ShopBot Desktop router up for the challenge?

[Monochron]

Our team is in a position to buy a CNC mill or CNC router in the neighborhood of $10K and I was hoping to get a feel for the pros and cons of our options from people who are actually familiar with mills and routers . The four factors we are trying to balance are 1) Tolerance 2) Space savings 3) Cutting volume 4) Noise level.

Right now I am leaning towards the ShopBot Desktop with spindle and enclosure. It can fit on our benchtops (32" deep), the enclosure will help with sound, the cutting area is decent (24"x18"), and they are local to us. Does anyone know if the Desktop has the tolerance to cut 1/4" aluminum plate for a gearbox? I know that the Velox routers do, but their size makes them a little less attractive.

We have the ability to outsource large or complex parts to a sponsor, but would really prefer to do 80% of the work in-house if possible. We have a grant opportunity to help fund this, so buying new is more convenient, but could probably go used if it is available now.

We are also looking at different CNC Mills. The speed and tolerances they provide are really attractive, but it looks like they will all have to take floor space, and the noise may be a problem in our small shop. Also, am I right to believe that mills would make machining aluminum tubing much simpler?

• Is the ShopBox Desktop capable of cutting 1/4" aluminum close to +/- .001" similar to a Velox?
• How much easier is it to machine aluminum tubing on a CNC mill vs a CNC router?
• Would the extra speeds possible on a mill negate the noise issue (ie. cuts are loud but only take 5 minutes vs 30 minutes?)

[sanddrag]

You could do a Tormach Mill with a little bit of tooling for right around the $10k mark (barely). If you were going to buy it, you should buy it right from the source rather than from Little Machine Shop. You may want to look into the 770 and perhaps even the 440. They are cheaper (and smaller) than the one you linked. Do not forget about the cost of a stand and possible enclosure. These things are worth it. I'll be standing next to a Tormach mill and their representatives this week. Let me know if there's anything you'd like me to look at or ask them.

I cannot recommend the other two mills you linked. They are oddball Chinese machines, and I doubt you would be happy with them.

As for noise, a router would likely me MUCH louder than a mill, especially in aluminum. And yes, it is substantially easier to cut aluminum on a mill than on a router, but the router can make bigger parts, whereas the mill can make thicker and more precise parts.

If there's any possible way you can swing it in the budget, it would be hard to go wrong with a Haas mill. They just introduced the Mini Mill Edu yesterday. But, you would need space for it and power and air for it.

[Owen Busler]

Team 303 has had a shop bot for 2 years now and we are starting to get comfortable with it. We have the larger buddy and bought the 8' power stick.


1) Tolerance: Center to center tolerance is quite good. We have made a few gearboxes in 1/4 inch plate, in addition to a lot of c-c chain runs and gear-driven mechanisms which require good tolerance. +-0.001? Probably not. Id say the tolerance for c-c is 0.003. Most of our gearboxes have come out perfect but we have had some super tight chain runs along with a few which are a little loose. But IMHO, 0.003 is enough for most any FRC application. The sb desktop page boasts a resolution of 0.00025”. I would be surprised if that was true. One thing to mention is that because of bit flex and I think the buddy's tolerances, the diameter of a pocketed hole always comes in about 0.005 undersized. To compensate we oversize a tad in cad then ream holes for bearings.


2) Box: We have machined tons of wood for prototyping, 1/8" sheet aluminum, 1/4" aluminum, 1x1 box, 2x1 box (both dimensions) and 2.5 x 3 box. The wood is amazing, with just a few screws into the wasteboard the buddy will fly through wood. The sheet aluminum is just as easy. We screw down the sheet in the corners, drill any holes and put more screws in them, then we profile it. As for box, originally we tried holding the box to the wasteboard with wood screws and washers but it was not nearly solid enough and a dangerous and bad idea. Next we tried screwing two vices down to the washboard and that was okay. It took a while to get the vices perfectly square but we eventually got the hang of it. In this offseason we built a more elaborate setup with a wasteboard and two vices off to the side just to keep the vices out of the way of the board. We are really liking this setup.


I am now just realizing the desktop doesn't come with a wasteboard, but rather an aluminum deck and that you plan to get the spindle when we have the router. I cant speak for the spindle but I highly recommend permanently attaching a vice or two to your aluminum bed along with a wasteboard as it will make sheet and box much easier. Once you spend a while getting them perfectly aligned, it becomes a breeze to machine box. I highly recommend the 3 axis zeroing plate:


https://store.shopbottools.com/colle...ant=7825832513


It makes finding the edge of box super easy, plus it tells you if your piece isnt aligned with the machine.


Just a few final notes: 18x24 is pretty small. If you plan on doing primarily gearboxes then you will be fine but we have made drive rails and longer box cuts with great success with the longer bed. Just keep the desktop max in mind. Be prepared to break a bit or two when learning. We use these bits:


http://www.amanatool.com/products/cn...uter-bits.html


Mostly with ¼ cutting diameter. We also have a 1/8th which we use to drill 10-32 holes in gearboxes. In comparing it to a mill, it will be easier to do box on a mill but it is certainly possible to do it on a shopbot. Another good tool to have is this:

https://www.amazon.com/Fowler-54-575...ds=edge+finder

It helps when trying to manually find zeros or if you need to shift a long piece of box and zero with a cut in the middle

Wow I didn't expect to write this much. If you have any questions feel free to ask here or PM me.

[Cory]

Originally Posted by sanddrag

As for noise, a router would likely me MUCH louder than a mill, especially in aluminum. And yes, it is substantially easier to cut aluminum on a mill than on a router, but the router can make bigger parts, whereas the mill can make thicker and more precise parts.

Yes, no question any router is going to be substantially louder than these mill choices.

[asid61]

That Charter oak mill looks interesting, although I've never seen one before (maybe somebody else could chime in?). It advertises AC servos, P3 ball screws, and and an NT30 spindle upgrade. Unless they're fudging those numbers, it should be a lot better than a Tormach. You could try getting a demo of some kind with them just to see what they offer.

[Monochron]

Originally Posted by asid61

That Charter oak mill looks interesting, although I've never seen one before (maybe somebody else could chime in?). It advertises AC servos, P3 ball screws, and and an NT30 spindle upgrade.

Yeah, that's why I am considering it, it seems to be made with great parts and has a much larger cutting area than the other new machines in our budget. Can't find too much online about it though.

Originally Posted by sanddrag

You could do a Tormach Mill with a little bit of tooling for right around the $10k mark (barely).

Tormach definitely looks great, but the small cutting area and floor mount are tough. IFF a smaller router can get us accurate gearbox plates in 1/4" aluminum, then that may be all we need. Let me ask this, what would make you buy a mill over a router?

I cannot recommend the other two mills you linked. They are oddball Chinese machines, and I doubt you would be happy with them.

What makes you say that about the Charter Oak one? What would it's downsides be?

Oh and THANKS for the info about a router being louder, good to know that I had it backwards

[Fusion_Clint]

I suggest you find a way to make room for a machine that will do what you need. Specifically, having the ability to cut your own rails. So I suggest an X or Y axis of at least 36 inches, so that you can do an entire rail without repositioning the piece.

I like our Velox, so in your position I would seriously look at the VR2536 with a 3 HP HSD spindle. http://imgur.com/a/sXwSB

At least look at the http://shopbottools.com/mProducts/desktop-max.htm but I would be leary of the 1 HP spindel.

A spindle is significantly quieter than a router on these type of machines and gives you a way of controlling your tool speed(RPMs). You will need to mount some type of coolant system compressed air and/or a mist system. You can't be recutting the same chips over and over, so compressed air to clear the chips is a must. These single flute tools from tools today do a great job on aluminum and clear chips pretty well. http://www.toolstoday.com/p-5801-sol...uter-bits.aspx

You can build your own enclosure and/or get a vacuum hood. https://www.youtube.com/watch?v=rrKKsYCb8Tg

I suggest you get something you can grow into, once you start your own machining I doubt you will want to do less.

[RoboChair]

Originally Posted by Fusion_Clint

I suggest you find a way to make room for a machine that will do what you need. Specifically, having the ability to cut your own rails. So I suggest an X or Y axis of at least 36 inches, so that you can do an entire rail without repositioning the piece.

I like our Velox, so in your position I would seriously look at the VR2536 with a 3 HP HSD spindle. http://imgur.com/a/sXwSB

At least look at the http://shopbottools.com/mProducts/desktop-max.htm but I would be leary of the 1 HP spindel.

A spindle is significantly quieter than a router on these type of machines and gives you a way of controlling your tool speed(RPMs). You will need to mount some type of coolant system compressed air and/or a mist system. You can't be recutting the same chips over and over, so compressed air to clear the chips is a must. These single flute tools from tools today do a great job on aluminum and clear chips pretty well. http://www.toolstoday.com/p-5801-sol...uter-bits.aspx

You can build your own enclosure and/or get a vacuum hood. https://www.youtube.com/watch?v=rrKKsYCb8Tg

I suggest you get something you can grow into, once you start your own machining I doubt you will want to do less.

THIS! EVERYTHING THIS.

Please find your selves more room to put a bigger machine in, the cost is marginal and the utility is HUGE. Please don't limit yourselves to 24", I know it's a lot of room but it is such a valuable machine. We machined at least 75% of all 3 robots we built last season with our VeloxCNC 50x50, you will use all the space you buy.

You could potentially mount it to a wall and not the floor to make the foot print smaller, Velox should be able to handle it without noticing. Just be clever and I'm sure you can come up with a solution, we build robots after all.

[AdamHeard]

Originally Posted by RoboChair

You could potentially mount it to a wall and not the floor to make the foot print smaller, Velox should be able to handle it without noticing. Just be clever and I'm sure you can come up with a solution, we build robots after all.

They're not designed with counterbalance for this orientation, so potentially you would need to add that.

Other than that, this is a fairly common configuration with lighter duty machines.

[Dale]

We have both a ShopBot Buddy 2'x4' router and a Tormach 1100. Both are fantastic tools. If I had to choose one, though, I'd choose the router without a second thought for FRC. With that tool with a 2'x4' build volume you can fabricate an entire FRC robot. Sure, there are 3D things you'd have a hard time doing without the CNC mill but you just design your robot for the tools you have. Being down the road from ShopBot sure doesn't hurt either. Check out the 2016 reveal video of Zuko which was build entirely using the ShopBot buddy, no other CNC tools and no outsourcing.

[Monochron]

Originally Posted by RoboChair

THIS! EVERYTHING THIS.

Please find your selves more room to put a bigger machine in, the cost is marginal and the utility is HUGE. Please don't limit yourselves to 24", I know it's a lot of room but it is such a valuable machine. We machined at least 75% of all 3 robots we built last season with our VeloxCNC 50x50, you will use all the space you buy.

The biggest thing holding me back from getting a Velox is the potential noise. Using our chopsaw to cut wood is loud enough to stop all conversation in our shop and I can't get a good feel for how loud the heavy duty 3.5HP router on the Velox's is going to be. Upgrading to a powerful spindle would help, but not at Velox's prices, and I don't know enough about spindles to find a reliable one from China.
Do you have a gauge for the level of noise produced by this machine?

[Steven Smith]

Same as you, when the chopsaw whirs, I stop mid-sentence to let it finish. I can now talk over the gantry mill.

For ours, with a 3kW water cooled spindle...The spindle on at cutting speed is just a hum, very quiet. We have a 2HP blower in the room that is a bit louder.

You do get some noise when cutting, especially if you have a poor cut or any chatter/vibrating, but that should be addressed for other reasons than just noise.

When we had a commercial router (air cooled), you had to yell to talk over the gantry. While i wouldn't characterize the new spindle it as "quiet" at least it is fairly consistent so you just adjust your voice over it. Additionally, normal routers force air down towards the bit for cooling, which blows dust everywhere. A water cooled spindle is a lot better for that natively, but you may still want air assist and a vacuum for chip management.

tl:dr;, Our setup isn't quiet by any means, but it isn't deafening, and we can work in the area while the mill is running without difficulty communicating.

[RoboChair]

Originally Posted by Monochron

The biggest thing holding me back from getting a Velox is the potential noise. Using our chopsaw to cut wood is loud enough to stop all conversation in our shop and I can't get a good feel for how loud the heavy duty 3.5HP router on the Velox's is going to be. Upgrading to a powerful spindle would help, but not at Velox's prices, and I don't know enough about spindles to find a reliable one from China.
Do you have a gauge for the level of noise produced by this machine?

We will all wear either ear plugs or earmuffs in the shop while doing part runs on our router(we do have the 3.5 HP router) and I can carry on a conversation with people in the shop while everyone is wearing plugs. It is loud, sure, but it is not unreasonably so. You will only find yourself close to yelling when right next to the router during heavy cuts, everywhere else you only need to raise your voice to be heard through ear plugs. We have cubicle dividers around our router to help attenuate some of the noise.

If you got the water cooled 220V spindle, they are WAY quieter. I will gladly help you find a source from China for a spindle if you desire as they are WAY cheaper(even if you need a VFD to get the voltage). I want to change out our router for a spindle because it is much nicer to work with because you can control your speed via code.

My offer goes for everyone by the way, machines are one of the biggest things I do on 1678 and I love talking about it and helping others with what I know.

[marshall]

Originally Posted by RoboChair

We will all wear either ear plugs or earmuffs in the shop while doing part runs on our router(we do have the 3.5 HP router) and I can carry on a conversation with people in the shop while everyone is wearing plugs. It is loud, sure, but it is not unreasonably so. You will only find yourself close to yelling when right next to the router during heavy cuts, everywhere else you only need to raise your voice to be heard through ear plugs. We have cubicle dividers around our router to help attenuate some of the noise.

If you got the water cooled 220V spindle, they are WAY quieter. I will gladly help you find a source from China for a spindle if you desire as they are WAY cheaper(even if you need a VFD to get the voltage). I want to change out our router for a spindle because it is much nicer to work with because you can control your speed via code.

My offer goes for everyone by the way, machines are one of the biggest things I do on 1678 and I love talking about it and helping others with what I know.

If you don't mind posting links to spindles, I would certainly appreciate that.

[RoboChair]

http://www.ebay.com/bhp/cnc-spindle-motor
or
https://www.amazon.com/s/ref=nb_sb_s...=2LEHNTN7VNJII

I would suggest a 2.2 kw water cooled one with ER20 collets. If you do not have 220V power you will likely require a VFD as well.
You will also need to make sure that you will have a mount to hold it.