|Douglas Johnston||12/02/2019 09:32:29|
590 forum posts
Yes, just a tad out of round at the front end, I can't imagine what mistreatment caused that .You will get great service from an ML10, I have had a Speed 10 version of the same machine for more years than I care to remember and it is still going strong. It might be an idea to restore the tailstock barrel to the round state by gently removing the high spot with fine wet and dry paper. If you roll the barrel on a flat plate, surface plate if you have one, or just a glass plate, you can identify the high spot. One thing is certain, you will never be happy with a tight barrel, it will annoy you for ever!
|Alan Donovan||12/02/2019 09:34:23|
|11 forum posts|
Two of the readings (appear) to be taken over the barrel keyway, therefore you will not have measured a 'true' diameter. It will be less than the true diameter as you have lost the 'crest' of the diameter, on one side only, to the keyway (I hope that makes sense). The third reading is taken in a different position which will give a true diameter.
In this case, I would also recommend using a micrometer rather than a digital calliper to measure these diameters as it is easier to get consistent results with a micrometer. You will then have a more accurate assessment of the actual barrel diameters and wear. I am confident it will be much less than the 0.008 inches it currently appears to be - as you say you have a 'tight' barrel.
3651 forum posts
Rather than any magical swelling of the solid steel quill at each end, your stiffness of motion is more likely to be due to something like burrs along the keyway slot that the guiding key slides in, or burrs or even just sharp edges on the key itself. Possibly burrs on the ends of the quill, especially if a hammer or drift have been applied to get it to move during the removal/replacement process. Also burrs in the inside of the tailstock body where the quill slides should be checked.
Go over the whole lot with a small fine file and remove all burrs and sharp corners and sharp edges then give a thorough cleaning to get rid of filings etc.
Also check the locking blocks for same and make sure they are physically pushed back out of the way and not dragging on the quill when checking for freedom of motion.
You should be able to leave the guiding key, quill locking blocks and handwheel etc off and push the quill in and out of the tailstock body by hand with no resistance. If it doesn't, that indicates some burrs etc on the main diameter that need removing. Otherwise, keep adding one component at a time until binding occurs and that should indicate where the problem lies.
Edited By Hopper on 12/02/2019 10:02:31
|Mick B1||12/02/2019 10:22:42|
|1127 forum posts|
Well, on the rear and middle you measured across the keyway, which is going to understate the diameter by a value that's hard to calculate.
Nevertheless, I'd guess from the front end measurement (which avoids the keyway) that, even if the quill fit is defined on a shaft diameter basis, it should be at most 1.000", so someone seems to've inserted that taper sleeve with great force, and probably with something trapped between sleeve and bore. You have to wonder how badly the inner surface of the taper is scored for them to have done that.
Plus what other damage they might've done elsewhere?
It'd be worth checking the quill at rear and centre avoiding the keyway, too.
|Dave Springate||12/02/2019 10:31:27|
56 forum posts
|Ok that's made my mind up I'm going to take the quill out again and paint the tail stock while I'm at it. Anyone know how to remove the key that slides along the keyway ?|
Edited By Dave Springate on 12/02/2019 10:31:58
|Dave Springate||12/02/2019 11:08:34|
56 forum posts
Hi Hopper I'm going to remove it again and go over it again as you suggest. Alan Donovan, thanks for pointing that out (newbie error) I will measure it again once I have it apart and post my findings.
Edited By Dave Springate on 12/02/2019 11:11:22
3651 forum posts
Not sure on the ML10 but on the ML7 the key has a round pin sticking out the side of it that goes into a round hole in the tailstock body. You can see the end of the pin if you scrape the paint off the outside of the tailstock body next to the key. Tap the end of the round pin with a hammer and small drift and the key should pop out into the bore of the tailstock.
|Dave Springate||12/02/2019 14:20:04|
56 forum posts
Thanks Hopper, the pin is visible so will give it a tap and see if that works, once I manage to get the quill out again.
Edited By Dave Springate on 12/02/2019 14:20:53
|Dave Springate||12/02/2019 20:17:40|
56 forum posts
Well, that was a productive evening, I started to strip the tailstock down again and unscrewed the lock handle and notice that the barrel that is underneath it was not freeing up when you loosen the locking lever. I took it out and have lightly rubbed all the edges with a bit of emery paper and cleaned it, put it back in and hey presto it's working as it should now the quill now has a nice smooth action. I've re-measured the quill avoiding the key groove and got a better measurement, sorry I don't own a micrometer yet so the cheapo digital caliper will have to do. Thanks for all your idea's on this.
Edited By Dave Springate on 12/02/2019 20:19:16
3651 forum posts
Well done. That's a good result. Our ML7 is much the same: when releasing the lock handle you have to give it a tap with the palm of your hand to make sure the locking blocks have released their grip on the quill. Seems to be nature of the beast. Your measurements look good. Half a thou is nothing to worry about.
Carry on lathing!
|4536 forum posts|
Well done, now you're an expert on ML10 tail-stocks!
I think your experience is typical of the fog through which new things are learned in an amateur workshop. Step one, an item of machinery that needs attention, perhaps it's broken, perhaps it just needs a clean and lube job. Step two, the discovery that how a machine works, how it's disassembled, and how it goes back together isn't always obvious. It might even be painfully difficult! Step three: experimenting, taking advice, and frustration. This is the dangerous stage: people reach for hammers, lose parts, and make horrible bodges. This is one reason it's important to check old lathes out before buying them - you don't know who else has been 'at it'. Step four - daylight. Once the machine is understood, or you guess correctly, it's easy. Step 5 - having done something like this before, you just get on with it, what problem?
Few tricks that may help. Don't underestimate the difficulty of a first attempt. Take the machine apart in an uncluttered area and put parts into trays that suggest the order in which they were removed. Take lots of notes and photographs - digital cameras make pictures cheap and easy. Have a good think and/or take advice before doing anything that requires force. Try and keep a sense of proportion - if something won't go back together and you don't quite know what you're doing, the most likely cause of the problem is you! If getting annoyed stop for a cup of tea. When severely irritated, take the day off.
On the subject of cheapo Digital Calipers, don't worry. They're good for most straightforward measurements in average workshops. Like as not a cheap model will be as accurate as an expensive one. Better calipers have other advantages - they don't lose zero (not having to keep checking and resetting them is important when time is money, less so to us amateurs), they have a smoother more reliable action, and - perhaps - better battery life. A positive advantage of cheap calipers is they can be cheerfully mistreated and replaced. Unlike an expensive caliper that stays permanently in a box because it's too good to use! When precision is important - like checking a suspect quill - a micrometer is more accurate than any caliper.
271 forum posts
|Nice useful lathe, good to see you have totally dismantled it for cleaning and reassembly, was it worn?|
'Toying' with the idea of one myself!
|Dave Springate||13/02/2019 10:43:44|
56 forum posts
Words of wisdom SillyOldDuffer and certainly looking forward to trying it out. I cant detect any looseness in the headstock bearings Alan and last night I also added the bottom bit of the tailstock and adjusted up the gib screws to get a nice fit. I only had a bit of 3in1 oil handy (I will get some of recommended oil soon) so lightly oiled it all, the tailstock base now slides nicely along the bed with no tight spots so I assume it should be ok. I do have a single little ding under where the chuck will sit but its not too bad and nothing hits it.
Thanks to all of you who offered opinions with this its all been very helpful and I'm sure I will be back with loads more questions over the coming months.
Thanks again !
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