Ive stripped gears in the head of chester conquest, please advise!

[pmdevlin]

well apologies before I start! its another newbie who has ignored the warning signs from my machine

My conquest mini lathe (2nd hand, but not much use) has been talking to me over the past few weeks, making noises! but I kept thinking, just finish this project and inspect things later, it was getting a bit noisy, and I was suffering with an occasional juddering when turning, I put this down to poor cheap ally that I was practising on, and poor tools.

Tonight, for the first time I was using good quality brass bar, and a brand new indexing tool, set at the right height, but still suffered from a "jerkyness" that actually locked the machine up, I was turning very lightly, and slowly, anyway, a few clunks, and a half hour strip down and the stripped gears are visible. They are in the head, on low range, and need replacing, so the questions,

I cannot fathom out how to get them out of the head (stupidly!), and when rebuilding, what grease should I pack them with that wont just spin off when running? Seeing as I now have a strip down, what other lubrication should I do, incidentally, inside the head is a dollop of horrible red sticky mess, that has fallen off the gears, so they have been running dry. I think.... the high/low lever was not engaged correctly, the fork that moves the gears seems a bit sloppy, and it looks like the fork has jammed on the smaller gear, causing the seizure, and stripping of teeth.

I was tempted to rebuild just using the high range, but slapped myself for even thinking it. I cant find an online exploded view of the parts, so expect I will have to ring chester and try to explain what I want, the real idiot question is, (another apology in advance) how does the chuck come off? will removal mean the shaft will come out of the head?? really confused now as the gears are bigger than the shaft hole?

Sorry! help appreciated

Paul

 

[joegib]

The Chester Conquest here:

http://www.chesteruk.net/products/detail/2

— seems to be pretty much the same lathe as the Arc Euro Sieg C3 lathe here:

http://www.arceurotrade.co.uk/Catal...athes/Model-C3-Mini-Lathe/Model-C3-Mini-Lathe

So, disassembly of your lathe's headstock/spindle should be much the same as shown in the Arc Euro procedure in this PDF:

http://www.arceurotrade.co.uk/machineguides/C3%20Mini-Lathe%20Dismantling%20and%20Reassembly%20Guide.pdf

The photo guide on the headstock starts at Photo 31. There may be detail differences so I recommend you make notes/take photos of your own machine as disassembly proceeds.

Joe

 

[lensman57]

Hi,

The head stock spindle has to be removed first before the gears could be replaced. If you visit Arc Euro Trade site and find the article for changing the head stock bearings on their Sieg C3, same as the Conquest, you'd then know what to do. The reason for the juddering though is another matter all together and needs to be investigated. While you have the spindle out you have the opportunity to change the bearings to taper roller bearings but you'd need to have a second lathe and a couple of tools for pulling the bearings out and pressing the new one back in, it is all explanied in the article with photos and text. A worthwhile exercise if you are up to it.

Regards,

A.G

 

[pmdevlin]

thanks guys,

I will be speaking to chester today to order parts, they sent me an exploded diagrams so I could identify what I needed, looks like the gears are in pairs, not individual, so I need to change all 4 in the head, not really looking forward to this!

Unfortunately JG I have no way of pressing bearings out, will have to see how bad they are when the shaft comes out, hopefully in the next few daysI will have things sorted,

thanks

Paul

 

[techonehundred]

Unfortunately JG I have no way of pressing bearings out, will have to see how bad they are when the shaft comes out, hopefully in the next few daysI will have things sorted

Look at the instructions here http://www.littlemachineshop.com/instructions/2909MetalGearKit.pdf

A little judicious use of Pipes and an all thread should all this to be done without the availability of a press.

 

[lensman57]

Hi,

Hope you get sorted out. Let us know how you get along please.

Regards,

A.G

 

[Ken I]

Paul,
Looks just like mine and I've torn it down twice because of that selector.

Comments (may or may not be valid for your machine)

The selector fork is held on with a shoulder screw (phillips / screwdriver head - doesn't tighten well) to the selector lever - it comes loose and then fails to select properly. If you remove the lever from the selector shaft you can get it out without removing everything else by sort of rotating it away from the selector shaft and you can then get it out (you are going to be taking everthing out regardless).
The selector lever on mine was made from sintered iron and it also broke once so I made my own replacement out of steel.

To get the spindle out (you can't remove the "faceplate" end) remove the square locknut from the tail end and tap it out with a drift / copper hammer.
The locknut is left hand and is also of sintered iron - mine also broke when I hit on the nut with the copper hammer (rather than on the thread directly) - that's how I found out it was made of SI - bugger - had to make a new one of those as well.
Once the spindle is out (note gear and plastic (Arrgghhh) spacers just slide off in this process - then the bearings can be knocked out (first remove the plastic (Arrgghh) keeper plates.

The rest is much the same - I'm posting this in the hope that you won't go breaking the same things I did.

Locktite the selector fork shoulder screw as well as the selector arm to the shaft - mine was forever coming loose until I did that.

Regards,
Ken

 

[pmdevlin]

Hi Ken, thnaks for the step by step guide, I have now removed the selector fork, which I agree is a bit sloppy and naff, after playing with it whilst the gears were all exposed, the selection was a bit vague, chester themselves on their instructions recommend modifying the location positions of the h/l handle with a punch, I think after some wear, and my inevitable noobie tampering, my selection of h/l has not been engaged correctly, and the fork has caught a gear, causing the seizure (fuse didnt blow suprisingly), will have to revisit the juddering if it ever goes back together, there now seems to be a worrying amount of bits on the workbench!!!!!!

I have the h/l shaft out, but cant seem to see how the main shaft is removed without a press, (I didnt uinderstand what you meant by the plastic keeper plates) I resisted the hammer treatment as I am going to Chester tomorrow morning for the parts, so will take the head and see what they recommend, if its a press job, I am hoping they take pity on me and do it for me, that will be a test of the customer service!

 

[Ken I]

Paul,
That's the disk immediately behind the chuck - held in by three screws.

Haven't met a bearing yet that won't defer to a big hammer - however when reassembling use heating and cooling as required to have things go together easilly - where a hammer is needed take care not to apply the force via the bearing itself or you'll brinell the reaceway.

Here's another dumb mistake by your's truely - when reassembling make sure you get the gears the right way around - they are symetrical and it works fine the wrong way but now your "H" & "L" indicators are reversed. Mine's that way around at the moment but I'll be buggered if I'm going to tear it down to rectify that.

Regards,
Ken

 

[pmdevlin]

THanks Ken, that would have been a mistake that I would have made!

Anyway, went to Chester yesterday, luckily only 40 mins from home, cant tell you how helpful they were, I reckon they realised I was inexperienced, and yes they removed the main shaft, not with a press, just confident hammer blows!

so its off to garage/shed now to reassemble so I can continue with my project, I hope I dont have any bits left over when reassembly is finished!

 

[pmdevlin]

well I am please to say its all back together, and running, quieter than before

For any other novices reading, it was daunting thinking that I would have to strip down all the gears and the head, but once into the job it was fine. No special tools were required, although circlip pliers made that part of the job easier, I used white lithium grease as recommded by Chester to lubricate all the gears.

Mistakes, yes, should have taken more photos as I was going, it would have made some things easier. I didnt remove the auto feed threaded rod (bet it has a technical name!), just removed the left bearing mount,and pushed it out of the way to gain access to the head mounting bolts, this has now caused a problem as the apron kept catching on reassembly, it took ages to sort this, and completely lost the cable mounting points for the cable that runs from the board to the chuck safety guard,

It was however a great opportunity to learn what goes on with the gears, and everything now is nice and clean, and well lubricated. I wonder if that judder will have gone? Next job is the tailstock, Its not set up right and is not drilling centrally, thats another job!, great news is I only have 1 washer left over

 

[Tin Falcon]

good going you got it repaired.
Tin