Clarke CL430 Lathe

Hello Friends,

I have just bought a CL430 lathe on a vat free day from machine mart... I would like to know if there is anything I can do to improve anything on this machine, such as modifications and/or upgrades??? I remember reading somewhere once that lapping the slides is a start to a big improvement on the machine... I have a bit of experience in engineering / lathe work and I bought the machine as it is big enough to produce parts for my aircraft project... I greatly appreciate all your help and advice on this...

Kindest Regards

Mike

My suggestion is to use the lathe for a while, and see how it goes, there's no use fixing it if it's not broken. After you get to know the machine, then you can try and cure the problem.

Ian S C

I agree with Ian.

Quite a lot of the info on the web dates back to a time when Far Eastern kit was rather rougher than it seems to be these days, at least in the UK. My collection of Chinese tools all worked out of the box. They've all benefited from minor tweaks identified after using them for a while. I feel that web advice suggesting that kit needs to be completely stripped, cleaned, polished, lapped and re-aligned before it can be used is misleading to the point that some newcomers are being put off the hobby entirely. An expert might want to tune up a machine in that way but that doesn't mean a beginner has to.

After you've used the lathe for a bit it will be much easier to identify what's worth fettling on your particular machine. I've found this forum to be excellent at answering specific "what should I do?" questions, but it tends to give over-complicated answers to broad questions.

Enjoy,

Dave

Edit : typos...

Edited By SillyOldDuffer on 11/08/2016 13:10:25

Reading the Dials is good for beginners to learn whats going on, but it soon becomes a chore, i would opt for making some fittings for digital calipers, the cheaper ones, see how that is, i eventually went the whole hog and fitted glass scales and a DRO unit, thats alot more expensive though, but definitely worth it.

Another point of interest is the tailstock unit, whilst sturdy and adjustable, its length is a little short for regular work and you find yourself struggling to reach over the width of the cross slide. This means you're constantly winding back and forth to get up and down the table and reach the headstock, it's a chore without a rack and pinion feed. (I will touch on that in a minute)

So one way to get around it is to use a MT extension socket, it works fine, but can be a little wobbly when it's fully wound out of the unit, so i bought a 2" square piece of T6 aluminium, and extended the tailstock housing to support the socket. I did this because a casting was beyond me and a piece of steel would've been hard going to bore out a 6" long 38mm bore, so i opted for the tempered aluminium for ease of machining. 

Bear in mind, that i have had a bad run of "failed mods", ones that i did my best attempt at and could not find a way to make them work with the machine. This included a rack and pinion feed, whilst i managed to mount a rack, there is hardly any room for a half nut mechanism, this meant i had to opt for a design which "wound in" to the feed screw, it wasn't great and the engagement was sketchy.

The dovetailed table makes a free moving table an issue, the gibs are very sensitive for decent movement. If you look at any of the major industrial machines, none of them use a dovetailed bed anymore and opt for a polygon styled rails, that the saddle sits on, it's much better at holding it fast without any sloppy movement, the sloppy movement makes for a terrible finish and would recommend sticking with what it was intended for, a permanently fixed leadscrew nut. 

I've also tried a Ram style tail stock, it isn't a great idea either because of the same reasons, the ram isn't great for harder materials and without a feed screw makes for ropey movement. 

There is scope for new avenues to be explored yet; Improving the fit of the changewheels, the shafts they sit on are unsupported from one side, and under load they can slip off the circlip tether. 

50mm of movement is a little thin, so you could try making a new left hand M12 feed screw for the tail stock, and make it 75mm or 100mm. Stepper or DC motor feeds could also be tried. I can advise you on this if you need help. Go for 24v motors not 12v they aren't beefy enough, for a starters. 

So heres hoping i can make good of some of my mistakes and guide you. My machine isn't permanently damaged by them because i always follow the rule don't do what you can't undo. I'm glad i gave it a go, but ultimately i'm happy with the way it performs, it's paid for itself for sure and an old reliable friend indeed. 

Michael W 

Michael W

Edited By Michael Walters on 11/08/2016 13:44:17

Edited By Michael Walters on 11/08/2016 13:46:30

ok here goes.

1 check in which fitting position chuck runs truest and mark it and mounting. ( mine was long way out in one position ).

2 runs way to fast for screw cutting even at lowest speed.

3 don't use screwcutting chart in manual unless it's been altered is wrong.

use chart on inside of back door.

4 also setyting pulleys up in manual was wrong when io got mine look at back of pulley on motor and you will see small pulley that is one to use to get lower speeds.

5 make sure tailstock is level from top and side ( mine was well out when i got it )

am in process of making adaptors to use my southbend and myford stuff on my 430..

have done fair bit to mine but in pces at min as fityting variable speed motor to do screw cutting.

Just out of interest when did you buy yours? i bought mine around 2012 and my 3 jaw run out is 0.02-0.03mm, all day long, regardless of position, i don't know about you but it sounds pretty good to me. I've tried in the past to find out who made the chuck, but it's only marked with a "H" and nothing else, can't find it on the internet. 

I have a variable motor and i assure you it's much easier than set speeds with jog mode, keep the pulley arrangement because it's good for more torque. 

Michael W

Edited By Michael Walters on 11/08/2016 14:33:32

got mine in 2012 as well.

am keeping the pulley set up on it.

I had the duo CL500 some yrs ago but part from the mill top half I found it a decent starting machine, but this was before they fitted the NVR switch so in essence the lathe was an early version of the CL430. I found the lowest speed was far to fast for screw cutting so wouldn't attempt going down that road just yet.

I found the intermediate pulley was not fastened too securely, just a two step pulley that fastened to the back of the sheet metal guard via a large washer & nut on the bearing shaft, maybe that's changed, haven't seen the latest version, so maybe it is possible for the pulley to flex the guard out of alignment & allow the belt to ride off the pulley. I would look at providing a better system of securing it.

George.

Just had a look at the latest CL430 product manual; the intermediate/idler pulley now has a plate stiffener on the inside of the guard so... as for the stand; I had mine on a wooden joiners bench & it was solid as the proverbial rock, the stands tend to be of thin sheet metal & would give rise to annoying vibration marks on the material being machined so I would advise you to keep away from them, or reinforce it further if you intend to get one later. never the less enjoy.

George.

Ditto George,

Mine is also on a 3 metre wooden bench and definitely sturdy, it's such a hefty piece of iron and the wood takes up all the vibration.

I have noticed a small backing plate makes the width of the contact area a little bigger for the intermediate pulley, having said that it does annoy me that it's just a bolt holding it there :P also makes it really annoying to adjust with the belts in play too.

Michael W

I have the CL500M which is the same machine with but with the mill/drill head as an extra. The lathe is great I think you will be very hapy with it when you get used to what it can do and get a feel for it. Mine is very accurate, turn the dial and it will take off what you asked of it. Instead of using the three bolts to fix the chuck on fit three studs into the holes on the back of the chuck. The chuck then easily locates in position and it is much easier spinning the nuts on than fiddling with the bolts. Will really speed things up for you.

As already mentioned it is a good idea to mount the chuck then put something true in it like a end mill, use a indicator to check for run out and write the amount down. Then true the chuck so the holes line up with the next hole and tighten up and again with the end mill in place record the run out. Do this for the three possible positions and whichever one gave you the least runout is the way you want to mount it every time. So just put a mark on the backplate and the chuck so you can line it up correctly every time. I just used a punch to mark mine lighlty.

Another thing that will get you down is changing the belts for different speeds as it is fiddly and time consuming. There is a tensioner which requires you tighten and loosen a nut to get the desired tension, real pain in the ass. A good little project is to simply replace the threaded stud with a another rod. This rod you just copy the dimensions of the stud but drill a series of holes down its length as close together as possible. All you need to do then is put a drill bit or small rod through one of the holes to set the tension. When you want to change the belt setting simply pull out the drill bit/rod and the motor will pivot free allowing you an easy and quick change.

Ady.

Mike,

I have a CL500 which is the same lathe with a mill attached, the one thing I have done is fit longer Gib strip grub screws on all of the slideways so that I can use half nuts to lock with the original nuts as I found that over time the one nut loosened thus allowing more play.

Martin P

I bought my CL500M off ebay about 20 years ago. Initially I used the milling head, but have invested in a small vertical mill, so removed this and put a cover plate on the headstock.

I fitted a motor an control unit, pre-wired CL750 by Newton-Tesla in December 2012 to my Clark CL500M. It is much quieter than the original motor and I am delighted by the flexible speed range. The motor pulley fitted straight onto the shaft so all I had to make was a new motor mounting plate. Change belt ranges gives quite a choice of speeds. I generally run on the small motor pulley to the large spindle pulley which gives me 75 to 1000 rpm.

It was an expensive Christmas present to myself, but I have no regrets and it would be high on my list of things to do on a new lathe. I chose the Newton-Tesla because all the wiring work is done for you.

The improvements I made:

1. Lapped in cross-slide as the machine was 2nd hand
2. fitted DR scales to the lead-screw and tailstock.
3. made a QC toolpost which is a boon.
4. made a new collar for the cross-slide to reduce backlash and a new collar with needle thrust bearings for the leadscrew.
5. built a reversing gearbox for the lead screw so that I can power feed in and out of bores and cut LH threads if need be. It also engages at the same point every time for screw-cutting. This was based upon a design off the internet.
6. fittted a digital speed display, bought off ebay complete with magnetic sensor. It is 12v and easy to fit.

It has been a great little lathe and is very capable of accurate work.

Cedric.

If you want to screw-cut occasionally, why not make a mandrel handle?

I use mine in preference to cutting under power and its ample for threads as big as as 1 1/2" by 16 tpi.

Neil

So a used CL430 might net me £350, what someone was selling on here for recently, how is that going to get me a better machine? definitely not new? So we should learn that you were lucky enough to fool someone to part with a much better lathe for under that, doesn't sound like amazing advice to a current owner i have to say.

This one is certainly alot cheaper than the current market, a little rough around the edges and still nearly double the cost of a new CL430 http://www.ebay.co.uk/itm/HARRISON-M300-Lathe-with-DRO-1-500-00-VAT-/232086061231?hash=item36096840af:g:YAUAAOSwPCVX3Zch

Michael W

Edited By Michael Walters on 03/10/2016 06:56:33

That is some attitude you have on you there my friend. I was merely trying to show the other side of the coin.

I have never "fooled" someone into parting with something for less money than it was worth in my entire life. I totally resent the implication that I would do something so dishonest. If I sold my own old machine and used the money to help buy a new one, what of it? My financial situation and transactions are my own and absolutely nothing whatever to do with you.

I have to say that your tone is unfortunately only too typical of this site and many of those who frequent it.

Carl.

This lathe provided at competitive option to the Myfords and more expensive industrial lathes when they first came on the market. Most of the adaptations are done by owners to improve their lathe and apply equally to more expensive lathes.

The fist addition was a digital scale on the tail-stock, cost around £5 to £10. You can use an old 150mm digital calliper. It makes it easy to drill to depth as you can zero the scale when you start the hole.

The addition of a similar, but longer scale on the length of the bed cost around £60 and makes turning to depth a lot easier and accurate. I still set the dial on the hand-wheel to zero at depth, as this is easier to wind to on repetitive cuts.

The collars to reduce backlash are just more accurately turned pieces of steel bar to replace the existing. You will always have some backlash and this can be overcome by winding back 1/2 a turn and feeding in. Cost pence.

The reversing gearbox for the lead screw was based upon the article in Model Engineer Website
**LINK**
The cost was negligible using bits of steel plate and bar I had in stock. I made the gears using a home-made fly-cutter.

The motor unit was around £400 at the time. It gives infinitely variable speeds and saves belt changing. Having said that, there is nothing wrong with the original system which is just as good as any others out there that uses belts and gears to select a pre-determined speed. In industry there is always a need to save time, but the home model maker should not be bound by saving seconds in the same way.

This mod led to me buying a Digital Speed Display off ebay. Cost around £7. Again useful with a variable speed motor, but not essential. 4-Digital-Red-LED-Tachometer-RPM-Speed-Meter-with-Hall-Sensor

These enhancements in no way compare with the cost of an more industrial lathe which in the main have 3-phase motors, which can be adapted to work with domestic supplies, but at an extra cost. Yes they offer screw-cutting gearboxes, but in the main taps and dies are used, and you can achieve good screw-cutting results on the Clarke lathe using the change wheels.

Personally, my lathe which in total has cost me less than £1000 including the enhancements does a great job and fits in a hobby workshop. The motor is a nice to have, but not a game changer. If I had unlimited room in the workshop and my bank balance I would no doubt buy a nice expensive lathe, but the parts made on it would be no better and still depend on my skill in the use of the tools at my hands.

It is good to have different views on lathe solutions, but be it a Mini or a Rolls-Royce, it does the same job.

Cheers Cedric

Edited By Cedric Norman on 03/10/2016 08:24:03

Edited By Cedric Norman on 03/10/2016 08:27:30

I'm sorry; it was a bit unkind Carl, and the last thing i want is to turn people off or away, so to speak regardless of my opinion on the matter.

I just didn't want people think they're missing out on a great deal... which doesn't actually exist.

Michael W