Results 61 to 75 of 75
03-20-2017, 05:23 AM #61
Since a new cross-slide nut would need to be fitted to the cross-slide (several manufactures will sell you nuts that need to be drilled and tapped in place for the exact machine, others have eccentric bushings, etc. to take care of possible misalignments) in most cases it wouldn't even be necessary to relocate the cross-slide leadscrew either. The original saddle, a built-up saddle would bring all the other lathes elements (leadscrew, feed rods, rack & pinion, etc.) in alignment and wouldn't disturb the meshing of the cross-feed gear with the apron. Do I miss anything?
I'm puzzled by the discussion of relocating the cross slide feed screw. Offhand, it seems much more complicated than building up the saddle or recutting the cross slide gear. Why would this ever be necessary?
Regarding the original argument, I believe that Peter was referring to his visit to RUEMEMA or the trip the previous year to other rebuilders, mostly in Switzerland.
Now that most of the dust has settled, let's go back to business.
03-20-2017, 05:46 AM #62
I'm not an expert in gears either. But I'm ready to bet that the mating gear will tend to wear more rapidly, developing sharp teeth, while the roots will remain fairly new.
How long it will take and if it could be deemed an acceptable compromise (i.e. partial engagement of the teeth of the mating gear result in significantly reduced maximum load of the very gear). But at my untrained eyes, it doesn't look great at all.
03-20-2017, 01:49 PM #63
I will continue to advise people how I will or would do it. You can take it or leave it. I am sick of all the BS and you guys arguing about things. The forum is getting back to the same old horrible way it was before. Advice from someone who if lucky rebuilt a Rung-Fo or his Powermatic wood lathe giving advice on "how to".
The forum was getting really good at giving good advise from all over the world from several people with good ideas who did or does this work as a profession and not a hobby. I apologize for saying something was stupid doing it that way. But to me is was bad advise. If you feel it would work for you, go for it. I figure many people do not cut gears and would need to send it out. Most gear Companies have a minimum charge, I bet it is $500.00.
I figure many of the ones who continue to egg me and others on have no life at all and this is the only place they get some attention. I just got a call from my friend Paul who reads the board too and he told me to get out of the house and start rebuilding again. I figure when it gets a bit nicer out I am going fishing.
Also next month I am headed to Denmark and Norway to help teach 2 classes. I love teaching these classes. I agree with Mate Phil and he is also a professional who have been paid and had to guarantee his work or starve to death. He knows who is full of BS and who is real!
Demons lowering everything works but to me it is work not needed and I would bet money in the long run gluing on 3 strips of Rulon, scraping it is cheaper and easier. You have to fit the saddle to the bed anyway and scraping Rulon is a whole lot easier then scraping Iron.
Then you will have a "Better then New" lathe with no stick-slip with the original Iron on Iron. If you figure your labor rate at a $25.00. You can buy the material for $100.00, glue it on in 1 to 2 hour. and I bet it would take 10 hours or more costing you $250.00 to move everything down.
You can also glue on Grade Linen Phenolic which is pennies on the dollar then Rulon. I just used it a few years ago on Drake thread grinder head and tail stocks. It work Great. Simple as heck.
I apologize to RON the OP who asked a question on grinding his lathe bed and got all this BS. That is why You Tube is getting so popular. You show your work and don't need to put up with all the BS. Ron please start a new thread when you get your bed back. Hopefully the few with their grand ideas will leave it here on this thread and not add it to that new thread. Rich
PS:I am done with this thread....time to move on.
03-20-2017, 02:39 PM #64
You do - and teach - what we could call the 98% to 100% - maybe even 110% - 'perfect' rebuild.
No one expects you to abandon your standards and start blessing or teaching "monkey-patching 101 for Idiots".
Problem is.. 80-90 percent of the shops out there in tough economy-land don't always have the time, the deadline headroom, the money, or the local skill to goal for a hundred-percenter.
They've no CHOICE but to monkey-patch ... or go hungry.
Helpful if the more skilled among us just rank those 'monkey patch' approaches as to:
"This approach does minor/no permanent harm, can be corrected, later, when there IS time and money",
"That other method does do permanent damage, is HARD to ever again put-right, and should be avoided".
No Fine Way you can take personal responsibility for the decisions made by the minders of a million tired and worn machine tools belonging to "other people", and you should not let that bother you.
They will do what they do, regardless of how good an example you have set.
Keep setting those good examples and teaching their methods anyway, please.
They are appreciated as a clear and valuable goal to strive for, whether others can quite match their quality or not.
03-20-2017, 08:54 PM #65
Personally I see it this way. The only time you would ever machine the apron/saddle interface to compensate for wear would be on a lathe that has no power cross feed. That would be on a tiny lathe or a very very old lathe. I did it on my 10EE only because it was warped and then only enough to remove the warp.
So my opinion is if I were you I would discard any notion of cutting gears or moving cross slide lead screw position.
That leaves either lowering the quick change gearbox and end support bracket or apply material to the saddle to build it up.
If you go build up the saddle you have many choices of material, from cast iron, bronze, to the plastics with additives. One thing to keep in mind the slipperier the material you choose, the less effective the saddle lock will be. That may or may not be an issue for you. Since putting a turcite like material on my 10EE, the saddle lock is a lot less effective at locking the saddle. Another thing often not mentioned with the plastics is you need to keep the way wipers in top condition. You could upgrade them to a modern lip type. You should keep way wipers in good condition anyway.
If I were in your position, I would build the saddle up with material. I would also use a generous thickness material and allow a generous amount for scraping it. I would rather have to scrape off 0.2mm then start with 0.05mm and by the time I get the saddle aligned end up 0.1mm low. And also you relieve the middle third of the saddle a couple of scraping passes so the ends touch and wear first. (well they always wear first regardless)
03-21-2017, 01:36 AM #66
I think it is not clear to all yet what we did with that gear
When you grind the bed the carriage drops Then also the apron (was looking for that word) would drop
That would bind the shafts
So you can compensate that to grind something off of the top of the apron were it is bolted to the carriage to get it higher in position again
But that will bind the gear for the powerfeed of the crossslide if it is too much
Our solution was to have a new smaller gear made for the powerfeed of the crossslide by a shop who did it as a fovor (Thats not for free as favors have to be returned )
And although some people here think otherwise adjusting the centre to centre distance on a set of gears is common practice in gearmaking It can be done by changing only 1 gear
If this is not clear to anyone please say so, so I can clearify the matter
03-21-2017, 02:09 AM #67
I don't agree it was among the several better options. Extra work was done to end up with a machine in several respects WORSE-OFF than wear had made it.
I can understand being so desperate as to have to go where y'all went. May have saved a whole two days over adhesive set up and scraping time, given 'perfection' was not on the agenda anyway. If that saddle was refitted after bed-regrind, it could have been built-up THEN refitted, and if molded filler was used, it could have even been less work.
If it was simply dropped, wear as-had, back onto a reground bed? Please lie to us about that part. It would be a kindness.
I cannot understand defending a monkey-patch on any grounds EXCEPT those of immovable deadline and/or dire economic 'emergency'.
Which was it?
03-21-2017, 02:23 AM #68
03-21-2017, 02:40 AM #69
03-21-2017, 02:46 AM #70
03-21-2017, 02:57 AM #71
It weren't mounted on no swing-arm, any typical double-walled apron.
That, tearing the apron apart to mill the top off the bugger, ELSE 'magic' the milling-cutter's nasty debris... putting it back together .. whole bunch of other collateral damage, all to avoid working with a bit of Rulon, Turcite, Moglice, or - forgive me Richard, "age thing", I prefer the stuff - GOOD grade of the right Bronze?
... and Ich still wondering if there was ANY refit of worn saddle to freshly ground ways, absent build up material quite aside ?
Undersized gear is just the symptom. Not the disease.
03-21-2017, 05:36 AM #72
Here is some explaining of the matter of toothcorrection
Making the gear smaller gives more undercut as you see Making them bigger less undercut
Making the pressureangle bigger also generates less undercut You can see examples of that on electrical tools where you sometimes have only 4teeth on the motorshaft Not possible to make these with a 20dgr pressureangle
Very informative site about gears BTW
Monarchist :Your arguments to oppose this way of doing are very vage and seem to indicate you have no or just little knowlidge about gears Or you are just stirring the pot
Tooth corrections at cylindrical gears | gears | Tooth corrections at cylindrical gears, tooth correction for pinion and rack, tooth corrections for internal gears| | tandwiel.info
03-21-2017, 06:04 AM #73
THIS thread is about bed regrinding, how to best exchange goals and progress with a contract shop at a distance, and how the end-results of their grinding will impact the OP's refitting of the carriage, TS, and HS on his lathe.
No part of your monkey-patch how-to / after-action report on an unrelated lathe has been relevant to the OP's lathe bed project by way of gears, steers, beers, or otherwise.
If you feel compelled to defend your choice, please just go and "tell it to the Marines".
Meanwhile, as to gears, start looking over your shoulder:
Check the surnames and locations of the authors. Note the sources used in a language they had to learn, and learn well, in order to use those sources at all.
Something HUNGRY is gaining - or perhaps already ahead of you, language AND technology both.
03-21-2017, 06:33 AM #74
Are you really from the US
The land of all those opportunities
All I hear is a lott of bitching and "not original parts" but no real technical arguments of why this is such a bad idea
I thought this site was all about exchanging ideas And if these ideas are bad at least come up with some decent technical arguments
Not "never done before by profesional rebuilders " or "too costly" or "scraping is much faster" or "monkey patch"
03-21-2017, 06:40 AM #75
Rebuilders aren't interested. They have enough shit to deal with as to not make that same mistake ONCE.