[jnnewton]

I've been searching and hoping to find something that met my requirements that would fit in my limited garage space, but have been unable thus far. I need a milling machine for a couple of very different applications. I made estimates of what I would use this for, and came up with a breakdown of the types of work.

50%: Machining cutouts in large plastic boxes. The Boxes are as large as 24x24x18" and get holes / cutouts on every side but the top and back.
30%: Will be flat steel plates 6" x 18" x 1/2" thick that get pockets, square cutouts, slots and through holes as well as 13ga sheet. Also cutoff, flats and snap ring grooves on 1/2" round stock are on the list, so adding a rotary 4th axis down the line would be a bonus.
15%: Aluminum work, no larger than 6"x6"x6" enclosures, and some similarly sized solid block milling, quite a bit of10ga sheet.
5%: Remaining work will continue to be shopped out, as i don't have the room or desire to accomodate it.

So, I'm wanting / considering a machine that, assuming the y axis (if it's a column mill type due to the steel) is the shortest has to be able to mill everywhere on that 24"x24" Face or the z axis if it ends up being a router type, must accomodate that 24" part + tool to do the sides and bottom. I've shopped around and getting a machine that will do steel and accomodate that large of a part is the size of a truck, and that isn't going to work. I need to keep the the footprint as small as possible, I have too much stuff (that I need) as it is. Not sure what the door height is, I can measure that If needed. Since he large parts are normally enclosures, so I don't think I really need more than a 6" of inches of working travel in the z-axis, but accomodating that 24" part while keeping things stiff enough to do the flat steel stuff is leaving me wondering the best way to go. I'm open to any and all suggestions. Thanks for reading.

[LeeWay]

All you really need is a machine capable of just over 12" of Y travel. You can index the plastic sheets and either spin or flip and just machine one half at a time.
It will still be a fairly good sized mill though. This is the one that comes to mind.
Torus Pro | Novakon

I will be receiving it's smaller brother tomorrow. Several guys here have this Pro model and really like it. Do search on here for "Torus Pro" and ask them a few questions.

Are you having to machine the BOXES? You can't machine the sheets and then make the box?

[jnnewton]

Lee,
Thanks for reading and replying. I'm interested in how I would be able to get to the "bottom" face of the box of the box with that mill. If i stand one on it's top it would be 24" tall. The z axis on that machine is only 11.5". Am I missing something? How would I get it in there? I understand the flipping around due to throat / y limitation, but this doesn't help with the z clearance / travel.

As for building the boxes, no way, they are UL approved electrical enclosures, that have been approved for use in the assemblies we build. Not going to change that. Once again, thanks for the info, and if i'm completely incorrect here, let me know.

[jnnewton]

I'm looking at possible designs, and reading about structures and that "loop" through the structure. It seems to me that since the larger stuff is plastic, and the flatter / smaller stuff is where the rigidity is really going to be necessary, if i did attempt to design / build, i could benefit from two designs:
1. a bridge type, where the table moves in the x, and the head is fixed to the y axis, then i could move the whole y axis assembly up / down, thereby decreasing the distance.
Issues moving the large mass of the entire y axis in the z. This would be slightly offset by the lack of a moving z-axis assembly (just the head / spindle / motor)
2. In the same thought, I could build a 4 post / cube style frame, and move the table up and down between the posts, keeping the head fixed in the z on an x / y at the top.
Issues: table / part could be heavy, and would take serious motor or high gearing to move / hold it. This could be handled through gearing, but would lose speed (I don't think i really care too much about it being fast, to some extent.

Second one seems the better in my mind, but the 1st is closer to more common designs. The best would be something I could buy and put to work.

[Dylwad]

I honestly think you need 2 separate machines for what you want to do, a purpose built router for the plastic boxes and a rigid mill for the steel. A machine to handle both while being rigid enough to handle the steel milling is going to be huge, and in the $80k+ price range.

I would get a decent mill like the torus pro and use it to make the parts to build the router, you should be able to do both for under $15k

Having two machines will speed up the process big time too.

Sent from tapatalk

[jnnewton]

Two machines under $15k seems a bit ambitious, and what I imagine would be a pile of support stuff (tooling, pc, etc). It looks as if the torus pro could handle about 60-70% of what we need (some of the plastic boxes are smaller). That's a little less than what I had originally envisioned, and so I'll need re-work the ROI. Does anyone have suggestions relating to the stepper vs servo version, or what exactly the quick change stuff is? I've looked at the tormach tooling system, Is it the same idea? I like the idea of having a future atc possiblity, although I don't see the need for one now. torus pro also has the 4th axis, which would be able to handle one other part we're currently having done outside (assuming the head would get down in close to the rotary table, the parts are only a couple of inches long, with a 1" flat on the centerline, and it's not a full on lathe like i saw on tormach, so maybe we could get it on / off without slipping a disk.

[LeeWay]

I would build a trolley system above the machine if I had heavy tooling plates or a lathe to place on there very often. That will save your back and the machines as well.
I didn't realize your boxes were already fabbed out.

24"" on a router would be pretty easy really. Just build a short gantry that runs on walls. You don't need much cut depth really, so it could be a very solid machine. I agree that the Torus Pro would be a good machine to build some of the parts you would need for a router, but CNC Router Parts has complete parts kits so you could source everything through them that you don't build. You may need a source for rails though depending on the design.

My small router would probably work if I didn't use a central screw in it. 30" x 48". Just lower the table and place the drive on each side and Viola. It cost about $2000 to build.

[Dylwad]

I think $15k without a bunch of tooling isn't too ambitious, a 24x24x8" router shouldn't be more than $2K to build using 80/20 & cncrouterparts components, you don't have to go overboard with it to get good results in plastic. Off lease IBM desktops with XP and a parallel port are under $100 on Ebay. Acme screws and a router will do nicely, I don't think ballscrews and a spindle would make much of a difference.

Steppers will work fine for what you want to do on both machines, quick change tooling on the mill would be nice, but it depends on how complex your parts are.

Sent from tapatalk

[wizard]

I've been searching and hoping to find something that met my requirements that would fit in my limited garage space, but have been unable thus far. I need a milling machine for a couple of very different applications. I made estimates of what I would use this for, and came up with a breakdown of the types of work.

I'm already thinking you will need several machines.

50%: Machining cutouts in large plastic boxes. The Boxes are as large as 24x24x18" and get holes / cutouts on every side but the top and back.

Electrical panel boxes? You will get to the point that laying out the work and cutting by hand makes more sense than trying to mill out cutouts on a milling machine. I've built a few panel boxes and upgraded/modified a whole bunch more, it here to the point size wise that it just isn't worth the time to do such work on tool room sized equipment.

I don't know the specifics about your panel boxes but you are right on the borderline of this not being rational. At best you could try to leverage a mill with the head turne 90 degrees with the panel box jacked up on parallels if required. You would need to change your plane of interpolation to do this.

30%: Will be flat steel plates 6" x 18" x 1/2" thick that get pockets, square cutouts, slots and through holes as well as 13ga sheet.

Obviously a standard mill can do the plate. With sheet metal milling is often less than desirable, shoot for traditional sheet metal approaches.

Also cutoff, flats and snap ring grooves on 1/2" round stock are on the list, so adding a rotary 4th axis down the line would be a bonus.

To do lathe work buy a lathe. Flats can be done on a mill or you can get a lather that supports live tooling.

15%: Aluminum work, no larger than 6"x6"x6" enclosures, and some similarly sized solid block milling, quite a bit of10ga sheet.

Same problem, handle sheet metal like a sheet metal.

5%: Remaining work will continue to be shopped out, as i don't have the room or desire to accomodate it.

Personally I'd look closely at contracting out the sheetmetal work to a shop that specializes in sheetmetal works.

So, I'm wanting / considering a machine that, assuming the y axis (if it's a column mill type due to the steel) is the shortest has to be able to mill everywhere on that 24"x24" Face or the z axis if it ends up being a router type, must accomodate that 24" part + tool to do the sides and bottom.

You don't want a machine, you want machines. If you are hell bent on machining the enclosure you may be better off considering a horizontal mill

I've shopped around and getting a machine that will do steel and accomodate that large of a part is the size of a truck, and that isn't going to work.

Now you know why panel work is often done with hand tools. Beyond that trying to machine unsupported sheetmetal is a pain and extremely frustrating. The bigger the box the more unsupported metal.

I need to keep the the footprint as small as possible, I have too much stuff (that I need) as it is. Not sure what the door height is, I can measure that If needed. Since he large parts are normally enclosures, so I don't think I really need more than a 6" of inches of working travel in the z-axis, but accomodating that 24" part while keeping things stiff enough to do the flat steel stuff is leaving me wondering the best way to go. I'm open to any and all suggestions. Thanks for reading.

Well more information might help.

If these are electrical panels consider buying boxes with removable sub panels. These sorts of panels have side walls that you can remove and machine to your hearts content. That is one approach but the reality is much of the panel work done these days is hand cut or punched out. A good industrial electrician usually will have a large collection of Greenlee hole punches in round and various DIN cutouts. It is just more cost effective for very low volume production.

If you do try to do sheetmetal on a machine tool and that unsupported sheetmetal gives you trouble you might want to try using tooling designed for sheetmetal. Other options include clamping backing plates or other supports to deaden some of the vibration. Interpolate as many holes as you can with smallish end mills.

One possible approach would be a gantry type mill / router of a reasonably stiff design that allows for a horizontal orientation of the spindle. In effect you have a horizontal milling machine. I don't know of any cheap off the shelf machines at the moment so this is likely to be a custom job. It would also be custom because you would need more Z than most such mills provide for. The other problem, common with most router designs, is suitable spindles that cover every thing from steel to aluminum well.

[wizard]

Lee,
Thanks for reading and replying. I'm interested in how I would be able to get to the "bottom" face of the box of the box with that mill. If i stand one on it's top it would be 24" tall. The z axis on that machine is only 11.5". Am I missing something? How would I get it in there? I understand the flipping around due to throat / y limitation, but this doesn't help with the z clearance / travel.

There is no easy way to do this on many stock mills. If the mill has a rotate able head you are much farther ahead but you still have work holding issues on any "garage sized" mill. Depending upon the mill their might be right angle heads available for it. None of these are ideal approaches for sheetmetal boxes though. Considering everything you have listed in your first post you might as well give up on trying to buy one machine to do everything.

As for building the boxes, no way, they are UL approved electrical enclosures, that have been approved for use in the assemblies we build. Not going to change that.

That sound very absolute. Have you even looked around for sheetmetal shops capable of doing this sort of work? Seriously custom built electrical panels happen every day in industry. I'm not sure who is responsible for the UL sticker but I have to say a UL sticker on a sheetmetal box doesn't mean a lot.

Once again, thanks for the info, and if i'm completely incorrect here, let me know.

No one is completely incorrect, well except for a few politicians, so I have to wonder about your volumes here though. It is pretty easy to justify a custom box even at relatively low volumes. Further how do you fit in here, are you just doing the machining work are are you building the complete panel electrics and all? In the end if you are as pressed for space, as you imply, I don't really think you have the ability to do it all. That means sub contractors.

I mentioned removable side panels but if you need to work on the doors too, removable doors are also helpful and make for easier machining. The problem is still one of getting to the center of that door on smallish doors, supporting that door. This is where a router type machine might be a good investment, given that it can machine steel effectively.

Volume of course impacts the ultimate solution here but if you are already overcrowded in your shop I don't see you effectively outfitting it for everything described here.

[jnnewton]

Wizard,
I just read through most of that, and I think you missed the part about the enclosures being plastic. The holes include large LCD cutouts, and some slight counterbores on some of the holes. They also have a pocket in the front, a very shallow one that allows a lexan label to lay flush with the surface of the enclosure. I'm still reading through all that, but at first glance, I think you have just jumped on the idea that I'm simply doing knockouts for conduit or something.

EDIT:

None of these are ideal approaches for sheetmetal boxes though.

Good thing I'm not doing any sheet metal boxes!

[FannBlade]

This need to be CNC? Sound like you could get away with a Bridgeport style knee mill if the production runs were small in manual mode. The snap ring could be done in 1/2" collet and cutter in the vise. Not sure the specs on the Z but I think they could handle the 24". Something more to think about! If this is going to be every day thing.....Whole different can of worms. That steel plate is killing you with the 24" hieght for the plastic. LOL

[jnnewton]

Boxes are about 50-75 / month, with accompanying panels that go inside. Everything else is about 5-10 pcs/month (usage), about 10 unique pieces off the top of my head that are normal usage. Several one-offs here and there for different stuff (which gets even more expensive shopping out). I've got several new projects in the pipeline too, so this is going to go up soon. Everything we would machine is for internal usages, no build to print type work here. Manually doing all of that on a bridgeport sounds aweful, but my machine shop bills are getting larger and larger, hence my starting this thread. Maybe keeping things the way they are is still the best route. Plus, I've got stock on different parts sitting, because sometimes it takes a while to get stuff made at a reasonable rate, which I do understand. I was thinking our workflow, inventory cost and cash flow would be better if the inventory was raw material, and we could do some of the machining as part of our procedure. I could very well be wrong.

[FannBlade]

I agree on the bridgeport. Have you thought about a 4'x4' CNC router and just do the plastic parts? You could setup 4 at a time but it would need on tall Z.

[jnnewton]

Yeah, I was imagining a router setup where the platform is the z-axis, or even a short z with a way to set / move the platform, or even a platform with a hole in it that some sort of fixture could be mounted to / through. It would probably have to be one with the screws on the sides though, instead of one right down the middle, or have enough room between the edge and the screw to get the boxes in-between. I haven't seen anything for sale that caught my eye, so it'd probably be a build, which I'm thinking is a a risk to take on without another machine in the shop to make / modify parts as needed, one I don't think I'm willing to take.

[wizard]

Wizard,
I just read through most of that, and I think you missed the part about the enclosures being plastic. The holes include large LCD cutouts, and some slight counterbores on some of the holes. They also have a pocket in the front, a very shallow one that allows a lexan label to lay flush with the surface of the enclosure.

I understand the issue with some of the boxes being plastic but I think you need to be realistic here. Your best bet is it machine through holes if you want good results with simple setups. Otherwise you would need to find a way to rigidly support that plastic.

I'm still reading through all that, but at first glance, I think you have just jumped on the idea that I'm simply doing knockouts for conduit or something.

Not really, but Greenlee type punches come in all sorts of profiles. The industry has developed around DIN and other cutout standards because it faciltates working on large sheet metal boxes. Once you go off program you put yourself in a difficult position.

EDIT:

Good thing I'm not doing any sheet metal boxes!

Err you pretty much said that you will be working with sheet metal.

However I really don't see what your attempting as realistic. It doesn't matter if your box is sheetmetal, plastic or fiber glass they won't be that rigid.

[LeeWay]

I can tell you one thing for certain, it doesn't matter what you are machining, if it isn't held very rigid, you are going to loose money on time and tooling.
Laser cutting may yield the best results with all of this, but then that $15,000 ain't going to get close.
I don't think one machine will do it.

[wizard]

You have me thinking though. Wood workers often set up their routers with a provision to mount boards vertically. This makes working on the ends of boards easy as long as they are short. Some commercial routers will even over drive the router on a side or end due to this common need. If you came up with a suitable machine you could mount the panel boxes vertically and as long as the router has the reach you could machine the sides of the panel boxes. This won't solve any door machining issues but I'd seriously look for a way to remove the doors.

Yeah, I was imagining a router setup where the platform is the z-axis, or even a short z with a way to set / move the platform, or even a platform with a hole in it that some sort of fixture could be mounted to / through.

I don't know of any machines that do that. The great majority of machinery out there works over the table with the Z on the gantry. Ideally what you would want is a machine that can operate the spindle off one or more sides of the machine.

It would probably have to be one with the screws on the sides though, instead of one right down the middle, or have enough room between the edge and the screw to get the boxes in-between.

There may be some machines out there that allow you to remove the table and drop a part between the rails. I don't know of any by name at the moment also most machines have a lot going on under the table

I haven't seen anything for sale that caught my eye, so it'd probably be a build, which I'm thinking is a a risk to take on without another machine in the shop to make / modify parts as needed, one I don't think I'm willing to take.

A build would be a big distraction but might be the only way to get what you want.

Your other option would be a largish horizontal/vertical combo mill. These are getting rare and even more so in CNC configurations. Get one suitably big enought and it would handle your work envelope. These are not however small machines when trying to cover the envelop you envision. Staying with mills, there are machines with so called universal heads that allow position the spindle axis in interesting positions. Even with these so called universal machines you still are talking relatively large hardware. You might as well forget About a CNCed machine of this design.

Another approach for a home built machine is to go horizontal. If you take a look at Woodgears.com you will see more really unique manual machines. The concepts would be easy to extend to machining plastic and further to CNCing. These are ideas that would require plenty of engineering at you end to realize a CNC horizontal solution. Further to build a machine that is suitable for production implies at least some metal construction and a suitable shop to build the machine.

In any event I don't see a low cost single machine that can solve all of your mentioned needs. From the sounds of it you need a lathe and a mill both preferably CNC'd. Those machine will only solve your basic machining needs. Then you need a machine to handle those large control panel boxes. If they are all plastic a decent router might do the job.

This idea might at first cause revulsion but have you considered hand held routers and templates, jigs and fixtures? It immediately solves your space issue and if you need extreme precision or durability you could have a machine shop fashion robust units. With a little fore thought you might be able to solve the thin material issue by using a backing plate that gets bolted to the template to stiffen everything up. For example drill two or more holes, spaced well apart, for switches or what have you, mount the template then do your machining and the go back and finish off the two mounting holes as needed. This should give you very high precision and might be the only solution if the boxes grow in size. The reality is a template can be stored against the wall, or hung from the ceiling when not in use. Since you will need a conventional mill and probably a lathe you will preserve a lot of shop space taking this route.

[brcarls]

One thing you don't want to hear is that the box is no longer UL approved after you have substantially modified it... You'll probably never get caught, but that un-approved sticker could be very expensive if a big company buys your product and audits your UL approval.

Given that, making your own boxes from flat material (and pursuing a legit UL sticker) is probably the way to go. You probably still need 2 machines though.

[handlewanker]

Hi, the problem is you need capacity not power for the cut outs on the enclosures, and also to do it without manual manipulation of the work pieces, IE fasten it down, push the green button and all the holes get cut in sequence.

This sounds like a rotary metal base for the workpiece and a robot with an arm mounted tool to move round it......a robot arm would handle thin metal or plastic unsupported box sides without the need to be totally rigid for solid metal milling etc.

At the same time you can have any size of enclosure you want, size is no problem when the robot/tool is independent of the base, but firmly related to it for positioning.

Back in the 70's I worked on a machine called a floor borer.

This design had a huge cast iron base plate, 10 metres X 10 metres square with Big Tee slots cut into it to bolt the jobs down on.

There was a large trackway slide alongside the base for the X axis that carried the moving head Z axis, like the column of a column mill with a ram that worked as the Y axis.

The milling cutters were mounted on the end of the ram.

This enabled large fabricated structures to be bolted down solidly without moving, and the moving X,Y and Z axis'ssssss moved over the structure to mill the various cavities and flat areas etc.

This is something like having a robot arm that moved over the job instead of having a huge solidly brace machine structure that needed to be massive just to bear it's own weight and have capacity for volume which also made the machine envelope huge.

This is something that could be custom made for a relatively small outlay.....maybe utilizing an ex welding robotic arm and a large rotary table etc.

The solid aluminium work could be done on a small CNC column mill in one corner of the shop, and a 4th axis might do the other functions you mention.

You haven't mentioned a budget, so I assume money is par for the course, whatever it takes etc.
Ian.