Probotix Nebula?

justallan1 · October 10, 2015, 11:06:57 PM

Well I'm getting closer to buying a cnc router and am looking real seriously at the Robotix Nebula from http://www.probotix.com/
It sure seems to be everything that I want in a cnc and although it's not free, it does come in cheaper than everything that I've seen with a working area that big.
Any thoughts are greatly appreciated.

mesquite buckeye · October 11, 2015, 12:07:05 AM

I thought you were heading out on an intergalactic space mission from the title. ;D 8) 8) 8)

xlogger · October 11, 2015, 05:55:56 AM

I don't have one but did you look at Shopbot Tools. They are in my area and before I retired I work with a National Trucking company and pickup lots of tools from them. They where great people and seem like they had a good service after the sale.

21incher · October 11, 2015, 09:07:53 AM

The title sounded like you were selling a new drug.
It would be nice if you could find one in your area that you could see run, but it looks well built. I see a parallel port so I am guessing that it runs using mach 3 as the controller. You will need a good cam program to create the g-code and it should be a great way to get into cnc.
I recently was looking at the X-Carve 1000MM from Inventables that is a extremely light weight cnc router kit that runs off a arduno processor and allows you to draw the part and create the g-code online for $1,200.00 to play with, but decided to build my own from spare parts I have laying around. I just started building a 30" x 30" x 4" travel one to get into small sign making to create a use for my scrap wood.For being able to push it hard I really like a closed loop servo system, but there are millions built out there running on steppers to keep the cost down.

justallan1 · October 11, 2015, 10:31:45 AM

I'm only 50, but am feeling the need to start looking at something easier than chasing cows around for retirement, when that time comes :D
My grand plan is sawing a few logs, drying it and making signs, toys, puzzles and hopefully specializing in entryway doors with your family crest carved into them. We'll see how that all plays out.
A big part is that Montana can get a bit chilly in the winter and playing outside is out of the question, plus I have the money to spend now and who knows what we'll all have in 10 years.

Texas Ranger · October 11, 2015, 01:59:11 PM

Several years ago there was a Chinese piece of CNC that appeared in Houston that caught my eye. I visited with them and they exposed their entire operation, including the failure rate of the then new machines. I am sure the newer stuff is better, but the best bet, as has been suggested, is to see one run. From start to finish. take the type of wood you will be using, I took mahogany and was not impressed with the end results (Making doors at the time).

It, like a Woodmizer, was never purchased and still on the lip of the bucket list.

justallan1 · October 11, 2015, 02:30:32 PM

I'd fully agree with seeing one first, that's a bucket of money if it's not what I'm happy with.
Thanks

jueston · October 12, 2015, 08:29:51 AM

what is your intended us? that will decide what machine you should get. just like tractor shopping you don't need 250HP to mow your front yard, but you better have a lot of time your hands if your going to cut hay on a little yard tractor...

i purchased a CNC machine in a similar price range to that and found that it was fine for making signs but i couldn't get the accuracy or cut quality i was looking for out of it.

i was able to return that one and then i built a pro4848 from CNC router parts, its a kit machine and they give you some instructions which aren't perfect but i got it built.
http://www.cncrouterparts.com/pro4848-4-x-4-cnc-router-kit-p-251.html
this machine cost was close to $7,000 by the time i was finished with it, but i'm completely satisfied with it. where the $3,500 machine felt like a toy that would break if i wasn't careful, the CNCRP PRO4848 weighs more than a thousand lbs(ask the movers i hired to move it last week) and it feels like a piece of industrial machinery that doesn't leave me worried every time i lean on it.

what i learned from my first CNC machine is that you will eventually need to take your machine apart to fix something, and if you build/assemble your own, you will be very qualified to do so. if you purchased an assembled machine things seem much more confusing when you start taking things apart, and you might miss a step during reassembly.

while building a machine from scratch is a great way to get into CNC for less, i was more interested in cutting things on my CNC then learning about building CNC machines, so i made the decision that i was not interested in building from scratch.

i made efforts to see both my machines in person before i purchased but failed with both, there are lots of people with hobby CNC machines but the majority of them are hard to find, and there are so many different types of machines that its hard to find someone who wants to show off who has the right machine near by. both times i decided to take the plunge sight unseen.

if you do go and see one, i will give you my 2 cents for what to look for, since i would have had no idea before my first machine. you want a machine that is rigid. so with the machine powered up the stepper motors lock all the axis's in place, grab the bit in the spindle and try to push it around. on my first machine i could move it more than an 1/8inch to each side just by pushing hard enough. with by pro4848 i can't move it any perceivable amount, this is important because the machine has a couple horse power up there cutting through wood, and the force of that cutting is not constant, when you cut a circle for instance, on one side it wants to pull one way and on the other it wants to pull the other way, if the machine is sloppy and can be pushed around, then the power of the spindle in the material will push it all over the place. also the more slop you have the faster your bits wear out and the lower your cut quality.

feel free to PM if you have any specific questions you have that you don't want to post out here, there are a few other forums that are specific to CNC and might have more specific info.

justallan1 · October 12, 2015, 08:59:20 AM

Jueston, thank you very much for the info. I'm now in the process of trying to find one of Probotix machines within a couple hundred miles of me to go check out.
So far the only gripe 've heard on their machines sounded more like operator error to me.
Thanks again.

hackberry jake · October 13, 2015, 02:37:23 AM

I looked into the probotix line before I built mine. They seem like a good value with decent linear bearings. I have heard that their motors are higher impedance and operate best with higher voltages than what the machine comes with. I think most of their machines use a 24 or 36 volt supply. A 48 volt supply would likely allow much quicker movements and more torque at higher rpms. I think you should build one from scratch. I may even have a few extra parts I could send you. The stepper drivers are the heart of the electronics and good ones are pricey.

edit- I just checked their website and a lot has changed since the last time I looked. It looks like it comes with 420oz motors and a 40v power supply. That should work nicely.

justallan1 · October 13, 2015, 07:56:53 PM

Thanks Jake.
It crossed my mind to ask you for a bid to build one.
I've been hunting around for awhile now and just couldn't give up the money for what size machine that I want and couldn't afford to buy a "practice" machine for the time being either. I found Probotix by accident and am certainly glad I did.
For everything I want it will go about $8g, including the 4th axis and V-carve Pro. In reality I'll probably make due with the basics on it, make my own spoil board, make my own vertical attachment for doing dovetails, add the 4th axis later, but still go with the V-carve Pro and come in at about $5,500 and shipping. I can live with that.
The best news is I went to the bank today and the pretty little lady that does loans says that I can have that on a signature, plus at a better rate this time. ;D

5quarter · October 13, 2015, 10:47:33 PM

Quote from: jueston on October 12, 2015, 08:29:51 AM
...you don't need 250HP to mow your front yard....

says you... ;) :D

low_48 · October 13, 2015, 11:56:20 PM

Those are assembled right here in Peoria. A good friend of mine made a barter deal with Len for a Nebula. He got the rotary axis as well. He has had some electrical trouble with the VFD that controls the spindle. One of the stepper motors would loose steps while the job ran. They replaced a board in the controller, still trouble. He now has the VFD mounted on the wall, about 20' away, and it runs just fine. I'm not convinced it isn't a grounding issue, or they didn't use a good enough shielded wire. Let me know if I can help you, the business is less than 10 miles from my house.

justallan1 · October 15, 2015, 07:29:10 AM

Thanks low_48
Len and Melissa seem to be great people and are putting up with my 3,000 questions with a smile.

justallan1 · October 19, 2015, 08:42:24 AM

Well after much digging around, comparing and whatnot, I pulled the trigger on the Nebula cnc from Probotix.
Through all my searches I could only find one gripe and that easily could have been operator error. I'd say that's a pretty good record!
A good part of why I went with this machine was the size of the work area, it can carve up to 37x50" and it's made entirely of aluminum and steel, which boosts confidence a lot. Nearly everywhere else that I looked, anything near that size machine was well out of price range or had other hang-ups.
Another big reason I went with this company is that they are made in the USA and between them and their forum I've had every question answered in words that I can understand.
I downloaded the trial version of Vector V-carve pro and so far really like it. I haven't used any CAM programs in 12 years and was able to pick up a lot of the 2D stuff very easy.
Here's the machine if you want to see what I'm getting. http://www.probotix.com/CNC-ROUTERS/NEBULA-CNC-ROUTER

jueston · October 19, 2015, 09:19:33 AM

what add-ons did you get?
what spindle/router?
4th axis? that's something i really want someday, i think i'm going to build one out of a wood lathe set into the frame work of the cnc machine

you should invest in some high quality carbide end mills, V-bits, and ball mills. i started out with some really cheap MLCS HHS end mills and they are good throw away bits while your learning, then go on to more expensive bits after you've gone through a few of those and shot your first piece of scrap across the room.

i like watching my CNC machine cut more then i like watching tv, its just so interesting watching it move under its own power and cut whats on the screen. 8)

hackberry jake · October 19, 2015, 09:22:42 AM

Congrats! You're going to love having a cnc router. That should be a good size.Mine is 28"x48" and sometimes I need just a tad more.

21incher · October 19, 2015, 06:14:21 PM

Congratulations on your new router. Looks like a real good starter unit. It would be nice if they could flip those 2 motors to the backside so they are not sticking out on the working end of the table.

justallan1 · October 19, 2015, 07:15:41 PM

Thanks guys.
Jueston, I got the 4th axis and I've got a Bosch 1617 VSR on the way. I bought it without a spoil board or deck to save on shipping and feel I can make my own dovetail making jig for it, which is something I'm interested in for hobby stuff.
Jake, my final goal is to carve entryway doors is the biggest reason that I went this big. This one is the biggest that Probotix offers, but I'm sure it will be all I need.
21incher, I agree on the motors, but will more than likely set it sideways against the wall.

Kbeitz · November 01, 2015, 07:42:22 PM

I built one from scratch back in the 80's.
I used a Grizzly mill drill and powered it with a commodore 64 computer with a digital relay board.
Writing the program with the basic language was the hardest part.

PC-Urban-Sawyer · November 02, 2015, 01:12:50 AM

Quote from: Kbeitz on November 01, 2015, 07:42:22 PM
I built one from scratch back in the 80's.
I used a Grizzly mill drill and powered it with a commodore 64 computer with a digital relay board.
Writing the program with the basic language was the hardest part.

I can see lots of peek() and poke() in that code...

justallan1 · November 02, 2015, 07:23:49 AM

Kbeitz, I have what looks to be about the same mill, but mine came from HF. I'd considered adding CNC controls to it, but it didn't have the work area that I wanted.
It is a good little machine though. I bought mine to make custom 1911 .45 gripeframes for high end paintball guns and if I remember correctly it paid for itself in a day or so. Any more it's just a drill press.

justallan1 · November 02, 2015, 07:45:46 AM

I have to brag on Probotix here. They got me my CNC 6 days early which is just unheard of

I got it all set-up and after 1 error code which was my own fault for not plugging in my remote for it, I carved a sample piece that comes installed already. It works flawlessly.
So I draw up a little sign, put it on my flashdrive, load it in the CNC computer and it won't go. Turns out I didn't specify what exact machine I was writing my toolpaths for. That's set automatically now, but again 100% my fault. :-[
On my first go at doing something start to finish I didn't set my zero correctly, so it carved my sign over the edge of the board 1½ inches, no biggy.
So here's a video of the second "start to finish" project that I did on it. My girlfriend loves her cats and I've been threatening her with this sign for 7 years now, so.............

https://www.youtube.com/watch?v=YbhPfJ5JyfA

Don_Papenburg · November 02, 2015, 11:56:08 PM

Why does it jump all over the board instead of finishing one line at a time?

jueston · November 03, 2015, 08:59:48 AM

Quote from: Don_Papenburg on November 02, 2015, 11:56:08 PM
Why does it jump all over the board instead of finishing one line at a time?

i believe he is using V-carve pro and it looks at each cut as its own individual action, it doesn't group by letter or area or anything. when it finishes one cut, it just moves to the cut with the closest start and does that cut.

to our humans brains writing one letter at a time from left to right might makes the most sense, but the programming is trying to reduce the amount of time it spends "cutting air" or moving without the bit in the wood.

more advanced software offers you move options for how to cut, and how to order events, and some of them will increase efficiency. if he was making a million of those signs saving 4 seconds per sign would be important, but when making 1 sign that level of efficiency doesn't matter.