Aluminium 80x50mm what to make?

[Dave Smith the 16thParticipant @davesmiththe16th]

I melted some aluminium down and the excess got poured into a can. It shrank enough to enable me to get it out and i have a round slug approx 80mm diameter and 50mm tall.

Nice simple project to make using a lathe? Possibly the mill when i get it. Maybe a few weeks away yet though. A few bills to pay before i fully decide on which one. (unless there are bargains at the Doncaster show)?

Suggestions for a simple project where accuracy is optional and additional parts are minimal.

2109 Lathe, small drill press, 4×6 bandsaw and a few other bits. Never soldered but i do have various gas torches. I also have a 3D printer.

Suggestions please.. (not rude ones, the missus has already suggested a use for it)

[Dave Smith the 16thParticipant @davesmiththe16th]

[Neil WyattModerator @neilwyatt]

If you have a perspex rod you could make a base for an optical centre punch.

[An OtherParticipant @another21905]

Hi, Dave,

Maybe going further than you intended, but it may be worth searching for 'lost foam casting' on the internet. I have used this method of producing many castings for all sorts of things, from bearing housings for a bench polisher to bits for linear guides. It basically involves making a copy of what you want to make using hard polystyrene, burying it in sand, then burning the polystyrene out with molten aluminium. Similar process to lost-wax casting. With care you can make some extremely complex parts. There is tons of stuff on the internet about how to do it, and making the necessary equipment, none of it particulary complicated.

Bear in mind it can be dangerous – red-hot liquid aluminium, so wear appropriate protective clothing and safety glasses, and take care – and don't pour the aluminium into or onto damp surfaces – it explodes everywhere.

[Michael Cox 1Participant @michaelcox1]

I made my first ball turner with just such a piece, see:

I have since made two other ball turners and the first one , shown above, I gave to someone in the USA.

Mike

[Dave Smith the 16thParticipant @davesmiththe16th]

I need to be careful with the melt / casting. I live in a very built up area in a terraced house with only a small back garden. I need to be sneaky and not annoy the neighbours. I think i need to make proper moulds. I have some playsand and a large bag of bentonite clay (powder). Anyone in the Birmingham area need any Bentonite clay in powder form?

I don't think they will like the smell/smoke from burning foam. My propane furnace is fairly quiet so no complaints yet, although i think it needs a fan to get the best from it.

Ball turner looks an ideal solution. I wonder what i can use to make the toolholder?

Ideas on mounting a tool holder without using a mill to cut a slot into it? And i do not fancy filing it

[Neil WyattModerator @neilwyatt]

> I don't think they will like the smell/smoke from burning foam.

I'd guess it's a fairly short-lived puff of smoke? Mike C. can confirm or deny…

Neil

[Michael Cox 1Participant @michaelcox1]

Dave, the toolholder was made from 12 mm x 50mm steel bar crudely cut to shape by chain drilling and then filing.

The 6 mm hole for the tool was drilled using a drill in the lathe chuck once the toolholder was champed to the base. This ensure that the hole is on the lathe axis.

The tool was a piece of 6 mm silver steel shaped with a file and then hardened and tempered.

Cutting the slot in the aluminium base was achieve by mounting the the base on an angle plate attached to the cross slide and then milling the slot using a 12 mm end mill.

Lost foam casting does produce a small amount of smoke and flame when the aluminium is poured. However, the amount of smoke and flame is small. Most of the polystyrene melts and goes into the sand and does not burn. I think it would pose little nuisance to neighbours.

I hope this information is useful.

Mike

[Dave Smith the 16thParticipant @davesmiththe16th]

Just had a closer look at yours and expected mine to have all those pock marks in the casting but after just a small skim to get it all fairly true, most of them have gone. How do you get a cleaner casting without those marks?

I do not remember using any flux or degassing so maybe there is the answer?

I have a small corner garden with 3 properties bordering it. May have to have a test on how much smoke/fumes it produces. Someone mentioned using PLA plastic to do a similar job, not seen much info on that though.

Is the slot angled to adjust the toolheight? What secures it into the slot? Any other pictures?

I dont think i have any scrap around that size, i wonder what else i may have?

Thanks.

[Michael Cox 1Participant @michaelcox1]

Dave, I have just uploaded some more pictures of the ball turner to my album "Ball Turner".

The slot is not angled. As stated earlier the hole was drilled with the toolholder clamped in base block. This ensures that the ball is exactly on centre. The tool is filed to half diameter. This puts the tool just on centre. The tool is held in the tool holder with an M4 screw. On one of the pictures you can see the screws in the base that clamp the toolholder in the slot.

Regarding the pock marks, I have to say that I made this very shortly after I started aluminium casting. The aluminium was melted, skimmed and poured. Nowadays, I would add "Low Salt" as a flux, stir, and then carefully skim the dross before pouring. This gives much cleaner castings.

I have no experience of PLA but I can imagine that a hollow PLA pattern might well behave like a foam pattern.

Mike

[frank brownParticipant @frankbrown22225]

Going back to lost foam casting, I did some at night school, 30 years ago, we used a "anti gassing" pill, from memory it was square and light blue in colour. It was meant to stop the casting being porous. We did the pour inside, the smoke was not that bad.

Frank

[Dave Smith the 16thParticipant @davesmiththe16th]

Excellent, Thanks.

Uploaded a couple of pictures myself (slug) and i think i have found a suitable toolholder, the bracket from a caravan stabiliser. 12.5mm thick.

Before

After

Toolholder?

Apologies if the picture are messed up. My first attempt at pictures on here.

How do you scribe the cross of mark the centre on an optical punch? Seems like a nice and easy project.

Thanks

[Neil WyattModerator @neilwyatt]

How do you scribe the cross of mark the centre on an optical punch? Seems like a nice and easy project.

With the perspex rod in the chuck scribe across it with a sharp tool at centre height, then turn it 90-degrees,

nEIL

[Dave Smith the 16thParticipant @davesmiththe16th]

Is a scribe mark all thats required? No additional marking to highlight it?

Any cheap sources for a rod? I do like a bargain and would prefer to buy something with a rod in it and strip the parts out. Maybe i just like taking things apart? Although i do "sometimes" put things back together

[HopperParticipant @hopper]

Posted by Dave Smith the 16th on 17/05/2016 18:53:48:

I need to be careful with the melt / casting. I live in a very built up area in a terraced house with only a small back garden. I need to be sneaky and not annoy the neighbours.

Easy. Set up a small barbecue, don your chef's apron and smoke away!

[Dave Smith the 16thParticipant @davesmiththe16th]

Keep a couple of sausages and recycle them each time?

Is low salt the key to clean up my casting? Its not as bad as one aussie? youtuber who had deep craters in his castings. Only the deeper he went the worse they seemed to get.

Eager to run away with the CC and accidently find myself on ARC's doorstep. Are they at the show this weekend? Better to wait until next week?

The more i look the more i like the WM12 machine though. Although the specs appear to be wrongly printed either on their website or in the adverts. 250mm travel or 350mm or something else?

So many choices..

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