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Working with metal

I recently decided to upgrade my home shop a bit with some metal working tools.  I bought a 6″ bench grinder, a metal-cutting band saw and a 7×16 mini lathe.  I’ve also been looking around at all the various options for mini lathes and I’ve mostly decided on one particular brand.  Unfortunately, it isn’t in stock right now so I’m playing the waiting game and looking for other alternatives.  The one I’m waiting for is sold by Little Machine Shop.  Once I have this, I should be able to fabricate just about anything I want out of metal as long as the project is small enough.  There are definitely limits to the size of the work you can handle with these tools but to go larger would be an order of magnitude more expensive and just doesn’t seem worth it right now.

The band saw can handle up to 4″x6″ rectangle or 4-1/2″ round stock which is also about the limit of my tools so was a perfect fit.  I tossed both of the wheels that came with the grinder and got a fine grit quality aluminum oxide wheel for grinding high speed steel cutting tools for the lathe.  The other side I plan on using for buffing and polishing so I bought a hard and soft air gap buffing wheel and a soft wire wheel for it.  They wouldn’t fit as it came from the factory but I was able to lathe a spacer that fits on the shaft and they work great.

The lathe came with a 3″ 3-jaw self-centering chuck which is good for working with pieces up to about 2″ to 2-1/2″ round.  I also bought a 4″ 4-jaw independent chuck which can handle up to 4″ round stock and can also hold non-round parts as well.  Some people have experimented with 5″ chucks on these lathes but I’ve heard mixed reviews doing so.  I think the motor starts bogging down a bit trying to rotate that much mass and really I don’t even know if the cross-slide can handle working on a 4″ piece.  I also got a quick change tool post which not only makes it simple to change tools but also makes it a breeze to set your tool height.  With the standard tool post you do this with shims if the cutting edge is too low.  If the edge is too high, you have to regrind the tool or just use something else.  With the quick change post and holders, you can easily change the height up and down for any tool and once it’s set, you’re good every time until you put a new tool in the holder.  I also bought a bunch of cutting tools.  I got an 8-piece set of high-speed steel tools, a large knurling tool with replaceable cutting wheels, a nice set of boring bars and a set of five indexable carbide insert tools from CDCO Machinery Corp (in the picture gallery) and a 4-piece center drill set.

I came up with two beginners projects to start learning how to use the lathe.  The first is an air assist nozzle that I need for my laser cutter and the second is a brass hammer; useful around any shop.  The first is a precise piece that needs to have very tight tolerances to function properly but is a fairly easy design and the second is more open to whatever I want to do with it.  My first attempt at an air assist nozzle went OK but I made quite a few mistakes and wasn’t really happy with the way it turned out.  The second attempt turned out nearly perfect.  Even after making several mistakes on the first one, I followed through and finished it to hopefully learn as much as I could before starting attempt #2.  I think failures are an important step in learning a new skill as long as you learn from them and don’t make too many of them more than once.

I’m currently working on a tachometer for the lathe.  It has a port for one, but they want $125 for it and I can build one for much less than that.  The hard work of figuring out the signals was already done by a gentleman named Jeffrey Nelson.  His website is MacPod.net.  His work on the tach specifically can be found here.  I already have the electronics banged out and working, now I’m just waiting for a new LCD so I can throw it on a perfboard and put it in a nice project box.  This would have taken me weeks or months to figure out without his work.

That’s about it for now.  Next week I plan on getting the laser cutter skinned and all the electronics mounted and wired.  After that it’s just a few sub-systems and then the laser tube.  Hopefully I’ll be able to make a new post next week about it.

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