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10th Jul 2020, 07:45 PM #1I break stuff...
- Join Date
- Aug 2010
- Location
- Toorloo Arm, VIC
- Age
- 39
- Posts
- 1,270
A reminder: Never, ever, look at the ways on your Chinese machine.
Yep. I committed the cardinal sin. What has been seen cannot be unseen... Don't do it.
I wanted to rework (finally) the mount for my QCTP on the AL335, as the 't-nut' was a piece of scrap plate that the previous owner had driven into place, and the stud was bent, so when you unlocked the rotation nut, it would lift off the compound slide on one side. It annoyed me, so I decided to make a new stud and t-nut, and make sure the face where the QCTP sits was flat. I also wanted to see if I could deburr or otherwise improve the nuts/studs for the rotation of the compound slide itself, as its painful to try and make small adjustments, the studs kick over on a bit of an angle, and you end up having to jiggle it all over the place just to move another degree. That, and having 17mm nuts right up against the side of the compound is an incredibly terrible design choice - the nuts are now half chewed out because you can't get a spanner all the way on them, and there are little divots worn into the side of the compound from the tips of the spanner, so I wanted to see about putting some cap screws in instead.
And finally I figured I'd strip it since I had it off anyway, and give it a clean and maybe a deburr, and look at redrilling the oil points so they actually supply oil to the right spots, instead of just trickling oil somewhere near and hoping it'll actually get where needed. The crappy ball oilers are stuffed anyway, so at the least it was getting tapped for some grease fittings as I've done elsewhere (much easier to oil through those, oil comes out of the grease gun with enough pressure to really blast any crud out).
The pictures below should tell the story - note the shiny spots in the first, where it's been running - keep in mind, I only actually use the compound for tapers, which is pretty occasional, the rest of the time it's locked. No idea how much the previous owner used it in the year or two he had it (Machine says built 08 10, which could either be August 2010, or possibly October 2008, I've had it since May 2011). Not pictured is the bottom of the compound nut, which has been dimpled with a centre punch all round to make it a tighter fit in the slide Nor the dovetails, which are varying degrees of lumpiness.
The gib - contact in one thin line down the middle, backside is ground but is warped.
And yes, the blue is excessive, but it basically matches what you can see in the first photo for general high/low areas. Obviously the thick blue makes it look like better contact than it actually is though. Putting a parallel on those blued "scraped" finishes shows massive amounts of daylight through underneath. I have to imagine that when the Chinese were instructed how to do this, there was the typical typo involved in the reading material, as they certainly "scrapped' any precision the surfaces may have had after machining.
Looks like I might to have to give in and order that surface plate from ToolingOnline I've been thinking about for a while. And then.... something something. Need to choose from the 4 options.
1. Nothing to see here, works beautiful!
2. This bin's heavy.... Replace with a solid toolpost mount. Won't really fly, I have a need to do internal tapers on occasion, so no tailstock trickery for me.
3. Stefan Gotteswinter. He did a compound tidy up in one of his videos without scraping, I think this will be the most likely path. I do have a dovetail cutter that appears pretty close to the angle. Not sure whether the degree or so its off is warpage of the slide, poor machining, or by design. As the first photo shows, it seems like I've probably got plenty of gib to work with, so if I can keep cuts to a dusting, should be able to rework it and use it.
4. My arms hurt. Learn to scrape. Probably as a follow up to the above, I think.
Either of the last two options requires a surface plate, and there have been a few times recently where one would have been mildly useful anyway for checking out various things (like my absolutely terrible old Hercus vice on the mill, but that's another story - I took the 'easy' way out on that in the end).
And yes. The cross slide. Yes, from the little bit I can see without stripping it, is the answer to your first question, and no to the second. For the moment I'm going to ostrich that one. The compound in my mind at least, can be treated as an independent entity. The cross slide... not so much. Too much has to align with everything else, whereas the compound simply needs to travel square to it's circular base, and in a straight line. If it's not square to the headstock, rotate the damn thing. And if I decide to do the cross slide later, I just need to ensure the mounting surface for the compound is square to the ways of the cross slide (after squaring it to everything else in the universe).
I also need to finally build a proper stand for the lathe, as the bed has enough of a twist in it that it simply picks up one of the tailstock feet when you try to level it. Not much point attempting anything with the saddle and cross slide until that part is sorted.
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10th Jul 2020, 11:37 PM #2Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,943
I think I read somewhere that machinery from China is an assembled form of a kit, requires cleaning and finishing.
I don't envy your choices.
KrynTo grow old is mandatory, growing up is optional.
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11th Jul 2020, 01:57 PM #3Golden Member
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- Dec 2011
- Location
- Sydney
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- 505
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11th Jul 2020, 07:48 PM #4Senior Member
- Join Date
- Jun 2007
- Location
- Victoria, Australia
- Posts
- 114
Excellent post. I think even more depressing is the price companies charge for these lathes. I sometimes think that a lathe on the Showroom floor for say $5K might cost less than $1k all up for these importers.
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12th Jul 2020, 01:30 PM #5Senior Member
- Join Date
- Jun 2007
- Location
- Victoria, Australia
- Posts
- 114
There is no question the Chinese can produce top quality products. Sometime ago, I was discussing with the Company which makes the multi-fix toolpost holders about quality. It was of real concern to them that the Chinese have this reputation for producing poor quality products. The engineer made it clear, they produce products exactly according to specification and here in lies the problem. We are not the customer, the companies which import these products are the customer. So if the typical importer of lathes has second rate stock, blame them and retaliate by not buying.
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12th Jul 2020, 02:29 PM #6Novice
- Join Date
- Jul 2020
- Location
- Brazil
- Posts
- 16
Thank you for your answer!
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