Colchester Student Mk1 Won't Start

OOOH exitin! Have a ring round your local electrical wholesalers, CEF, Tep, and YESSS! See who, if anyone, is open, all should carry stock of this, very common item. I guess you will have done, but if not, clean the dust out of the inside, especially around the contactors, and keep fingers away from the capacitors, they bite hard even with the power off! If nothing else, tape over the spare holes, you could get a mounted socket and fit it to the box, save having the flying socketThe moment of truth approaches!

Be safe,

Phil.

Oh, and check the earth continuity from the single phase socket to the lathe! Most important!

Edited By Phil Whitley on 06/04/2020 12:18:04

I'll check continuity later

The socket on the machine is 5 pin 3p+E+N but the converter doesn't have a neutral and neither does the lathe

So, do I get a 4 pin 32 amp socket to fit to the machine and get a 32 amp 4 pin plug to go on the lathe(up from the 16 that's there, although it shouldn't be drawing anywhere near 16amps) Or can do I need to change things around?

I don't know if a 16 amp 415v plug is smaller than a 32 amp one though?

TEP is closed for non-essential customers, they're only open in the mornings and even then it's only for account holders since they can't take card or cash for some reason. the man said he'd sort me out if I got really stuck, but I think I'll just order from Rs and get them tomorrow. I just need to know what I need?

I would get a 16a 3pole +earth 4 pin socket, no need at all for a 32A, the only 32a socket I have is for the welders! if you add the FLA on the motor and the pump, I doubt it will come to 10a! 16 anp is smaller than the 32a.

Phil

Edited By Phil Whitley on 06/04/2020 12:55:40

Make sure you wire an earth from the incoming supply earth in the phase convertor to the output socket earth pin! It does not appear to be earthed at the moment!

Are there any safety advantages of putting a 32 amp plug and socket on instead?

NONE! all my 3 phase machines runs on 16A sockets

Edited By Phil Whitley on 06/04/2020 13:14:50

I took the motor out and put that spare gland I had on it. It's holding the conduit very well. It's not the stuff that threads in, but it's doing the job

I'll keep the motor out for when the socket arrives tomorrow. So I can just test without a load. I'm pretty happy with the converter so far. Much more satisfying to turn on than the Clarke static one 😄

Yup, that gland is fine Richard, just remember that when you try it out, the motor will not be earthed!! put a seperate earth to the motor when testing!

Phil.

Socket arrives around 2.30 so I went straight out and fitted it. Lathe works beautifully. See videos for footage. I did turn it on once or twice and it didn't turn on(see 2.22 in the first linked video), so I presume some contacts need cleaning. Possibly in the c and d switch on the back. There's a clicking noise coming from the lathe too, but that's just where the belts are flexing and hitting the frame, a tiny bit of filling will sort that. I still cannot hear the contactor pulling in like I'd want. See what you think from the video

Video 1. Not start at 2.22

I need to get better at using a lathe now, since I don't really know about feeds and speeds and tooling to get good finishes. Plus parting off with hss just scares me. I always seem to struggle. How are they meant to be ground?

Cutting some steel

The no volt release works, as shown in this video

No volt release test

As I said I would, I made a spacer to go where the missing one was. It was fun to try and get them to be as identical as possible, but was difficult with my available tooling(no boring bar big enough and not a drill bit the right size) still, I managed

Well done you and Phil!

Dave

Phew! good to hear my wiring was correct! success! Well done Richard. I hate parting off too, make sure that the tool is square to the work, minimal overhang, lock off the saddle, cutting oil! Rigidity in the setup os where its at!.

Phil

Just watched the videos, Excellent stuff Richard, I am well pleased for you! Knew we would get there in the end, now the fun part, shaking out the fine details, and making stuff! I am trusting that you have earthed it all properly!!?

Phil.

Edited By Phil Whitley on 07/04/2020 19:23:41

Thanks Dave, good to know someone else is still interested. But don't worry, it's far from over yet😄 (potentially thinking DRO, and more painting and things) lots of things to iron out first. Lighting transformer is next on the list

Parting off started okay but then I have no idea what happened, just went terribly ended up snapping the tool. I had changed the shape of it a bit and made a weak point so I'll look into it tonight.

The lathe started to make a horrible clunking noise. So I took off the motor again, turned out the grub screw wasn't tight enough, so easy fix.

As for grounding, the only grounding there is is coming from the plug to the box that those wires go into. Here

Also, my dad is concerned that the lights flicker for a second when the phase converter is turned on, and then again when the lathe is turned on. Could you explain why this happens?

I played around with some aluminum, just turned the end part and did a large 4tpi thread on the end. I didn't have the thread gauge on the lathe so I just left the half but engaged. But it went well. I forgot to move the tool back out a few times so it made marks on the return since the threads have some slop in so they don't line up back and forth

Taking a cut to remove some surface marks from messing the thread up!

The spacer fits well

flickering lights is just a bit of volt drop, my workshop lights flicker when the compressor starts. Nothing to worry about.! As long as the earth wire is firmly arrached to the isolator box, which is in turn bloted to the lathe, it should be fine. If it was a lathe where the weight of the motor tensioned the belts, and the motor was on a pivot, or the motor moved to change speeds via belts, I would recommend a seperate earth to the motor case, but the motor is bolted solid to the frame of the lathe so that should suffice.

Phil

Edited By Phil Whitley on 07/04/2020 20:21:58

Looking at your well made spacer, I see three red wires emerging from an unbushed hole with no flexible conduit in sight! Get it sorted before there is a bang and a flash, and the phase convertor goes up the pictures!

Phil

Those wires are the ones coming out of the back of the isolator. I'll look at it tomorrow. Why would the phase converter be damaged from the lathe wires being damaged?

Any thoughts on why the lathe doesn't always switch on? Could it be the switch contacts?

And any thoughts on why I don't hear the contactor pulling in like a big clunk like your one did?

And does the coolant pump seem very noisy/ growly to you?

Glad to see that you are making progress!

Parting off can be a problem. FWIW, I would suggest:

Minimum tool over hang

Plenty of lubrication

I cheat and use a rear toolpost, and being a cheapskate who hates grinding away good HSS, use Zero top rake.

This reduces the chances of a dig in.

For some reason, parting with a back toolpost seems to produce fewer problems that with the tool mounted in the front toolpost. But it may not be possible to fit a back toolpost to your lathe.

Keep a steady, but not hard feed. Don't let the tool rub.

Also, lock the Saddle to minimise any side load on the tool.

HTH

Howard

I'd never realised what a rear tool post would be for, I'd seen them before on listed lathes and things but it hadn't quite clicked. So that's very interesting!

Zero top rake sounds good to me, no angles to deal with!

I'll attempt this and report back. What sort of speeds should I be looking at

Much appreciated Howard

Being bone idle, I just grind the front face by approaching the grinding wheel head on. Hopefully, your parting blade already has clearance built in on both sides. If it hasn't, you need to grind some, but not too much.

You only need to produce some front clearance, effectively about 5 degrees. Too much takes away support from the cutting edge and weakens it.

Stating the painfully obvious, it is important that the cutting edge is on the centreline , and not above it. Tool rubs if you mdo.

Below and it will leave a pip in the middle of the job.

There are arguments as why a rear toolpost is better for parting off, all about the thrust being upward or downward on the dovetails. Have not followed the fight, just found that more dig ins and broken tools happen in the front toolpost. Am now getting so brave that power cross feed of about 0.0022"/rev gets used!

Speeds:

I tend to be cautious and run slower that for turning, about half usual surface speed.  Don't let the swarf build up for fear of jamming the tool on a deep parting cut..

HTH

Howard

Edited By Howard Lewis on 07/04/2020 23:01:45

Brilliant stuff

Although, I use a belt grinder instead of a bench grinder, so I use a flat platen so I don't get a hollow.

Also, struggling to get things perfectly centered since I'm not used to a 4 way tool post. I'll get better at shimming. I'll get some material for it

Thanks again