Author Topic: New mini-lathe fun... (Read 2580 times)

zebra50 · « **on:** February 09, 2012, 03:25:30 PM »

Hello!

I think this might be my first post in the machine shop!

I have just treated myself to a mini-lathe - it was held up by the snow, but finally arrived yesterday, so thought I'd share....

The lathe is a SIEG SC2 thing, from Axminster tools. These SIEG lathes are available under a few different names, but Axminster had a showroom not too far away, so I could actually go and see the different models in real life. The SC2 was a good match for the space available, and for the wallet too.

Once unpacked, I did a couple of quick jobs as part of the learning curve. First up was to machine a little spindle to hold bobbins for my coil winder. It is very handy for making little tools like this.

And then I replaced a broken connector on this B&O microphone, by cutting off the old on, and re-threading for an XLR output...

Today has been a bit of a learning curve, finding the right speeds and tool angles for cutting different materials, but so far so good. Although the lathe itself is rather small, it has a 500W motor and seems to have plenty of power. Now I just need to get my turning skills up to scratch.

MagnetoSound · « **Reply #1 on:** February 09, 2012, 05:19:18 PM »

I am happy for you, that looks really useful. Wish I had the space for stuff like that.

Do you have any thoughts about offering your services in the future?

zebra50 · « **Reply #2 on:** February 09, 2012, 06:02:24 PM »

Hi Dan,

Absolutely - I am always happy to help forum members. Just drop me a message if you need anything.

The coil winder has been a very useful toy too, and well worth the initial layout and time spent. I'm also hoping for a (larger) milling machine later in the year, if funds permit.

Cheers!

Stewart

grantlack · « **Reply #3 on:** February 09, 2012, 07:46:45 PM »

way rad. such a handy size! maybe once the car is paid off...

plans for a mic body in your near future?

gemini86 · « **Reply #4 on:** February 09, 2012, 09:31:15 PM »

I have a friend with a 3 in 1 combo lathe mill drill press... I'd be using that thing constantly, he hardly touches it. That bastard...

zebra50 · « **Reply #5 on:** February 10, 2012, 04:20:24 AM »

Quote from: grantlack on February 09, 2012, 07:46:45 PM

plans for a mic body in your near future?

It certainly crossed my mind, but it is early days.

I think the SC2 lathe would be good for prototypes and one offs, but I think for a production run you would want something a bit bigger.

Quote from: gemini86 on February 09, 2012, 09:31:15 PM

I have a friend with a 3 in 1 combo lathe mill drill press... I'd be using that thing constantly, he hardly touches it. That bastard...

You need to steal it!

zayance · « **Reply #6 on:** February 10, 2012, 05:25:23 AM »

Nice Stuff, Congrats...

It's true that if you want precision, than heavier Lathe's are better, but when you get to know your machines and how to use it,
you get better at it as always, or get frustrated as "why i don't have the bigger one " haha

Have Fun!

gyraf · « **Reply #7 on:** February 11, 2012, 01:57:42 AM »

Very nice indeed!

Will a machine of this type be able to do the type of fine threads found in e.g. AKG's C451/CK1 mics?
(I never fully understood the dimensioning of lathe thread-making mechanism)

Jakob E.

zebra50 · « **Reply #8 on:** February 11, 2012, 02:40:05 AM »

Hi Tony,

Well, yes of course I want a bigger one already - If I had more space and a lot more money. But I think this one is good for learning, and hopefully I won't lose a hand on something this size!

You need a big budget for tools and accessories as well....

Quote from: gyraf on February 11, 2012, 01:57:42 AM

Will a machine of this type be able to do the type of fine threads found in e.g. AKG's C451/CK1 mics?

Hi Jakob

That is the theory! You get a set of different gear wheels that are changed for different threads. At the moment I have a metric set of wheels that goes from about 0.2 to 2 mm pitch, but others are available including imperial sizes.

But i am learning to do the simple stuff first before I get into thread cutting. The internal threads look hardest to do, and these are probably best still done with a tap where available.

My next little job was to make a spinner for winding guitar pickups. The picture is bigger than real size.

I started with 15 mm brass, and machined one end down to 8mm to fit the winder. The thin spindle end is only about 2.8 mm diameter! Probably a bit thin for brass, so if/when it breaks off, I will machine down a steel screw and tap the brass block.

The lathe is quite happy tacking 0.25 mm cuts from the brass, which means reducing the diameter by 0.5 mm each pass.

In action...

gemini86 · « **Reply #9 on:** February 11, 2012, 04:15:13 AM »

internal threads can be just as easy as external, but you're doing it blindly. Once you have outer threads down pat, internal will be cake as well.

zebra50 · « **Reply #10 on:** February 11, 2012, 05:36:01 AM »

Thanks Rodney - that is good to hear. All part of the learning curve!

Gus · « **Reply #11 on:** February 11, 2012, 09:35:16 AM »

here is a good link http://www.mini-lathe.com/Default.htm

rob_gould · « **Reply #12 on:** February 14, 2012, 09:32:05 AM »

Ooh tool envy! I've loved metalwork since being a schoolkid so seeing new stuff (even other people's) always gets me excited!

My latest treat to myself was a bench pillar drill - no more drilling holes in project cases with a hand drill.

The lathe looks great and incredibly useful though. As others have said, things like cutting threads is tricky at first but with patience and practice it's OK.

sahib · « **Reply #13 on:** February 14, 2012, 05:51:49 PM »

Quote from: gyraf on February 11, 2012, 01:57:42 AM

Very nice indeed!

Will a machine of this type be able to do the type of fine threads found in e.g. AKG's C451/CK1 mics?
(I never fully understood the dimensioning of lathe thread-making mechanism)

Jakob E.

The relation is between the travel speed of the cutting tool in horizontal axis and (naturally) the number of rotation of the material (chuck head). On older type industrial lathes as well as having mechanical speed control, you would also have a set of driving gear that you would change to depending on the thread you are cutting. There is actually look up tables for that. I have a Colchester Bantam and that's how it works.

JohnRoberts · « **Reply #14 on:** February 16, 2012, 10:59:34 AM »

I only worked in a machine shop for two summers as a high school puke, but after a while I demonstrated I wouldn't lose any digits if they let me play on the big toys, even though I was too young to legally operate machinery. The coolest thing I machined on a lathe was a crude ball joint, or ball and socket... This was a round shaft with about a 3" ball machined on the end of it, and a mating socket with a matching 3' diameter spherical cut out machined into it so the ball could seat into the socket and rotate and vary off axis 45-60'. The tool base to do this was a cutter that mounted on a pivot so it could rotate in an arc. To machine the ball part it faced the side of the round stock on the lathe. To machine the socket the tool base was mounted on center with the round stock, cutting in from the end away from the head stock. There was no automatic feed for this, it was all done manually with a handle that you moved to make the cut.. So it took a steady hand and small cuts to not mess up.

The shop I worked at was supporting Columbia University's oceanographic research vessels. The ball joint was for a rock dredge that got dragged behind the boat along the ocean floor to collect "rocks" off the bottom... The ball joint seems like over design to me for the application but apparently they needed several degrees of motion. Making the ball joint was the fun part of making that rock dredge, I also had to make the chain mail bag to hold the rock samples by literally taking 1/2" lock washers, gripping them with two vise-grips, bending them open one at a time. Assembling them together with hundreds of other lock washers to make a flexible but robust metal bag to hold the rocks they dredged up. That wasn't even the worst job in the shop, that I had to do (making and sanding fiberglass water barrel hoods in the heat and humidity of mid summer). I also recall getting paid the princely sum of $1.25 hr, which after taxes was like $33 a week take home pay, but the experience has served me well, IMO.

JR

gemini86 · « **Reply #15 on:** February 16, 2012, 12:20:20 PM »

I once made some aluminum drum sticks in high school metal shop, they looked good and played awful.

zebra50 · « **Reply #16 on:** February 16, 2012, 02:05:39 PM »

Quote from: gemini86 on February 16, 2012, 12:20:20 PM

... they looked good and played awful.

Like a few singers I know!

I'm having a lot of fun with this little beast, and have found lots of uses for it already. It's one of those tools that would now be hard to live without.

The big challenge seems to be keeping the thing clean. Particularly with brass, the little chips seem to go everywhere! Any tips? I think making a bigger plexi shield would be a start.

Marik · « **Reply #17 on:** February 16, 2012, 02:32:14 PM »

Quote from: zebra50 on February 09, 2012, 03:25:30 PM

Hello!

I think this might be my first post in the machine shop!

I have just treated myself to a mini-lathe - it was held up by the snow, but finally arrived yesterday, so thought I'd share....

The lathe is a SIEG SC2 thing, from Axminster tools. These SIEG lathes are available under a few different names, but Axminster had a showroom not too far away, so I could actually go and see the different models in real life. The SC2 was a good match for the space available, and for the wallet too.

Sweet memories...

That exact lathe was my first one. An excellent way to start learning how different materials feel.
To make the bed more rigid and reduce chatter and vibrations I'd suggest to bolt it down to a heavy bench. Make sure to shim it, so there is no bed deformation.

It cuts brass and aluminum pretty nicely. With light passes it can handle even steel, but you will need patience if need to remove lots of material. You will find quite a bit of chatter on those lathes, so play with different cutting speeds (that machine is very convenient, as it has variable speed control) and cutters (BTW, have a nice grinder near by, so your tools are always sharp). The threading feature is a nice detail and an excellent way to learn. Keep in mind, the chart does not have all the possibilities, but you can recalculate and cut even 60INS threads found on Gefell and B&K measurement capsules and many others.

I'd suggest to get a quick tool change--you will find it much faster and easier to work with. Instead of shimming tool bits you will just set the height with a nut.

I am sure, like myself, at some point you will outgrow it (it might happen pretty soon), so don't invest much into chucks and other accessories.

I sold mine long ago and by now have three lathes:

Monumental super precision Hardinge HC chucker with automatic turret station and spindle runout of 0.6um:

http://www.machinemanuals.net/web_pages/hardinge_hc.htm

Super precision Hardinge DSM-59 second operation lathe with tailstock turret and production slide:

http://www.machinemanuals.net/web_pages/hardinge_dv.htm

and Dunhan speed lathe with hydraulic tail stock.

Quote

And then I replaced a broken connector on this B&O microphone, by cutting off the old on, and re-threading for an XLR output...

How about for the next project making that Neutrik thing from scratch?

Best, M

zebra50 · « **Reply #18 on:** February 16, 2012, 03:59:25 PM »

Hi Mark,

Thanks for sharing your experiences - you have a pretty awesome workshop!

I'm sure that I will be looking for a 'grown up' machine in the future - but this is great so far for small parts.

Quote

How about for the next project making that Neutrik thing from scratch?

Great idea! I'm half way there, been making XLR inserts for Reslos.

Bill Wilson · « **Reply #19 on:** February 25, 2012, 12:12:51 AM »

Hi Stewart: Glad to see you were able to acquire a lathe. Looks good for a small unit.

Bill Wilson

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Author Topic: New mini-lathe fun... (Read 2580 times)