COLCHESTER CHIPMASTER
ERIK WERNER HANSEN FROM DENMARK HAS KINDLY OFFERED TO WRITE ABOUT HIS CHOICE OF DREAM MACHINE FOR HIS DREAM WORKSHOP.
I can’t really confirm that the Colchester Chipmaster as being my ”Dream Lathe” until I have finished rebuilding it. The lathe has speeds ranging from 35 to 3000 RPM and a centre height of 143 mm, but it has a length between centres of only 500 mm (20”). Tony of www.lathes.co.uk claims it’s a do-all lathe, for both production and tool rooms. That should make it ideal for serious hobby use. Some claim it’s the British equivalent to a Monarch 10AA (at least a poor man’s one – Monarchs are expensive). It runs on belts, even fine feeds can be driven by belt. So it should be able to do a very nice job.
There weren’t many accessories made for it as it’s an industrial lathe instead of a too-small modelers lathe (read all-in-one tool), but both steadies, a taper attachment, stops and a revolving tool slide were made.
And having the Camlock D1-3” spindle nose, many chucks can be used with it. I have a 5” 3-jaw, an 8” 4-jaw independent plus a Multisize collet chuck – all Pratt-Burnerd, of course. I may be a bit of a snob – or maybe it’s because a British lathe should have the proper British chucks. The cone inside the spindle nose is a British size, sort of like a Morse 4½.
The apron has a functioning stop mechanism, but the well made copy-stop I bought often just slide along the bed instead of stopping the apron.
Back when I had Myford Super7 lathes, I hated the sight of the Chipmaster – strange and ugly!
But after reading enough of the praise from Tony Griffiths website, I ended up wanting one. Tony is of the opinion that the variator should be kicked out and replaced with a VFD. So I bought two expensive Danfoss 3 HP VFD’s (one for the lathe and one for the mill). And I found a Chippie on “Preloved”. The seller claimed it was about as good a Chipmaster as one can get. And the price was right; back then I paid £1500 delivered to my address in Denmark.
Back when I had Myford Super7 lathes, I hated the sight of the Chipmaster – strange and ugly!
But after reading enough of the praise from Tony Griffiths website, I ended up wanting one. Tony is of the opinion that the variator should be kicked out and replaced with a VFD. So I bought two expensive Danfoss 3 HP VFD’s (one for the lathe and one for the mill). And I found a Chippie on “Preloved”. The seller claimed it was about as good a Chipmaster as one can get. And the price was right; back then I paid £1500 delivered to my address in Denmark.
But upon receiving it, the 4-jaw chuck was missing. And when I powered it up, all was not good. The variator had a steady “bonk, bonk” sound, and I was furious with the seller. What to do? In the meantime I had discovered the VFD would leave a large RPM gap, as it does not have as large a useful power range as the variator. The variator has a factor of 9, from 35 to 300 RPM or from 350 to 3000 RPM. A VFD is best from 50% to 200%, that is, from 700 to 2860 RPM. Or from 70 to 286 RPM. A gap from 286 to 700 RPM.
So I opened up the variator. I found the sound came from a hollow point on a drive cone – with cracks radiating out. Fortunately I had been given most of an older variator, which had made “the big bonk” – destroyed. As a cracked ramp was the only defective part, maybe I could use a drive cone. And as it turned out, it was identical – just looked slightly different. I changed the bearings also, but I don’t think they needed changing. It now runs perfectly and I feel no need to use a VFD, even though I find them very “sexy”. So, now knowing more about this simple, sturdy device, I wrote Tony a small article about how easy it is to care for a variator instead of destroying if by ignorance, but he hasn’t seen fit to include it on his website. I feel bad about it, as you need only two things to keep a variator happy: The one and only oil (Shell Morlina S2 BL10) and the correct preload (Allspeeds has a good manual that mentions it). That’s all, but few know of it. The variator I was given would’ve run well today, if it had not been neglected. It was in very fine condition, but a ramp piece had broken because of no preload. And he wanted to use a VFD anyway.
The other thing wrong was, the lever for the clutch/brake had had its pin replaced by a thinwalled tube – not ok. So I took it to a toolmaker friend and had a conical pin and a new spring fitted – now feels like new.
The brake didn’t really work, so I took out the brake housing and fitted a thick gasket to make up for wear in the brake cone. But when I assembled the spindle dock and ran the lathe, it now made a sound, while it had been quiet, before I took it apart. And it leaked a lot of oil, all over the Matrix clutch (which should be dry). I have had to take the drive apart, remove the gasket and I am now (still) in the process of fitting new oil seals on the input shaft. And I now feel sure the brake is for thread cutting only.
The brake didn’t really work, so I took out the brake housing and fitted a thick gasket to make up for wear in the brake cone. But when I assembled the spindle dock and ran the lathe, it now made a sound, while it had been quiet, before I took it apart. And it leaked a lot of oil, all over the Matrix clutch (which should be dry). I have had to take the drive apart, remove the gasket and I am now (still) in the process of fitting new oil seals on the input shaft. And I now feel sure the brake is for thread cutting only.
Being of a metric mind, I own the “Continental” (metric) version and I feel cheated. The original imperial model came with Thread Dial Indicator included in the apron, but a TDI is not a possibility at all with the Continental. And the imperial can even cut the usual metric threads anyway – not vice versa. There is an algorithm I can follow in the manual, so maybe some inch threads can be cut anyway. A set of changewheels could be had, but they seem to be very rare. I have seen just two sets – and they came with the respective lathes – not for sale separately.
The pyramid shaped base of the lathe has the worst welds I have ever seen. They look like the ones I once made outside in the dark with defective glasses while it was raining. I couldn’t see a thing, and I still think I did a better job than this. A blacksmith’s newly started apprentice would be ashamed of himself to have done this! But if any should crack, they can be fixed – not crucial.
I look forward to using it after reassembly. I have loads of projects waiting for it.
I look forward to using it after reassembly. I have loads of projects waiting for it.
IN PROGRESS