29Sep 2013

Entering the CNC world with a probotix fireball

After having borrowed my work's CNC so many times, I figured it would be better if I bought one :-)

fireball V90

Choosing the CNC you need

I occasionally need a CNC to machine slots in enclosures I buy. For example, Hammond manufacturing sells very neat boxes that will accommodate most of your projects. However, things may get tricky if you plan on using a display of any sort, as you'll need to precisely drill the opening. Moreover, a CNC is also a good tool to produce PCB prototypes.
I don't have a strong background in mechanics, which also influenced my decision to buy a CNC
What you need to look for when picking a CNC:
- the frame material: an aluminium frame will allow you to machine aluminium, which may not be true with a wooden one
- the community behind the machine (forum/mailing lists...) as they'll be the ones answering your questions
- the attainable precision: you'll need to define your needs to deduce what kind of precision you want
- the work space: how big are the pieces you want to make?
- if/how the spindle position is measured

The probotix fireball V90

fireball V90
I chose the fireball V90 for two main reasons: the low price and the community. I deeply regret my choice now (continue reading for the details). Anyway, as I live in Europe, the guys in the US were kind enough to offer me a rebate. The machine is sold as a kit and it is up to you to assemble it (assembly instructions here). The spoil board is 'fixed' while the gantry moves in the X&Y directions.
The frame is made of MDF wood so rigidity is not the best. It uses Oilite bearings which is essentially a porous metal filled with oil sliding on rails. For information, medium to high-end CNC machines use linear bearings which are much more reliable in the long term. All in all, this means that I'll often need to tighten the machine and oil its rails.
The assembly was quite easy even if there were a few bad surprises that I'll detail later. I chose the following options: 3 axis probostep motor/driver kit, anti-backlash drive nuts, pbx-usb control board, t-slot table, cnc-usb control software. The latter is very intuitive to use and I quickly got used to it. I don't remember why I didn't go for the free EMC2 though. I bought a wolfgang engineering spindle, which is very light and is supposed to turn at 20k rpm. However, the belts that drive the spindle dry and break after a few months (I'm still waiting an answer from the seller on the matter). Luckily, these belts can be found for very cheap here as they basically are o-rings.

What surprised me is that the white plastic bits supporting the rails aren't precisely positioned (the mounting hole is quite bigger than the shaft). Therefore, I chose to move the CNC gantry to the X/Y limits and then tighten them. X/Y/Z limit switches are not included in the kit so you'll need to build something like this:

X and Z limit switches
To hold the pieces I want on the machine, I bought a cheap vice on ebay (search for shars vise):
As for the endmills, I found this seller's store to be very resourceful. The fireball V90 uses stepper motors. For those who don't know, a stepper motor (or step motor) is a brushless DC electric motor that divides a full rotation into a number of equal steps. The motor's position can then be commanded to move and hold at one of these steps without any feedback sensor. Therefore, there is no absolute spindle position sensor on the CNC. The resolution you have depends on the motor's number of steps and on the leadscrew pitch.

Probotix support

This truly was a patience tester. When I looked for more details about the fireball V90, I found this website which was detailing all the assembly steps but also mentioning that probotix support was good. This was not my experience at all.
When I received my order, I was unlucky enough to see that my control electronics enclosure was damaged:

Somehow the panel was pushed, which resulted in a few components behind torn off:

Oddly enough, one aluminium piece which is supposed to fit in the t-slot table groves was not machined correctly (see how the hole is smaller than the screw?):

From there, here is the list of events that happened (the same list from Probotix's side can be found here):
- August 5: damage signaled to probotix
- August 5: probotix informs me that they will start an insurance claim with the transporter (UPS)
- August 8: probotix informs me that there are no news from UPS
- August 9: probotix informs me that UPS will contact me regarding the claim
- August 9: I ask probotix if they'll only send me the replacement parts if the insurance claim succeeds
- August 10: probotix informs me they'll send me replacement parts even if the claim doesn't succeed.
- August 16: probotix informs me that UPS will contact me a few days later
- August 19: UPS contacts me to set a meeting date to check the package state
- August 22: UPS comes and takes pictures of the package
- August 26: I ask probotix for news, they inform me there are none
- August 28: Probotix informs me that the claim has been denied and that they'll send replacement parts to me once they're sure I can keep the package I received
- August 31: I query probotix for news, emphasizing that it had been already three weeks since I received the order
- September 3: Probotix tells me the claim has been overturned and is now approved.
- September 3: An UPS agent comes to my house and took other pictures of the package.
- September 3: Tired of waiting, I casually mention I'm a writer for Hackaday and ask why they had to wait for UPS' decision to send me replacement parts
- September 3: Probotix informs me that the replacements parts have just been shipped. As for why they hadn't sent the replacement parts yet, they write: "we were waiting to ship out the replacement parts because we wanted to make sure that UPS wasn't going to take your entire order since we are only shipping the replacement parts for what was damaged"
- September 15: After 40 days, I finally receive the two replacements parts:

replacement parts
However, another problem came up when assembling the t-slot table:

screw problem
One of the four screws was shorter than the others, making it impossible for me to correctly assemble the spoil board. I contacted once again probotix, that shipped the replacement part a few days later. I'd gladly have bought another screw myself if it hadn't been a non-metric one.

And the nightmare continues...

Shortly after having machined a few parts, I noticed a play in the z-axis assembly:

The answer from Probotix: "We discovered some variances in the bushing sizes and we are looking for a resolution currently. We will probably send you out a new Z-axis.".
Which makes me wonder if there's any testing before shipping out orders? So 10 days later, they sent me a new z axis assembly....

Just kill me already

One month after having discovered that there was a problem with my original z-axis assembly, I received my new one:

Ok now I'm pretty sure there definitely is no testing at Probotix. In the video I mention that the acme screw is bent, but there's also a misalignment between the stepper axis and the screw.
I therefore contacted again Probotix, but after many emails and videos showing the problem, this was the conclusion from them: "I have reviewed the video link you sent and I just don't see a problem.". As long as I make the z axis stepper turn slowly to avoid any vibration, no problem....

And the solution was so simple

After a while I actually realized that my problems could be solved using this:
... which can be bought for $11 on ebay (shipping included). How come this was never suggested?


It took six month to get to the point where I can machine parts correctly, so I'll let you imagine how frustrated I was. Still, I learned many things. While I was waiting, I therefore had plenty of time to make a soundproof box:

CNC box
The box is made of two parts that can be easily lifted using handles. The foam that I used can be bought for around 6 euros per square meter. A led panel is attached on top and an acrylic glass is placed on the front. The machine is now very quiet, which allows me to use it whenever I want :-) . And here is a simple test I did:

cnc test
If i had to do it all over again, I think I'd go with making my CNC machine myself. There are plently of people out there explaining the process, and this chinese seller ebay store have many things for it.
I also contacted the guys over at planet-cnc about the MK1 USB controller that Probotix uses. Here is what they told me about it:

I really recommend Mk2 controller. It works much better than Mk1. Mk1 is getting obsolete.

And when I told them about my misadventures:

I know what you mean about V90. There are better alternatives. I always say, that one buys/makes at least 3 CNCs. First one is useless but helps you learn about CNC. Second one is better but not balanced. Third one is right one.

Wise words indeed.


1. On Sunday, October 6 2013, 18:38 by disappointed

My experience with Probotix convinced me to never buy from them again as well. I purchased a 2 axis kit with motors, drivers and PS, and was convinced to upgrade to the 40v power supply (a good idea). They replaced the 24v PS with the 40v PS and increased the price by $75.

After placing the order, I did a little math and realized that if I'd bought each part separately, it would have been about $45 less than I paid. I tried explaining this and first was told that it's a package and so it's cheaper -- not true, then that it's more because it's a "convenience".

I figured an easy way to fix it would be to just pay the $10 balance of the total of the kit with the 24v PS and the 40v PS. I knew I'd always find a place for a 24v power supply, but they said no, the sale was final. That pissed me off and I kept after them until they finally refunded $45 to be equal to the price of the parts purchased separately. In the end, I think they paid me to make me go away -- at no time did anyone acknowledge that their pricing didn't make sense.

Funny thing, last time I checked, they STILL have this "$10ea, 2 for $25" pricing scheme on their 2 axis kits. I know I should have paid more attention, but my experience buying from small businesses in the maker community has been almost uniformly positive and I like being able to assume a certain level of trust. I just got burned by these guys -- in order to get my $45 back, which had become matter of principal, I forfeited any future support I might want from them.

I've since found better and less expensive sources for similar parts, but I do wish this hadn't happened. Probotix can be a good information resource for a beginning CNC builder. I just can't recommend buying from them.

Live and learn.

2. On Saturday, November 2 2013, 11:21 by Frans


3. On Friday, December 6 2013, 15:27 by Sebastien Brulais


Very interesting article! Congrats for being fail of the week on HAD ;)

I'm currently making myself a CNC (right choice I guess), and I'm really curious to know where did you buy your foam you used to make your soundproof box? It's exactly what I'm looking for...

PS: I'm living in France as well

4. On Friday, December 6 2013, 16:07 by limpkin

@Sebastien Brulais : Thanks! I got my foam from flexolan :)

5. On Friday, December 6 2013, 19:32 by salomon

OMG, I'm so concern right now, I've bought a Fireball Meteor and I'm waiting the shipping to my country, I hope yours is an isolated case!

(sorry my English)

6. On Wednesday, December 18 2013, 21:54 by Mike

I've seen a few articles like this about Probotix but many more that were very positive. i just assembled my Fireball X90 and the only complaint I have is the lack of included instructions and a few things like no limit switches. I also would have preferred hardwood over composite board parts (something that should have been noted before the buy). Most of the complaints I hear about Probotix seem, like this one, to revolve around things being damaged in shipping. My table came fine but I can say it was a little light on the packing considering it was 70lbs and an aggressive shipper could have easily damaged it.

7. On Friday, January 24 2014, 17:51 by Denis

We bought 6 tables from them.
Only one of them was good.
The others have:
S shape machined screws. Need to make them more straight. We asked to be replaced and they said they dont have spare screws !!!!! I sent pictures and they did not care.
Wooden parts are not all exactly machined right. Not aligned shaft to wooden parts.
Need to add washers there and there to fit the shaft on the table.
One table cannot be assembled cause the wooden parts are well made.

NEVER buy cheap CNC machine.
THEY DONT test or assemble them before shipping. There is no double check part list before shipping. It s not professsionnal.
The school is desapointed about the investment.

8. On Tuesday, May 6 2014, 18:51 by salomon

@salomon : I have to say that I'm now pretty happy with my purchase, My Fireball Meteor arrived Home (Venezuela) without any problem (well, only a shaft coupler screw was loosening but I fixed it with some loctite), so far we were learning how to make our designs and now we are making very good parts with it (we have not break any bit so far!! yeah!!). Best regards and sorry for my poor english.

9. On Sunday, December 14 2014, 19:25 by gatergrotto

This story seems all to familiar. I too received the unit broken in the mail. They did however replace it with another unit and got it the next week while I was waiting for ups to get there side done. After getting my machine set up and using it about maybe 5 time one of the driver boards is not working. Going to call them this week and see what happens. So far I they have fixed as promised, but we all know that can change in a heartbeat.

10. On Saturday, January 3 2015, 23:07 by Kummin

Was this purchased in France, but shipped from the US? Or is it a French subsidiary of an American company? Or is it a French company that sells in the USA? Or what?

11. On Monday, January 5 2015, 00:21 by limpkin

@Kummin : purchased in france and shipped from the US using UPS.

12. On Friday, January 30 2015, 14:58 by MS

I also have Fireball V90 with all problems which came with it. I bought it in 2012. I need a couple of weeks to get it going.
But until now I did not have so many trouble because I use it only for PCB milling.
Some time ago I want to carve bigger piece of wood and all went wrong.
The Y axis carriage started wobbling, first I was thinking that the problem is in some lose bolts but then I discover that the problem are oilite bearings.

Now I am planning to change them with linear ball bearings.
Does someone tried to do that?

Since I am from Europe I want to use metric bearings which means I have to change 3/4" Y axis linear rods with 20mm or 16mm rods. I think that for Fireball V90 are 16mm more than enough.

I need a 3d model of Y axis carriage, I want like to print it or carve it.
Does anybody drawn 3d model parts of Fireball V90?
If so it would be nice to share.

I have put so much work in my Fireball V90 until now so I do not want to buy another CNC machine.

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