Power feed vs thread gear setup for PM-1127VF-LB or PM-1130V

[skcncx]

Do you HAVE to change gears when switching between a power feed rate for a turning operation and when threading for a particular TPI?

I plan to thread mostly ¼ 20 TPI (#2 pic attached) but it appears when I switch back to turning with slower feed rates from .0025 to .01 (#1 pic attached) I have to change physical gears. I was hoping I could setup for my most common TPI... but then still get the slower feed rates (A,B,C feed rate selector) for turning operations without physically adjusting the gears.

Since this model has a lead screw for threading and a different shaft for power feeding, I was hoping I'd get best of both (at least for one TPI setup) as it's not a quick change gear box. I would think the power feed shaft spins considerably slower than the lead screw for a given gear setup... and therefore power feeding even if setup for 10 TPI gears would be much slower when power feeding vs threading.

This is leading to my purchase decision... PM-1130V (same gear box setup as PM-1127VF-LB) OR the PM-1228VF-LB which has a nearly complete QCGB covering a huge range.... I've even considered, though, likely out of my needs/expertise level is the PM-1236T (overall better quality and power... AND $$$ more)... that's my understanding at least.

 

[epanzella]

Besides the difference (if any) in speed between the leadscrew and the power feed shaft, there's also a set of gears in the apron that are only used for power feed. When threading the lead screw is directly coupled to the half nuts without any further reduction.

 

[skcncx]

Besides the difference (if any) in speed between the leadscrew and the power feed shaft, there's also a set of gears in the apron that are only used for power feed. When threading the lead screw is directly coupled to the half nuts without any further reduction.

Yea, that makes sense, gears in the apron, possibly reducing the power feed. That's what I'm trying to confirm. I think I can deal without a QCGB, but not if I have to switch between power feed rates and threading.

From PM support, the 1130 has a more traditional VFD setup where as the 1228 has proprietary electronics... neither of those are a deal breaker, but the QCGB will be. There's a reason I'll never do single point threading on my Atlas 618... everything required gear changes. There's a good chance I'll never do threading period, just not sure I want to sacrifice it for the "future me"... taps and does go a long way and are simple. The 1130 comes with a few more options and micrometer stop, both have clutch system to prevent crashing but the 1228 just comes with a basic stop block... minor diffs.

 

[benmychree]

In the end, most folks would find a "loose change" lathe quite frustrating.

 

[skcncx]

In the end, most folks would find a "loose change" lathe quite frustrating.

I'm not up on lathe vernacular... what do you mean by "loose change"... as in, you have to change the gears a lot?

If so...yes, that's what I'm trying to avoid for my 90% usage scenario. I got my first lathe, an atlas 618 a couple months ago... it's great, learning a lot, having fun and for me the size is pretty decent, even power is ok for what I want to do.. but the effort just to try different feed speeds is the reason why I haven't tried threading or even different power feed rates. I want DRO and some other creature comforts so it's an easier jump to buy something out of the box with what I want... now that I have a much better idea of what I'll find useful or not... that that may change as I do more projects.

 

[benmychree]

I'm not up on lathe vernacular... what do you mean by "loose change"... as in, you have to change the gears a lot?

If so...yes, that's what I'm trying to avoid for my 90% usage scenario. I got my first lathe, an atlas 618 a couple months ago... it's great, learning a lot, having fun and for me the size is pretty decent, even power is ok for what I want to do.. but the effort just to try different feed speeds is the reason why I haven't tried threading or even different power feed rates. I want DRO and some other creature comforts so it's an easier jump to buy something out of the box with what I want... now that I have a much better idea of what I'll find useful or not... that that may change as I do more projects.

Yes, loose change is the counterpoint of quick change, that is, change gears must be set for any changes in feed and threading; its the dark ages all over again.

 

[skcncx]

Yes, loose change is the counterpoint of quick change, that is, change gears must be set for any changes in feed and threading; its the dark ages all over again.

Thanks for the clarification. That's kind of a bummer... I figured, since the PM-1130V had dual feed shafts, one for threading and one for power feed.. they'd be independent to some degree.... I guess the only purpose is to not wear out the threading lead screw when all you need is power feeding.

I guess it's the PM-1228 or the PM-1236T (but that's almost double $ by the time I accessorize them equally)

--Scott

 

[tweinke]

If you want the 1130 over the 1228 you could build the Clough 42 ELS and not have to worry about the QCGB. I just ordered a PM1130v with that thought in mind. I have not done much threading since I got my first lathe so for me it will work out fine. If I get to the point of cutting threads regularly I will go the ELS route. I guess a guy could also get an extra banjo and gears and set up for threads on one and turning on the other. But at that point the 1228 or 1236 would be the better choice. For me the 1130 with all the goodies just fit my budget and work size the best in my eyes.

 

[skcncx]

If you want the 1130 over the 1228 you could build the Clough 42 ELS and not have to worry about the QCGB. I just ordered a PM1130v with that thought in mind. I have not done much threading since I got my first lathe so for me it will work out fine. If I get to the point of cutting threads regularly I will go the ELS route. I guess a guy could also get an extra banjo and gears and set up for threads on one and turning on the other. But at that point the 1228 or 1236 would be the better choice. For me the 1130 with all the goodies just fit my budget and work size the best in my eyes.

Good input... I'll have to take a look at the clough 42 ELS and I'm sure there are others as well... just was hoping to get a ready to run with all the feature I wanted out of the box... though the ELS would be a fun mod.

I don't get why manufactures for these small mini lathes don't just do the ELS...of course drives up price, but it's seeming (on the surface) not that complicated and could easily be applied to many small lathes.... I'd pay an extra $1K for it. If they make and buy all the electronics in bulk seems like it's a good idea.. and of course, I'm probably over simplifying it.

Honestly, I may never do single point threading, 90% of the time I speculate and buy feature I think I'll need, never to use it and the other 90% of the time I buy something I never thought I needed only to wonder how I got by without it. However, changing feed rate, even minor adjustments would be nice... and the 1130 does provide that.

The 1130 is about $700 cheaper when you compare them with DRO package and AXA tool post.... so... is the QCGB worth the $700?? The 1130 does have a more traditional VFD motor controller. If I knew the 1130 is in a different class/higher fit and finish quality it would be a no brainer to skip the QCGB... hence why I'm even thinking about jumping to the 1236T ultra precision and foregoing DRO and extras for awhile... like a long while. I just don't think I can/will really get out of it what it can give... considering I'm just a hobby, making small stuff and so new to this.