Mini Mills and such...

[TyRex]

OK.....I need some advice from the more experienced mill users in this forum. I'm gonna fork out the money for a mill this summer and I need help deciding on which one to get. I like the prices and selection at harborfreight.com and I am wondering which of these is a better all around deal:

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=44991 - $500

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=36739 - $550

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42976 -$390

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=39743 - $400

Now some of you I'm sure are thinking "for that kind of money he could buy 10 waterblocks". This is true, however I have a terrible weakness when it comes to tools.........The more the better. Building a waterblock makes for a good excuse to buy more tools.... anyones comments are welcome.......especially if you have experience. And also.....these are the only ones from harborfreight that fit my budget..........If I didnt have any self control at all, then this would be sitting in my garage right now..... http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38850

 

[broken003]

well, I am a little biased (I just bought one a couple weeks ago). I read nothing but good things about the Taig equipment. I bought the CNC ready version (about $770) and added my own motors and controller (roughly $300). Those machines might be able to take larger cuts than the taig, but I am not sure about their quality.

There are yahoo groups on the taig tools
http://groups.yahoo.com/group/taigtools/

and also general mill or lather groups where you can research
mini cnc mill
http://groups.yahoo.com/group/mini_cnc_mill/?yguid=106381670

if you need anymore information PM or email me

EDIT:
oh yea and you can find out the prices for the taig stuff at www.cartertools.com (you get a discount off the prices they list on the taig site) and the Nick is great to order from and answer your questions.

 

[LiquidSquirt]

I wouldnt get anything from HF, personally. I hear that their CS sux and it takes forever to get any response....Also, I hear that they have a lot of quality control issues with there stuff.

I purchased a Grizzly mini mill myself....But if i had it to do all over again, I would have bought one from homier.com for $399 with an R-8 spindle. The dovetail mini mills are all made by the same manu.....Seig.

 

[LiquidSquirt]

Taig is a bit overpriced IMO....and uses proprietary tooling that is hard to come by(meaning that you can either custom make the tooling for the strange sized spindle or you can purchase the limited tooling that Tiag has to offer for it).
Also, I frequent alot of mini mill groups and I hear very mixed things about the Taig mills.
The good thing about a Sieg type mill is that you will have no problems findings tooling for its spindle(MT3 or R-8)


I own 2 CNC mills and have converted them both myself(no retrofitting kits)The first of which was the Grizzly mini mill. And it was nearly a breeze to convert to cnc w/ ballscrews.......zero backlash! Its a good investment
I then purchased a RF45 and converted it.....which was a peice of cake after having mounted ballscrews on the small mini mill.

Taig isnt a real rigid machine by the looks of it. And copper is a real PITA to mill.
Go with a dovetailed, cast iron based mini mill.......you wont regret it

..... a cast iron mini mill like the Grizzly, the homier, the micromark, the wttool, the HF, w/ a rigid dovetail column, a standard spindle taper(MT3 OR R-8).
They are pretty tough little machines, and fairly precise out of the box...the only thing I didnt like about mine was the nylon gears in the geared head assembly(which I replaced with a belt drive)
But the variable speed control on them beats the heck out of changing belts to change spindle speeds as you would with a Taig.

 

[broken003]

....and uses proprietary tooling that is hard to come by(meaning that you can either custom make the tooling for the strange sized spindle or you can purchase the limited tooling that Tiag has to offer for it).

THe sherline 3/8 endmill holder screws direclty on the Taig, no modification necessary.

 

[wormwood]

Don't know if you've seen this one...

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=47158 $299

Not that I would recomend it, but it sure is cheap. I've seen it on sale from time to time.

I would stay away from the multi-purpose machine.

I would subscribe to the 7x10minilathe mailing list on yahoogroups. Get a hotmail account first to avoid spam. You'll learn a *lot*, but they do ramble a bit.

The one that's $390 frequently goes down to $300. Please note that this is a mill-drill and lacks fine grain Z movement. It's also HUGE and HEAVY. If you could have it somehow materialize in your workshop, it'd be a great tool to have, but god help you if you ever need to move it.

Despite the Seigs sheer size, don't think you can take massive cuts. There are plastic gears that will break well before the motor would ever stall. The Little Machine Shop carries these gears, but it's best to take lighter cuts anyway.

Taigs are great. If you have the dough, they'll kick a Sherline in the teeth. For millin' on the cheap, the Seigs do have an edge. The Seigs also have an edge in in-expensive tooling and tooling availablity.

And for completeness, I must mention www.maxnc.com and particularly http://www.maxnc.com/page12.html . It is a Dremel CNC mill, for $895. No, I'm not recomending this either, but it is interesting to say the least.

But after seeing what Hoot did with a drill press, I'm re-thinking my personal need for a mill. A mill is a sizeable investment, and after seeing what can be done with drill press and table saws, it seems the money can be better spent.

If you do get a Seig, get it on sale. For Taig, I think it's Carter Tools or some such that gives a really good deal.

* edit: I should have read broken003's post fully first. He covered Carter Tools and the mailing list. *

 

[TyRex]

Damn, some good info here...........broken03, some real good info there, gonna have to learn some of the terminology and do a lot of research. You also convinced me to go CNC now.

Wormwood, I agree about staying away from the multipurpose machines as well........especially when milling copper.

Sounds like the grizzly mini mill would be a nice platform to start out with for CNC, at least cost wise......The tiag looks nice too, a little expensive, but looks easy to convert to CNC

I really appreciate everyone's opinion......keep them coming.

 

[LiquidSquirt]

The grizzly model Seig mill is nearly the most expensive of the bunch($549).
The homier version is what you want at $299. They are all the same thing just different colors and a few of them offer a choice of MT3 or R-8 spindle.
Id go with a Homier.com, R-8 spindle version. Youll have no problem whatsoever finding tooling for it anywhere that sells machinery and tooling.
The mini mill can be converted real easily using the stock leadscrews. I just needed more accuracy and repeatability, so I opted to install preloaded ballscrews on it.

Whatever you decide to get and do with it.......welcome to the wonderful world of CNC...
Where the more money you throw at it, the easier it becomes!

 

[JFettig]

I have a seig mill, same as grizzly and the harbor freight mill, but from homier.com, I highly suggest that one over the others. Youll spend about $500 after shipping, plus another couple hundred on tooling. get a good collet set for $50, a good vice(I wish i would have to start with) for $100 at grizzly.com 4" vice is good for that mill. then youll spend probably $50 on end mills. spend some on a stand for the mill, some on oil and grease for doing all the sliding parts and whatnots, and a lot of time.

It took a good chunk of time to get the mill close to optimal, I still got a ways to go to get it going perfectly.
I like it a lot, If I could have done it different and had money, I woudl have bought a bridgeport. but I really couldnt for where I live. where my mill hasta be, In my basement. Theres no other mill I could put down there except a cheaper one.(dumb choice)

I would get your end mills at jtsmachine.com, i have a direct link to nice carbides at home. I got my collet set off of ebay for $45 or so, and made the stand and collet holder.
heres some eyecandy



-EDIT- Liquidsquirt, can you link me to some info on ballscrews? maybe ones to use on my mill if I would convert. and maybe some more info on getting it more acurate? Im having problems getting the Y axis to not bind. it squeeks a little here and htere and changes my scale a little. Its kinda anoying.

Jon

 

[TyRex]

ok.....so the seig and the grizzly are the same???? and which one from harbor freight is that one??? Also, the grizzly/seig IS easily convertable to CNC???? Sorry, i'm still a real newbie this.....the info you guys have provided so far has been great


Also, at homier.com, there's a mill there that looks identical to the 500 dollar one at harborfreight, but its 100 bucks cheaper(go fig). It says its a speedway series....is that also a seig???

 

[JFettig]

yeah, thats the one, but it costs $80+ to ship it. thats where I got that number they are all seig mills, just with different names.


Jon

 

[TyRex]

jfettig, is the one you have easily convertable to CNC???? and also it only has 2 speed settings.......would you recommend a multi setting???

 

[LiquidSquirt]

JFettig........
I used Thomson-Saginaw 5/8th-5TPI ballscrews from www.reidtool.com
They fit nicely under the table with minor removal of material off of the table for good clearance. I used 2 ballnuts per screw and preloaded them against eachother for no backlash(that I can measure)
They are pretty cheap @$24 a ballnut and about $12 a ft. of screw for non machined ends.....Not sure how much more the machined ends would cost since I had a lathe and turned the ends down for the thrust bearing assembly.But never the less, Riedtool has em'
If I were to do it all over again, I would just use one nut and get 1/2 the count of ballbearings in the nuts, a larger size and put one every other ball in the nut to take up the play in the nut.
I assume that you completely disassembled the mill after you got it to clean off all the grease(or whatever that $hit is) from the mill right? You did grease the ways and the dovetails really good before assembling them?I used white lithium grease on the leadscrews before I converted and it lasted a while before I had to recoat them. And I used mineral oil based lithium grease from Wallyworld for the ways and gibs, ect.
Have you disassembled the table to check to make sure that your table or saddle dovetails are not warped? When I first got my mini mill sometime ago, I accidentally tightened the lock on the table too tight and bent the table dovetail and it did the same thing you are describing. Does it bind at exactly the same spot?
On the end of travel ... Y+ or - ?
It could be a number of things..
could be that the dovetails have a burr(s) on them that are rubbing against the steel gib strips and causing it to bind.
could be a bent dovetail
a bad leadscrew thread or misaligned leadscrew that only binds in a certain spot.They arent that great anyway(leadscrews)
Its hard to give you any real suggestions without knowing, in detail, what exactly is happening when it binds and where in travel it takes place.

Have you replaced those gibstrips yet?That was one of the first things I did(well after I had to replace the table that I bent anyway)I used Delrin instead of bronze(which most people use for them), to make the replacement gibs and it moves so smooth that I can push it from end to end with one finger if I disconnect the shaft couplings from the motors. And its much more accurate than when I had the OEM gibs.

Let me know something and Ill see if I cant help you a bit more.

 

[LiquidSquirt]

jfettig, is the one you have easily convertable to CNC???? and also it only has 2 speed settings.......would you recommend a multi setting???

The Homier,Grizzly, Micromark, HF and WTTOOL mini mills are all the same mill.....just different names and spindle sizes(MT3 or R-8)and colors.

I didnt know anything about milling machines and I converted it from reading through the posts at CAD_CAM_EDM_DRO yahoo group. It was very simple and I used the mill to make everything I needed to mount the motors and all to convert it.

The mills all have a low gear(0-1100 RPM) and a high gear(1100-2500 RPM) with a variable speed control when in either one of the gears. If i were you(or anyone else who hasnt had it happen yet) .....(broken gears)
I would convert the spindle drive to a direct drive pulley system(or toothed belt) and bypass all those plastic gears in the drivetrain. I made pulleys for mine that lets me get 10.000 RPM out of it....which is all I dared try because of the bearings that ship with it .
Hope this helps

 

[TyRex]

Thanks liquidsquirt.........I've got the perfect spare computer to use for it. That CAD_CAM_EDM_DRO yahoo group is a good place for info.

I read about those nylon gears....doesnt sound to reliable. I will definitly take your advice about the DD pulley system

 

[Excelsior]

ARGH!

Damnit you are all making me think abotu going to buy a mill when i dont have money

 

[Stedeman]

LiquidSquirt how do you control your X and Y axis’s (CNC) do you have it hooked to a laptop / PC or a homebuilt controller box of some sort?
The reason I ask is that for some time I have been thinking about getting one of these mini-mills and I will also be taking some NC classes latter this year so this could give me everything I am looking for if it easy to do
PS sorry for the thread jacking

 

[NeoMoses]

Beware, beware, beware! Machining is a very addictive hobby, and makes most others look cheap.

CNCZone is a pretty cool place for those of you looking to get into CNC machining. It's definately worth a look around.

Here's my best advice: Buy the biggest mill you can possibly afford. I would recommend a Rong Fu dovetail Z-axis if you can swing it. They are quite nice for the price. If you have the room for a bridgeport, get one! They're probably the best mill you can get, and will outlive you if you take care of them.

Machining has been the biggest detractor of my time lately. After I converted my first mill to CNC, I was hooked. I'm now working on a Bridgeport Series I, a BP Series II, and getting ready to play around converting a lathe.

My best advice if you are converting a manual mill to CNC.
- Start with a good quality machine. If you sink $1000 into a POS, you'll just have an expensive POS.
- Use ballscrews.
- Use large servo motors. There's no such thing as too much power.

 

[TyRex]

Beware, beware, beware! Machining is a very addictive hobby, and makes most others look cheap.

CNCZone

I was just about to post that place....google turned it up......Lots of info

Neomoses, you're right about it being addicting.....I can tell right now I'm gonna blow all my free time during summer doing this. You're anodizing info in the classifieds section is giving tons of ideas...... I'd love to see some pictures or maybe even an how-to on your setup.....

 

[LiquidSquirt]

On my mini mill, I use an old P3, running turbocnc(dakeng.com) as the controller. I use stepper motors on the Griz(305 oz-in hybrids), powered by 3 -Gecko G201 microstep drives(2000steps per rev.)running @18Vdc/4.5A each.
the drives , PS, and breakout board(connects the parallel port of the controller to the drives' correct pinout)are installed in an old server case I was given.

Taking some NC classes is a big plus I guess. But not necessary.
Most good CAM packages do a pretty good job of optimizing toolpaths and reducing cutting times, and if you know how to use a decent CAD proggie, then the learning curve is significantly lower with CAM.
Im not saying that it is easy. Although machining the part(s) is easy.......setting up the code , sometimes is not so fun. Probably 4/5ths of the time it takes to machine a part is spent designing the part and tweaking the G-code. And for me in the beginning, setting up the machine to cut where I wanted it to start was the hard part..took me almost a month to get that right! LOL
But its been worth it.....the feeling I had when the first project that I did actually worked out the way I planned, was almost as good as my first nut!

If you dont get anything else out of it all, it will be worth the time just for the learning experience.