CAMaster Stinger II rack and pinion when cutting aluminum

[Craig Day]

All,

I've been researching my brains out on CNC routers for the last several weeks and I've narrowed my options down to a few machines with the CAMaster Stinger II being probably my top contender. My only issue I have with this machine is the rack and pinion design. There's so much conflicting information out there it's hard to discern what to believe. This is where I turn to this wonderful community in hopes to getting some real world feedback from people who either own a CAMaster machine and have direct experience with the rack and pinion design, or from people who have owned both rack and pinion systems and ball screw systems.

I'm going to be cutting a number of different materials including some harder materials like G10 and aluminum. My real concern here is with aluminum and what sort of results I can expect from a rack and pinion system like the Stinger II vs a ball screw design (say theShopSabre 23). From everything I've read people are very happy with their CAMaster systems. Everything I've seen and read is in alignment with this when it comes to CAMaster. It's been tough to find a lot of information on how the CAMaster systems perform with aluminum. Is there really a noticable advantage with a ballscrew? The Stinger II claims a repeatability of +- 0.001"... this is just as good as the ShopSabre 23 at +- 0.001".. so is there really any difference in the results of these systems when cutting aluminum?

I'm hoping folks with a CAMaster system can comment on their cut quality/surface finish/accuracy of what they've been able to achieve in harder materials... especially aluminum.

cheers,
Craig

[Michael Burnside]

My personal opinion is that you’re looking at the right set of manufacturers. I too had a hard time deciding. I am absolutely thrilled with my ShopSabre but I think I would probably be equally happy with CAMaster. There is a lot of quality bits on both brands, making them top tier IMHO.

If given a choice I’d go ball screw, but that’s probably more my father, who was a machinist, talking more than anything else.

[Craig Day]

My personal opinion is that you’re looking at the right set of manufacturers. I too had a hard time deciding. I am absolutely thrilled with my ShopSabre but I think I would probably be equally happy with CAMaster. There is a lot of quality bits on both brands, making them top tier IMHO.

If given a choice I’d go ball screw, but that’s probably more my father, who was a machinist, talking more than anything else.

Thanks Michael. Can I ask which ShopSabre machine you have? The 23 is what I was considering but I’d really like to have a 4’ x 4’ platform… which I can in their RC series… but this is rack and pinion and their repeatability number is +- 0.002 where CAMaster is +- 0.001.

[Bruce Page]

Craig, I have an SR23 Stinger with R&P and haven't had any problems with it. I don't think there's enough performance difference between the two systems to worry about it. There was a lengthy thread about it on the Camheads forum awhile back that came to the same conclusion.

[Craig Day]

Craig, I have an SR23 Stinger with R&P and haven't had any problems with it. I don't think there's enough performance difference between the two systems to worry about it. There was a lengthy thread about it on the Camheads forum awhile back that came to the same conclusion.

Have you tried cutting aluminum or any other hard material on your Stinger? If so what has been your experience?

[Michael Burnside]

Thanks Michael. Can I ask which ShopSabre machine you have? The 23 is what I was considering but I’d really like to have a 4’ x 4’ platform… which I can in their RC series… but this is rack and pinion and their repeatability number is +- 0.002 where CAMaster is +- 0.001.

Hey Craig, I have the 23 with phenolic t-track bed, vacuum table, HSD spindle and 4th axis. It’s an absolute beast. The build quality, bearing, guide rails, motors, spindle, etc are outstanding, honestly.

I’ve measured various movements with some precision instruments I inherited and it’s crazy accurate. I cut mostly hardwoods, brass and a little aluminum. Overall the size suites my needs perfectly as I build fine furniture and various templates/knick knacks that fit well within 30x40 bed. I have tiled a couple of times, but I like the footprint overall. My goal was to get a machine that fit 80-90% of my jobs and tile if possible. So far 100% of countless jobs fit, so for me it’s been the perfect size.

I may buy the Pro 404 in a few years when I retire because why not, but I’ve been super happy with my experience.

Shopsabre sales are, ahem, a bit overzealous (I don’t blame them, they believe in their product, but it was a bit much). Their support is outstanding. I had a few stupid questions or clarifications when reading the manual and they responded very fast and said to call if I needed someone to walk me through anything. The day I got the machine I had a wiring clarification and they responded to my email within 1 hour!

I will say that’s one ding on CAMaster. My sales guy was slow to respond (very slow actually) and I got the sense I was a small fish because I was only going to spend around 19k. But that doesn’t mean the product isn’t great.

[Mick Simon]

I don't think you could go wrong with either one, but focusing on ballscrew vs rack and pinion is, IMO focusing on the wrong thing. Both machines will cut aluminum with ease and with excellent precision and accuracy.
Michael apparently had a similar experience I've had with sales at CAMaster. I felt like a very small fish while he focused on the whales shopping for larger, more expensive machines, even though it would have been my second CAMaster purchase. After waiting two weeks for an answer to a simple question about the footprint of the machine, I went a different route. Others have had similar experiences. I will say though, that the CAMaster we purchased for our school (Stinger II SR44 w/servos) has performed better than I expected it to in a sometimes challenging student environment.

[Keith Outten]

I have one of the first Stinger II CNC Routers that CAMaster built so lots of hours on my machine.
Although I have not machined aluminum I have machined a tractor trailer load of solid surface material making commercial signs. As you know solid surface sheets are a very hard acrylic, even so I have been very happy with the cut quality and the performance of my Stinger. I can also tell you that the newer Stinger machines have been improved considerably since I purchased mine.

[Jim Becker]

IMHO, the rack and pinion is a non-issue and it's employed on the X and Y axis because it's efficient and low profile while also being very rigid, being physically attached its entire length. The Stinger II uses a ball screw on the Z axis because it shines in that application. The Stinger series is built in the same industrial way that the larger true-industrial machines are made. No worries. The Stinger machines are "very stout" and that's frankly an understatement. (And yes, I own one...a 2018 vintage)

[Craig Day]

IMHO, the rack and pinion is a non-issue and it's employed on the X and Y axis because it's efficient and low profile while also being very rigid, being physically attached its entire length. The Stinger II uses a ball screw on the Z axis because it shines in that application. The Stinger series is built in the same industrial way that the larger true-industrial machines are made. No worries. The Stinger machines are "very stout" and that's frankly an understatement. (And yes, I own one...a 2018 vintage)

Does your stinger II have steppers or servos on it and what would you recommend? I"m leaning towards the servo option at the moment.

[Bruce Page]

Have you tried cutting aluminum or any other hard material on your Stinger? If so what has been your experience?

I have cut some aluminum, but my machine is not set up for metal machining. I found it very messy and slow.
I have a conventional knee mill for metal working.

[Jim Becker]

Does your stinger II have steppers or servos on it and what would you recommend? I"m leaning towards the servo option at the moment.

Servos were not an option on the Stinger II at the time I bought mine. Although there is no intrinsic need for servos for my personal use, I likely would have bought them had they been an option. For your stated application, the increased precision can be helpful, IMHO. I took "all the things" when I ordered mine with the exception of the extra two inches of gantry clearance which I have personally regretted. While that option doesn't increase Z travel, it does provide more space under the gantry which is handy for furniture parts and "visuals". (I did not opt for the recoil ornamental lathe, either as I knew I would never use it)

[Craig Day]

Servos were not an option on the Stinger II at the time I bought mine. Although there is no intrinsic need for servos for my personal use, I likely would have bought them had they been an option. For your stated application, the increased precision can be helpful, IMHO. I took "all the things" when I ordered mine with the exception of the extra two inches of gantry clearance which I have personally regretted. While that option doesn't increase Z travel, it does provide more space under the gantry which is handy for furniture parts and "visuals". (I did not opt for the recoil ornamental lathe, either as I knew I would never use it)

What sort of gantry clearance do you have now? I wonder if it's changed at all to the current stinger II? Their website states 7" at the moment. When I talked to Cody he said this should be more like 6" with the table top installed. I think this should be enough vertical clearance for all of my planned uses. I would worry about the rigidity of the system with a raised gantry when machining the harder materials.

[eugene thomas]

the bit lenth also will eat up some of the 6" clearance.

[Michael Burnside]

Rigidity worries? No way, those gantries are built like tanks. I'd say if you were looking at a lighter weight material like aluminum then it might be a concern, but I wouldn't worry at all even at 10+ inches.

Regarding servo vs. stepper, it's really a matter of use. In a lot of ways a closed loop servo is better not because of the loop but often the motors are just "better". Servos are awesome for high speed, high torque while steppers are best at incremental movements and all things equal can be highly accurate. You should not expect any more accuracy with either, if you're buying from a reputable manufacturer, it's really a matter of use. Servos have a lot more going on due to the control system too (ergo, new points of failure), so if you don't need the high-speed, high-torque, personally I would save the money.