PM1340GT vs PM1440BV

Kamloopsendo

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I've Sent Matt a deposit on a 1340GT with 3 phase motor planning on adding a VFD to it. BUT, noted later that the switch between high and low range requires change of the belt drive which the way I read it is a significant hassle. Also talking to my electrician friend who will wire it up for me it's going to run me close to a $1000 by the time I run power, add the VFD, box for the VFD, make the internal wiring changes required to take advantage of the VFD. The 1440 is chinese not Taiwanese and I'm sure not as nicely done but does come with a simple plug into my existing wiring, DRO, variable speed drive, a lever to change from high to low range and a 2" spindle bore. I've a friend with a chinese 1236 and one with a grizzly 1440 both are happy with them.
I'm a bit anal about stuff, like it neat and nice but am having second thoughts about giving up spindle bore, and DRO and over $1000 difference in the end to end up with a "nicer" but perhaps somewhat less capable lathe
Thoughts anyone? AND, thanks for the time to read this far.
Alex
 
Be interested in what you decide & why in the end. Aside from the spindle bore increase on the 14", I cant think of too many features you would be gaining over the 1340 +/-some accessories that might sway you. A bit of apples & orange reference but I gave a Taiwan (1997 King label) CT-1440G which I suspect is kind of like an old uncle to the current 1340GT. Despite a few hiccups I'm experiencing, its amazingly nice compared at least to (my local) Chinese offerings, especially around the tactile things, knobs & levers. DRO makes this not as important but I would just say fit & finish overall. Maybe Matts are different.

I cant speak for the VFD because I don't have one. I can visualize the upside but ya, that's some extra shekels. What type of machining operation or other advantages do you envision utilizing VFD? The nice thing about current lathe offerings either way is they come with taper attachment. That was a spec-up-front option in my era & completely different cross slide screw & assembly. And better n the fly gear changing. I am now incensed with jealousy :)
 
Unless I actually needed that 2" spindle bore I wouldn't even bother to compare the two lathes. Spec sheets don't tell you things like quality or accuracy that are much more important to me.

I spent the time to modify my 1340GT to use a VFD, and while I don't remember the particulars, it didn't cost anywhere close to $1000 dollars. Largest expense was the VFD itself, and I bought mine from Matt. I also already had my eyes on a different DRO so had no need to buy one already installed. As for the belt change, well I haven't changed from the high range since installing the VFD. Don't need to, as I don't do really coarse threads and the VFD allows me to turn below 100 rpm on those rare occasions that require it. Almost all of my threading is done between 100 and 200 rpm. Other folks put the belt on the low range and never move it. Different folks, different usages. If I ever do upgrade to a real VFD rated motor that will go to 120Hz, I may make my own single step pulleys that take advantage of the extended abilities of the VFD and motor and eliminate the factory two-step pulleys altogether. Problem solved. :)

My current lathe configuration is very accurate, and that is the most important quality for my uses. I don't care about pretty. The only thing left to upgrade is the stand, which I don't 'need' per se, but I'd like to have the added stability of the cast iron stand. Had it been available when I bought my lathe I would have ordered it then.

The only other lathe I would consider in this size/capacity range would be Matt's new 1440 from Taiwan, but honestly, it is outside my budget range. :(
 
Thanks to both of you for the thoughts. As to the cost thing - I'm in Canada and our Canadian Peso has dropped considerably in the last few years so a $249 VFD from Matt comes in landed at $370 Cdn, the lathe costs $250 more (without a 4 jaw chuck also) so that's another $370 and I need a box and probably a bit of labour from my electrician friend who I refuse to let work for free just 'cause we're friends so well over $1000 CDN the way i see it.
I'm figuring that most of what i'd use a 4 jaw chuck for I can do on a mill so not sure I'll even end up really missing that option although I can always add one later.
The 1340GT also uses a D1-4 Camlock vs what I understand to be a stronger D1-5 arrangement on the 1440BV chinese lathe
I may be reading too much into the complications of wiring the VFD and can do it myself in which case it would be just under $1000 Cdn total cost. The Chinese offering does come with a heavy cast iron base std. The 2" spindle bore is appealing but truthfully at this point I'm not even sure what I'll use it for - just like the option I guess.
I can always add a DRO later I know - just becomes a how much do I spend and when does it stop (NEVER apparently!). Nice to hear about the speed Range with the VFD on the GT Bill, Matt had indicated to me that with VFD I would not have to worry about speed range but I had read another thread on this site about a VFD on 1340GT in which he would not vary more than about 25% for fear of overheating the motor which sounds like it really is not a concern. Thats a strong point for the 1340 'cause that belt change sounds like a PITA.
At this point my use for a lathe is associated with my hobby of fixing up old Japanese Motorcycle from the '60's and early 70's some of which require reasonably precise parts.
I noted your tag line Bill - about removal of warning labels and wonder if you're the same guy on the VJMC list as I've seen the line before (and it makes me smile!)
Let you know what I decide in the end.
Alex
 
OK, just another opinion.

DRO on the lathe (to me) falls into the "nice, but a luxury" category. 'Nuff said.

3 phase is really nice--I have it on my 1236. Belt changing is a moot point, especially with the VFD. I leave mine on low, and can get 48-2000 RPM. I have my VFD set for 40-90Hz.

You didn't specify (or I missed it) if you are experienced with a lathe. If you are, then 3-phase & VFD is probably the way to go. If not, why not learn on a standard drive? Untold thousands of lathes are in use without VFDs. I'm not, in any way, saying that a VFD is bad--I'm just thinking about someone just getting started, & diving into the deep end too soon.

As to the wiring & setting up a VFD. It is not that tough. Especially when you consider the quality and quantity of very knowledgeable help available here on the forum.

I have done 2 VFD installs. One on a Grizz mill several years ago while living in Alaska. I had ZERO help available. No blue smoke at all.
The second was recently on my 1236. It was considerably more involved due to all the whistles & bells on the lathe. With some hand holding by MKSJ & a couple of others, I got it up & running--again without any blue smoke. I used a totally different VFD than most (irrelevant). It came in a water-tight enclosure. It has two rather serious drawbacks. First is cost, & second is that it has no provision for a braking resistor. It does incorporate some type of regenerative braking and will stop significantly faster than without the braking turned on.

1236 VFD.jpg


Here is what I see as the biggest factor (other than money) in your decision. (The following is not intended to be mean or hateful or derogatory.)

"I'm a bit anal about stuff, like it neat and nice"

Neat & nice generally cost more (in some cases -- LOTS MORE). As you can see in the above pic, I have 3 wires connected to the VFD. One of them is in power from the outlet on the wall to the left. Second is out power to the motor. Third is control cable to the existing power box on the back of the headstock.
Since I am pretty "unclever" about electricity & electronics, I left all of the "stuff" inside the box. I disconnected the wiring from the various switches and reconnected them to the appropriate terminals inside the VFD via the control cable (It has 9 wires inside it.). I have NO HIGH VOLTAGE inside the box on the lathe. The only thing missing from my install is the "jog" feature. That would require running another separate wire to the VFD since I used all 9 of the ones in the control cable. I do not have the coolant system connected, and have the non-oem work light connected to a "wall wart". Power for it arrives via the silver connector on the back splash panel below the VFD.

So, in summary, I would go with the 1340GT Single Phase, and upgrade in a year or two.

Best to you,
Jerry in Delaware
 
One of the guys on our local forum is from Edmonton Alberta & had nothing but positive things to say about Matt personally after successfully landing a milling machine into Kanuckistan. Sounds like the shipping & customs paperwork was relatively painless, which is what caught my attention. He goes the extra mile apparently.

Not to dissuade your path, but provide more data points - Modern Tool carries 14" varietals, Chinese sourced (with their specs, bearing upgrades? CSA...) & usually bundled with chucks, DRO, taper attachment etc. Closest to you is Vancouver. Unfortunately they don't carry Taiwan lines anymore in this size so no equivalent to the PM & I saw nothing with VFD. Also convince yourself you actually like the quality of bundled accessories, that's another consideration. I'm not sure about KBC in Vancouver, they might have different 14" flavors under their own name. Same deal with King Canada, seems to be a common business model.
http://www.moderntool.com/products/category/lathes-new/

I just peeked at this 14"model on the floor in Calgary. More weight, higher cost, wider bed, but some nice extended features if that's of interest. Again, comes complete as a package. Coincidentally looks like Matt carries this one or a variant so could speak firsthand to pros & cons & matchup to your work.
http://www.moderntool.com/products/modern-14-swing-40-between-centers-gh-1440-zx-heavy-duty-lathe/
 
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I have to agree with Bill on all his points, the difference in machines is more apple to oranges, and it really comes down to how much you want to spend and what you want to do with it. I started out I was looking at 12x28-36 or smaller, and I ended up with a 1340GT and spending almost twice as much as my original budget. I also had "0" experience with VFDs. So maybe a few comments and suggestions, we all see things differently so it is all shades of grey.

1. In general, a Taiwanese machine is going to cost something like 25% more, the difference is in the details and the fit/feel of the machine. Compared to the less expensive Chinese machine, they will both give you a finished product and hold similar tolerances at the end of the day. But there may be a number of annoying idiosyncrasies or palpable difference in how the controls work and the user experience. Myself, I had a higher quality Chinese mill that I used for years, but I put a lot of work into making it better. I sold it for a Taiwanese knee mill, and I will never buy a Chinese machine again. That being said, I had more wiggle room on the budget and I saved through the years for the upgrade.

2. I think there is a lot of merit in going with a 3 phase machine for a number of different reasons. It is generally accepted that the surface finish on a 3 phase machine will be better and you do not have an issue with the failures seen with single phase motors, usually due to the capacitors failing or the starter switch. When you are doing operations that require frequent on/off motor cycling, the start capacitors tend to go quickly. Single phase Chinese motors are notoriously bad for failing in a year or two. On this one, on a lathe, I would only go 3 phase. You also have the added issue on the 1340GT that it is not easy to drop in a 3 phase motor at a later point, there are very few motors that will fit and they can be pricey.

3. VFDs are an adjunct and make life easier in dialing a sweet spot and have a few other control features that can make you life a lot easier. If you are old school and run an RPC, that also works just fine. Cost wise you can put together an RPC for not very much, so a few hundred dollars and you are up and running. You have probably been getting some misinformation on the speed range of VFDs and what works, along with the belt changes. So the stock 1340GT 3 phase motor is very decent, a reasonable operating VFD range is 20-90Hz in sensorless vector mode. Keeping the 1340GT belt on the low speed belt range, you are probably talking a speed range of 40-1200 HZ. I never had to change the belt position on mine, and even if I did, it would have taken about 2 minutes to switch speeds. Using an inverter motor, I use a 20-120 Hz range, with a single pulley, I have a usable spindle RPM of 40-1800. I have never been able to bog down either motor, and an inverter motor will maintain +/-1 RPM. VFDs have the advantage of electronic braking, this is more of an issue with the 1340GT that has no foot brake. With electronic braking you can stop the chuck in about a second, but day to day I use 3 seconds. This makes for very controllable acceleration and deceleration. Add an electronic stop and you can stop the carriage repeatably to an accuracy of better than 0.001".

4. You can do a fancy VFD system, or I have outlined in a previous thread of a simple conversion that you can do in a few hours and the machine will operate exactly like a stock 3 phase machine with the VFD variable speed and braking. It only requires a speed pot, an enclosure for the VFD and a braking resistor. You want to add more, this can be done later. You can have the electrician check out your high voltage wiring, but you are talking a very small nominal cost. A $1000 to install a VFD is a bit over the top, but the components can add up if you want to do a complete system replacement with all the bells and whistles. I both help people with this and on occasion build them. I would have pretty high expectations if you are going to shell out that amount.
http://www.hobby-machinist.com/thre...g-the-stock-control-board-and-switches.49022/

5. All this said, the 1440BV is a lot of lathe for the price, and basically being able to hook it up to power and have a purposely built VFD machine at this price level and capabilities is over the top. I do not know of a comparable factory VFD lathe that isn't twice the price. If going with this machine I would get better quality chucks and be done with it. Scope of work wise, I consider the 1340/1440 to be very close, so you are not missing something as far as what you can do on both machines. A slightly larger spindle bore, great if it comes with a machine, but not a huge difference in day to day use. Actually a 2" bore in this size machine in a rarity, and even larger more expensive machines do not have 2" bores. No big deal with a D1-4 vs. D1-5, the latter being a little less common and more expensive. I doubt you will find anybody that says it makes a difference in rigidity at this size level of lathe. The primary advantage is the accommodation of a larger spindle bore, and you need a larger chuck like an 8" to have a large enough through hole to get stock through the chuck.

So all in all, they are both great machines. One is more turnkey and you get a lot of bang for your buck, the other is a more honed/finish machine but will require the cost and time to upgrade to a VFD. Many of us went with the 1340GT because of the pleasure with using it, and that was important to us. But the 1440BV is a strong contender, and offers so much more than say a generic 1236 machine. They all are capable machines, so it is a difficult decision. There is also a wealth of information as to opinions and assistance at this site without getting flamed for asking.
 
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Add the 1440hd into the mix and you know my pain
A youtube review on the 1440 bv is here
seems to be a decent review for that machine
neither is a no brainer for me. I might lean more for the 1340gt because i already have most the tooling to fit this lathe, the 1440bv, 1440HD or 1440GT would require more costs .
the costs are all incremental for the next model and features, and each time i start at the 1440BV, than go for another... I can get... and for another, I can get.... and eventually end up staring at the 1440HD at 6900 and 3000lbs

hth
rich
 
I've watched the video a couple of times Rich, and it's part of why I leaned towards the 1340GT - a sense that while the BV is OK it is a bit rough and he wishes he could have a taiwanese version!!
Mark: I had read your threads on converting the 1340GT to VFD and in fact that is what I asked Matt to sell me (with an upgraded 8" 3 jaw). My $1000 is Cdn and is a combo of the cost of the lathe being a bit more, the cost of the VFD (in this case the Hitachi that Matt sells) (the two of which landed is $750 Cdn) and a little allowance for wire, control box and a bit of guidance from an electrical contractor friend.
I know from nothing about electrical issues other that from an academic perspective so am a bit apprehensive about getting involved in converting the unit to VFD and cost becomes more of a factor if I have to pay a tech to do the conversion for me.

A big part of why I looked at 3phase and VFD is simply the range of speeds and the ability to add a brake as you noted the GT does not have a foot brake. If I understand what you've said the Hitachi unit that Matt sell requires considerable work to install or am I misunderstanding you. I can follow instructions quite well but have no intuitive understanding of electrical issues hence my concerns here. If I can convince myself that the GT is simple enough to convert to what I want I think I can swallow the $ but if I have to get an electrician involved to rewire it then I think I'm going to go for the BV.

Ultimately it does largely come down to cost as I could keep going to the 1440GT for considerably more $ etc, etc or go for the simpler but less elegant route of the 1440BV!

With respect to Modern in Calgary, they sell the twin to the Grizzly G0709 1440 lathe for $7500 Cdn (plus tax) which is a full $1000 Cdn more than the grizzly lathe landed in Canada so a bit of a tough sell from my perspective. I did phone and talk to a sales rep in Calgary and while he did sound reasonable the price point is a bit out of line and the PM1440BV sounds like a better lathe for less money.
 
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