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Member postings for Jon Cameron

Here is a list of all the postings Jon Cameron has made in our forums. Click on a thread name to jump to the thread.

Thread: questions about setting up my Myford ML4
24/06/2020 10:07:50

Hi,

For drilling the hole in the ML7 gears, the easiest, though possibly not the best if you intend to use the gear a lot. Is to line up another gear on a piece of steel turned to the bore dia. (5/8" from memory). Since you have the 50T gear with a broken tooth, it makes sense to use this one as the pin will no longer be easily retained without making a plug to fill the drilled hole.

Line the 50T up on the shaft, along with the new gear you want to drill the pin hole in. Hold together vertically in a vise with the hole for the pin in the old gear facing you. So that they cannot move while drilling. (packing pieces may be a good idea, Brass or aluminium strips). Then Drill right through the hole in the 50T (with the broken tooth) to the new gears that you have bought. You don't need to drill completely through only about half way through. check the pin will go in the hole then seperate and do the other one.

With regards to fine feed, As above go for the smaller to larger gears towards the leadscrew. In your case, and for the best fine feed with what you have available. 20T on the tumbler, 1st stud, 50T:20T, 2nd Stud 60T:25T Leadscrew 70T. If you wanted to change for a faster feed all yould do is change the tumbler gear to a 30T or 40T and you will increase the speed of feed. With the 20T on the spindle it will be a slow feed.

Regards

Jon

Edited By Jon Cameron on 24/06/2020 10:09:35

23/06/2020 09:02:57

Hi Andrew,

Nice work on the little handle, you have no idea how handy, and how many times that will come in useful.

With regards to the lawnmower and bearings, that stuff is terrible to cut, and i did have a chuckle to myself about the silly string comment. Very true. Its great been able to make a part that the dealer tells you doesn't exist anymore.

Now moving onto your feed, it looks as though you haven't got them set up for compound gear train, possibly as they don't fit as they are. The banjo bolt closest to the lead screw gear, is driving onto its inside gear, from the next banjo which in turn is striaght from the reverser. Your only gear reduction is the gear on the reverser, and the gear on the leadscrew, the rest are idler gears and are not effecting the gear reduction as they are not driving onto another gear as a coupled set.

What gears do you have? The lower banjo stud, next to the leadscrew. Try putting a smaller gear to the inside, and a larger gear to the outside, to enable the small gear to mesh with that on the leadscrew, and the larger gear to mesh with the smaller outward facing gear on the stud above. If this still doesnt work, possibly change from top to bottom the two gear pairs, as i think you have the larger gear to the top which isnt helping to bridge the gap further down. Ideally, 60T in mesh with the tumbler gear, 20T joined to it by a 3/32" pin, The 20T in Mesh with a 65T on the next stud down, connected to a 30T again by 3/32" pin, The 30T in mesh with the gear on the leadscrew (smaller if possible).

Hope this is of help. Knowing what gears you have a fine feed can be made easily, but in short your changegears in effect are idle and doing nothing to change the gear ratio.

Jon

Thread: Injector testing
19/06/2020 09:17:17
Posted by Paul Lousick on 19/06/2020 02:40:29:

Attention The ME Administrators.

The injector test rig comes from an article by Bill Carter in ME Volume 141 would be of interest to a lot of readers who have an interest in model steam engines but the ME archives do not go back that far.

Is it possible to re publish this article.

Paul.

+1 to that.

It looks a relatively good test rig, and i assume you can also vary the boiler pressure to see if it will pick up and deliver water at varying test pressures, so as little as 20-80psi to instance. Knowing that the injector will reliably pick up at varying pressures is certainly reasuring especially on the move.

Jon

Thread: Jacobs morse taper chuck.
19/06/2020 08:47:31

Hello,

Thank you for all your responses, I have a Bearing pulley exactly like the one shown, i will give it a try first. failing that ill go down the drill and knock out route.

The reason that i wanted to get the taper out is i believe the taper is bent and it doesnt run true when holding drill bits. I'll be mounting it onto a new arbour. If that doesnt work then i'll go down the route of buying a new one.

Jon

18/06/2020 12:53:19

Is there a correct and easy method of removing a jacobs chuck from an arbour? Or once its pressed on is that it fixed.

If so can anyone enlighten me please.

Jon

Thread: Machining cylinder from solid
13/06/2020 02:50:54
Posted by old mart on 12/06/2020 16:52:05:

I have just bought a Sandvik boring bar, it is 25mm diameter, but the cutting height is more like 12mm. I would guess that the minimum size of hole for it is about 40mm. It will have to have a custom mount made, and I will have to mill 2.5mm flats on three sides of the shank. Even this large size bar has a recommended max depth of only 100mm, 4X the diameter.

I'm curious as to your reply, why would I need a 25mm boring bar and why is it a such a problem to bore the hole? What is this custom mount that you speak of, as I was under the impression that between centres boring bar needed nothing more than a straight piece of steel with a HSS bit poking out. Between two dead centres and a dog to drive it. Please elaborate as for the woes.

Neil I'll buy a mask!!!

12/06/2020 16:26:22
Posted by JasonB on 12/06/2020 16:14:52:

Don't forget CI bar has rounded corners but with the excess in the 180mm direction that should not be a problem

That is something i hadn't thought about. I was just finding the next available size up from finished dimensions. Doesnt help matters having to convert to metric sizes when trying to figure out what would be the best stock to use. But hopefully i've got there.

Jon

12/06/2020 15:48:04

Hi Phil,

I only have access at home to an ML4 lathe, and it has on its tail of the bed an Alomco milling attachment.

I should have enough reach if a flycutter is used though havent figured out how id mount it yet for squaring up i only have a small myford vice so will have to make a slide vice for the cross slide as i think the most the myford vice will accept is 3" (havent checked that yet)

Jon

12/06/2020 15:40:20
Posted by Fowlers Fury on 12/06/2020 15:21:44:

I would have thought that purchasing a CI cylinder casting from one of the ME suppliers was the preferred start but respect your decision to machine from a chunk of CI. Your "raw block" seems to have plenty of machining excess which sadly, many commercial castings do not.
Suggest that first priority is to generate a flat datum surface (one that will be in contact with a frame side?) and do your marking out from that. Many critical dimensions and need for parallel surfaces so maybe generate next surface at a true 90 degrees to your datum.
Next I would then FIX the block exactly on the cross slide with that "90 deg" surface truly parallel to the face plate and bore out the main cylinders.
Almost certainly others will advise on a completely different sequence !

Have you looked at Minx postings here?: **LINK**

If you're going to c/s the tapped holes, do it before you tap them, not after.

Unfortunately you wont find the Minx castings for sale as Julian replied on a thread on the forum youve linked to they haven't been available for some time. After some searching i found which suppliers and castings would be suitable, then looked at the price. Whiich would be a none starter for me, hence my decision to machine from solid. AJ Reeves currently list the MOK cylinder casting set at £249.60, reduced from the listing price of £300. My lump of cast iron costs less than £45 + Postage, or i can pick it up for free. Yes the set contains other castings than just the main block. but you hopefully see my point. The lump sawn off can be used for some of these parts that would be otherwise included in the casting set.

12/06/2020 14:22:23

Hi,

I have for a long time looked at LBSC's Minx as a loco to build. I am looking at the cylinder block then wheels as a starting point, if these two components are right then i have a good basis to progress with the rest. There also the biggest single cost next to the boiler. The cylinder for those that don't know is a twin cylinder inside frame jobbie.

So Cylinder first, am i correct in saying if its been cut from solid cast iron block that first it needs to be taken to overall dimension and squared up in the mill on all six sides before proceeding to look at marking out for cylinder bores, and milling the port openings.

The raw block will start at 180x90x75mm, and finished size needs to be 4.1/8" x 3.1/4" x 2.1/2" (roughly 105 x 82.55 x63.5mm) I intend on sawing off 60mm from one end for use another time or elsewhere. This is the closest size i can find to what i need available in barstock material.

Essentially what i'm asking is machining sequence. What order to do everything. Square up, mark out, line bore, then mill cylinder valve openings and drill for valve block mating surface, also do these holes need to be lightly countersunk to get a true flat surface after they have been tapped. I've read that tapping the holes will raise the surface slightly around the hole.

I already have a boring bar made, but need to make a fly cutter with a 3/8" shank to fit a collet on my mills spindle to square any work up.

Jon

Thread: Myford ML4 leadscrew dials
12/06/2020 08:49:09
Posted by geoff walker 1 on 12/06/2020 08:38:40:

Hi Jon

With reference to your original post, if you fit a leadscrew dial do make it adjustable so it can be zeroed before use.

I put a fixed dial my M many years ago and whilst it has been very useful it is sometimes a pain marking pencil lines on the dial and doing mini calculations to make adjustments.

Geoff

Very good point. Having them fixed as you say can sometimes be tricky, While been able to reset the dial on the fly is certainly handy. The ones id seen where only fixed, marked off on the hand wheel boss itself.

I've been enjoying reading the posts put forward with regards to the cross slide and compound leadscrews. I didnt think that my comment would have the reaction it has. I did think it was common knowledge but having thought about it i couldn't tell you what the thread was in another other lathe.

Jon

11/06/2020 08:48:53
Posted by Hopper on 11/06/2020 00:04:41:

I dont see the ML4 cross slide screw error as a big deal. Close enough for roughing cuts and on a 2 thou finishing cut the error is only .08 of a thou. Thats .00008" so not enough to worry about on a lathe where normal tolerance is .001" at best.

Indeed, For my use i cant measure more than 0.0005" anyhow so the error is unnoticed unless it becomes accumilated by traversing the cross slide or top slide.

I'm glad that this query sparked off some useful discussion, though my point wasn't intended to do so. Just relaid what id read, and as i said for some reason they had built an error into the lathe.

Thanks for confirming my thoughts regarding the lead screw, at least i know in that direction i only have backlash of the half nuts to worry about, oh and disengaging the banjo from the spindle so i don't break the sheer pin (again), and watching that line so that i don't over cut on the first pass, oh and............. lol

Regards

Jon

Thread: Which one to build
10/06/2020 13:43:18
Posted by Brian H on 10/06/2020 11:49:31:

Hello John, have you thought about a steam lorry such as the Clayton? They are not usually as heavy as a traction engine.

Brian

John, another vote for Clayton as it breaks down into two parts. The articles are posted on this forum in PDF format and a quick search you'll find them.

With the smaller traction engines have you considered a 2" Ruston, or even a 3" Simplicity, Large enough to be comfortable, but also small enough to lift due to the small prototype size they scale down as quite small models (for their scale).

If you went with a larger one, perhaps the purchase of a bike lift would negate the worry of having to lift, the engine could be rolled up onto the bike lift for work, this would mean anything upto 3" scale is possible. It does rather depend on access for such a thing though. Even a 3" scale Clayton could pull you around quite easily in your garden, with the addition of a bike lift would make servicing easier on the scaled up wagon.

What ever you decide there certainly plenty of available options to think about.

Jon

Thread: Myford ML4 leadscrew dials
10/06/2020 12:25:51
Posted by Nick Clarke 3 on 10/06/2020 11:42:46:

I knew that Myfords took over manufacturing the Drummond 'M' type at the start of WW2 because, to quote lathes.co.uk "their contemporary models, the ML1, 2, 3 and 4, were completely unsuitable for professional work"

Could this be because of the inaccuracies in the slide leadscrews?

You might well have a point there Nick. I've never explored why they were unsuitable. Just accepted the powers that be didnt want to use myfords for whatever reason. Perhaps Tony has an answer on this if anyone is just that bit more curious than I.

Jon

10/06/2020 10:31:46
Posted by Hopper on 10/06/2020 10:16:39:

Yeah that might be the smart way to do it.

12tpi thats a bizarre one. Even my 1930s M type has 10.

I can only assume that it was designed so a new one could easily be made with a standard set of change gears if the need arose. Not sure if the standard set of change gears would allow a 10TPI thread? Brian would be better qualified on that one. As ive already said to him elsewhere i'm rubbish at maths hence the original question, i struggle working out gears and ratios. Took me a very long time for the penny to drop with dividing, but that's digressing!

Jon

10/06/2020 10:06:37

Hi Hopper,

Yes i had considered that however given the time it would take and that a leadscrew handwheel with 125 graduations is available for £25 i am inclinded to take that route so was just checking. All i would need to do is make an adaptor to get to the 7/16" size as i believe though i need to check that the end of the leadscrew on mine has 1/4" BSF thread.

With regards to the leadscrews Myford used 12TPI leadscrews in the earlier lathes, for the cross slide and compound which creates a small error not a lot but still there.

Jon

10/06/2020 08:34:43

Hello,

As i hopefully near the end of the lathe refurb, i am wanting to add graduated dials for the leadscrew. I will be using the lathe for milling with an alomco milling attachment, (the base has an adaptor plate to fit the bed). With the half nuts engaged this should hopefully help to have small increments of movement using the leadscrew handle, instead of larger sometimes jerky movements when using the handwheel on the apron, which is direct drive onto the rack.

Would i be right in saying with an 8TPI leadscrew i will need 125 divisions on the dial, so something like the ML10 dial would possibly be best. I have already become accustomed to using the dials as an approximation to finished size as i know there is the slightest of errors that Myford built into the leadscrews on the carriage and compound.

Thanks in advance

Jon

Thread: Beginner's engine build. Simplex 5"g.
09/06/2020 08:28:28
Posted by David Wasson on 08/06/2020 17:04:10:

The eccentric is mounted on the front axle. There is plenty of room for the eccentric strap.

My appolagies, must have been having a bad day yesterday. Don't know how i missed that??

Thread: Hello I am from Aylesbury
09/06/2020 08:20:17

Hi and welcome to the forum, as Lee says above there is a good facebook group for drummond lathe users if you wish to join it and have facebook.

When the term levelling the lathe is used it doesn't mean that the lathe has to be perfectly level to the surface of the earth to work. What it means is it must be level to itself, so there is no twist in the bed which would cause you to cut a taper. Although you wouldn't want to a lathe could be mounted and levelled on a vertical surface, they were also used on ships in the navy, which should hopefully give you some idea that the lathe doesn't have to align itself with terafermer. So long as it is aligned with itself and doesn't cut a taper, although it may be difficult to do much with a round bed in the way of levelling, (others have posted their way of levelling a drummond round bed). What id suggest is to look up rollies dads method of lathe alignment, and have a read of a PDF that you'll find through google. This explains the principle very well and should explain why you do a test cut to make sure that the lathe isn't cutting a taper and how to go about it, and adjust it out if needed.

Regards

Jon

Thread: Material for engine block.
08/06/2020 16:53:19

I would use 2014 Ali, as Jason suggests, parrafin for lubricant could be used, but i've always found WD40 works really well for Ali, and so long as the cuts aren't too aggressive. The tool can be kept lubricated with a squirt every so often. It also seems to help with keeping the Aluminium from cold welding to the tip of HSS as youve found happens. Not sure how well it works with the likes of insert tooling but seems to work very well for me on my old ML4 with HSS tooling. It can also be bought by the 5ltr bottle with a convenient spray bottle which is easy to fill up with a funnel, from various sellers on e-bay.

Regards

Jon

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