cl 300 lathe problems

[Ernie Smith 1Participant @erniesmith1]

Hi, I usually subscribe to the RCM&E model aeroplane forum, but have a wee problem that you guys might help me solve

I'm setting up a clarke CL300 lathe, and have a problem with the apron. The manual saddle feed gears are not a close fit to the teeth under the bed, so there is a lot of slop. I guess the gears could be raised by quite a few mm, and I can't see any way of adjusting this.

Now, it's very possible that I'm missing something obvious because I'm something of a turning neophite

thanks ernie

[Ernie Smith 1Participant @erniesmith1]

[HopperParticipant @hopper]

I'm not familiar with that exact lathe but in general, there is sometimes a shim between the apron and saddle that can be reduced to raise the saddle traverse gear up to mesh with the rack. Problem is it also raises the half-nuts which then may not engage correctly with the leadscrew, unless leadscrew or halfnuts are adjustable for this?

Is it possible to go the other way and loosen off the rack retaining screws and bring the rack down lower to meet the apron gear?

[Bob StevensonParticipant @bobstevenson13909]

The cl 300 is a bog standard 'Chinese mini-lathe'…in American parlance a "7x Asian mini-lathe". Fortunately the web is well loaded with mini-lathe sites and info. These lathes (I had a similar one for several years) are excellent for what they are but take some 'inside knowledge' to get the best out of them. Fortunately they are a very simple lathe type and teh learning curve is fairly shallow and quick, so take heart!

Steve Jordan's youtube channel has some good advice …….https://www.youtube.com/channel/UCEpeQtxhVUTtMZzBpdegp-w/videos

Gadgetbuilder is another good one; http://www.gadgetbuilder.com/

And Frank Hoose's site is one of the original /best source of info; http://www.mini-lathe.com/Mini_lathe/Start/start.htm

[Ernie Smith 1Participant @erniesmith1]

Thanks guys, The rack is separate from the bed, There are three allen head fixing screws, I'll try taking it off tomorrow (after hogmanay) and see what transpires.

Also, i'll have a good look at these websites

ernie

[Michael HornerParticipant @michaelhorner54327]

Hi Ernie

This the Gadget Builder link for removing excess play in the hand wheel **LINK**.

Apron Handwheel Backlash

Not done the mod myself yet, only had the lathe 15 years! Do make sure the screw in the handle is tight. I have had that come loose and you get lots of free play!

Enjoy

Cheers Michael.

[Danny M2ZParticipant @dannym2z]

G'day Ernie. While you have the apron off, this is a very worthwhile simple mod to make. It keeps swarf and crap from getting into the gearbox. I made the acrylic version (just because I had a few sheets of acrylic lying around).

**LINK**

* Danny M *

[Brian Sweeting 2Participant @briansweeting2]

Adjust the leadscrew bracket at the right hand end to realign the thread and gearwheel.

[Ernie Smith 1Participant @erniesmith1]

This is all fascinating stuff….All I want is a wee bit for my Fokker….I'm starting to get a wee urge to look more closely at all this…But first I'll look at all the bits you've unearthed, and get everything working as it should

ernie

[Neil WyattModerator @neilwyatt]

I have one of the early Cl300's

The truth is the rack is fitted a bit too high and it would 'feel' better if it meshed better, but it makes no practical difference once you take up the backlash.

More recent machines I have looked at have a better mesh

Cure is new tapped mounting holes for the rack, move it along by about 7 or 8mm (so the new holes don't overlap) and down by whatever is needed. The rack is longer than needed so the sideways movement doesn't lose you any motion.

You could mill a slice off the top of the apron, but at the risk of spoiling the halfnut's mesh with the leadscrew.

Neil

[Ketan SwaliParticipant @ketanswali79440]

Posted by Ernie Smith 1 on 31/12/2017 12:25:26:

Hi, I usually subscribe to the RCM&E model aeroplane forum, but have a wee problem that you guys might help me solve

I'm setting up a clarke CL300 lathe, and have a problem with the apron. The manual saddle feed gears are not a close fit to the teeth under the bed, so there is a lot of slop. I guess the gears could be raised by quite a few mm, and I can't see any way of adjusting this.

Now, it's very possible that I'm missing something obvious because I'm something of a turning neophite

thanks ernie

Hi Ernie,

A Clarke CL300 is a 'C2 SIEG mini-lathe'

The issue you are referring to is probably relating to 'the fit' or alignment of the rack under the bed, and/or the longitudinal leadscrew. Have a look at this dismantling guide for the C3 lathe (not SC3). A Clarke CL300/C2 is broadly speaking a shorter bed version of the old C3 lathe.

I would suggest you first read through this picture guide.

In particular, for the rack, pay attention to points 84 to 88. when you remove the rack, look out for swarf/cast iron dust resulting from original drilling/tapping of holes during assembly, which could have distorted the alignment of the rack.

For the saddle assembly, leadscrew and related brackets, pay particular attention to points 100 through to 120.

Ketan at ARC.

Edited By Ketan Swali on 03/01/2018 15:51:10

[norman royds 2Participant @normanroyds2]

I would elongate the hole in rack or even make the slot bigger where the cap head washers goes so it well take bigger washers and will give more support and will make easier to adjust also I would not break out when you elongate the hole as would make the rack to weak and defeat the purpose of the alteration norm

[Ernie Smith 1Participant @erniesmith1]

Thanks to all of you, your enthusiasm reminds me of the RCM&E site. I need to spend a few hours fettling things, but firsr I'll check out all the links, so I'm sure about what I'm trying to do. That metal stuff is very different to balsa.

I'll get back and let you know how I get on

ernie

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