Thread: Chinese Machines now on Ebay

So I've started sending some questions to Romaxx. What spindle did you guys go with? Given the US ones will not be 240v, I assume we have to buy local. Roger suggested the Bosch colt, but our version, the GMR1 is not variable speed. Is that important?

Also, what software do you guys recommend. I don't see how anything less than Vectric Aspire will work if I want to do anything like 3D. It's a pain Its missing 1 feature only from Cut3D and PhotoVCarve, or it'd be an all in 1 solution.

Russell.

Originally Posted by JNorton

Interesting that the machine on the Romaxx site seems to be much smaller and sleeker in design for its bed size than most of the home made ones I've been researching.

Does it flex at all?

I'm just wondering if it wouldn't be worth paying to have similar parts laser / water cut as opposed to using Ally T section for gantry, etc.

No "flexing" that I have come accross so far, I have run a 1/2" end mill into a bit of spotted gum here I had making a test guitar body with no probs, each pass was 6mm cut with 4mm step over. I am not sure what you are refering to as the T section gantry? My gantry is box section with the ball screw through the center and tig welded end plates bolted to the gantry sides which are 3/8" thick all alloy is 6061-T6. I am not suggesting to anybody they should go out and buy a Romaxx, just saying that there is other options to the chinese stuff out there.

Originally Posted by BoomerangInfo

So I've started sending some questions to Romaxx. What spindle did you guys go with? Given the US ones will not be 240v, I assume we have to buy local. Roger suggested the Bosch colt, but our version, the GMR1 is not variable speed. Is that important?

Also, what software do you guys recommend. I don't see how anything less than Vectric Aspire will work if I want to do anything like 3D. It's a pain Its missing 1 feature only from Cut3D and PhotoVCarve, or it'd be an all in 1 solution.

Russell.

I ended buying one of the ebay chinese spindles and vfd's, a few guys here seem to be using them without any problems so I thought I would give one a go. So far so good, followed the post here on wiring and settings and It has run like a top, very quiet and very smooth. I went for the 2.2KW water cooled model but the 1.5 probably would have done, Ron said the Romaxx gantry would handle the weight of the 2.2 so I went that way. The spindles on Ebay are not that expensive, so if dies it's not like you are going to have to sell the farm over it anyway. In know way is this a recomendation but I got mine through the "Happy shopping" dude,You don't have to use a Vectric CAM program, get another one that suits your needs. Cheers Paul.

So these types spindles?

1.5KW AIR-COOLED SPINDLE MOTOR ENGRAVING MILLING GRIND | eBay

And then a matching VFD like this one?

VARIABLE FREQUENCY DRIVE INVERTER VFD 1.5KW 2HP 7A NEW2 | eBay

I've been browsing around the CNC projects thread. Apart from the physical dimensions of the pieces, and those done on a rotary axis, is there any limitation on specific machines as to what they can do? I mean, guys are showing pieces without specifying what their machines are, so if I see something I like, does the machine I have restrict whether I can try similar items? Does that make sense?

Sorry for the newbie questions. I've been browsing around Sawmill creek, CNCforums etc, but apart from basic newbie info, it's a lot of old thread trawling trying to find answers that everyone else already seems to know.

Thanks. Russell.

What the machine can do is subject to the dimensions of your material and your XYZ movement of course, also if it can be done on a 3 axis machine or if a 4th axis is needed? The rest is just software restrictions, most machines use Mach3 for post processor, this is the software that runs the G code. You can use almost any CAD or CAM program you choose. Common files such as dxf can be used in most CAM software, stl files will need software that handle 3D, what do you predominately want to make with the machine?

Well, I'm an eclectic sort of guy, and like to do a variety of things with the tools I have. I'm into decorative and functional art pieces. What I am currently doing is primarily

- making sport boomerangs out of 6mm ply by hand with bandsaw and belt sander
- making wood/resin/polymer clay pens (and would like to be able to carve/engrave on them)
- Intarsia & chip carving

What I also want to expand to is

- making decorative wooden boxes for the pens
- prototyping and building custom molds for casting pen blanks
- crafting other tools/accessories for pen makers from plastics/wood
- Plaques & sign making small items for markets/cottage industries & gifts

Looking through the other things people have done, other ideas come to mind such as clockmaking etc - things that are functional yet works of art, but they are add-ons after I get the above worked out. The boomerangs and pen work are the main things that started this off.

Hi BoomerangInfo

For engraving pens you would still only need the three axis'.

Z for the up and down (Depth of cut)
Y for the length of the pen (Writing the length of the barrel)
X to spin the pen (Turning the barrel beneath Z)

Bob Willson

Originally Posted by Bob Willson

For engraving pens you would still only need the three axis'.
X to spin the pen (Turning the barrel beneath Z)

Thanks Bob,

I understand only needing 3 axes, but how do you mechanically change the router motion from transverse to rotation on the X-axis? Wouldn't it require a 4th axis component like those EBay ones provide anyway? Or are you saying you need one of those add-ons but you can then just take one of the outputs from your controller and plug into the additional attachment?

Originally Posted by BoomerangInfo

Or are you saying you need one of those add-ons but you can then just take one of the outputs from your controller and plug into the additional attachment?

Yes, that is what I am saying.

Bob

Originally Posted by epineh

The machines themselves are not too bad, they seem reasonably rigid and the ones with ballscrews and linear rails are pretty decent mechanically.

The letdown parts for me are the electronics and manuals, or more to the point the lack of manuals or any kind of legible instructions.

If it were me buying one of these, I would ask if I could get the machine with steppers installed but no electronics, possibly reducing the price. Also I would think of replacing the spindle, the ones with the flexible drives seem pretty dodgy, the others may be OK, we are still getting to that stage.

Apart from that if you are prepared to do some tweaking they would most likely do everything you need, at the moment I am replacing the electronics on my friends machine with some Gecko's and I expect it to make a huge difference. The existing drives made the steppers growl and miss steps, even with the motor removed from the machine and totally unloaded.

It is still a work in progress so I can let you know how it goes, should know in a week or two.

The 4th axis actually looks pretty sweet, I am thinking of trying to buy one by itself one day.

Ok I'm back here again. The lure of the 4th axis for my work keeps bringing me back to this model. I'm concerned about your comment of the steppers missing steps though, as that's certainly not got.

For someone not into rebuilding/rewiring machinery, how difficult is it to do the mods you are suggesting, and what sort of costs are involved? I doubt very much the company selling these is likely to sell them stripped down.

Thanks. Russell.

I guess anything is easy when you know how, for me I just used the the existing controller box which was a little cramped to say the least, then gutted everything inside and started again. New power supply and three Gecko's later and it is up and running again, though my mates PC had died in the meantime (I tested the box at my place on the bench with one motor and it worked really well)

Once he fixes his PC I don't expect any more problems with the machine.

The cost was about $130.00 bucks from Jaycar for the power supplies and assorted bits and pieces, then you would need four Gecko's, or a G540, check Peter Homan's site (he is the Australian distributor), I think he was having a special on the 540, dunno if it is still going or not...he has the G540 listed for $243 bucks so that should come to about $373 bucks for the parts, depending on how you go about it.

If you say it quick it all sounds easy, but if you are not that way inclined you will need a little help, either via forum or getting somebody to assist in person. The Gecko manuals are quite good, maybe have a look at the G251 or G540 manuals and see if it makes any sense to you, that would probably be a good start. Ask some specific questions about wiring them once you read through the manuals and you will have an idea if you can handle the re-wire. Power supplies are nice and basic, I prefer transformers/rectifiers/caps but I know a lot of people use switchmode power supplies.

Russell.

Looking at Peter's site, he has a bundle of G540, power supply & parts + 4 motors for $512.68 for 269oz motors. Are they suitable for these machines, or do you need to go to the 387oz?

I assume that kit has everything needed?

Do the motors just unscrew & screw back to replace the chinese ones, or do you need to make adjustments to fit belts etc etc?

I am just using the motors supplied with the machine, they don't have much info on them, but have a current rating of 3amps so I assume they are around the 300oz/in size.

If I was to buy steppers I would probably just get the 387's anyway, they are the biggest size that the 540/251 can run and is what most people using steppers seem to use ( I don't use steppers on my machines so I cannot really add much more than that)

I would think you could pretty much swap the motors over if the shaft size is the same if you really wanted new motors. They should both be NEMA 23 size...

Russell.

Originally Posted by epineh

I am just using the motors supplied with the machine, t

Oh OK. I thought you were saying the motors were no good since they were skipping. Is the skipping caused by problems with the controller?

I also just realised that the control box on that ebay model with the rotational motor has a non-aus looking plug, I assume for the spindle. That would be a problem changing the controller wouldn't it? I assume the controller is powering the spindle, not just passing through power?

For reference, this is the one I am talking about

NEW 4 AXIS CNC ROUTER ENGRAVER MACHINE PCB'S ROUTING e4 | eBay

If you stick with the existing motors, that connector on the rotary axis would have to be rewired I guess? And how do you convert from the DB9 outputs for the motors to that single connector the ebay unit uses for the main 3?