New toy: Setting up Colchester Student lathe

[Andrew Wilding]

Looks like a good sturdy machine. Those old colchesters are capable of hard work. Is the bed hard or soft? Some of the roundheads had soft beds. Watch out for the gamet bearings. If you have to get new ones you may have to dig fairly deep!

Even if the lathe is old it does not mean it has had it. Just look at the old DSGs and Halifax lathe in the mech eng toolroom at the uni!

I am sure you will enjoy taking cuts with a machine with a bit of meat. The saddle also has T slots which are great for boring jobs.

[Jonathan]

Looks like a good sturdy machine. Those old colchesters are capable of hard work. Is the bed hard or soft? Some of the roundheads had soft beds.

There's a sign on the bed saying "Induction Hardened Bed"

Watch out for the gamet bearings. If you have to get new ones you may have to dig fairly deep!

Are they not a standard size then? They seem fine at the moment - if I disengauge the motor and spin the spindle by hand it feels very nice and smooth. Having said that the headstock did get a bit warm near the chuck end when I ran it at 1200rpm for a while. I'm not sure if that's normal.

Just look at the old DSGs and Halifax lathe in the mech eng toolroom at the uni!

I would if I was allowed in. I asked about if I could use the machines and they said only if I do the training (health and safety reasons), which I don't mind though I doubt it would be more than I'd done at school. Anyway, it never happened so the nearest I've got it watching standing on the balconies!

I am sure you will enjoy taking cuts with a machine with a bit of meat. The saddle also has T slots which are great for boring jobs.

Definately - at school they have two M300's and one M250 which I used a lot. I never thought I'd own a similar lathe. There was also a bigger lathe - over 50 years old I think and it was better than the Harrison, except I was about the only one to use it because it had imperial dials. Now sold to make space for laser cutter...waste in my opinion!

Anyway I'm going a bit off topic...

Just to test I faced 50mm MS & aluminium bar and chamfered the steel, here's the result:





Not the most interesting test but it got a nice shiny finish. Happy!

The coolant pump only uses a fraction of the power the spindle will use, so I personally wouldn't say it's going to be a major issue in terms of doing anything bad to the VFD, especially considering the coolant pump isn't likely to be running near it's rated power.
However, what if you want to use the VFD to change the speed of the spindle?

I reckon I'll try them together tomorrow. Why would I want to change the spindle speed with the VFD significantly? It's easy to change the gears and keep the motor at full speed which will surely get more torque. If I want a speed between the standard ones I won't have to reduce the frequency much.

At the moment I've only ran the motors at 50Hz, however they both say 50/60Hz. I'm going to test the actual rpm of the spindle tomorrow.

[Jonathan]

I've found some standard oil for a better price:

http://cgi.ebay.co.uk/Smith-Allan-T3...item3a6147458c

T68 is the same price from that seller and as far as I can see T## is equivalent to ISO## oil. 10W oil is equivalent to ISO32, and 20W equivalent to ISO68 according to this site:

http://www.engineeringtoolbox.com/is...il-d_1207.html

I'm not sure if that means, for instance, 10W40 as used in car engines is suitable. It's widely available (Halfords, B&Q etc).

[Jonathan]

EDIT: I must have been looking at the wrong page in this thread when I wrote this so this post is a bit of a duplicate!

I somehow missed the last post here...

Even if the lathe is old it does not mean it has had it. Just look at the old DSGs and Halifax lathe in the mech eng toolroom at the uni!

I would if I was allowed in! That's the problem with doing Electrical Engineering...

I am sure you will enjoy taking cuts with a machine with a bit of meat.

Yep, now I've used it a fair bit I'd say it seems as good as the Harrisons (M250 & M350) at school. I've not cut anything too ambitious on it yet though, so we'll see.

The saddle also has T slots which are great for boring jobs.

Why are they useful for boring? It's not something I've come across. I've got a travelling steady for it now which fits in the T slots.

The coolant I got works well. It's not caused any rust yet and I've been using it liberally I've also put tools in 7 of the holders which makes changing tools very quick.

[Andrew Wilding]

great for line boring between centers for a good parallel bore.

[Tom_W]

Jonathan

I managed to get a hold of a Colchester student 2 last weekend. I am in the process of getting some oil for the gear and head ( hence how I found this thread ) - and a new micro switch - can I ask how far up the glass you filled each with oil.

Cheers

T

[m_c]

can I ask how far up the glass you filled each with oil.

Somewhere visible on the glass. Personally, I aim for just above the middle, but it's not an exact science, and lathes are hardly pushing the boundaries of the oil, so provided it's not majorly under or over you shouldn't have any problems.

[Tom_W]

Many thanks,

Another question for Jonathan, you refer to a machine (old) spares supplier in Nottingham area - do you mind telling me where as I need a few tool posts.

I normally would go to Rileys in Attercliffe in Sheffield - but your may be closer?

I am specifically look for gears 22 and 28 teeth so I can get it to screw cut metric.

T

[m_c]

The coolant pump only uses a fraction of the power the spindle will use, so I personally wouldn't say it's going to be a major issue in terms of doing anything bad to the VFD, especially considering the coolant pump isn't likely to be running near it's rated power.
However, what if you want to use the VFD to change the speed of the spindle?

Other option is a simple static phase converter using a capacitor to power the coolant pump.

[m_c]

Mutli-viscosity oils such as 10W40 have viscosity modifiers so the viscosity remains more constant over temperature change.
A 10W40 oil acts like a SAE10 oil at 25degC, and a SAE40 oil at 65degC (at least I think that's what the temps are, but they're maybe 5deg of!).

Engine oils also have a lot more additives and detergents (with the exception of the more specialist SAE oils aimed at small engines/classic engines), which there is a possibility may cause issues with some seal types, and the detergents can dislodge drit/grime that would otherwise be sitting causing no problems.

Hydraulic oil on the other hand, is pretty much one of the purist oils you can get, with minimal additives, and certainly no viscosity modifiers.