The_Yellow_Ardvark
https://www.death-clock.org/
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- Going Away.
Alas I do.
But you know were my smpathy is.
- Thread starter monkeymark
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But you know were my smpathy is.
Screwdriver
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You can cut a metric thread on an imperial lathe and disconnect the half nut?
That's news to me.
Seadog
Save the planet. It's the only one with rum!
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Me too, Steve. It just isn't possible. Change wheels just give you the correct ratio. But, and don't quote me on this, the relationship between the TDI and the tool position is only correct every 127 turns of the spindle once you disengage the half nuts.
Easywelder
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No, got the table and engraver working fine but not enough juice to power the plasma where it is currently located, I’ve some infrastructure work to do as well as changing 3 phase supply from 100amps to 200amps(just a meter and fuse change, supply already there) so may buy generator as temporary measure needs 26 kva I think.
Kram
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New grinder for finger callouses. Also good for abrading dirt out of your fingers. I needed to use the old one about 10 minutes after every climbing session, eventually wore out the motor, this has a bit more power to it.
Also comes with a razor blade skin peeler
Nope. This bit will not be used.
Also comes with a razor blade skin peeler
Nope. This bit will not be used.
Screwdriver
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My intuitive self says that but when I try to describe it in words, my brain goes a bit soggy. Intuitively, the gearbox (and therefore the desired thread) is not geared in a low enough integer ratio like 4 or 8 to remain in phase with the lead screw by "hitting your mark" to re-engage (when cutting metric on imperial). You can't just use 254/127 marks on the TDI because 1. that would be impossible to see and 2. the coarse teeth would not necessarily engage at that exact point. You'd need a massive 254/127 tooth 8tpi pickup for the TDI and it would have to travel miles before you hit the correct mark to align with the leadscrew/gearbox.
Similar situation with a carriage stop. Once you have lost the phase relationship between the lead screw and the gearbox (by disengaging the half nut) the linear position of the saddle does not guarantee the half nut will re-engage in the same phase.
Interesting observation that the TDI would have to turn 127 times to re-synch itself, that does sound right. 127 is prime so there's no escaping it by cleverly dividing the dial face. Why they made it 25.4mm to the inch god only knows. There's probably a good reason but my brain is fried so you'll have to ask Google or @Seadog, he'll know...
Seadog
Save the planet. It's the only one with rum!
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The figure may be wrong, in fact I'm almost certain that it is. But when you have an odd number of teeth you introduce 'hunting' into the equation. It was very common on gear trains, for example the Norton Commando timing gears, to introduce an intermediate gear with an odd number of teeth. Known as a hunting tooth arrangement, it spread wear across all of teeth. Something you needed to aware of when lining up the timing marks, rotating the engine a few times, then trying to understand why your marks no longer lined up. The fact that the intermediate drive in this case is a 100/127 tooth combination, where the two gears have no relative motion between them, causes the mistiming.
Screwdriver
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I think it has to be a multiple of 127 because you can't divide it down...
Your example proves the point. 100/127 gives you a 1.27 (or 0.7874...) relationship between say input/output. When do they next line up to a whole number.
Answer: only after 127 turns. There isn't any whole number (number of "turns") between 1 and 127 that brings the relationship back into synch.
Your example proves the point. 100/127 gives you a 1.27 (or 0.7874...) relationship between say input/output. When do they next line up to a whole number.
Answer: only after 127 turns. There isn't any whole number (number of "turns") between 1 and 127 that brings the relationship back into synch.
Mick Annick
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New grinder for finger callouses. Also good for abrading dirt out of your fingers. I needed to use the old one about 10 minutes after every climbing session, eventually wore out the motor, this has a bit more power to it.
Also comes with a razor blade skin peeler
View attachment 361442
Rock climbing I assume? We’re in Corfe Castle this week, youngest and his wife are hanging off of Winspit at the moment…
Maker
Most folk just call me; Orange Joe
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What's wrong with a bit of sandpaper glued to the back of a hold brush?New grinder for finger callouses. Also good for abrading dirt out of your fingers. I needed to use the old one about 10 minutes after every climbing session, eventually wore out the motor, this has a bit more power to it.
Also comes with a razor blade skin peeler
View attachment 361442
Kram
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Id like to try Winspit one day, mostly indoors on plastic this year. Its a bit too far away.
The 10 minutes would turn into hours!What's wrong with a bit of sandpaper glued to the back of a hold brush?
The resulting dust reminds me
25.4_mechanic
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Screwdriver
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Page 28 and page 41 explain how you can cut a metric thread on an imperial lathe, disengage the half nut, reset the saddle manually, using the TDI?
Do tell. It appears to be impossible.
500e
Always buy fire insurance a flood is a hard start
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Melvyn Best
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Isn’t that what finger files are for??What's wrong with a bit of sandpaper glued to the back of a hold brush?
Olderisbetter
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Spotted a tin of old nuts and bolts outside a house for scrap, it would have been rude not to take them away.
DAPPH
as dyslexik as I'm daft
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Page 28 and page 41 explain how you can cut a metric thread on an imperial lathe, disengage the half nut, reset the saddle manually, using the TDI?
Do tell. It appears to be impossible.
ATLAS, CRAFTSMAN, COMPANION, DUNLAP & AA
Discuss any issues dealing with Atlas & Atlas-Clausing lathes, drill presses, mills, etc. in this forum.
www.hobby-machinist.com
You do have the basics but seem to have over complicated things by your thinking .
Set the gears to the correct metric thread feed .
Using a clamp on saddle stop at the chuck end to always bring the unclamped saddle back to the same position by rotating the lathe backwards by hand will always bring the TDI back to a ready to start point every time ... note the TDI position or
put a spot of your pink nail varnish on it to read to the start point .Run the thread off the RH end of the stock . Disengage the half nuts sharpish , stop the lathe , back off the cross slide & cutter to clear the major thread thread by a few thou , hand wind pullies back wards so the saddle is fully to the left on to the stop . Check the TDI is in the right position adjust if needed , advance the cutter in a few thou , engage the half nut fully , start the lathe .
As the lathe is in slow rpm there is no conflict about taking off a few thou on start up .
If you undercut the left hand end thread max diameter by the thread depth plus say 4 thou it will give you an under cut space space to get your tool in without having a tear out of metal .
DAPPH
as dyslexik as I'm daft
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In that MOLO it's page 119 , thanks for putting it up.
