[alvyalvy]

HI All,

I'm newly registered in this forum. A total newbie in the cnc scene. Been lurking as a guest for a long time reading a lot on these chinese machines and everything about CNC operations. Been going through a lot of decision making on which machine to buy. There is Quick and Jcut and many others, but Jcut has the machine with the size I wanted, 1500mmx900mmx150mm. spoke to taney but quick doesn't offer the machine i wanted. Had a very long chat with Mandy from Jcut. Threads from butterknife and blog from argghh were also very encouraging. Finally ordered the 90150B with linear guideways + all axis ballscrews, 3kw spindle, Jamen JNC-40M usb controller, dust extractor, single phase 220v and auto lubrication.
Mandy was extremely helpful and patient when I was a total nuisance, checking on every little detail from stepper motor models to ballscrew dimensions as well as the usb motion controller. She was basically calling her technician every few minutes as I was flooding her with technical questions which she clearly cannot answer. As i can speak, read and write in chinese, those user manuals for the controller, inverter and steppers were easy for me to understand. For those who want to understand how the jamen works or want a chi-eng translation, I may be able to help. I'm pretty happy so far with the ordering process. Mandy assured me about the aftersales as she explained that they have recently employed an english speaking tech, but that doesn't really affect me as I can converse in their mother tongue.

The wait for delivery will be a long one. I hope i won't be disappointed with the product when i receive it months later.

[alvyalvy]

JCUT 90150N Review:
Basic Specs:
CNC Cutting Area: 1500mmx900mmx150mm
Ball Screws for all Axis: 25mm for X & Y, 16 for Z, all 10mm pitch.
Stepper Motor: 85byg all axis
Stepper Driver: 860H 1600 microstep from factory
Linear guideways
USB Controller to be used with mach3
spindle: 3kw water cooled
centralised lubrication
Damage: ~approx USD5-6k


Finally received my 1st CNC machine, the 90150B, 2 days ago. I was shocked by the sheer size of the package! Thank god my dad ran next door and borrowed a forklift as the freight forwarder came without any means to offload the cargo!

Unpacking was simple after you get the top off the timber box. But be wary of the rampant nails all over the place when you strip the box. From my 1st impression, the machine looks strong, rugged and heavy. Took about 9 Singaporean men (yeah we are smaller and weaker than you westerners) to shift this monster into a workshop!! Definitely, you'll notice that the aesthetic component of these chinese machines is lacking. The paint finishing is sub-standard, the bottom support frame surface are not totally flat but somewhat wavvy, but this is on the side and should not affect mechanical performance of the cnc router. There are some dings here and there on the surface..yes..i'm nit picking like I'm inspecting a new car.. Still for a cnc machine where aesthetics is not even qualified as a secondary concern, the rigidity of the chassis and the gantry is noteworthy! The supporting structure and the bed frame of the cnc machine is cast iron. The gantry on the other hand is cast aluminium. IN fact everything painted grey in the pictures are aluminium, cast or machined..i verified with a magnet.

Taking advice from some disgruntled owners who purchased some "dirty/sandy" machines from jcut previously, i stripped the gantry bellows for some visual inspection. Nope, no sand that i can see or feel with my fingers, no metal shavings too, whew!! Checked the gantry (X-Axis) ballscrew (i opted for ball screw and not the suggested R&P), yup, seemed cleaned of dirt and glimmering with grease. Checked the Y Axis ballscrew at the connection points and supporting bearings..clean but some white foam particles had stuck onto the grease during unpacking..what a disgusting experience digging for the foams with my finger nails. Have stripped to Z Axis too but did not take photo due to greasy fingers.. I did took some photo of the electronics before I 'lubricated' by fingers..

The VFD is a SUNFAR C300A. Did not touch the control options as the 3kw spindle looks deadly dangerous if i fiddle with the vfd conrols.. All stepper drivers are leadshine 860H. All steppers are 85byg, not sure which version but seemed to be the smaller of the 85byg series. Cables are more or less neatly tucked in the cable management. One blaring problem is the AC socket. The AC inlet socket is 3 pin but the earth pin is not connected anywhere. I decide to perform some recabling exercises by doing some grounding on the chassis to the inlet socket and some heat shrink everywhere to neaten the cables. no sweat...

the usb controller is a Jamen JNC-40M 4 Axis controller. Only 3 axis in use, the 4th should support axis A or a slave stepper or servo for X or Y axis. Installation of the usb driver was simple, but you need to specify mach3 folder to install the drivers. After which, you get a nasty surprise when you start mach3 as you see a chinese mach3 interface! The english user manual kinda suck as i've read the chinese version before and it was much clearer than the translated english version....as i skipped through pages, i got impatient and decided to take a quick drive on the new toy..

1stly i set the motor settings. Since each turn on the ball screw moves 10mm linearly and each motor performs 1600 steps to turn 1 rotation (factory configured by JCUT for the 860H on the 200 steps 85byg), i configured 160 steps per mm.
UP,DOWN moved Y Axis, left right moved X Axis. and Page up down moved Z Axis in mach3. Simple and it worked!!!. The travel also seemed to be accurate in terms of distance moved. I was sooo excited!! this is my 1st attempt in CNC!! I've never operated a CNC before..i need to explore and try everything..and then let my stupid finger pressed the Home button in mach3. Yes as expected, one by one the axis moved towards their negative direction. Without me specifying the input pins where the limit switches are on (read my action as skipped reading and configuration step thanks to stupidity and impatience!), my first casualty struck X Axis! The linear block crashed onto the limit switch and broke it along with the alum bracket!!! And that also marked my 1st test on the E-Button! It worked, but i killed a limit switch!! Good thing Mandy packed 2 spare switches in the package. Reinstalled the switch and configured mach3 to recognize the limit switches. There are only 1 switch per axis. Each switch will function as a limit switch as well as a home switch. After testing that the switches worked for all axis, i jogged the gantry to the opposite end along the travel. Taking heed to move to the other end far enough so that it will maximize my working area but not crash against the chassis structure. I set the soft limit here with the values displayed on the DRO. Seemed that all test works now without any axis crashing. It is necessary to restart mach3 each time i make changes to the home/limit switches settings or it won't work right after the settings are configured (yes another crash onto the x axis to confirm this, but good thing, my hand is already on the e-stop this round, so no damages).

i've been reading a lot about cnc accuracy and precision as well as backlash. I've also purchase some measurement tools prior to buying this machine, a mitutoyo dial indicator and a mit digital vc. Since the CNC is a MIC (made in china) product, i'm very skeptical about the manufacturer's claim or 0.01mm backlash. I followed some instructions online to test backlash with the DI and BEHOLD..X and Y axis suffer backlash of around 0.01mm or slightly more but definitely not close to 0.02mm. My DI can only read to the lowest 0.01mm. However it consistently register a 0.01mm to 0.015mm or so backlash. This applies to X and Y axis. I did not test Z axis yet but I'm confident it will be good. Next i tested repeatability. And results are very good at around 0.02mm. It seemed to fluctuate between 0.02mm and 0.025mm (in between 0.02 and 0.03). Next i setup to verify X-Y squareness. I started cutting with the water cooled 3kw spindle (WITHOUT RUNNING ANY COOLANT through the spindle, yes stupidity and impatience again) Drew up a 300mm diameter circle inscribed to a 300mm length Square in CUT2D and exported to mach3 format in mm. With the toolpath, and being really cautious, I performed the cut in mid air. Looks fine. Threw in a 15mm mdf, setup the Z axis and started to perform surface cutting. The 3mm bit sank in 2mm as configured in cut2d and started engraving the square 1st followed by the circle. After which, i did a rough measurement of the diagonals with a metal rule. From this rudimentary measurement, both diagonals appear to be same length. If there was a difference, i would need to measure it with some precision tool since my naked eye couldn't tell the difference. The circle looks fine too and totally within the square. SO I do think I have confirmed X-Y plane squareness. I still have to check Z axis to the horizontal plane squareness but i need to level my machine 1st since it is slightly off level now.

For now, I'm familiarizing with the mach3 controls and cnc as a whole new hobby since this is my newb cnc experience. I'm very grateful to mandy who was a blast to work with. She writes and communicates fairly well in english, though i tried to help her by conversing in chinese. The package i opt for came with a dust extractor system which I've not setup up. Mandy packed in a handful of cutting bits which included some carbide cutters and engravers. She also provided 2 ER20 collet for 3mm and 6mm. I've yet to fully explore the functions in mach3, nor have I played much with the spindle though i'm very sure mach3 was able to control the speed as i throttled the sro values. Until I test the Z axis squareness, I will not conclude this review. So far the performance in terms of mechanical accuracy and precision is promising.. this machine is definitely NOT A LEMON!! I'm looking forward to work on it soon.

PS: the centralized lubrication system is totally manual! I opted for an electronic, automated one..already informed mandy.. she'll verify with the builders and ship the correct one to me if they've confirmed the mistake.

[alvyalvy]

Hi, I'm reporting back again after 2 months having my machine. I've since upgraded the motion controller and the limit switches. The original Jamen JNC-40M card is usb, and i came to realised that usb connectivity for cnc machining isn't ideal. Especially when my mach3 is installed in a notebook, the usb connection is not stable. it could be my notebook's physical usb port problem, but i took the plunge and upgraded to an ethernet motion controller. Ethernet connectivity using the TCP/IP stack is VERY stable. And my connecting cable length can go long, not just 5m (usb) but up to 100m!

The mechanical limit switches that came with the machine works, but after a few crashes due to my mistakes in mach3, i broke a couple of them. And the way the switches are mounted in the motion path of the gantry, is less than ideal. So i resorted to inductive proximity switches which proves to be more accurate in home referencing. And i mount them out of the motion pathway so that they won't be crushed if anything happens.

Oh, i've also added industrial strength wheels and some adjustable stump footings to the machine for ease of leveling and positioning adjustments if necessary.

Here are the photos:

[aarggh]

That's great you have the machine working well, despite the lack of build quality I still think they represent great value. One thing I did with mine was to jog to the very extremities manually and before the limit would trigger, and then manually cut a fine line while jogging it to create the largest possible rectangle it could do, I then used this to as accurately determine the error in psotioning and accuracy. From memory I had to adjust the steps per pulse slightly to get the highest degree of accuracy.

I'm curious to see how you go with the limits for positioning, I thought they aren't very repeatable to any high degree of accuracy given they inductively pick up the "nearness" of the metal? If your using Mach3, you might want to have a look at the interfaces from Ger21 or hossmachine for auto-zero functionality. I'll eventually convert mine from NCStudio to mach3 for exactly that reason.

cheers,
Ian

[alvyalvy]

That's great you have the machine working well, despite the lack of build quality I still think they represent great value. One thing I did with mine was to jog to the very extremities manually and before the limit would trigger, and then manually cut a fine line while jogging it to create the largest possible rectangle it could do, I then used this to as accurately determine the error in psotioning and accuracy. From memory I had to adjust the steps per pulse slightly to get the highest degree of accuracy.

I'm curious to see how you go with the limits for positioning, I thought they aren't very repeatable to any high degree of accuracy given they inductively pick up the "nearness" of the metal? If your using Mach3, you might want to have a look at the interfaces from Ger21 or hossmachine for auto-zero functionality. I'll eventually convert mine from NCStudio to mach3 for exactly that reason.

cheers,
Ian

Hi arggh,
I too was pondering if induction switches are useful as limit switches in terms of accuracy. The only thing i could do to "improve" on accuracy is to place the metal surfaces very close to the sensor sweep path. The gap between the sensor and the alum plates is less than 1mm. very very small gap. Hopefully this helps with the accuracy when i home. I've have not tested the repeatability yet because my alu boards were stripped apart, hence no surface to mount my dial indicator.

When you say you have to adjust the "steps per unit" to get an accurate travel, it might meant that your ballscrew or r&p's threads are not spaced accurately (all my axis ball screws' threads are spaced 10mm per rotation) or your stepper's rightful per rotation steps are not really rotating 360deg (again mine is 1600 microsteps per rotation). From my cuts of some square and circle blocks, the measurement seems correct and corresponds to the steps per unit value. I have not done a large cuts to verify any off in axis travel.

[danielcoyle]

Saw this posting while shopping for a Jcut with Mandy. Looking at buying a JCUT 25S with two spindles, a tool changer and dust collection. IT is 1300x2500. Any general advice would be very helpful.

I asked if I could get the machine in Mach 3 but it is a choice between NC Studio and DSP. Of the two do you have any preferences? How hard is it to change out to Mach 3?

[phongshader]

I'm purchasing the same machine and want to upgrade to the ethernet motion controller as well. What did you use for your motion controller? Did you need an additional breakout box to accommodate it?

[FGG]

Hi, I will probably be buying the same machine but with the desktop version. I am currently in contact with Mandy to get the exact specs of the machine. Here is what I found so far as well as what I am missing

ETHERNET OPTION :
Looking at Alvyalvy machine, looks like you upgraded to a ethernet smoothstepper board and the C32 breakout board from :: CNC4PC :: iNtRo . seems like a very nice board with a lot of expensions/safety features.
If you choose the ethernet option from JCUT, you will also get the smoothstepper board with a CNC4PC C25 breakout board and C41 spindle driver board. I asked about the C32 board upgrade but apparently JCU does not provide it.


GANTRY height UPGRADE : is 250mm (10") it too much ???
I am debating to increase gantry height from 150mm clearance to 250mm clearance (~200 USD upgrade) to be able to do a few 3D molds in aluminum . I don't mind if I have to spend time/go slower to minimize stress on the gantry . Yet, I am not sure if this is a wise choice because of the potential increase in Gantry flex. As per JCUT/Mandy technician, it should still be OK. Any advice or sharing of experience on the matter would be welcome.


STEPPER MOTOR:
Model from JCUT is Chuangwei 86BYGH450A-06SD () Yet, I cannot find the exact model on their website. Does anyone have the torque specs for this model? looking at similar model, I suspect it is around 12kg.cm. What minimum torque would you recommend for such a machine . In other words, did some of you need to upgrade to beefier motors?


SPINDLE:
They are supplied by Qiancheng or Jiesite for 2.2 or 3KW models. I did not manage to get the specs from JCUt about their runout values. Did any one manage to get those specs ?

Thanks in advance for any info you may share.

[TONYDG]

I got the exact machine from Mandy. but I get my machine stall very frequently. Did yours did the same with the USB connection ?
Thank you

[jason-weihong]

Are you using ncstudio? email me if you need help with NCstudio. [email protected]