Colchester Student Mk1 Won’t Start

[Mat StoeckleParticipant @matstoeckle91130]

Nice work Richard .. must be good to get your hands on the ol lathe .. I know I miss mine after a day of work away from the shop

I'm pretty sure I'm squeezing down on the rubber but I did order the 1mm (1/16 inch) stuff .. I believe you have 2mm (1/8?) stuff going right? I'll see how tight it gets without anything in there and maybe that was my problem .. the paper gasket would've been even thinner .. maybe I'll double up on the 1mm stuff ..

Back to my burning question on preload however .. there is the one locking collar right behind the main spindle bearing (front bearing) that's inside the gearbox .. how tight? and how do you even measure that?

then there's the locking collar at the tail end of the spindle .. you mentioned "get it really tight" .. but how tight is that? and how do you gauge it or what do you gauge it by? I'm really unfamiliar with preload and don't know what to wiggle to check for play or how much and where and such .. so, any info would be great to get it right-ish ..

thanks!

[Herman van der MerweParticipant @hermanvandermerwe76509]

Mat, the tension should be the same as per this message.

https://colchesterlathe.groups.io/g/main/message/3292?p=,,,20,0,0,0::relevance,,spindle+tension,20,2,0,59019379

and

https://colchesterlathe.groups.io/g/main/topic/59016048#1793

and

https://colchesterlathe.groups.io/g/main/topic/59013653#852

 

Let us know which one is correct!

Edited By Herman van der Merwe on 23/12/2020 05:52:17

[Richard Kirkman 1Participant @richardkirkman1]

Yeah Mat, it's really satisfying to come home to a working machine after 3 and a bit months at uni with no practical work!

I think mine was 1.5mm or something. I can't imagine the difference in thickness is making that much of a difference.

As for preload, I haven't done anything specific. I left the bearing closest to the chuck alone. I just tightened the other one enough. Not too sure really. I do know preload needs to be set so the machine functions. Phil's lathe turns much more freely than mine, so It may be worth setting my preload correctly one day. Perhaps when I do a full repaint.

Hermans links will tell you more than I know. Thanks Herman

Anyway, I got the light mount mounted today, so the lathe is almost in one piece!

It seems to be in just the right position for me, so I'm very happy. I need to find some more turning to do now…

[Howard LewisParticipant @howardlewis46836]

Maybe we should all collaborate and produce a book on "The Joy of Turning"

Having once experienced the use of a lathe at a moments notice, if, for any reason, it is out of commission, you feel absolutely vulnerable.

With it functioning, you feel confident to attempt almost any task.

You have all done a splendid job.

Good on yer, boys!

Howard

[Richard Kirkman 1Participant @richardkirkman1]

Thanks Howard, It really is a weird feeling just having access to such an amazing machine.

Speaking of which, I did a bit more turning today, just a little aluminium for a project I'm working on (some incense burners made from wood, but need metal inserts to hold the incense)

Anyway, when I was turning I did a finishing cut with my cutter and it produced a lovely surface finish, as do most cuts on aluminium. However, I saw imperfections in the surface finish. Having studied metallic structures at university I really should know what this is. However the steel samples I've looked at only showed their structure under microscope after being polished and etched.

So, just out of interest my question is, are these lighter and darker spots in the aluminium impurities, spots of different hardness, or grain boundaries?

Also, I took off the side cover after the lathe had been running for some time. I had noticed that the oil level had gone down a little so I thought I'd check to see if I could see the leak location. Pretty hard to miss, It was significantly dripping, even for an English machine, it's excessive. I think It needs sorting asap! Time to take it to pieces again!!!!!

Back to University on Thursday, with assignments due and exams looming, I suspect a full lathe teardown will have to wait. But I should still be able to tighten the bolts to see if that stops it. Otherwise, it'll be the oil seals again! In which case I will have to order leather ones instead of the double lip rubber ones I used.

[Herman van der MerweParticipant @hermanvandermerwe76509]

Me thinks those are oxidized aluminium. Was the raw stock stored in a sealed container of sorts?

[Richard Kirkman 1Participant @richardkirkman1]

Posted by Herman van der Merwe on 29/12/2020 05:38:09:

Me thinks those are oxidized aluminium. Was the raw stock stored in a sealed container of sorts?

It was just some 20mm diameter. I didn't think oxidization would have penetrated that deep? That was immediately after a cut of around 1mm from the diameter. The raw stock is just kept on a shelf in the garage. I've not seen it on the other aluminium I've been turning. But I don't know what type this aluminium is, I was given it when I went to Scarborough.

[Howard LewisParticipant @howardlewis46836]

Not a metallurgist, but crystalline boundaries produced during the extrusion process?

Localised heating produced by the carbide tool?

I e Does the same happen with shallower cuts, or with HSS?

Someone on here MUST know

Howard

[john fletcher 1Participant @johnfletcher1]

Hello Richard, I see more progress with the lathe. All the other bits and pieces have almost gone from Howard workshop clearance. Lathe went to a club member and mill to a club members son, all local. What a job Brian and I had, there was quite a lot of metal as well to be moved, and access wasn't good. either so all had to man handled. Happy new you to all and I'll be looking out for Part 3 when its published.. John

[Phil WhitleyParticipant @philwhitley94135]

George Lodge at 80 English st in Hull have a good stock of NOS leather seals Richard, and they are real helpfull. Sorted me one out for my old Ben patents 22cu/ft/min compressor!

Phil

Edited By Phil Whitley on 29/12/2020 18:58:31

Edited By Phil Whitley on 29/12/2020 18:59:04

[Richard Kirkman 1Participant @richardkirkman1]

Howard, I'm not sure was much heat in the cut, it wasn't a massive cut. I didn't get time to try shallow cuts or any turning today, the car was in the garage.

Hi John, I'm glad to hear the toolings all gone to new homes, I'm definitely still using mine as much as I can! Happy new year to you too!

Thanks Phil, I'll look into them if I need to. I hope you've had a nice Christmas, especially considering how much you love it! Bah Humbug

As for today's progress, I've attempted to tame the leak.

This was the leak when I got home

And this was the leak today. Much more oil

I suspect the bolts and things have shrunk slightly due to the colder temperature in the garage. Alongside using the lathe heating up the oil will increase its viscosity so it'll leak faster.

Luckily I have been doing some wood turning, so it was very easy to mop up the oil. I haven't used this method before, I was surprised how well it worked with nice dry shavings. Very minimal mess!

All clean once again. Much easier to see future leaks!

So once it was all cleaned I went to where I suspected the leak was coming from

The bolts holding these gaskets tight were not fully tightened as snugly as they should be. So I have just tightened them up a little more. Still not overly tight, but I think they're good now

I checked to see if the oil seal in there had leaked as well, but it seemed dry when I stuck my finger in the slot. Very surprising. It looks like I've made it work.

Anyway I'll turn some more tomorrow. Last day at home so I need to make the most of it. I'll do a little turning playing with the surface finish on that bar, I'll go deeper too and see if its still there. And hopefully warming the lathe up will tell me if it leaks or not! If not, new gaskets need to be made

Happy New Year to all!

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Richard Kirkman 1 on 29/12/2020 11:56:48:

Posted by Herman van der Merwe on 29/12/2020 05:38:09:

Me thinks those are oxidized aluminium. Was the raw stock stored in a sealed container of sorts?

It was just some 20mm diameter. I didn't think oxidization would have penetrated that deep? That was immediately after a cut of around 1mm from the diameter. The raw stock is just kept on a shelf in the garage. I've not seen it on the other aluminium I've been turning. But I don't know what type this aluminium is, I was given it when I went to Scarborough.

At what depth do these disappear? It can oxidize quite quickly especially in the absence of oxygen.

[roy entwistleParticipant @royentwistle24699]

It can oxidize quite quickly especially in the absence of oxygen. ?

Roy

[Oven ManParticipant @ovenman]

Posted by roy entwistle on 30/12/2020 09:57:37:

It can oxidize quite quickly especially in the absence of oxygen. ?

Roy

It's the same principle as Richards oil viscosity increasing when it gets hot. But we all know exactly what he means.

Peter

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by roy entwistle on 30/12/2020 09:57:37:

It can oxidize quite quickly especially in the absence of oxygen. ?

Roy

Sorry, the correct word would be "corrode" in the absence of oxygen. Oxygen is the only thing protecting alu. Take it away and you have many problems. Richard, if I remember lives next to the coast so he most probably is seeing inter-granular corrosion.

[Herman van der MerweParticipant @hermanvandermerwe76509]

@Richard you have lost some images on page 1 …

[Richard Kirkman 1Participant @richardkirkman1]

Posted by Herman van der Merwe on 13/01/2021 09:14:31:

@Richard you have lost some images on page 1 …

Thanks Herman

They're on a post by SillyOldDuffer so it's not too do with my album. I presume something may have happened on their end. Deleted the album perhaps?

All my pictures are still there

[Richard Kirkman 1Participant @richardkirkman1]

I hope everyone is well.

I seem to have acquired a few new toys. I saw these pop up in Grimsby and the seller offered to deliver them to Hull for a very reasonable price. Not extremely cheap, but I'm very happy.

Now I won't have to cut up my 4-way tool post in order to attach a QCTP. Hopefully, there will be a fun build making the T bar to go in the slot and making the mounting post(depending on if the QCTP comes with one) I'm considering this one. Alongside this being a nice upgrade for the lathe, my topslide is quite worn and is easy to turn at one end, and very difficult to turn at the other, so this should be an all-around improvement. I'll take the best parts from each and put them together.

Arc QCTP

I didn't really need the 8 Inch 4 jaw, but it's not often I see them come up, and for the price, it was worth it. The faceplate may come in handy at some point as well. Plus it'll be fun to clean and paint them both.

I did pop home for easter as I was allowed, however, the lathe did not get touched as I was busy making wooden things! I suspect it is still leaking so this will be addressed at some point in the summer.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Richard Kirkman 1 on 13/01/2021 10:21:21:

Posted by Herman van der Merwe on 13/01/2021 09:14:31:

@Richard you have lost some images on page 1 …

Thanks Herman

They're on a post by SillyOldDuffer so it's not too do with my album. I presume something may have happened on their end. Deleted the album perhaps?

All my pictures are still there

Just checked. The images in my post were linked to Richards google album at https://photos.app.goo.gl/eWFpzzp7p7Wasart9, which is now a dead link. Richard started by hosting images on Google and later moved to to hosting them directly on the forum, in his album. This is where they probably are now, but the move broke the links in my post. 'Gone away, not known at this address!'

Out today, not sure if it can be fixed, I'll have a look this evening.

Dave

[Richard Kirkman 1Participant @richardkirkman1]

Posted by SillyOldDuffer on 01/05/2021 09:16:57:

Just checked. The images in my post were linked to Richards google album at https://photos.app.goo.gl/eWFpzzp7p7Wasart9, which is now a dead link. Richard started by hosting images on Google and later moved to to hosting them directly on the forum, in his album. This is where they probably are now, but the move broke the links in my post. 'Gone away, not known at this address!'

Out today, not sure if it can be fixed, I'll have a look this evening.

Dave

Thanks Dave

I suspect I have probably had a tidy out on my google photos at some point

I'm not sure how important the images are at this point, but if you can fix it, it would be appreciated

Thanks

[Richard Kirkman 1Participant @richardkirkman1]

Quick update

I no longer have access to a milling machine at home, so I enlisted the help of Phil to machine me a 304 stainless steel t-nut for the top slide so I can mount the new tool post.

I did initially go to the university engineering workshop to ask for their help but they were not interested as it was hard steel and they wouldn't let me in to do it either.

So, Phil helped me out greatly. Big thanks to Phil for all of his help

304 is a pretty tough steel, especially for an unexperienced person like me, but we made the best of it. We started using a face mill to make the block square, then we took it to size.

Cleaning it up gave quite a nice finish. Although I did get some chatter later on.

The end dimension had 10mm to come off, so it was much quicker to cut it off with Phils very nice mechanical hacksaw.

Some faces had 1mm or two to come off, so It took me quite a while when taking 0.2mm cuts. The steel got some very nasty burrs too, if that's the right word when they're so large! I presume that'd due to the steel being hard and due to my milling direction.

Then I cautiously moved onto using a hss endmill to cut in the slots. After 30 passes of 0.2mm cuts we has a 6mm recess for one side, then the other side was done.

The hss worked surprisingly well. I had bought a carbide endmill to use, but it wouldn't fit in any of Phils chucks.

Now to size, it was time to deburr and drill the hole

The drill size was stepped up very gradually as the metal is tough and we didn't want to work harden it at all.

Then we got the 5/8ths sae tap to go in the hole and lead it in using the drill press to ensure it was square

The tapping was slow but worked well with lots of lubrication. But it all went smoothly from that point. A very nice fit for a novice like me! Room for improvement in the future, but I'm happy.

Tool post fitted. I can't decide if I'll turn down the extra thread on the end. It doesn't add any value, but who knows if I'll need it in the future.

Next step is to get back home from university and disassembly everything to clean and get parts from both top slides to pick the best of each. Then onto some turning!

Thanks again to Phil for his time and help, if you want to see more there will be some footage of the milling on his Youtube channel.

[Phil WhitleyParticipant @philwhitley94135]

It was a pleasure mate, really enjoyed the day, anytime you need to borrow a mill! Richard is being modest about the drilling, it was tough going!! this morning a penny dropped when I remembered that I had not stiffened up the Y axis with the table lock, hence the chatter! My bad!!

Phil

Edited By Phil Whitley on 05/06/2021 16:36:58

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