Author Topic: Bumble Fingers courts disaster! (Read 9510 times)

John Hill · « **on:** August 16, 2009, 03:05:16 AM »

Bumble Fingers noticed that coolant was flowing around the compound and running over a little plate covering the cross slide screw so I thought I would just take the plate off and see where the coolant might be leaking to. Quick as a flash the little screw which held the plate on made a dash and fell into the carriage gearbox!

No more power feeding or thread turning untill I find and remove that little blighter!

Hmmmm, there must be a clever solution that does not require dismantling the carriage?

bogstandard · « **Reply #1 on:** August 16, 2009, 04:53:35 AM »

John,

You can almost guarantee the little blighter has found it's way to the bottom of the box. But just in case it hasn't, put the shaft into neutral (bottom RH round knob), and turn the drive shaft by hand, with one of the feeds on the apron selected. By turning it backwards and forwards, you should be able to tell if it is jamming anywhere, or even dislodge it until it finally gets to the bottom of the box.

Get your best washing up bowl, and drain out the oil. Lift up the lathe on end and shake to see if the screw will fall out of the drain hole, if that doesn't work, then using a wiggly stick with a small bend on the end (piece of wire), try to hook the screw out thru the same said drain hole, or a tiny magnet well fixed to a thin metal stick. Don't try the magnet trick from the top entry point unless you can guarantee the magnet is stuck on the stick forever, as it will try to stick to everything on it's way down, and you don't want another gear cruncher stuck down there.

If you have used a clean washing up bowl, you should be able to reuse the oil. Don't forget to wash out the bowl before using it to clean the pots in.

John

John Hill · « **Reply #2 on:** August 16, 2009, 03:33:02 PM »

Lift up the lathe and shake it? Now why didnt I think of that?

I will be calling in to the local car accessories place today looking for a magnet retrieval thing.

Maybe after draining the oil dumping in a quantity of thinner liquid that might get it out, what do you think about kerosene as a flush liquid?

Wish me luck!

(I didnt actually see it drop in to the gearbox so you can imagine I will be sorely tested if it is really hiding in among the swarf!

)

CrewCab · « **Reply #3 on:** August 16, 2009, 04:01:03 PM »

No real bright idea's JH, a bendy magnet jobbie inserted in the drain hole sounds like the best bet

Just thought I'd pop in and wish you good luck though

CC

sbwhart · « **Reply #4 on:** August 16, 2009, 05:21:56 PM »

Quote from: John Hill on August 16, 2009, 03:33:02 PM

Maybe after draining the oil dumping in a quantity of thinner liquid that might get it out, what do you think about kerosene as a flush liquid?

Great minds John I've been pondering your ? and was going to suggest that, fill it up and pull the plug to see if it flushes it out you could repeat it two or three times .

For bendy magnets you could try those magnetic notice board things, or fridge magnets.

Good luck

Stew

John Hill · « **Reply #5 on:** August 16, 2009, 05:28:48 PM »

Stew, good one on the fridge magnets!

John Hill · « **Reply #6 on:** August 17, 2009, 03:34:12 AM »

I suppose it is an ill wind etc etc.... when I got to actually looking into this issue I find the apron gear box has more cooling fluid than oil and a layer of 'mud' under that!

Still no sign of this errant screw, which really, really must be found or I need to clean and examine inside the gear box to establish it is not there.

So now I am looking at how to take the apron off, might be easy, might be hard but if I can do it I can clean that mud out and settle the screw issue.

bogstandard · « **Reply #7 on:** August 17, 2009, 04:06:35 AM »

John,

Did you get a decent manual with your lathe, or did you download one from Grizzly as I suggested. There should be a blow up in the parts schedule to give you some idea of how it comes apart.

Maybe you should also look at sealing the access plate with some silicone gunge or thin silicone gasket material, just to keep the coolant out of there, a couple of extra screws might help as well. But make sure you count them all in and out, you don't want a repeat of what is happening now.

Your problem has never occurred on my machine, as I don't use the flood coolant, and will never consider it in the future. Up until now, a WD40 spray or a bit of coolant squirted out of a washing up liquid bottle has done me, and in the near future, when time allows, I will be setting up a spraymist system. That coolant tank is locked in that back cupboard until the time comes for the lathe to be moved. Hopefully, not in my lifetime.

John

John Hill · « **Reply #8 on:** August 17, 2009, 04:29:22 AM »

John, I received the toilet paper parts manual which shows all the parts clear enough but no mention as to the sequence for taking any parts off! I asked the same question over on Gareth's site at least his people should know what sequence is required to get the box off the front but I do not know how often he looks at that site.

It might be easier to lift the saddle off which would be an alternative I suppose.

I have the Grizzly manual too but it does not show anything about disassembly.

The design is extremely poorly protected against coolant entry, the little metal plate has no sealing surfaces and had no sealant of any kind and any coolant that gets on the top of the cross slide can run off the end and on to that plate though I suppose it is a risk that depends on mode of operation. i.e. position of the cross slide. However it will be easy to seal down when I put it all back together again.

There is no sign of coolant having got into where the threaded part of the cross slide screw is but that area is wide open to the gear box too!

Of course I am kicking myself for having got into this pickle but in the last few minutes I have found another disaster waiting to happen in that the grub screw that locks the cross slide pinion was loose, so that was waiting to drop into the gearbox too!

bogstandard · « **Reply #9 on:** August 17, 2009, 04:39:02 AM »

Maybe this was a fortunate thing to happen at this time.

Just take your time, make lots of sketches, and don't force anything apart. Keep everything in a box, and make sure you have nothing left over when it is finished. If some little Chinese chappie with no skills can put it together, I am sure a man of your calibre can get it apart.

Just remember, in your distant past, you most probably came from a race of world beating Victorian engineers, lets see if any of those genes are still in there.

John

John Hill · « **Reply #10 on:** August 17, 2009, 05:15:53 AM »

Probably fortunate in a couple of aspects. I will be more careful now about where that coolant goes and I am really relieved I found the grub screw on the pinion as that would have surely caused a cardiac event being likely to drop out while it was running! Shudder.

I have had a few complex pieces of machinery apart in my time and managed to get them all back together again, at one time I was the local 'guru' for fixing sewing machines (tropical island 4000 population) and of course I have almost lost count of the number of car and motor bike engines I have spread across the garage floor but this is slightly different being both heavy and delicate as I am sure there are lots of "slidey" surfaces I must not ding!

There is nothing that I am not confident about but it would be nice to know how those half nuts come away, obviously they must totally disengage the lead screw or be left behind when the apron comes off. They seem to be mounted in a dovetail and I presume they are designed to be removable without too much trouble. Lets hope Gareth is going to tell me to just remove the gib to release them from the gearbox. Otherwise the design appears to be quite straight-forward and one could almost say posessed of a certain functional elegance!

I dont recall hearing about any engineers in the family tree they were more the agrarian types but of necessity they were known to DIY fix anything from a wire fence to a combine harvester!

P.S. I am sure glad I got the little engine finished before this happened!

bogstandard · « **Reply #11 on:** August 17, 2009, 09:30:28 AM »

John,

There is no need to take the half nuts off. There is a block at the extreme RHS that three shafts are supported by. Take that block off and the leadscrew and power shaft should just slide thru the apron if the apron is taken along to the end. Or take the block off, and disconnect the two shafts at the break points near the lathe head. That should allow you to lift the apron away from the machine, with both shafts still thru the apron.

Normally, once you remove the bolts that hold the apron from the top, it will just come away from the main saddle casting.

John

John Hill · « **Reply #12 on:** August 17, 2009, 02:27:46 PM »

Thanks John.

Gareth's man Arthur called me (I had only been asleep for an hour) which I thought was rather beyond the call of duty as they knew it was not supplied by them. His advise was to take out the pins at the head end of the shafts and to remove the right hand block then everything would come away once the four cap screws are removed. It should be an fairly easy task. He did mention that some lathes have a break away clutch on the feed rod drive and of course I do not have to take the switch rod off if I remove the switch lever bracket.

Off to the office now where things could be interesting, after weeks of trying to look busy we have received enquiries from Baghdad and Prague (both repeat business) and Sri Lanka.

bogstandard · « **Reply #13 on:** August 17, 2009, 02:53:20 PM »

Fine John,

Basically the same as I said, in the second stage.

Mine does have the break away clutch rather than taper pins, but I didn't know if yours has.

I told you Chester UK has a very good support team, that is why I always go back to them. Nothing is too much trouble for them, as they have shown in your case. I think any other company would have told you to go away, or in other words, the second utterance would have been 'off'.

John

CrewCab · « **Reply #14 on:** August 17, 2009, 04:45:22 PM »

I hadn't realised it was Chester UK's Gareth that was providing support here to John H ............ that is impressive Bogs

Nice one Chester

CC

John Hill · « **Reply #15 on:** August 17, 2009, 04:57:48 PM »

Yes I am certainly impressed and I pinned a notice to that effect on the board in the tea room over at Gareth's site!

If they were not 12000 miles away a pint or two would have been in order.

My local supplier was very keen to help but frankly admitted that they do not handle enough to have had any experience in taking them apart. (Well I know they do not handle many as mine was in their showroom for four years or so!)

I took a quick peep at mine as I was leaving for work this morning and I have a clutch on the feed screw but not on the drive rod.

Thanks for your advice too John.

CC, it is something we do not see much of nowadays but they dont arf tork pharney!

John Hill · « **Reply #16 on:** August 18, 2009, 02:57:06 PM »

Well that all came apart easy enough! I even found the little screw at the very last moment in fact I had almost given up swilling kerosene around inside and pouring it out.

The construction appears to be "quite good" although there are a few places where I would have expected there to be a bearing. There is no real effort to keep the oil in the box and even two of the bolt holes to attach outer brackets are drilled right into the box and there is nothing to seal oil seepage through the threads! There is no provision for lubication to get to the power feed worm and wheel which is at the back of the box and not easily convenient for manual lubrication. Although the half nuts could be easily removed for cleaning it is impossible while the apron is on the lathe as the chip pan prevents it, even on my lathe which has had very little work, even less using the feed screw, the half nuts had a nasty collection of greasy gunge and metal particals ready to grind away at the feed screw!

sbwhart · « **Reply #17 on:** August 18, 2009, 03:49:16 PM »

Thats good news John pleased you tracked the little bugger down

Hope the rebuild goes well

Stew

Darren · « **Reply #18 on:** August 18, 2009, 03:52:04 PM »

Blimey, it was actually in there then......my usual is to find it on the floor or some such place while I've got the bits all in pieces......

Well done, glad you found it......

CrewCab · « **Reply #19 on:** August 18, 2009, 08:47:10 PM »

Nice one John

Glad it's worked out OK

CC

John Hill · « **Reply #20 on:** August 20, 2009, 02:26:58 AM »

It is all back together and ready for testing but first I need to put new oil in. No oil left from the initial oil change so off to buy some more, oh dear! The 'hydraulic' shop has closed! So I try to buy some from various oil company outlets but it appears they have all retreated to their national depots in some far away place leaving no stock except motor oils and no knowledge either. I ask for the oil and they tell me it will be here tomorrow, or the day after.

After some

I go to an engineering workshop where I ask if I can buy some oil for my lathe. 'No problem' he assured me as he passed me a half full 20 litre can, 'This is lathe oil', he assured me. So I looked at the label and sure enough it is ISO46 hydraulic oil, recommended for several applications including lightloaded spur gear gearboxes. Cant get better than that!

bogstandard · « **Reply #21 on:** August 20, 2009, 04:01:40 AM »

John,

I use a product called Tellus 32, but almost any fairly thin hydraulic oil will do. Yours will be spot on.

Many of the lathe manufacturers don't actually specify an oil for their gearboxes, so people are using slideway oil instead, because that is what they have got in stock, and that is way too thick and sticky for a lathe gearbox, but OK for external gears as it tends to 'cling', whereas a thin oil will wash any wear shavings from out of the teeth and allow them to settle in the bottom of the gearbox, so causing no more wear, and they will be flushed out when you do your regular oil change. The first couple of oil changes are usually full of debris as the new gears get bedded into each other, but after that, it comes out rather clean

Quote

the half nuts had a nasty collection of greasy gunge and metal particals ready to grind away at the feed screw

Remember me telling you to put the shaft into neutral. Well the same knob works for both lead and power shaft. So you should only ever select them to turn when you really require them. So if they are not turning, bits of swarf and gunge can't be wearing anything away.

John

John Hill · « **Reply #22 on:** August 20, 2009, 05:06:38 AM »

John
We used to see Tellus oils around here but I not sure where the retail outlet would be. I can buy just about anything I like from the oil companies just by phone call and waiting a day for delivery but their minimums are 20 litres, it is getting so I am seriously thinking of buying a lifetimes supply and be done with it!

Meanwhile I am not getting to excited about oil for the ways etc and have been using whatever is on hand, right now I think the oil in the can is 'cream seperator oil' which must be really old! Some decent slideway oil is on the list to acquire especially as the little shaper really needs it as what-have-you oils only stays on the ram slides for a couple of minutes!

The first oil change for the apron box was likely wasted as it had a really thick layer of congealed dragon fat (or something) which of course did not come out in the first oil change. During this latest cleanout I washed it pretty thoroughly with kerosene and got all that out before putting the new oil in.

I never run the quick change gearbox unless I am using it, I just set the fwd/rev lever to the mid position. Not only does that stop the quick change gearbox from turning but it also stops the change gears. The point I was making about the half nuts is that when they are used they will scoop up whatever there may be in the thread and there is no easy way to clean them. Lesson, always thoroughly clean the lead screw before use because on these lathes it is rather difficult to clean the half nuts!

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Author Topic: Bumble Fingers courts disaster! (Read 9510 times)

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