MadModder
Gallery, Projects and General => The Design Shop => Topic started by: fluxcored on January 19, 2011, 05:22:44 AM
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Hi All,
Can you please comment on the feasibility of using an aluminum backplate to mount a 160 mm 4 jaw chuck on a screw thread spindle.
I've got a little bit of scrap which I want to melt this coming weekend to produce a rough casting for a backplate.
Its mostly aluminum siding with motor housings and some hard disk cases thus keep in mind that the casting's aluminum is going to be of unknown pedigree.
Regards.
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It will definitely be too soft to withstand being taken on/off, plus the pressures being put on it during cutting. Either the spindle nose threads will shave material off, or the metal will deform under the rigours of machining.
For something like an RT mount, then that would be OK, as it will be working under lower forces, but for a lathe, I personally wouldn't use it.
Bogs
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Allright, I'll just have to save up and order me some steel blanks then.
Thanx.
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I thought cast iron was the preferred material for backplates?
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I heard so too, till I saw a guy on the net making his out of mild steel.
As I'm currently building my house without a home loan, I've been trying to save money visiting the scrappies looking for suitable flywheels or barbells to make a backplate out of, with no luck. Which is why I hoped the ali idea would fly.
I'm happy to go with CI, I like doing things right the 1st time around - or at least I try to.
I'm still a few weeks off, really badly needing a backplate. Am in the process of setting up to cut a change gear to cut spindle nose thread and still need to make a few parts to achieve that. So I've got some time to save up or find some suitable scrap material.
Regards.
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Hi, I got a few 'rounds' of various sizes and thickness from a place that does plasma cutting. Unfortunately there is are ugly bits where the jets first went through but I repaired those by drilling them out and driving a rod in then welding to fill in the rest of the holes.
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Here in the UK you can buy cast iron blanks, most probably cheaper than the gas you would use for melting the metal.
Even finished ones for Myford and Boxford are rather cheap. Not worth the trouble of buying a blank and machining up yourself.
Bogs
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Maybe you could look out for an old brake disc, big enough to get a 4" blank out of one side of it.
Andy
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Andy, I like your cheapskate ideas!
What are brake disks made of?
Oh, and what are the disks from hard drives made of?
Jose
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Hi Jose,
According to Wikipedia, cast iron unless they are for high performance cars when they are sometimes made from exotic materials. But the one from an old Rover which I sawed up (just the disc, not the whole car!) seemed to be more like steel than cast iron.
The disc in a hard drive I broke up for the sake of the rare earth magnets in it seemed to be made of something very like glass. At least, it shattered like glass.
Andy
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Magnets from disk drives are great. I have some on my shop, on the back of a piece of plywood I have on a wall. I use that plywood as a vertical tool tray for the tools I'm using at the moment.
So the HD disks shatter easily... I'm starting using the ones I have for indexing. I'll be careful.
Jose
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Maybe you could look out for an old brake disc, big enough to get a 4" blank out of one side of it.
Andy
Will keep a lookout for that - I never looked at them twice but will investigate closer.
Found a nice large disc wheel that I'm converting to a pulley for my saw this weekend at the scrappy.
I try to salvage as much as I can from HDD's, sometimes even the bearings but recently I've started to toss the platters because I have'nt come up with a use for them.
Thx all.
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A flywheel from a car would make a good candidate too if making a faceplate too. I have a renault clio one waiting for this and its made of cast iron.
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Don't dismiss the discs to much as a lot of the cheaper drives are made from Ali as well just very hard. Place them in a cloth bag and bend them. If they shatter they are not Ali. If they bend they are. I melt them all the time and add a couple of copper Tees or elbow pipe fittings which help a bit in a 1-2kg melt.
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Hi Jose,
According to Wikipedia, cast iron unless they are for high performance cars when they are sometimes made from exotic materials. But the one from an old Rover which I sawed up (just the disc, not the whole car!) seemed to be more like steel than cast iron.
The disc in a hard drive I broke up for the sake of the rare earth magnets in it seemed to be made of something very like glass. At least, it shattered like glass.
Andy
Thats because they are glass at least some are
Stuart
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We used to sanitize computer disks before they went off for secure destruction (tipped into a furnace somewhere in wales), and we used to put them in a large cloth bag and hit it with a brick hammer a few times.
The ones that sounded like they were full of sand from all the glass particles moving round were deemed to be ready to go onward and we used to strip the others and feed the platter through our shredder on the survivors which turned out to have some sort of alloy based platter instead. They are both materials, with probably the odd mystery variant in some exotic stuff.