. Dunno what I was thinking when I did that. Looks like I will have to do some re-engineering on that one.....he, he. I appreciate your comments. Since I made this I bought a heap of round HSS dirt cheap, so I will probably try to re-jig it to take that , and keep my TCMT inserts for their intended purpose. This must be good for another video :) Cheers to all who commented on this. Rob
Shouldn't the lathe be turning the other way? The teeth were not cutting but just plowing through...Im looking at the directional switch going..." Im the newb, but turn that thing the other way"
redneckhippiefreak No. You always rotate the cutter towards the front of the lathe , so it's pushing the job DOWN onto the ways. The teeth/inserts are on the wrong angle, and that cutter has since been scrapped. Rob
+Danilo Lattaro Yes. That's what I've stated. It cuts OK, but not correctly. I've since scrapped it and converted it to a single point HSS mill cutter. Rob
if you would artificially age that casting in the furnace, bring it upp to about 300C, hold it for 30min, then cool down and bring it up again to about 200C in ordinary kitchen oven or something for 6-8 hours.. it will machine alot better... and not so gummy. =)
***** Very unlikely. Hydrogen gassing usually only forms very small round air bubbles no bigger than the head of a pin and widely distributed throughout the job. This irregular void is more likely to be from some dross that went into the mold. Rob
What is the benefit if holding the billet in the vice and cutting with the milling head as opposed to mounting the billet in a 4 jaw chuck and turning it down?
Cool. I was just wondering weather or not I should get the same set up to be able to square up home cast stock. Not sure what I will use it for as yet. Just like having shiny square lumps of metal sitting around the shed
Nathan Dean I always wear close fitting eye protection/goggles. I don't like sheet shields as cuttings/grindings can and do bounce up behind them. Your choice. Rob
It's nice to see somebody actually mill homemade aluminum castings. Haven't seen too many videos about it. Thanks, keep it up.
I have to tell you I have seen SO many auctions for milling lathe attachments, but never understood how it worked... until..... NOW!
Hi all. Following up on some comments by viewers that the carbide cutters on the face mill are at the wrong angle, I had another look, and have to agree. Totally. So don't bother copying this great piece of engineering.
These are situations where you wonder just how the hell you did that, BUT, when the pain subsides, grit your teeth and have another go.
Stay tuned for more on this setback.
Cheers. Rob
xynudu Steve Ramsey (Woodworking for Mere Moortals) once mounted his circular saw blade backwards in one of his clips m) it just happens.
At first I thought it was the wrong alloy, there are some which don't mill too well.
There is a trick where you can do this to cut sheet metal. I tried it and it works,but not great, noisy,and rough, and eventually it tears the carbide teeth off.
Like most people I have accidentally run the lathe in reverse and wondered why it wasn't cutting very well. LOL.
Rob
@@Xynudu When you smelt aluminium, add a spoon of kitchen salt, that will prevent cavities and bubbles to form in the casting
Wow, now that I have seen you use custom made facing tool and mount a vice perpendicular, the sky is the limit on what i think I can do. Good on you for those adaptions and thank you for sharing!
Hi Rob, about those big bubbles (voids) in your aluminium block. (Later you have cast much better billets so you must have found some solutions) On the top face you have this big crater. This top face remained liquid the longest because it was only air cooled. All other faces were cooled by the steel (or sand) mold and solidified and shrunk first drawing more liquid metal behind it creating that crater and big voids. One remedy could be preheating the steel mold before casting or use a higher cast temperature so that the excess heat will heat up the mold sufficiently to get the mold above alu melting temp. And you could additionally use your gas burner to heat the top surface to keep it liquid so it has more time to flow and fill the shrinkage of the solidified metal. (That way they keep the gold bullions shiny all around when casting gold.) Use a fuel rich yellow not blue flame in order not to oxidize the metal surface unnecessarily.
If you have more or less equally distributed pin head voids then this is hydrogen out-gassing. This can be reduced by bubbling argon gas through the molten metal in the crucible. Hook up a hose and metal tube to your TiG argon gas tank and stick it in the crucible and bubble it lightly. (Dont blow the melt in your face!) The often demonstrated sodium carbonate tablets make bubbles too but do not remove the hydrogen. Waste of time.
Hi Rol,
Thanks for the info. I think one of the main things is not to overheat the melt. I've noticed that if you keep the temperature lower it doesn't gas as much. I have tried using degasers and while they can work, a lot depends on the alloy type and the temperature.
I now preheat the mold, which as you suggest is a good idea. Also fast cool down is not a good idea. Overall the grade of alloy has a big bearing on pinholes. Some gas badly and others hardly gas at all. The Toyota wheel rims are good but don't machine as well as some softer alloys. It's hit and miss.
Cheers Rob
cast wheel rims are an interesting raw material for your remelting. The cast wheel rims are heat treated after casting. To get the good mechanical properties and free machining back you better heat treat your billets after casting too. If I remember right you have to quench it at 500 degC down to RT and then hold it at a not so terribly high temperature (~250 degC) for a few hours. I think the holding can be done in a kitchen oven. The properties only appear after a few days. For quenching you could throw the whole mold in water shortly after casting and then put it in a oven at 250degC for a few hours. To get the exact figures an alloy datasheet could help.
Really don't know how i got here, but it's oddly satisfying to watch.
love your channel. melted some some old can's my self. worked good. keep up the good work
THX!! it was my fisrt intension, too.. now I got a manual milling machine, China, 300 Oiro, works well, too...
Hey Rob. Those big bubbles on the top are strange. I sometimes get small ones but not that big. I knew you would not have to mill too deep to get rid of them. Also you are right in saying the temp at the time of pouring affects things. I too get great results without degassing and fluxes. Nice little lump of ally you have there, and the price.... Well the price is unbeatable :) You should have a go at casting vee pulley blanks that incorporate a hub. Multi step pulleys are also achievable. I started with a round biscuit tin and a small tin can and some setup jiggery, but the problem was it was a pita to setup and only good for one go, then had to be destroyed to get it out. Now I have some wood split patterns. The wood pattern can be pushed into and packed around the surface of a mix of fireclay and sharp sand in a container, or used as intended in a 2 part casting flask.
Casting model 'engine' parts eh?... You have got my attention :) Paul
djpaulk The bubbles were a bit unexpected. Maybe some dross went in. The rest was excellent. Making pulleys would be easy using a built up lost foam blank - glued up polyurethane with a plaster covering, surrounded by sand. That method will be my next experiment. Rob
xynudu Yeah, probably a bit of dross.. Nothing to worry about. When I consider the price, I can deal with a few imperfections.
My wallet hinges get a bit stuck when it has to open to pay a metal supplier for large lumps of ally.
Cool idea, lost foam... That's a thought that never occurred to me... The patterns will be one offs but would be cheap and way easy to make. Well I will be looking forward to see how you go with that for sure! I think they shape the foam with a red hot cutting wire? Anyhow, sounds interesting. Paul
I think you need to heat up your aluminium more when casting and making sure you scoop up all the slag from it before the pour
Gday mate. Very interesting video. Next thing we know you will be operating as the Xynudu aluminum company. Thanks for sharing.
cerberus Ha Ha Ha that's very good. I think I've done enough on this subject for now. Cheers Rob
That's trammed in surprisingly well...
They work OK, but not as good as a dedicated milling machine, as the mill slide/carriage will try to cant back under load. You may have to compensate for that. I try to brace the mills slide with the tailstock where possible. Makes a big difference. Cheers Rob
Hello, I think these holes originate when the outer part of the block is solidifying and the core is still liquid. Because the inner part still shrinks it pulls hard enough on the surface to break small holes in it and sucks air pockets in that form the holes. If my theory is right cooling the block slower should fix the problem.
Morkvonork That sounds like a pretty good theory. I will let the next cast air cool and see if that works. Cheers Rob.
Nice concept, however it just puts limits on the lathe compared to using a mill....
A hand ground slot drill with small 45 deg corners and quick hands would have you squared up while you were setting up the lathe...and putting it back to a lathe..
Good filming I have to mention
Tim
you should do a close up on the lathe and the work your doing. it would be cool to check out the work.
+kals nez from the beginning I meant say.
wondering where you found the vertical slide for your conversion?
I got it from a local lathe and tooling supplier. I've also seen it sold on Ebay. It's a generic no name slide.
Do u have a video explaining that milling cutter?
Rob,
Thanks for another machining of your pour video. Did you figure out what caused the holes on the top? Perhaps air trapped at the end of the pour? Anyway, thanks for sharing an interesting video! There doesn't seem to be anything you can't do with your little Chinese lathe!
Have a good one!
Dave
Swarf Rat The little lathe punches well above it's weight. Not bad for an $1100 unit. Rob
Well Jay Gauthier, and ardvarkkkkk1, I agree with you fully! the inserts are "plowing" badly.. when the inserts are turned to a horizontal position you can plainly see they are off center by over an inch which would cause the noise, vibration, plowing, and poor finish. A little more milling to your milling Head Rob to turn the inserts inline "flat" with center will do the trick! Just offering an opinion
riggerr1 These are not mill inserts. These are TCMT inserts I had laying about, and the nose geometry is the same as for general turning. Cheers Rob
xynudu Sorry dude, but I'll agree with rigger1, Jay & others.... whether they be mill inserts, turning inserts or whatever, they should not be used as hammers, which is what I see from here. Do yourself a favor - take 20 minutes (at the most) and throw together a simple fly cutter ( NOT fly hammer) and use hss on aluminum. You just might surprise yourself. No offence meant, just saying.
2harrynipples Yes, you are all correct. I finally got around to looking at this again, and the cutters are definitely at the wrong angle for the arc. Dunno what I was thinking when I did that. Looks like I will have to do some re-engineering on that one.....he, he.
I appreciate your comments. Since I made this I bought a heap of round HSS dirt cheap, so I will probably try to re-jig it to take that , and keep my TCMT inserts for their intended purpose.
This must be good for another video :)
Cheers to all who commented on this. Rob
Great video thank for sharing. be great if you film the model engine build :)
For that kind of finish u dont need the inserts on the tool holder...
You ought to put those molds in a vacuum chamber and put it under vacuum when you poor the molten aluminum in.
good job man..
las cuchillas de tu aditamento no estan cortando con los filos sino con el costado .
Si yo se esto. Me desechó este diseño y lo hice en un único punto de corte HSS mosca.
bien .
Shouldn't the lathe be turning the other way? The teeth were not cutting but just plowing through...Im looking at the directional switch going..." Im the newb, but turn that thing the other way"
redneckhippiefreak No. You always rotate the cutter towards the front of the lathe , so it's pushing the job DOWN onto the ways.
The teeth/inserts are on the wrong angle, and that cutter has since been scrapped. Rob
I'm under the impression that this tool holder does not hold the inserts in the appropriate angle.
+Danilo Lattaro
Yes. That's what I've stated.
It cuts OK, but not correctly.
I've since scrapped it and converted it to a single point HSS mill cutter.
Rob
+xynudu oh, this is the first time I comment without reading the comments first (smartphone), silly me. Sorry for that :)
Anything does NOT go if you have any intention of doing quality work!
if you would artificially age that casting in the furnace, bring it upp to about 300C, hold it for 30min, then cool down and bring it up again to about 200C in ordinary kitchen oven or something for 6-8 hours.. it will machine alot better... and not so gummy. =)
Is the holes in the stock because no degassing agent was used ?
***** Very unlikely. Hydrogen gassing usually only forms very small round air bubbles no bigger than the head of a pin and widely distributed throughout the job. This irregular void is more likely to be from some dross that went into the mold. Rob
What is the benefit if holding the billet in the vice and cutting with the milling head as opposed to mounting the billet in a 4 jaw chuck and turning it down?
None really. Just depends if you intend to do more than face it off.
Rob
Cool. I was just wondering weather or not I should get the same set up to be able to square up home cast stock. Not sure what I will use it for as yet. Just like having shiny square lumps of metal sitting around the shed
de-gas maybe ???
hey where your cheapo lexan sheet shield. to protect your face an body from chips.
Nathan Dean I always wear close fitting eye protection/goggles. I don't like sheet shields as cuttings/grindings can and do bounce up behind them. Your choice. Rob
some will have bent upper part as well.
but its your choice as well. i hope you wear a face shield as well.
centrifugal casting should give you better results
Ugly is only skin deep....sometimes :-)
Thank you for not pronouncing it as alooonam
Edit Alooominum