G9729 Left Hand Thread Cutting

Re: master machinists, used to be when Henry Ford ran Ford in the early days they had a simple test to get hired on as a machinist. With hand files, file a round hole to a 1" square and file a round bar to a 1" square to fit in the hole, all four directions, with 0.004" clearance.

IMO talking about whether a machine tool has certain features or not making the machinist a master is a distraction. If you are able to make a part to specifications with the tools you have (hand or machine), you're off to a good start.
 
Yes I agree with that 100%. Look what 3rd world country's do with just had tools. For instance the Pakistani's making fine firearms sitting on the dirt floor using files, cheap grinder two batteries as their arc welder. I've see things done in the Philippines that were just unbelievable. They have done so much, for so long that they can do anything with nothing! (They've come al "long" way since I lived there is the '60's and 70's) Some of the more successful have been able to get hold of a lathe. And to think I complain about my crappy Chinese 3-in-1 lathe!

This getting away from half nut discussion but heck this out!

 
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I'm thinking the reversing gear is going to have to be done in a different configuration. If any one of the gears is changed to another, for different thread, then the gear won't be engaged with the lead screw gear. Gonna have to give this some thought and see who has some suggestions for me!

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How much room is there between the spindle gear and the firsts gear on the gear quadrant, if you swing it the full distance away from the spindle. What I envision is a tumbler gear set between those 2 gears instead of your current first choice. Makes for a more normal set up.
 
LX Kid said:
90amp tig or mig. I always get the two mixed up! No gas just the wire feed which kept sticking and messing up! There must be some kind of "You Failed" award given by this forum! LoL

I could probably just Bondo up everything and paint it. Who would know?
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Looks like your polarity is reversed assuming you were using innershield wire. With innershield wire, the work ground is the positive lead. If you were using solid wire, no gas is not an option and the work ground is the negative lead.
 
LX Kid said:
90amp tig or mig. I always get the two mixed up! No gas just the wire feed
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MIG.

TIG uses rods, not wire feed.

Not surprising it looks like hell without using a cover gas (or self shielded wire). It also looks way too cold. 1/4" plate on a 110V box s tough.
 
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Forgot to mention, you can use the factory bracket to mount an idler gear when cutting most LH threads. Just use the smallest final gear option and add a stud to the unused center slot for an idler.
 
LX Kid said:
Doesn't seem to be that many people who have bought these machines. Maybe that's some handwriting on the wall that I should have read somewhere. I bought my Grizz G9729 beginning of last summer and have only been able to do anything with it in the last 30 days. The heat, here in Florida, just kept me out of the shop. Anyway after a "lot" of modding and repairs I have it online to make some chips. My biggest problem was the pivot gear was squeezing the rack gear. I had to do some shimming of the cross-slide gear box to make it usable.

Now after rambling, has anyone made a reverse tumbler for their lathe? These lathes have been around for long time and only thing I see is DC motor drive mods attached to the lead screw. I would prefer a mechanical idler gear to enable reversing the lead screw. Anyone know? I do have a treadmill torn down, and ready to do mod, but have but have been reluctant.
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Many common threads do not require anything other than another gear stud inserted in the unused center slot for a reversing idler. What LH threads are you expecting to cut?
 
Pictures are worth a thousand words........this is geared for 6, 12, 24 tpi.

LX Kid, With that large final gear in the pics you posted, it looks like the gearing you set up to run in reverse is for fine feeding instead of threading....if I'm wrong, it won't be the first time!

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