Which would you choose?

We used to have some areas of 25 cycle - I can remember visiting relatives in Toronto who had flickering lights - but no 50 cycle that I am aware of. OTOH the GE 1/2 HP motor on my little G-D compressor specs 50 cycle on the name plate, no Idea why, it is a yard sale motor I got for $1. Gerry :-)} London, Canada

As another "which would you choose", assuming you could get the following lathe for the same price as the (new) one above, which would you pick?

The photo doesn't reveal possible wear or internal damage, otherwise it's well equipped for making small parts with the lever collet closer and Multifix tool post. I would take a close look at it.

jw

Thanks, Jim. Maybe for a first-time lathe buyer without any experience a new unit might be a better choice to come up to speed with (possibly unless the used model was at a low price).

Jon

The resetting of the speed pot to minimum to restart (on the mini lathe) isn't an extremely difficult to use, it's just different than any other machine I've operated (although I don't have a treadmill, or the need for one).

It's nice that the contros are near the top of the mini lathe, though. On machines where the controls are located near the bottom or benchtop surface, tools and stuff can get in the way. On the 3in1 that had controls near the bottom, I moved them to a separate box which could be placed above the headstock. The controls are always in sight and easy to access.

I'm not sure that I'll utilize the mini lathe motor, as I mentioned before, it's about the size of an AC/corded drill motor. If I happen to want more power, I'll get the steel gears and use a larger motor. A larger motor will most likely require a speed control with a greater current capability, but I have some of those.

That lathe is equipped for serious work, which is good as long as the user kept it oiled. If one of the chucks on the bench grinder stand is a 4-jaw it may have everything it needs. Mine came stripped except for the collet closer and I spent about as much again to equip it, mainly on new chucks and collets. You could drop $1000 on just the collet setup and that tool post if you bought them new.

If you set the leather belt drive loose it will tolerate mistakes, especially with the work in low-inertia collets. The back gears on those give a stump-pulling low speed that's good for learning to thread to a shoulder.

Can you have someone experienced go with you to check it out?

Jim Wilkins

You are a good investigator/researcher Michael. Those pictures of the 10x18 reveal quite a bit.

I was a little suspicious that this model was lacking a few of the better features, especially when I noticed the handwheel on the right end of the longitudinal feed screw. The feed lever on the apron doesn't have two feed rate positions, which means it only engages and disengages the carriage. That's not as good as other lathe aprons that have two feed positions plus disengage (such as the

That means turning the length of a workpiece will have to be cranked by hand, or by the use of changing gears inside the box on the left end.

The selector handles on the headstock only change the spindle speeds. For feedscrew ratios, changing gears in the box on the left end of the lathe is the only method of changing those ratios. This can be a nuisance, because there is no quick change gearbox, and there are not two feed rates on the apron.

So you end up feeding longitudinally by the handwheel for convenience, or you rearrange the change gears to get a fine feed when desired (if a fine feed rate can be set up).

I encountered these same limitations with my 3in1 machine, and they aren't easy to get used to, they will remain a nuisance. The other feature I want to add to the 3in1 machine is a reversible feed motor with variable speed and a clutch to engage/disengage it.

The lever below the headstock is the feed engage/disengage, and the 10x18 model doesn't appear to have a selector lever to reverse the feed screw. That's also inconvenient at times.

The dials show metric and inch increments, which is bogus because it can't be both. This isn't a major problem for making small adjustments, but when you go more than one full turn, one of the units of measurement is off, so you need to keep in mind which one is accurate, and convert those units when you're trying to attain the other units. So you gage the feedscrew threads to find out how far one rotation of the dial represents, and then measure the travel to make sure. Sometimes the divisions of the dial and the screw pitch aren't related, more like just a guesstimate.

Someone on the CNC forum thread (mentioned by malcomsmit) states that the longitudinal feedscrew is (an unusual) 7 tpi, so the dial is worthless. Another comment mentioned that for the compound and cross feed screws, one is metric and the other is inch.

So with all these shortcuts that the builder made, probably just for their convenience/cost, the 10x18 machine appears to be a project from the beginning IMO.

The owners say it has considerable weight, so it may be more rigid than lighter lathes, but there are too many inconveniences or lack of features to make it attractive to me, even at a lower price. It may be a good candidate for CNC conversion, for someone else, though.

The one owner said the compound adjustment screws stripped, I think, within days of purchasing it. So you see, there are many things that can and will fail on the cheap imported machines. That owner said it's a simple matter to replace those screws with a couple of 5/16" hex head bolts, but I know this isn't a good solution. The previous owner of my 3in1 machine had done that and the hex heads kept digging into the cast iron, making adjustment of the compound very frustrating. I smoothed up the slots the bolts travel in, and made some T-bolts with oversized curved heads so adjusting the compound is nearly effortless.

In general, it's a good habit to replace all of the very poorly made fasteners on many of the cheap imports, and AC motor failure rates are fairly common, not a high percentage rate, but not uncommon.

Thanks Jim, I appreciate the information. It does look like it comes with a lot of goodies, which is something I noticed about it.

Jon

Thank you.

I am going to save all this for my library. Things are never simple! BTW here is the manual:

Assuming good condition (subject to inspection), that one, of course. Quick-change toolpost and holders. Lever operating collet closer with set of collets. Steady rest. Albrecht style keyless chuck in the tailstock. Looks as though it has four chucks total -- one on the spindle, and three sitting on the cabinet with the bench grinder. I don't see a follower rest, but that is likely to be in the drawers given all the other stuff which comes with it.

Not sure what size it is, or what series of collets it takes, but it is a major improvement over either of the import machines, if in good condition.

Just as I am very glad that I got my Clausing 12x24" lathe with bed turret and lever style collet closer for 5C collets. Mine has hardened and ground ways on the bed. If this one does as well, it is a total steal at that price.

I wonder which Salem that happens to be? (Not that I am close enough to any of them to make a difference.) I guess that I could look up the area code to tell. :-)

Enjoy, DoN.

Well ... no reverse threading, no quick-change gearbox, no power feed on the apron (just using the half-nuts and the leadscrew, though some of the drawings seem to suggest that part of what is needed for fine feed is in there -- but there does not appear to be a separate control on the apron for that. Normally, there is one control for engaging or disengaging the half-nuts (normally just for threading), and a separate control for engaging power feed (which is transferred to the big crank wheel on the apron), and (on the better machines) also transferred to the cross-slide for steady speed facing. There are interlocks to keep both the fine feed and the threading half-nuts from being engaged at the same time, which could otherwise lead to noisy and violent self-disassembly.

Oh yes -- it is now clear that 27 TPI is not available on this machine -- at least with the supplied change gears.

I personally would now suggest that you skip both of these, and look for something like the South Bend which was posted somewhere in this thread as being on Craigslist.

Good Luck, DoN.

On 27 Dec 2008 02:33:18 GMT, the infamous "DoN. Nichols" scrawled the following:

-- We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality. -- Albert Einstein

Holy S..t! I think I shall take up flower arranging...or drinking. Alternately I can try and build one from scratch, using nothing but my mini-mill and a dead blow hammer.

Happy New Year!

My amateur opinion is that the Busy Bee has what it need, minimally. The South Bend would be a pleasure to use, the Busy Bee a chore.

Thanks Don, I appreciate it. This one is in the Salem in Oregon; I know of the one in Mass., but I'd imagine there are other Salems out there as well.

Jon

I knew I'd seen this recently:

a home-made, effective-looking QuickChange Gear Box for the 7x lathes. Haven't tried it yet, but it does look do-able.

Mike in BC

Can you provide a URL where that pdf is located, Mike? I can't seem to find it, and there is no Save Target in this hack/spitWindowssucks crapVista Mail.

I saw a shop-made QCGB maybe 5 years ago, but don't remember where or what machine it was for. It was an open style gear selector added on to the left end of the lathe bed.

The ratio between millimeters and inches is 25.4000000000, by definition of the inch. The prime factors are 254 are 2 and 127, which means that somewhere in the gear train a 127 tooth gear is needed. The

To calculate gear ratios for threading you find a gear combination that turns the lead screw at the same speed as the spindle. Usually this is any 1:1 ratio. Those gears will give a thread the same pitch as the leadscrew. Then for any other thread pitch you find gears in the same ratio as the thread pitch to the leadscrew pitch. For example my little lathe's leadscrew is 16 threads per inch. To cut 32 TPI I need to halve its speed with any 2:1 pair that fits the available space. One thread pitch equals half a turn of the leadscrew.

I made a spreadsheet with all the threads my larger quick-change lathe will cut, and the corresponding metric modulus, none of which came out even. Next I referenced a cell with 127/100 or 127/120 etc in the formula, which shows the effect of those two compounded into the gear train, one driven and the other driving the next gear. Some of the thread pitch cells then displayed standard metric modulus values. 120 and 127 gave the largest number of fine lens threads so I bought them from Boston Gear.

Then that laser optics job stopped abruptly and I haven't cut a metric thread since. My little gold and flat black precision mechanisms went into the company museum.

Jim Wilkins

One can use certain gear ratios (100:127 is the ideal, smaller ones come close) to provide a conversion between metric and imperial threads.

However -- there are multiple points at which the half-nuts can be closed, and only some of those will retrace the previous cut (which you want to do -- only deeper). For this, there is usually a "threading dial", usually on the right side of the carriage, though I have seen them built into the apron and flush with the top of the carriage.

Anyway -- the dial tells you when to close the half nuts to retrace the same thread path.

On imperial lathes with an imperal leadscrew, this works only with imperial threads.

On metric lathes with a metric leadscrew the threading dial needs to have a selection of (typically) four different gears to engage the leadscrew to deal with the different ratios which metric threads require.

In either case, you *can't* use a threading dial for an imperal leadscrew to cut metric threads -- even with the 100:127 transposing gears.

And -- you can't use a threading dial for a metric leadscrew to cut imperial threads even with the 100:127 transposing gears.

So -- the only way to cut threads on the other system (unless you are cutting a fine enough and shallow enough thread so you can cut it in one pass) is to halt the spindle before you reach the end of the thread, perhaps use a hand crank locked into the spindle, to crank the rest of the way to the end of the thread, back the tool out of the thread, crank in reverse to the starting end, crank the tool back in with the extra depth for the next pass, again use the power for a long thread but being sure to stop it before you reach the end, and crank again and again.

So -- you *can* cut metric threads on an imperial lathe or vice versa with the transposing gears -- but is is a royal plain. So modify the statement to read "You can't *conveniently* cut X threads on a Y lathe" and it becomes true.

The only exception to this is on CNC lathes, where there is no direct gear connection between the leadscrew and the spindle. Instead, the spindle has an encoder which gives one index pulse per revolution, plus a lot of incremental pulses ever few degrees. The computer handles turning the leadscrew the right amount for each incremental pulse to cut the threads. The computer then backs the tool out at the end of the thread, and reverses rapidly to reach the starting point, and then waits for the next index pulse to start the same thread pass again -- deeper. So -- it is a mater of telling the computer whether you want to work in mm or inches. (Oh yes -- and learning to program the computer. :-)

I hope that this helps. It would have been easier if you had already had the practice of cutting threads on a manual lathe of one system or the other, so you would know what you would be missing.

Enjoy, DoN.