[bmx4637]

Hey all,

I am building my own cnc machine and have been looking for spindles for hourrss. Anyway I saw these set-ups to buy at littlemachineshop

Box Assembly
LittleMachineShop.com - Mini Mill Spindle Box Assembly R8

Head Assembly
LittleMachineShop.com - Mini Mill Head Assembly R8 Spindle

My question is with the box assembly can I attach my own motor to this? I'm looking for something like 2-3 hp, maybe 5? At around 2000rpm. I know this is meant for a small mill so I'm not sure if it can handle that power. Or the 0.47hp head assembly is good?

This is for cutting Aluminum primarily.
Also, if this should be in another thread please lead the way..there are a lot of topics for the forum list and this seems to be the closest.

Thanks,
Alex

[SCzEngrgGroup]

What makes you think you could possibly make use of 2-3HP, much less 5HP, on any machine with such a small spindle? And why on earth limit yourself to 2000 RPM, especially if, as you indicate, you will be using it mostly for aluminum? How did you choose those specs? They make no sense at all....

Regards,
Ray L.

[eartaker]

good lord... you are not going to get 2-5HP on that little head, those are for the X2 mill. My 2HP motor on the ZX-45 is larger than the whole head assembly together.

[bmx4637]

lol well by the responses I must have clearly read something wrong.

what kind of spindle would be good for 2-3hp then? And what rpms am I looking at for aluminum?

Sorry for the newb q's but someones gota start somewhere :boxing:

[joeybagadonuts]

bmx4637,

Tell them to go big or go home.
[nomedia="http://www.youtube.com/watch?v=y1Op4IHcWRI"]YouTube - R2800 JRL Bikes TWO[/nomedia]

JoeyB

[eartaker]

bmx4637,

you need at least a RF-45 clone head to run a 2-3HP motor.

[eartaker]

This is a 2HP motor on a ZX-45 head.

[bmx4637]

Awesome, thanks for the quick reply man. I'll check out the rf then. How about a 5hp? how do you know what head assemblies can handle what?

[arizonavideo]

The head is limited by the amount of torque and RPM, not just a HP #.

If you could run the head at 20,000 RPM you could deliver 5 HP no problem.

You can't run that head at 20k but 6K with new AC bearings is a safe speed that might still require a add on fan for cooling.

At 6K a 1.5 or 2 HP motor should be OK.

You never said what type of machine the head will be on or the size of bits you plan on running.

I would be a bit worried about running a 3/4 carbide cutter in steel at 5K on a X2 body. The head just might explode and pitch some parts all over.

A 3/8" cutter in AL at 6K RPM with a RF-45 body just might be fine, in fact I may do just that someday.

I would add that the plastic gears would go and have to be replaced with a belt setup.

[eartaker]

BMX,

Why would you need 5hp?

[LeeWay]

Not to go against comments so far. They are right about the higher HP motors, but I use a 2HP rated DC motor on one of these heads and get good results.
I doubt it's actually 2HP, but pretty close. Maybe 1 3/4. It runs on 220 VAC though. I did change to a little better bearing but not AC's. I have just been cutting some Fortal aluminum blocks this past weekend. It did really well. It can run up t 6600 RPM. 3/8" cutter as well.
I have need to cut several more blocks and have no doubt that it will run fine.
It is a good solid little head and perhaps the very best part of an X2. You don't need the full head or even the assembly though. Just the casting and the spindle with nut. Install new aftermarket bearings from the start and add pulley and spacers to suit.

[arizonavideo]

Lee: How much run out does the head have?

[LeeWay]

Initially it wasn't great. It was over .001" with some cheap collets. Better collets got it down less than that. Maybe .0008".
When I started using TTL from Tormach, it was even worse. Once I trued the face of the spindle though, it was even better at maybe .0005" or better depending on the tool.
This is with replacement bearings. This machine runs full time and the bearings last about a year. I start seeing a little more runout toward the end of the bearing life and that is when I know they need changing. I think it is about $20 for a set of bearings.
It's really not bad at all for such a cheap spindle.
I will also say that these heads and spindles can vary a pretty good bit. I happened to get good ones for my builds, but I have heard of some that were not so good. Perhaps a bit of a crap shoot.

I will try to post some images of the mold blocks I just cut when I get a chance.

[bmx4637]

cool, some pics would be awesome.

Ok, so I've been looking around for zx-45 spindle assemblies like the one I found for the R8, but I can't find them. I also was thinking of the iso-30 or iso-40 head assemblies. Do you guys know where they are to buy and tooling availability? with tooling and all? I've been clicking ads and links and searching google like crazy but I always see collets and tools w/ no prices or anything to click on, I'm going out of my mind bookmarking tons of websites for every little thing.

newb question: How exactly do the tools go onto the spindle? Is it like iso-xx taper spindle to iso-xx tool holder to collet, then that tightens the endmill?

Thanks in advance,
Alex

[SCzEngrgGroup]

cool, some pics would be awesome.

Ok, so I've been looking around for zx-45 spindle assemblies like the one I found for the R8, but I can't find them. I also was thinking of the iso-30 or iso-40 head assemblies. Do you guys know where they are to buy and tooling availability? with tooling and all? I've been clicking ads and links and searching google like crazy but I always see collets and tools w/ no prices or anything to click on, I'm going out of my mind bookmarking tons of websites for every little thing.

newb question: How exactly do the tools go onto the spindle? Is it like iso-xx taper spindle to iso-xx tool holder to collet, then that tightens the endmill?

Thanks in advance,
Alex

No offence, but you seem to be just shooting in the dark as far as setting requirements for this machine. If you don't start by defining what you intend to DO with the machine, you'll never end up with anything anywhere near ideal. In a couple of days you've gone from an R-8 X2 to an RF45, and now now an ISO spindle. Selecting random parts is a recipe for a whole lotta wasted money and time.... What is it you're trying to do? What do you plan to cut? Out of what materials? How big? How many? What kind of accuracy do you need? What kind of repeatability do you need? 2D? 3D? 4- or 5-axis? Is this for hobby use, or business? Do you need a toolchanger? What kind of resources do you have for building a machine? Casting ability? Welding? Access to a machine shop? Why not buy a machine (almost ALWAYS a better idea than scratch-building one....)?

Regards,
Ray L.

[bmx4637]

Cool, here ya go

I'm planning to build engines, like small 2 strokes. I want to cut in aluminum and, occasionally, steel. I want a workable area of 15 inches by 15 inches (at least, hence why I would like to build instead of buy one with that kind of ridiculous width). High accuracy .0005 inch. 3D. 3-axis. hobby and business. Yes for tool changer but automatic maybe in the future. Resources? I work in aviation as an NDT Inspector so I occasionally bring scrap metal home w/ me and a lot of overtime.


Thanks Ray, for clearing it up for other people. Nobody really asked so I was trying to go down my list piece by piece. Maybe you can help me out with these specs now.

Anyways, I saw maritool.com Tool Holders, Collets and Machine Accessories - MariTool which is probably the best site I've found so far (thanks to cnczone) however I see BT-30 tool holders and iso-30 toolholders separate, are they different or will they both fit the same spindle?

Thanks again,
Alex

[SCzEngrgGroup]

You should seriously consider buying a used VMC. A home built machine with 15" x 15" travels will NOT be good for 0.005" precision. Getting that kind of accuracy over such a wide range of motion will take a LOT of mass, to make it stiff enough. If you can't manage a VMC, consider a knee mill. My Bridgeport clone does a bit over 14" in Y, and 34" in X, and cost about $4K, brand new. But, by the time you add the cost of a good CNC conversion, you'll be up in the same price range as a used VMC, only you won't have the enclosure, or the toolchanger. And you'll spend many months getting everything fully sorted and working at its best.

Regards,
Ray L.

[arizonavideo]

Alex:
I'm sure you have skills but it sounds like you have almost no machining experience. What you said you want to build could not be done by most anyone here and the ones who could would most likely buy a machine if you want to hold .0005. Go to .003 and it is more doable.

You also did not say how much Z you needed.

I would convert a benchtop mill and make a mini motor for fun if you just want to learn. A 15" x 15" machine to do metal with a 12" or so Z is going to be a fairly hard task if you want it to be able to do aluminum.

I like to build things so a guess of cost and weight would be about $2500 and about 500 pounds.

This would be if you used rolled ballscrews that would be +/- .001 per foot.

For a smaller part of around 3" you might be able to hold +/- .001 but for a larger size or deep bore you will not be anywhere close to that.

[doorknob]

Ok, so I've been looking around for zx-45 spindle assemblies like the one I found for the R8, but I can't find them.

The Grizzly that is equivalent to the ZX-45 is the G0519 (G0519 Mill/Drill/Tapping Machine).

You might be able to order parts for the G0519 from Grizzly - here's the parts list and diagram:

http://cdn0.grizzly.com/partslists/g0519_pl.pdf

[LeeWay]

I have the same head on a round column mill that I bought from HF new for $660. Someone had ordered it and never picked it up. They kept reducing the price and then I added a 20% coupon.

My home made mill has much smaller travels.
It is 14" X and 9" Y and Z. I don't think I would be comfortable building anything bigger. The base units are out there for sale at a good price already.

If I did attempt to build one with those travels, it would be a gantry mill, so it could be very solid and heavy duty.
Perhaps concrete over a steel skeleton for the base.
I saw at least one guy doing similar here somewhere.

I don't particularly like the head on the mill I bought. It is a mill drill type machine, so it has an action like a drill press. The square column mills of this type are much better set to convert than a round column type just for that reason. When looking, look for square column.