Colchester Student Mk1 Won’t Start

[Herman van der MerweParticipant @hermanvandermerwe76509]

Drum brakes all work the same. You need a drum brake spring plier to remove the bottom spring first. Then the two shoes will open up and you can undo the top spring.

Your shoes needs to be replaced. Not expensive as you take it to any brake service place and they glue new shoes on. Ask them to skim the drum as well and then sand the new shoes to match the drum.

Installation is the reverse of disassembling.

I have seen a guide somewhere. Will try and find it for you.

[Phil WhitleyParticipant @philwhitley94135]

Nice work on the speed change shaft and gear Herman!

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Phil Whitley on 16/05/2020 19:22:16:

Richard, you cant do with oil leaking into the brake drum like that, there is a seal in the flanged bearing (which is actually a bush), take of the brake shoes, and remove the allen screw or screws, depending on which it is, seems like on the early, there is one, but three on the later, and the flange should come off. there appears to be a cork gasket behind it. the circlip only hold the pivoting cam for the brake into the backplate. Have a look on the parts diagrams on the manuals, that makes it easier to see.

Phil

Edited By Phil Whitley on 16/05/2020 19:22:55

Edited By Phil Whitley on 16/05/2020 19:24:09

It is an oil seal part # 99.

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Phil Whitley on 16/05/2020 19:25:53:

Nice work on the speed change shaft and gear Herman!

Thanks Phil!

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Richard Kirkman 1 on 16/05/2020 17:03:01:

You have a bigger problem now…. your one V-belt is wet with oil. Oil and rubber in a belt do not go together as it will ruin the belt. More so when you have a matched set (which I trust you have). If one belt stretches more than the other due to the oil, or slips, your tighter belt will try to play catchup and hunt causing a vibration in your drive. For this reason I only use Nu-T belts.

Try and soak the wet belt in some acetone for a short while and rub it with a dry cloth to get the oil out. Repeat until no more oil is on the cloth.

Also clean the grooves in the pulley and if they are glossy sand the grooves with 600 grit wet sandpaper.

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Herman van der Merwe on 16/05/2020 19:22:58:

Your shoes needs to be replaced.

Sorry, I meant the shoe lining of each shoe needs to be replaced.

[Richard Kirkman 1Participant @richardkirkman1]

Posted by Herman van der Merwe on 16/05/2020 19:49:14:

Posted by Herman van der Merwe on 16/05/2020 19:22:58:

Your shoes needs to be replaced.

Sorry, I meant the shoe lining of each shoe needs to be replaced.

Shame, I was going to treat myself to a nice pair of stilettos

Last time I cleaned in there when there was only a bit of oil, they worked really well, so I don't think they need replacing.

Speed change shaft is looking very nice Herman. I'm glad I didn't have that much trouble with mine!

I had a nap to think on it then headed back out to try again. I managed to get it off, I pried it off at the bottom then undid the screw, while putting a block of wood on to keep it from snapping closed again, so it'll go back on more easily.

I'll see if I can get the spare brake shoes from Tracy. It's about time I messaged her again, it's been a month, but I was waiting on the bulb to arrive first so I could finish that chapter.

As for the flange/bearing thing, It doesn't seem to want to budge. So I put some penetrating oil on it and I've left it. The 3 screws that came out smelt quite funny, not like a normal grease but sort of sweet maybe? I don't know but it didn't smell normal.

I don't particularly want to order a new seal from the spares place as they'll probably charge a small fortune for something that I could possibly make myself? Or perhaps source from elsewhere cheaper?

All university work is done now, so I'm free to play for the next 19 weeks

[Richard Kirkman 1Participant @richardkirkman1]

A few more pictures to Illustrate.

There seems to be some red stuff which I presume is the gasket material. I think the bolts had some red on them too

Red stuff doesn't scratch away easily. Someone could have added glue to stop it leaking at some point?

[Herman van der MerweParticipant @hermanvandermerwe76509]

My lathe has the cap screws located in the smaller diameter collar that stands out from the larger flange.

This is how mine came out.

[Herman van der MerweParticipant @hermanvandermerwe76509]

The red stuff is gasket maker. You need to heat it up with a hot air gun and then stick two putty knives in there to wedge it apart while the gasket stuff is hot and soft. Only way to get the red gasket stuff off is to wire brush it with a brass wire cup.

You can also make three hard wood wedges and drive these in between the flange you want to remove and the headstock body.

Edited By Herman van der Merwe on 16/05/2020 21:01:55

Edited By Herman van der Merwe on 16/05/2020 21:02:54

[Phil WhitleyParticipant @philwhitley94135]

Red hermatite gasket cement, thats why it wont come off, it sets, not mega hard like Osotite, but hard enough to need wedges or an extractor to give it a straight pull. Hermatite is non standard on Colchesters, so I think we can guess it has been off before! Can you use a longer bolt in the threaded hole to push against the headstock and gently break the seal?

Phil

Edited By Phil Whitley on 16/05/2020 21:03:27

[Herman van der MerweParticipant @hermanvandermerwe76509]

Notice the wood bits left over on my last photo. I used three hard wood wedges. Came of easily. In your case, you need heat and patience.

[Richard Kirkman 1Participant @richardkirkman1]

We have success!

Heated with a heat gun till it was almost too hot to comfortably hold, then just gave it a little pull and it went pop! Very easy. Unfortunately, as I pulled a little further, the inevitable happened, oil gushed out of the hole. So I quickly plugged it back in and drained the headstock. Not something I wanted to do for this, but necessary.

The smell is back, so that must be the smell of the gasket cement. Definitely recognizable for the future.

I even found the original gasket in there too. It was stuck on very well so I had to use a box cutter blade to slowly get it off, but now I have a template for the next one.

So, onto the main problem. The leaking seal. It has a set of numbers on it, but I can't seem to get it out easily.

The seal looks pretty shot. Looks like a leather one like the other one I replaced, but thicker.

I'll get the numbers from the seal

[Richard Kirkman 1Participant @richardkirkman1]

Will a replacement be something like this

LINK

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Richard Kirkman 1 on 17/05/2020 13:55:10:

Will a replacement be something like this

LINK

Nothing like a bit of heat to make a plan work! Well done

I would recommend you go that route. Take the ID of the hole it fits into (in other words the OD of the seal) then the OD of the shaft it fits over and then the depth of the recess it fits in (in other words the thickness of the seal) then use the Timken oil seal selector to find what you need.

You might have to look at the various types of seals listed as the D-d difference is quite a small value.

Edited By Herman van der Merwe on 17/05/2020 14:29:45

[Herman van der MerweParticipant @hermanvandermerwe76509]

For reference and possible assistance here are two photos of the seal in my lathe. It has the number 1621 stamped on it.

[Richard Kirkman 1Participant @richardkirkman1]

Thanks Herman, very useful, I'll go for a seal like that.

I got the numbers from the old seal, 16210037. I'll just find a new one with the measurements I took

Anyway. I started by trying to use a socket to push it out from the inside. This didn't work well as it just pushed out the leather and messed it up. Not a good start.

Immediately that stumped me as I couldn't get any grip on it any way or tap it out from the inside as it wasnt working. Too tight in there. So I resorted to using my rotary tool to cut away one section of the seal to release the pressure and allow it to come out

This worked quite well but I went a little too deep and took a lttle out of the bore, but that shouldn't make a difference really.

Then I measured

So we have

OD=1625 1 5/8ths

ID=1000 1 inch

T=a bit more than 350, probably 3/8ths

So, I'll find a standard size closest to that 1 5/8×1 5/8×3/8

Like This

Question is, do I want double lip or single lip? And whats the difference

[Richard Kirkman 1Participant @richardkirkman1]

That seal I linked to has almost exactly the same number as the old seal, just one more zero. Maybe I misread it.

I've remade the gasket and it fits perfectly. Undersized holes in the gasket to make it stick to the bolts and be easier to install

Then I was playing in the headstock just moving the gear selector back and forth. I noticed it wouldn't move all the way. Turns out one of the bolts had come very loose! Very bad news. I must have not done them up tight enough when I put them back in. I've tightened them all very tight now, but its worried me quite a bit.

My dad and I bought an old non working ransomes mower(Ransomes 24" Mk8A) to restore together, £60 and local so it was a steal. It's from the 1930s but I don't know anything really about lawnmowers. My Dad wants to get it working, but I'd like to completely dissect it and make sure it's working perfectly so I can learn too. I might have to start a new thread for that.

Also, the paint on the traveling steady was just not going hard at all, even after putting it in the oven a little overnight with the heat leftover from cooking, It could still be taken off with a fingernail. So I've stripped it and reprimed it. This time I put a very very thin coat on, and it seems to have dried. It needs another coat of primer as i sanded it back, but then it will be ready to paint. I found a cheap paint sprayer, so I'm going to try to use that to paint the steady as a test and then hopefully the lawnmower too. I'm also going to get dove grey paint to match the lathe as I've changed my mind about painting it all red.

 

Edited By Richard Kirkman 1 on 17/05/2020 18:25:57

[Herman van der MerweParticipant @hermanvandermerwe76509]

You will have to get some RTV silicone gasket maker and fill the new cut and then hammer the seal in while the silicon is still wet. Next time use a oil seal removing tool or an old tack nail remover.

Go for the double lip seal. One lip keeps the oil in and the other keeps the external grime out and away from the internal seal.

When you install the seal do not smear the silicone around the circumference of the seal. Get some glycerine and smear the oil seal and then use a socket that just fits into the "hole" where the seal must go. You want to hit the seal on the lip that forms the OD of the seal. Anything less in diameter and you are going to bent the flat surface of the seal, destroying it. If you do not have such a socket, you will need to take a wood dowel and carefully punch around and around and around the circumference of the seal until it is seated. Seated is when it is about a hair's breath lower than the housing's flat external face surface. In addition oil the shaft very well before sliding the seal on. Otherwise the edge of the oil lip will bent over and will not seal.

[Richard Kirkman 1Participant @richardkirkman1]

I've ordered the Double lip

I'll put a bit of epoxy in the cut, but I really don't think it'll make a difference. The cut isn't bad at all, so I think it'll be fine. I'll make sure to use a socket to seat it

The seal should be here soon enough, probably before the lightbulb!

Herman, sorry to hear about your drill bit shear pin. Not a great thing to find.

Edited By Richard Kirkman 1 on 17/05/2020 22:51:57

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Richard Kirkman 1 on 17/05/2020 22:40:45:

I'll put a bit of epoxy in the cut, but I really don't think it'll make a difference. The cut isn't bad at all, so I think it'll be fine. I'll make sure to use a socket to seat it

You will be surprised what a bit of temp rise can do to air pressure inside the headstock. It will push out oil anywhere.

I would not go the epoxy route as this means you need to let it dry and shape it before inserting the seal. If you insert the seal while the epoxy is wet, it will spread anywhere unseen and could change the stiffness of the lips ensuring a bad seal. I have used RTV silicon on many such damaged seats and it really works well.

Yeah, shear pin should be aluminium on these lathes AFAIK.

[Herman van der MerweParticipant @hermanvandermerwe76509]

Posted by Richard Kirkman 1 on 17/05/2020 18:21:18:

Turns out one of the bolts had come very loose! Very bad news. I must have not done them up tight enough when I put them back in. I've tightened them all very tight now, but its worried me quite a bit.

I would recommend you undo these again and use Locktite on the threads. Just get the correct number Locktite that can work in oil submerged conditions. Torque it to wet conditons specifications for mild steel bolts of the cap screw diameter. Your weakest material here is the gear with material strength which should be in the range of mild steel. You are doing engineering studies so you should know about material strengths by now!

Tip, after you have opened the Locktite bottle, stick a metal head sewing pin in the hole before you screw the cap shut. It seals the opening and your expensive Locktite stays good for a long time!

Edited By Herman van der Merwe on 18/05/2020 08:55:46

[Herman van der MerweParticipant @hermanvandermerwe76509]

Sorry @Richard but I aneed to hijack your thread a tiny bit!

@Phil can you please tell me what paint you used to paint your lathe green? I was referred to this paint, but that is not available in South Africa, so I have asked my paint specialist to find something similar. He asked if it is possible to give me the paint code? If you do not have the code readily available can you install an app on your smart phone and just scan the colour and post the colour code?

Secondly @Phil, please let me know what the colours are for the indented numbers on the index dials on the carriage? Some are red and some are black I know, but I have no record as to what each should look like. I hope you did restore this as well!

Thanks @Richard, I think you will also need this info in the future.

[Richard Kirkman 1Participant @richardkirkman1]

Hijack away, All the info you need is helpful and interesting to me too!

Although I've encountered more problems

I'm planning to leave my index dials just as they are, no colour, as I can read them just fine.

I'm not a fan of the Colchester green, So I'll be painting mine Colchester dove grey, but not from the paragon paints, that stuffs expensive. I found a code for dove grey BS381 694 which looks right but obviously it doesn't say Colchester. I'll probably use tractol stuff or tekaloid, I still need to decide, but I don't know the pros or cons of each. So we'll see. Need to find out soon as I need to paint my traveling steady and inevitably a lawn mower

Phil, how many liters of paint did you use for your full lathe?

The second lightbulb arrived today, first one is definitely never showing up. So I went out and plugged it in and tried it. Nothing happened, no light, no flicker. How can I start to troubleshoot it? Wiring all seems right, but i'm getting nothing. It's a very cool little bulb with lots of LEDS

Still waiting on the oil seal, and I've ordered some loctite for the gear.

Also, I bought some steel from my local place yesterday. I'm looking forward to turning some bigger chunks. I found that only turning 1 inch or less steel, I didn't really have high enough speeds to get the correct sfpm for a great surface finish. Anyway, I made sure to get 10x50x300mm flat bar so I can make myself a ring spanner for the tailstock as I'm sick of having to keep putting a spanner on it. The lathe should have had a spanner to begin with, but mine didn't arrive with one.

[Richard Kirkman 1Participant @richardkirkman1]

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