Colchester Bantam Lathe

Lofty,

Found one at the bottom of a box of bits that I thought were scrap that came with the machine, the size threw me as it was a lot bigger than I expected, thanks for the offer.

The end stop I use all the time but not on power feed - perhaps it will trip as the later Colchesters do - but don't want to chance the stop slipping as it only has the single bolt. I use it to gauge lengths as the handwheel has no dial, set stop and use the cross-slide at 90°

Sandy, will look at mine tonight and post some sizes tomorrow.

As an aside, the Bantam is the best piece of kit I have ever bought, £450 off ebay, single phase motor and soft starter already fitted. Had to travel to Frazerburgh to collect though - 1000miles and £300 in diesel but was worth every penny. Shame my brand new Clarke mill/drill is such a nail in comparison.

Trevor

Sandy, if and when you get fixed up with a bed-stop and if you want to adjust the clutch to trip reliably I may be able to help with the relevant info.

I'm using a home made stop and yes it needs to be tight if the bedways are lubricated. I'd be keen to see dimensions of the Colchester stop.

Trevor, I have to agree on the Bantam. Probably the ideal smaller, rock-solid lathe for the home workshop.

John

This is the carriage stop that came with my Bantam. No idea of the parentage but it likes to be nipped up tight. I fitted the keyway and replaced the bottom piece so that it sat better on the ways. It's loose here, so not sitting square but you can see the idea. I've never found the micrometer dial worth bothering with. Instead I usually finesse the position using the top slide.

As ever, the picture is sideways as a testament to Windows 8 which knows better than me which way to orientate the photo.

And here's my cross slide stop. It is pretty basic and only works for feed direction away from you due to impatience when I made it but it can be pretty handy when facing with power feed. There are 3 tapped holes which allow it to be fitted in 2 positions, giving me all the adjustment required in combination with the threaded stop bar. The transverse and longitudinal power feeds will trip out in both directions against any firm stop.

Murray

Edited By Muzzer on 30/05/2014 04:47:01

Sandy,

some images of my stop which I believe is original are posted in my albums under Bantam carriage stop. What looks quite simple on the outside is a lot more complicated when you get to look inside....

If you still want dimensions then I will post some Monday - the drawing package on my pc is rubbish so will need to use Solidworks on works pc.

Trevor

PS tried to load images on this page but the text and photos kept getting mixed up.

Colchester users may find this useful,some years ago I bought an all metric Student lathe,one feature which i had never seen before was a dial fitted on the saddle handwheel ,one rotation of the dial was exactly 25mm and it was accurate and useful. It was also fitted with variable speed and was short bed,it was a pain to use so I then bought a master 2500, which was imperial with dual dials,out of curiosity I checked the saddle travel against one turn of the saddle wheel, it moved 25mm so I came to the conclusion that they must be fitted with metric module racks so I took the dial off the student and it fitted my master, so I now had an imperial lathe with metric reading dial for saddle travel.I then sold the student minus dial, Most of the time I work imperial on the cross and topslide and metric on the saddle and it is so useful despite the imp/ metric mix. I then looked at my all metric triumph 2000 the rack was module so I went along to G & m tools and found a suitable metric dial which could be converted to fit the triumph hand wheel. I have Colchester bed stops but they are not reliable as they do slip and never use them now that I have saddle dials. One thing on my ex naval triumph is a 2ft long engraved sign stating "this machine is fitted with a metric threaded leadscrew" I have often wondered if someone made an expensive cock up confusing 0.2inch imperial with 5 mm metric pitch leadscrew. Going back to the student ,the mechanical vari speed and the phase converter was a useless combination ,I asked a machine tool dealer if he had experience with variable speeds ,his comment avoid if possible any variable speed powered by 3 phase conveters.

My Bantam has metric threads and dials on the cross and top slides and the tailstock but is otherwise an imperial machine ie has imperial leadscrew and gearbox. It seems this was quite common and is most likely something to do with the number of machines that were supplied to schools and colleges. I'm ashamed to say I've owned this machine for nearly 20 years now and it was only recently that somebody pointed this out to me....

BTW, there are various Bantam / Colchester owners active on the homeworkshop.org.uk forum. It's good to check in there from time to time.

Murray

Mr Trevor Wright,

Did you post dimensions for the carriage stop? if so whereabouts.

As these things are about as rare as hens teeth I am making one. Currently producing drawings.

Some dimensions would be helpful, Overall length, diameter, and the bolt size. I am planning on making the thing metric although it would appear that the bed on my metric machine is imperial. By my reckoning the V should be 3/4" having filed out a template.

If I have got it right the picture should be my initial design done with CREO

Marcel,

Started to dimension the stop but the angles were too difficult to measure accurately, was waiting for someone to ask.....looks like I will have to now lol.

Give me a couple of days to dismantle and measure.

Trevor

Trevor,

I have made a template of the lathe bed and taken dimensions from that. The measurements were taken in mm as being a metric machine I assumed that the bed dimensions would be metric. Not apparently so as my conversions bring it out at 3/4" on the slope. I am afraid that my drawing did not go to a jpg very well, the angles appear to be 90 deg and 135 deg. which would make sense from a manufacturers point of view along with 3/4". These are the key dimensions for the stop.

The main problem areas for me are hoe wide the is the brass clamping piece, as I guess this to be critical, too narrow and it is likely to slip, and the diameter of the bolt. I was working on 5mm but the one in your photo appears to be about 5/16" (8mm) and quite coarse (Whitworth?)

Try as I might I cant get a decent copy of my drawing to upload. Any suggestions?

Marcel,

Have added dimensions to photos of the Stop-block, the perspective of the pictures is confusing but the faces the dimensions are attached to are true.

Edited By Trevor Wright on 19/10/2014 16:04:43

There are more images on my album, no doubt there are dimensions missing and someone will inform me, but post and I will supply the missing information.

Have added this as I cannot add text below a picture.

Trevor

> Have added this as I cannot add text below a picture.

Click on picture and hit right arrow, should work.

Neil

Thanks Neil.....too late to edit now though.

trevor

Thank you Trevor.

I guessed the diameter to be about 2" I will now do some working drawings and make one from that. If all goes OK I can post the drawings. Unless there is a way to allow for others to download files.

Marcel

Hi everyone,

I'm probably posting this in the wrong place, but go easy as I am a newbie!

I have a Colchester Bantam, and I what to do some general machining and would like to use the auto-feed for a traverse cut.

But the layshaft is going to fast, which is fine for thread cutting.

The gear train I have is as follows: 120B 127B 35B 30B .

What gear combo would I need to slow the layshaft down to a sensible speed.

Sorry but I am just learning all about machine turning hence the ignorance!

Thanks

Dave

On my imperial machine it's 21/120, 100/60 which I think gives 0.001" per revolution.

On yours changing the 30 to 60 (assuming this is gear Y) should reduce the feed 50%

I think most of the std feeds assume 35t on the top (spindle) position and 30t on the bottom (gearbox) position. The intermediate gear (120t) is just an idler and doesn't affect the overall ratio. I leave those in position but at one time I changed the 30t to a 60t to half the feed rates.

If you select range A and gear 6 on the gearbox, you end up with something like 1"' per rev, which is pretty much what you need? Mine has an imperial leadscrew.

Do you have the plate showing the feeds, ranges and gears - it's riveted to the front of the machine.

Murray