View Full Version : Advice Sought for Lathe
04-10-2013, 01:53 PM
As I'm getting dangerously close to producing stuff with my CNC Router, the other machine I'm looking at getting is a lathe.
My requirements are not that clear, but I guess I'll have a budget of circa £1K and Single Phase ideally (although I guess I could use a VFD for a 3 phase, as I have a spare 2.2Kw that normally goes with a spindle). The machine needs to be fairly compact and I have a decent square section steel workbench, so something with an overall length of ~1metre.
Materials will be up to occasional stainless steel, but more regularly probably mild steel and some aluminium.
I have had a look at the Sieg Super C6, which seems to fit the bill, but opinions welcome.
04-10-2013, 02:21 PM
I started off powering my lathe (Colchester student) with the 2.2kW VFD from my CNC router. Just put the right settings in and it'll be fine, up to 2.2kW of course.
If you have reasonably easy access to the workshop from the road, then definately consider getting a second hand lathe which is bigger than the C6. So log as the bed and bearings are in good condition, it doesn't really matter if it's quite old - mine is about 45 years old and it's still easy to make accurate parts with it:
You'll get so much more for your money if you get a second hand lathe. Bear in mind they can be very heavy. Something like a Colchester student (or "cholesterol student" if you believe the spelling checker in chrome!), harrisson M250/M350 would comfortably cut the materials you need, but there are plenty of other examples. They're maybe a bit bigger than you're thinking, but the difference in how well they cut compared to what you'd get for £1k new (i.e. 'toy' lathe like the C6 or myford) is pretty indisputable. Just look on eBay for items nearby...
Having said that, even with a small lathe you can, up to a point, make reasonably large accurate parts so long as you're patient. e.g. I several years ago I made the front two of these wheel rims on a Sieg C3 lathe which only had an 80mm chuck. The fun bit was milling the hexagons without CNC. The other two I did more recently with the Colchester lathe in a fraction of the time.
What size of things would you like to turn?
That is probably a bigger deciding factor.
05-10-2013, 11:20 AM
I reckon I'll be turning and threading mostly sub 20mm round bars, but do have the need on some pieces I'm making of boring into stock at 20-25mm and about 80-100mm deep. The latter operations won't be into stainless but possibly mild steels.
Oh and also some gear cutting possibly, so a divider plate will be a likely future add-on.
05-10-2013, 11:34 AM
Have a look @ The Emco V10-P in the classifieds and see if it's been sold, these are a nice piece of kit and it comes with a milling head, i have the Emcomat 7 and it has given me good service over the last 36 years, i do gear cutting on mine.
New, the Clarke CL430 has 25mm through hole.
I've had a CL500 for nearly ten years now, which is the 430 with a milling head, but the milling head was only ever on it for a few weeks, and it's done well in the time I've had it.
I spent some time comparing various new lathes earlier this year, and the Clarke was the only one in it's size range that came with a 25mm through hole, everything else was only 20mm.
Second hand, you will pay a premium for smaller lathes, but you've got to be wary of what you're buying.
Colchester Bantam may be more suited to your space requirements than a Student.
Boxford xUDs (I can never remember what the first letters mean!), Harrisons are good makes.
Other option is check out Warco/Chester to see what sits in yoru size range and see if any are available secondhand on the usual places.
06-10-2013, 10:34 AM
Googling lathes seems to bring up the same brands, so the additional makes above are very useful. I'll throw some saved searches out on ebay and keep an eye out.
Also keep an eye on Advert - All Ads (http://www.homeworkshop.org.uk/) although JohnS is likely to beat everyone to any bargains :)
02-11-2013, 04:28 PM
Still mulling over a lathe purchase, but the requirement has now some urgency (i.e. this week) as I have secured orders for some parts to do on it (6082 aluminium stuff).
The order has given me some more concrete requirements and a question that needs answering - when someone is quoting a 4 or 6" chuck are they referring to the size of the chuck or the diameter of the workpiece it will hold? Reason I ask is I have a need to turn down some 88.9mm (3.5") rounds to around 70mm dia. with an 85mm dia. flange, so the chuck will need to hold those. Hopefully that will narrow down my search, but I'm thinking of new and obviously somewhere with stock, rather than 2nd hand.
Thanks in advance as ever.
02-11-2013, 04:34 PM
The order has given me some more concrete requirements and a question that needs answering - when someone is quoting a 4 or 6" chuck are they referring to the size of the chuck or the diameter of the workpiece it will hold? Reason I ask is I have a need to turn down some 88.9mm (3.5") rounds to around 70mm dia. with an 85mm dia. flange, so the chuck will need to hold those.
They're referring to the external diameter of the chuck. Google and you'll find the range of sizes a particular chuck size holds. You'd hold that size with a 6" chuck using external jaws. 8" would be nice if the lathe is big enough to support it.
02-11-2013, 04:42 PM
I have a Myford ML7, and I would recommend it if you are tight for space. Otherwise I would go for a Colchester with a DRO, if you are doing production stuff a dro is an absolute must.
The best thing I ever bought for my lathe was one of these diamond tool holders. Diamond Tool Holder (http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=2&Itemid)
Its all I ever use for basic turning and it leaves a great finish and its super easy to sharpen which is a time and money saver over carbide inserts or complicated/skillful hss sharpening with a grinder.
As jonathan says, chuck size refers to the diamter of the main body. Depending on jaws, you can hold stuff bigger than the chuck diameter, but it's not always advisable. 85mm parts should be quite comfortably held in a 4" chuck.
Lathe capability is more important that chuck size. Lots of smaller lathes rely on electronic speed control, so are pretty useless for dealing with larger diameter parts as at low speed they lack the required torque to handle decent cuts. I'd personally look for something where speeds can be changed via belts (gear change is probably out of your price range) to make the lathe more versatile.
If you're wanting the lathe urgently, I'd be checking Arc Euro Trade, Axminster, Warco, and Chester to see what models they do that would suit your requirements, then making some phonecalls to see how quickly they could deliver.
12-11-2013, 07:49 PM
Quick update guys and firstly thanks for all the advice.
I had a look at what's out there and in the end went for a Sieg SC4 lathe, as a. it was in stock and b. whilst not as sturdy or precise as some of the bigger/more traditional makes and models does have some nice features i.e. T-Slotted cross feed/carriage etc.
It arrived yesterday and after bribing the wife and daughter to help lift it onto its stand (would not recommend this as its junk, but fixable and was available) I did a quick and dirty setup and started on my first piece. Not having used a lathe since I was at school (iirc Blondie or The Police were in the charts back then ;) ) I quickly got down to feeds and speeds - isn't it always?......
After a bit of digging about I grabbed some formulae from Wikipedia and came up with the attached spreadsheet and so far it has worked OK, but would like a second opinion if anyone has the knowledge and/or time and feedback if I've made a cockup. It maybe useful for someone else......
Off to start my second part and hopefully I'll see the results on a GT racing car in future, which is where all the CNC and engineering stuff is going towards :)
12-11-2013, 11:32 PM
Congrats on your new purchase, just had a quick look to see what you had bought and it is similar to my Elliot Emcomat 7,but seems better in the saddle department, i believe there is no dedicated drive shaft on the machine(mine's the same) so i would not take too much notice of of the feeds ect, what i have been doing over the years is using the rack and pinion to traverse the sadlde(while rough cutting ) and only engaging the leadscrew for the finishing cut,this way it cuts down wear on the leadscrew and nut,Copious amounts of oil applied to the length on the leadscrew you will be using, this will mean you can manufacture a half decent screw thread if you need to, whatever happens the leadscrew is going to wear nearer the chuck end of the bed, but i have had mine in service for thirty odd years and its still performing well, using the rack and pinion for feeding you can get a better feel for how the material is cutting.
Hope that helps
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