[Spinnetti]

Background:
I worked as a machinist years ago (not an operator, but a crank turning, DRO reading old-school machinist) on full sized equipment cutting mostly stainless and plastics, all dry. I play at it still at home and have a Grizzly 12x37" 2hp lathe that just has a DRO, and a modified tail stock for "speed drilling". I also have a Grizzly G1006 2hp Mill drill that I converted to ball screws and Servo CNC with a 4 axis Gecko based controller from Dan Mauch.

Where I am now:
I'm making parts for Radio control airplanes/tanks/miniature I/C engines and some custom race car stuff, and MOST of the parts are very small and aluminum. Many of the mill parts are less than a 4x4" and much of that less than .250 thick. I tend to cut everything with cutters .250 and under. On the lathe, much of it is less than .500 diameter and less than 6" long (I do deep drilling on the lathe though). I still think like a production machinist, and get a little frustrated at how long it takes me to make parts with my slow machines. I think both the lathe and mill drill are overkill and the spindle speeds are too slow (The Mill doesn't seem that rigid anyway). I want to CNC the lathe, but don't want to spend the money for the bigger parts and capacity I will rarely use, and still have a slow machine that I can't really use manually anymore

So, here's the questions:
I want to have better accuracy, and higher speed for both lathe and mill. Both have to be servo since I already have a good controller. Given my desire to cut much faster, and since I'm cutting small aluminum pieces mostly, do I:

1. Lathe - Convert what I have to CNC, or buy a small lathe and convert that? I want to do cnc threading too. Ideally, I'd like a little slant bed machine with both gang tooling AND a tail stock - I don't plan to use a tool post, as the same 3 or so tools will cover almost everything I do. It would be pure CNC, so I'd toss most but the bed, tailstock and motor. Can those mini lathes do real work, like perhaps the MICROLUX 7x16 MINI LATHE, Seig C4 etc, or are they going to be just too floppy/low quality? Any small ones that spin faster? Bore hole size might be the limiting factor. 3/4" is kind of the minimum I think, and bigger is better.

2. Mill - Is there something small yet sturdy out there with a high speed spindle, or just build my own machine to do just high speed machining? I want it sturdy, and the column doesn't need to tilt. It could probably just have the motor move up and down rather than having a quill, and doesn't have to have a huge envelope, but it needs to spin a 1/8" and smaller cutter at efficient speeds. I'd rather have something smaller, faster and more precise than I have now so I can really whip out the little parts. Many of my parts are about the size of a dime or smaller and .125 thick that I cut out of 1/2 wide by .125 6061. I do lots of "buried cut" profiling, and a bit of drilling. The Tormach PCNC 770 which seems decent, but a bit too much dough for my budget - maybe if I could get it without the controller - something like that a tad smaller?

Thoughts, Links, Contacts? I can probably make most stuff, but if the price is right, would rather buy at least pieces rather than make them. Ready made CNC stuff doesn't seem that great a value, and the small stuff is usually stepper without real ballscrews anyway.

Here's an example of some of the stuff I'm making: This is a 1/13 scale (about 6" x 6" in size) functioning retractable landing gear for a R/C WWII bomber (a He-111 in this case).

[arizonavideo]

I have both a RF-31 (Grizzly G1006) and a Weiss 30 (BF30) and the Wiess is stronger and straighter than the 31 mill. I just sold the 31 and I don't really miss it.

You still have a slow spindle speed with the Weiss but with just a low cost gear change you can get to around 3500 RPM easy enough. 5K with a belt drive.

For smaller parts I would looks at Hoss's G704 mill when he finely gets to making parts, I bet the finish will be a fair bit better than the Grizzly G1006.

I also have a IH mill and I'm still trying to get it to cut as smooth as the Weiss but not yet.

If you had a Weiss in front of you, you would like the fit and finish a lot better than the G1006 type of machines.

I would use the Grizz to make one last CNC kit for a Weiss and then sell it.

[Spinnetti]

I have both a RF-31 (Grizzly G1006) and a Weiss 30 (BF30) and the Wiess is stronger and straighter than the 31 mill. I just sold the 31 and I don't really miss it.

You still have a slow spindle speed with the Weiss but with just a low cost gear change you can get to around 3500 RPM easy enough. 5K with a belt drive.

For smaller parts I would looks at Hoss's G704 mill when he finely gets to making parts, I bet the finish will be a fair bit better than the Grizzly G1006.

I also have a IH mill and I'm still trying to get it to cut as smooth as the Weiss but not yet.

If you had a Weiss in front of you, you would like the fit and finish a lot better than the G1006 type of machines.

I would use the Grizz to make one last CNC kit for a Weiss and then sell it.

Thanks for the mill info.... Do you have a link to the Weiss? - Not heard of that.

Is it possible to have servo that can also be a primary drive? - i.e. can I run the spindle as "normal" but also have it function as a servo? I'm thinking of making a tool that needs both "free run" and also be run as a servo, and would rather not run the spindle with two different motors... Got an idea cooking.....

[arizonavideo]

Well the USA Weiss dealer closed up but Precision Matthews is inporting the same machines.

PM-MV Milling Machines

The 20 and 25 are about the same with the 25 having a larger motor and table. I think the Grizzly 704 is the same as the 25.

The 30 is about 530 LB and is larger in every way but the head looks almost exactly the same.

They are also sold as BF-25 BF-30.

For some reason the last batch from Grizz had bad motors but I would think that is not a long term problem.

I have the Weiss 30LV which has the longer table than the PM-30V.

This is Weiss CN.

WEISS MACHINERY

They are based in Canada made in China and imported by the Taiwanese.

Hoss has a thread on the G704

[cjdavis618]

If you are primarily going to be cutting Al. Then I would say take a look at the Tormach again. I know you said it was out of your budget, but increasing your budget is easier than increasing your time.

The tormach pc770 and the Speeder attachement will allow you really chew through the AL at good speed rates. Anything you buy and retrofit will take time to tweak, setup and test. Then someday, you can make parts. I have an SX3 that I converted and it is a fine machine, but I am aout to buy the Tormach PC770 with the speeder since I mostly cut AL. The small parts you make would be very good for the high speed cutting you are looking for.

Simply put.

Make one - Might be able to beat the cost of the Tormach or might not - Max speed 5k rpm most likely.

Buy the Tormach, Built and ready to cut. Great service and support, up to 30000 rpm cutting speeds and speeder uses an ER20 collet so you can use that .250 bit and sing through the material.

I have been in your position, and I am glad I had the experiance of building one. But now I know that to realy make parts, before I go hungry. Just buy the machine built.

[Spinnetti]

Thanks for the feedback.... I think that covers the mill. I watched the Tormach videos, and that's pretty much what I had in mind - with my round column mill, I can only cut .125 thick stock at about 2ipm with a 180 degree engaged .125 cuter due to the spindle speed. Only thing about the tormach is that its stepper, and I already have servo and a servo controller.. I'd like to keep servo and get my moneys worth out of that.

Now the lathe. I MIGHT buy a decent mini lathe, toss it all out but the head, then mount that to my mill as both a lathe and a 4th axis. I emailed around a bit to see if I could just get the headstock parts, but looks like a non-starter... maybe I just need to do the whole bit from scratch.... Is there a motor that could be used both ways? (i.e. primary drive motor and only when desired, and also as a servo?)... I think this will be better than having another lathe and I don't have to duplicate the drive system... I can also fab up a gang tooling rack that mounts to the back of the mill instead of using the ram like Tormach does.. I think this is more sensible than mounting a whole lathe on the mill. Would be quite unique in the hobby world I think!

[mmprestine]

Not to distract you but the novakons seem better value with the larger tables.

edit: they will have lathes soon - http://novakon.net/nl150_cnc_lathe.html

[cjdavis618]

Spinnetti, you might try Littlemachineshop.com for the parts for the small lathe/4th.

Some of the users here actually used a X2 mill head as a spindle housing.

[cjdavis618]

Not to distract you but the novakons seem better value with the larger tables.

edit: they will have lathes soon - NL-150 Shop Series CNC Lathe

I'd be interested to see the lathe. I wonder if it is like the KX lathe that Smithy sells, but with a different door system. Also, does novakon have a machine that runs faster than 6k rpm? Do they have a high speed spindle system?


Spinnetti, one other thing to consider. If you are just looking for speed from your spindle, you might be able to get a High speed spindle from Keling that runs much faster than your current one. If your work envelope is that small, you should have room to make a fixture for your mill to mount it with on the side of the head. Problem is that with your column mill, you will have to make sure it is aligned with the column or tramming will be a big issue.

Services

[rowbare]

See this thread, the OP has built an interesting indexer/4th axis. He went through a couple of different designs so it might be worthwhile to read the whole thread.

Success! Mini Machining Center under Mach3 control - Video link

bob

[Spinnetti]

See this thread, the OP has built an interesting indexer/4th axis. He went through a couple of different designs so it might be worthwhile to read the whole thread.

Success! Mini Machining Center under Mach3 control - Video link

bob

Interesting... That's basically what I was thinking in broad outline anyway. Odd how the spindle stopped with every change of direction though. Probably a consequence of using it in servo mode?

How fast will a servo go? Maybe a std motor will go fast enough to just use it in servo mode all the time rather than "free run" OR servo like I was thinking..

Dang.. there's some real gaps in the hobby machining market... what we really need is some "CNC ready" machines so we don't have to rebuild them the second we buy them, yet aren't stuck with spending $7k right out of the box, or having to buy controllers/motors we may not need...

I guess what I really want is a modular machining center that I can buy a bit at a time, but will do real work. Looks like a scratch build is in my future somewhere. For the time being, I'll probably just make my own high speed 4th axis and tooling system. In the iterim I can just CNC my lathe, and when done, just sell off my existing lathe and mill. Good thing I don't rely in this stuff for my income!

[Spinnetti]

If you are primarily going to be cutting Al. Then I would say take a look at the Tormach again. I know you said it was out of your budget, but increasing your budget is easier than increasing your time.

The tormach pc770 and the Speeder attachement will allow you really chew through the AL at good speed rates. Anything you buy and retrofit will take time to tweak, setup and test. Then someday, you can make parts. I have an SX3 that I converted and it is a fine machine, but I am aout to buy the Tormach PC770 with the speeder since I mostly cut AL. The small parts you make would be very good for the high speed cutting you are looking for.

Simply put.

Make one - Might be able to beat the cost of the Tormach or might not - Max speed 5k rpm most likely.

Buy the Tormach, Built and ready to cut. Great service and support, up to 30000 rpm cutting speeds and speeder uses an ER20 collet so you can use that .250 bit and sing through the material.

I have been in your position, and I am glad I had the experiance of building one. But now I know that to realy make parts, before I go hungry. Just buy the machine built.

lol.. probably good advice.. my hobby is not building machine tools - they are a means to an end... Tormach work envelope is way less than I have already, and way-way less than I was used to when I was a machinist, so hard to spend that dough and get an itty bitty machine. Bolting on a fancy dremel doesn't appeal much, but looking at thier site, I thought the primary spindle did 10k rpm anyway? - that's not bad.. on a 1/8" cutter .125 cut depth I could still get about 7ipm maybe? (scaling from my current performance). Even if I do that, the first thing I'll start stewing about is a tool changer, so my work is cut out for me regardless!

Thanks for the feedback... Its hard to make up my mind to commit either lots of time or money or both and maybe not end up with what I want...

[Spinnetti]

Not to distract you but the novakons seem better value with the larger tables.

edit: they will have lathes soon - NL-150 Shop Series CNC Lathe

looks decent, but price is an issue... I already have a good 4 axis servo controller big enough to drive my 12x37 lathe, so I really need just the machine, without the electronics. I planned to just have the computer and controller on a stand that I can use with both lathe and mill. Looks like its hard to get just the machine without the extra stuff I don't need.

[cjdavis618]

Bolting on a fancy dremel doesn't appeal much, but looking at thier site, I thought the primary spindle did 10k rpm anyway? - that's not bad.. on a 1/8" cutter .125 cut depth I could still get about 7ipm maybe?

Thanks for the feedback... Its hard to make up my mind to commit either lots of time or money or both and maybe not end up with what I want...

I think maybe I didn't explain what I was talking about with the highspeed spindle. There are 2 attachments that work with the Tormachs, (and one will work with a Bridgeport as well).

One is the small Proxxon spindle for engraving, etc. The other is the High speed spindle meant for milling that is a speed increaser for the main spindle. Have a look at the top of the page here and you can see what I mean.

CNC Mill High Speed Spindle | Tormach | We provide personal small CNC machines, CNC tooling, and many more CNC items

According to my machinist feed rate calculator, you would be able to do 16k rpm, 128" per minute, at .05 radial DOC and .106 Axial DOC. with a 4 flute HSS endmill. That's roughing and .002 per flute. The same with a 2 Flute at 64ipm. These are both 525 sfpm

The Carbide shows 26004 rpm, 104ipm with same DOCs. 2 Flute. Then 208ipm with 4 flute. (Well past feedrates of the steppers.) That is 851 sfpm



That is the upper limit of the feed rate for the Tormach. I think you would make more money than lost time that way.

[Spinnetti]

I think maybe I didn't explain what I was talking about with the highspeed spindle. There are 2 attachments that work with the Tormachs, (and one will work with a Bridgeport as well).

One is the small Proxxon spindle for engraving, etc. The other is the High speed spindle meant for milling that is a speed increaser for the main spindle. Have a look at the top of the page here and you can see what I mean.

CNC Mill High Speed Spindle | Tormach | We provide personal small CNC machines, CNC tooling, and many more CNC items

According to my machinist feed rate calculator, you would be able to do 16k rpm, 128" per minute, at .05 radial DOC and .106 Axial DOC. with a 4 flute HSS endmill. That's roughing and .002 per flute. The same with a 2 Flute at 64ipm. These are both 525 sfpm

The Carbide shows 26004 rpm, 104ipm with same DOCs. 2 Flute. Then 208ipm with 4 flute. (Well past feedrates of the steppers.) That is 851 sfpm



That is the upper limit of the feed rate for the Tormach. I think you would make more money than lost time that way.

Thanks, I got ya.. what I was saying is the tormach 770 says it does 10k rpm anyway, and mine is only 3k, so I triple my speed right off the bat - Mostly I'm just getting tired of constantly fixing my chinese stuff. My lathe broke again today for the 4th time in a month (a 12x37 I bought new)... They just don't seem to be built for real work, and I'm just a hobby user. If I can sell a few parts first to justify the expense, I'll buy one... for the short term, I think I'll scratch build a high speed 4th axis since I need a 4th axis anyway, and my controller is already set up for it.

[mattbesquare]

I have been in your position, and I am glad I had the experiance of building one. But now I know that to realy make parts, before I go hungry. Just buy the machine built.

Ditto ditto ditto....amen and pass the amunition.