Member postings for gerry madden

With impending retirement I plan to build a small extension onto my garage to become a dedicated workshop. The structure will be well insulated and should need only a low level of heat input to keep it warm. To provide this I plan to embed a low-power electric heating element into the floor.

The heating elements need to be embedded in 50mm of concrete screed which would sit on top of 100mm thick polystyrene blocks.

My question is this: Is 50mm of concrete sitting on top of a relatively soft base material going to be strong enough to support machines weighing up to a ton ? Any thoughts or experience anybody?

A crack in the concrete would be a bit of disaster for the heating elements as one might imagine

Gerry

For those of you who are interested in the insides of the J&S 540 wheel-head spindle, then here they are after a bit of a clean-up.

50 year old grease abounded, but I think at some point the two covers had been removed and some fresh had been stuffed in. Even that looked and felt like it was at least 20 years old though! All the bearing seatings were good with no sign of creep or fretting damage. I was surprised to find the original Ransome and Marles bearings still in it. I stripped these too and was even more surprised to find them in a corrosion-free condition, especially as this unit doesn't have seals, only labyrinths.

The pulley end bearing was in almost perfect condition with just a few random metal chip indents in the raceways. There was however just a trace of wear on the raceways of the wheel-end bearing from dust ingress. However both definitely good enough to go back in for further duty and I'm quite sure they'll see me out.

Only one mistake so far - I forgot to measure the wheel-end spindle runout before I commenced the dismantling so now I don't have a target to meet or even exceed on the rebuild. Might need a little trial-and-error with ring positioning but good fun for a wet Saturday afternoon.

Just a word of caution for anyone doing the same exercise. When you pull out the free-half of the spring box arrangement from the casting, put your hand over the housing and collect the 12 springs before you do anything else. I didn't and the inevitable happened. I found 10 quick quickly, but the other two had bounced some distance and landed in one of the wife flower pots where they blended in nicely with the soil.

Gerry

Dave found and removed that 5th nut today! ...Now I wonder how I could have missed it ! The valve cover is off along with bits of its gasket. That should be an easy one to make when the time comes.

Next job will be the spindle the after that the table. I was thinking I could lift the table using an engine crane attached to blocks in the 'T' slots. Might be a little tidier than stops. What to you think ? Anything I've missed ?

Gerry

Dave I would like to join the club. I have a history of blunders but most recently I cut a beautiful righthand thread instead of a left hand one on a large lump of brass. 'Okay' I thought to myself, its only a significant amount of time and money. On the second attempt, determined not to make the same mistake I reversed everything and followed the guidance, measure twice, cut once, only to discover I'd only gone and produced yet another immaculate right handed one. It seemed to be a case of two wrongs making a right. I took a day off before the third attempt.

G.

It does Dave, that's excellent. Thank you for your efforts. I had another 'feel' tonight but nothing was obvious in the dark so I just need to look harder now that I know its there somewhere.

G.

Chris, ....mmmm... you may be right. Perhaps it is just a couple of dowel pins on the bottom edge....They might just need a more direct pull to get the cover off them.

G

Hi Bo'sun, I know it 'looks' ugly but I don't think its that too unhealthy for the belt. Where the teeth cross they don't seem to interfere with each other. Where the belt reaches the pulley the only effect is that the teeth land on one end first. It all looks quite comfortable really. Sure there is a little bit more stress and flexing in the belt but I'm sure it can handle that.

I think I have seen flat belts crossed like that before and a toothed belt isn't too far from a flat belt,... and it probably runs with less tension too. Certainly no signs of distress on my the belt after cutting five or six 40mm dia threads.

I did find reverse gears on baye for about £300 so at that price its twisted belts every time for me now .

Gerry

I sent emails and messages on the website just before Xmas and have had no responses.

What I was enquiring about was reversing gears to enable me to cut left-hand threads on my trusty D3000. Knowing that such parts would likely be expensive and not wanting to wait, I had a go at twisting the toothed drive belt to the leadscrew instead. I was more than pleased when this worked perfectly, several times ! You can see it in the pic below.

Dave, thank you for the offer. No rush, at you convenience.

G.

Evening all,

The refurbishment makes steady and very satisfying progress but had a minor hitch last night. I'm trying to remove the valve block cover which is the part shown in the pic below.

I have removed the 2 nuts designated 'H' plus two smaller cap screws located at the bottom left and bottom right corners of the cover. I thought that would be it, but there seems to be something else holding it pretty tightly near the bottom edge. I think this because I can lever the upper edge of the cover against the valve block and it will deflect off its mounting face by a mm or so. If I release the force the joint closes tightly. If it was just a sticking gasket I think that this would have broken the joint so there must be something else. The underside of the cover looks like this....

I have run my fingers up behind the cover but can't feel any screws holding the cover on from the other side.... but it is a bit gruesome back there so its possible I have missed something.

Just wondering if any one on here has done this job before and knows the secret to removing this part ?

One bit of good news is the company I bought the machine from contacted me out of the blue and said they had found the original users manual and a copy of the sales brochure and would I like it ?! Its great now to have a manual that fits exactly with ones machine and a few puzzlements I was left with after reading the one available on the web are all sorted now.

Gerry

Its funny you should think that David because I was also expecting the index ring to have been adjustable. But there is no suggestion of any modifications subsequent to manufacture and no vacant hole for a locking screw, at least on my parts.

If one studies the parts list cross section, it might be that this version has 'adjustability' but since it doesn't show all the screws its difficult to be sure. But it shouldn't be all that to modify the parts to give you this facility if thats what you wanted to do.

One can of course lock the fine feed in at zero with any position of the index ring so perhaps this is what one is expected to do if wanting to cross feed by a fixed and easily traceable amount.

The 'washer' is made of steel, and is quite soft. I'd actually call it a spacer because that's all it does. But quite frankly I don't know why its there at all. If they had just left 3mm more material on the index ring front face the 'washer' wouldn't have been needed at all.

Gerry

David, as promised here's some pics of mine. The 4 key parts (terminology as per Spare Parts Cat.) here are:-

1) Handwheel rim

2) Index ring

3) Washer

4) Cross-feed handwheel

In mine the index ring screws to the back of the handwheel rim, with the washer between the two, using 3 x 6BA screws. This sub assembly fixes to the cross-feed handwheel using 3 short caphead screws.

My index ring therefore has a plain bore which only spigots onto the OD of the cross-feed handwheel. This is not the same as the cross-section shown in the spare parts catalogue. So I'm not sure which design you have but hope the pics below may help.

Let me know if there is anything else you need to know.

oooops.... I have just noticed I have drawn the 6BA tapped holes on the wrong side of the index ring. They should be on the front as opposed to the back as drawn, as is obvious from the photo below the sketch.

Gerry

David, as it happens, I have my 540 cross-feed assembly in a thousand pieces right now. I'll make some picks in a couple of hours and put them up here.

Gerry

I haven't checked my wheelhead excursion yet but will do that later this week end and let you know. But by the sound of it I should be ok.

In the meantime I'm about to paint the valve cover.

Does any one know what these 7 1/4" holes would have been for ? Some are tapped and the alignment isn't that good..

Clearly something has been fitted at some time but not sure its important to me and at the moment all they do is let the muck in so I plan to plug them.

Thanks Mark. I'm glad you have brought that one up ! Rust growing between my table top and the chuck had bowed my chuck upwards by 20 microns so it was on my mind to find a way to stop it from happening again. I did think of using one of these preservative wax-based compounds but a heavy grease would be easier to easier to wipe away when required after a long period.

Gerry

Dave, yes my table top looks just like yours. I'm fine on the traverse and cross feed distance too.

That's a really good point about the covers. I took them all off yesterday except one which was under the head ! I was tight and I couldn't raise the head because the elevation wheel assembly was in the house following repairs and painting. Perhaps I need to temporarily re-fit the elevation wheel, remove the last cover, lower the head again and see how I stand then. Thanks for that steer.

Gerry

Edited By gerry madden on 07/12/2021 18:45:47

Nigel, yes you are right. Most of the grease nipples on the 540 should be fed with oil. I would imagine that most machines have been abused in this respect at some time or other. I found after removing a nipple on my elevation wheel I couldn't blow air through the hole. I had to press the brass bush out to find out that grease in the passages was the cause of the "blockage". Still to get oil in a nipple one needs to use a gun, so I imagine pressure from that would displace the grease without too much difficulty, but at least now I know it was nothing more serious.

Chris, thanks for your guidance re the table removal. Mine actually moves nicely. I can even slide it by one hand without the pump running. I can also see all the ways are fully scraped suggesting no great wear. Regardless, the table will be coming off. I think I'm like you...I just have to take things apart and don't worry about not being able to rebuild. Where there's a will, theres a way.

One thing I do have is some patches of corrosion on the top of the table where the chuck sits. There is some on the base of the chuck too of course but I can turn that upside down to grind it. However the standard wheel will not reach the table. Its about an inch clear. What I thought I could do is fit an oversize wheel (after checking speed limits of course) then I will be able to grind the table flat and remove the pitting. Is there is another way ?? I cant think of one other than have it machined when the table is off the machine.....but this wont be anything like as accurate. Any thoughts ?

Dave S - great info.

Thanks chaps for your help. It turned out to be a roll pin like Chris's model. Eventually with some unkind drifting it began to move and reluctantly came out, dry as a bone and clogged with dust and corrosion. After that it was just a simple matter sliding the handle off its shaft.....one hour later that was done too.

It was an ugly sight under the valve cover but thankfully just cosmetic...... but its all going to come apart anyway

By the way, if anyone out there is interested in me giving a summary of my refurbishment on this 540 as it goes along just let me know and I'll try to do that.

Gerry

As I expected I'm being sucked into fast to doing a complete nut and bolt refurb of my 540. I don't mind as getting into the minutiae of machine workings in one of life's pleasure as far as I'm concerned. So last nights challenge was this control knob.....

Again a slight mangling from a previous owner has disguised the means by which the knob is fixed to the shaft. On one side it looks like a hex socket grub screw, only I can poke a 1mm pin all the way through the knob and till it pokes out the other side. If it is a grub screw (with a hole in it) I cant find a key that seems to fit. It might be a roll-pin but when tap it with a pin punch it doesn't show any willingness to budge.

I might need to get more brutal but before I do I thought I'd check with others on here that usually know from previous experiences. Any thoughts please ?

As Mark Bolan said 'all I want is easy action' and that's what I now have on my mag chuck. It was a bit of a struggle to get the beast apart. I had to clamp the base-plate to my bench and get a crow-bar on the top-plate to separate it, but once apart it was really just a clean-up operation. A wire brushing and a dunk or two on a bucket of white spirit was mainly all that was required.

There were a couple of points worth mentioning for anyone else attempting this often frowned-upon task. The first one is that I found the epoxy fillings between the poles were protruding quite significantly above the inside surface for the top plate. Suspecting that these could be part of the cause of the operational stiffness I cut them back with a blade until they were absolutely flush. The chuck couldn't have been made like this so my guess is that the epoxy has swelled a little over time from oil absorption. In the pic below the 'white bits' indicate where the epoxy was cut back. This pic by the way was taken in the almost-finished condition. There was much more protrusion beforehand.

The second point was that the aluminium frame came with only one oil lubrication hole in it. This didn't make any sense to me as its just as important to let the rubbish out as put new oil in. So I drilled and tapped 3 additional M10 grub-screw holes so that there were two on each side.. I can now add oil and drain simultaneously whilst operating the chuck.

I have to say that this was a job well worth doing and I'm astounded at the improvement its made. I can operate the on/off handle easily with one hand now where as previously I needed two arms and an extension tube. Of course some might say that this improvement is because I have lost all the magnetism. I suppose I might have lost some, I can't actually prove it either way, but I honestly can't tell that the chuck is any different to before. If I put a rough cast iron plate 3" x 5" on the chuck I simply cannot move it by hand and that's good enough for me.

Gerry

Edited By gerry madden on 21/11/2021 12:56:34