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?

[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.

[Mel Fulks]

Spray denatured alcohol on aluminum to make it cut clean and smooth.

[Jim Becker]

Thanks for the tip! Quick question... how high is the table surface with spoil board on your Stinger II from the ground? I'm contemplating going with the Stinger III in 4x8 but this might interfere with my tablesaw out feed so curious if I'd clear the top of the CNC table or if If have to raise my tablesaw a bit.

About 34", give or take. I have my slider at 36".

Spray denatured alcohol on aluminum to make it cut clean and smooth.

The type of aluminum still matters...the really soft stuff gums up in not fun ways/

[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.

[eugene thomas]

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

[Cary Falk]

I have a 2019 Stinger 2x4 with a higher gantry and a 2.2k spindle. No issues cutting Aluninum but I take it slow. I don't do much of it because it is messy. I have a mister and use denatured alcohol. A special Al cutting bit helps.

[Craig Day]

I have a 2019 Stinger 2x4 with a higher gantry and a 2.2k spindle. No issues cutting Aluninum but I take it slow. I don't do much of it because it is messy. I have a mister and use denatured alcohol. A special Al cutting bit helps.

Thanks for the feedback Cary. What sort of things have you cut in aluminum? And what's the deepest you've cut?

[Cary Falk]

Thanks for the feedback Cary. What sort of things have you cut in aluminum? And what's the deepest you've cut?

I have cut some 1/4" plate. The thickest piece was a pommel and guard for a viking sword which was about 1" thick. I cut the pocket for the blade with an 1/8" end mill. My cuts are always very shallow and the feed slow but I haven't broken a bit yet. I haven't mastered chip loads yet. It always seems like a break a bit when I go by them so I go much shallower and slower that calculated.

[Mick Simon]

What sort of things have you cut in aluminum? And what's the deepest you've cut?

I was once asked to test maximum feeds and speeds for cutting 1.25" aircraft aluminum for a commercial aircraft seat frame manufacturer. They shipped us four 5 x 8 x 1.25 sheets of aluminum. I worked closely with the tooling manufacturers to get their input on chiploads, techniques, etc. I was able to achieve a ⅜" depth of cut per pass at 225 inches per minute using an Onsrud Cutter ⅜" aluminum cutting bit. It took a lot of different approaches to dial it in, such as creating a wider relief channel. As we got deeper and deeper the chips tended to load up in the kerf. We eventually abandoned the testing because of the build up and other factors.
That was 20+ years ago and I still have scars from smoking hot chips hitting me.

[Wes Grass]

Gummy aluminum? Sounds like 5052 ... meant for fabrication, bending, welding. Sucks to *machine* ...

Common for sheet stock, for the bending/welding purpose. 6061 not unavailable... just harder to source ... tends to crack while bending... better across the grain ...

But any of them would like at least a bit of spray mist lube ... even on a Bridgeport... which runs at about 1/6 to 1/3 the RPM you need to run on a router motor ...

A typical CNC router... table of MDF... gonna be a swollen mess of garbage to throw away.

Phenolic likely much better ... no experience... but I'd guess a bigger hassle to anchor parts with drywall screws ...

They DO break at some point.

I have ... or have seen (more likely) bed clamps that tighten 'down', but wedge for location as well.

Screws thru into the table for hold 'down' ... probably good enough in terms of friction to keep the piece(s) in place while machining. Assuming a puny 1/4" endmill ...