Just How Accurate Is A Modern Colchester Lathe

Well have had the machine up and running for a couple of months now.

What do I like?
Pretty much everything - especially the DRO - have not had one before.

What have I learned?
Well all you chaps who said accuracy is in the operator - are 100% right -
The good thing is I no longer blame the machine when I fail to hit the mark. I have a lot to learn - the really good thing is I am excited about each project - even the small ones.
Like machining up some new bushes for my grandson's billy kart's wheels. Also made him a little tow ball and put in brass steering head bushes while I was fiddling.

Yesterday machined up some pieces to use with the rotary table on the mill -

So yes I am happy - did I need to spend so much money? Heck no - I think I could have got a perfectly adequate machine for half the price -

Mal
 
Bob Korves said:
The spindle on my Chinese built Kent USA KLS-1340A is right at .0002" of runout. Goodbye, alibi! To get .0002" accuracy on actual work requires some careful fussing and tweaking when using any lathe. Ultimate lathe accuracy does not really do much for the results of your work, though better machine quality does tend to keep the machine's inherent accuracy in place for a longer time frame with less adjustment and repairs.

I laugh out loud when I see the test report sheets for Asian machines. For the price they are pushing them out the door for, there can be little real, careful inspection of the accuracy and quality of the machines. What it is, it is, and those test reports are almost certainly pencil whipped into being. The numbers reported are usually right at the tolerance limits, with a few entries a bit better. It is mostly a waste of time and money doing it at all, those completed machines are going out the door if they look like all the components are installed. Employees do what it takes to keep their jobs, and keeping production going out the door tends to work toward that end better than taking fussy measurements, sidelining marginal product, and refusing to write down the expected numbers, in most factories making things that stay in the earth's atmosphere...
Click to expand...

Yes most definitely, it is what it is.

Prior to buying my lathe I looked at many chinese made and some supposedly Taiwanese made. they were usually "big brothers to some of the more common Chinese ones.

OOPS.

Don't know what I did, but it appears the second half of my comment disappeared, so as I was saying.

After much looking and comparing. I decided that none of the chinese machines (I include the chinese/taiwanese hybrids) was up to the quality I wanted. they mostly felt stiff and gritty when turned by hand, some of the machined surfaces had visible defects.

Looking further afield I found a machine importer/distributor in Melbourne, some 500 miles away. that claimed to have a range of quality 100% taiwanese made machines, after further research I finally decided to buy one of these machines. And yes they were very good to deal with and have provided after sales support with my many questions,and a few extra parts.

Although I haven't had the time to use it much, so far so good. the machine has a great feel and appears to be defect free. All movements are firm but free with no discernable slack or slop anywhere. The fully geared headstock is fairly quiet, as is the norton style feed gearbox>

The lathe is fitted with an imperial leadscrew as was my request but is capable if metric threads with the classic 120 x 127 change wheel provided, It is claimed to produce some 24 metric threads and 40 imperial threads, including the often missed 13 TPI.

It cost about 50% more than a similarly specced chinese machines, but I believe I have the better deal. And yes I am happy just need more machine time.
 
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malmac said:
Well have had the machine up and running for a couple of months now.

What do I like?
Pretty much everything - especially the DRO - have not had one before.

What have I learned?
Well all you chaps who said accuracy is in the operator - are 100% right -
The good thing is I no longer blame the machine when I fail to hit the mark. I have a lot to learn - the really good thing is I am excited about each project - even the small ones.
Like machining up some new bushes for my grandson's billy kart's wheels. Also made him a little tow ball and put in brass steering head bushes while I was fiddling.

Yesterday machined up some pieces to use with the rotary table on the mill -

So yes I am happy - did I need to spend so much money? Heck no - I think I could have got a perfectly adequate machine for half the price -

Mal
Click to expand...

That's what we tried to tell you.
 
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