Inexpensive CNC Mill Desktop *Opinions Plz*

[Groth]

Jaydee's table just does x-y, the spindle moves for the z part. You can get mills where the table does the z, called knee-mills, big bucks big machines.

[jaydee]

Originally Posted by SysCrusher

So the table actually moves x,y,z? Not the chuck doing z, right? Pardon my newbness with the stuff but I'm learning as I go here. I have a cheap one where the table only does x,y and thinking about if it's worth my hard earned cash to get a new table or just get a rotary table to go with it.

As Groh pointed out the Z is not in the table. To make curves you turn one axis slower than the other. Mine is computer controled so it does it automtically.

[JFettig]

I just came across this mill, I have some more research to do but possibly looks promicing...


http://www.ahha.com/newitems.htm
http://www.calstatela.edu/centers/SC...nf/cad_cam.htm


thats about all I found so far

[Tempus]

that was 4k just for the software, interface kit, and stepper motors? wow. I knew it was trouble when I ask around work about a cheap CNC and they started talking about 50k bridgeports, but I figured they were just BSing me.

[jaydee]

Originally Posted by Tempus

that was 4k just for the software, interface kit, and stepper motors? wow. I knew it was trouble when I ask around work about a cheap CNC and they started talking about 50k bridgeports, but I figured they were just BSing me.

HAAS has a damn nice mini mill for 30K with a ATC. Just about bought the damn thing but thought better of it. http://www.haascnc.com/products/defa...ails.asp?id=39

I would think long and hard before you buy that little MAXNC 10. I doubt it would do what you want.

[SysCrusher]

Originally Posted by jaydee116

As Groh pointed out the Z is not in the table. To make curves you turn one axis slower than the other. Mine is computer controled so it does it automtically.

Thanks. That makes sense and explained alot for me. So much for trying to do that manually.lol

[Tempus]

Originally Posted by jaydee116

HAAS has a damn nice mini mill for 30K with a ATC. Just about bought the damn thing but thought better of it. http://www.haascnc.com/products/defa...ails.asp?id=39

I would think long and hard before you buy that little MAXNC 10. I doubt it would do what you want.

Do you think the MAXNC 15 would handle it better?

[|kbn|]

sorry to go off topic, but what about cheap non-cnc mills? Are there any in the $1500 range that would be adequate for making waterblocks and over stuff?
Im in the UK so the price would be more like £1000 with exchange rates... but stuff always costs more over here, probalby be £1500 for what you can get for $1500...

[jaydee]

Originally Posted by Tempus

Do you think the MAXNC 15 would handle it better?

Yeah. Might want to e-mail maxnc with details on what you want to do and get their opinion though.

[jaydee]

Originally Posted by |kbn|

sorry to go off topic, but what about cheap non-cnc mills? Are there any in the $1500 range that would be adequate for making waterblocks and over stuff?
Im in the UK so the price would be more like £1000 with exchange rates... but stuff always costs more over here, probalby be £1500 for what you can get for $1500...

Sure, should be a few good used one's around to.

[Butcher]

Originally Posted by |kbn|

sorry to go off topic, but what about cheap non-cnc mills? Are there any in the $1500 range that would be adequate for making waterblocks and over stuff?
Im in the UK so the price would be more like £1000 with exchange rates... but stuff always costs more over here, probalby be £1500 for what you can get for $1500...

Depending on shipping (not just cost but whether they will at all) it might be cheaper to buy one from the US and have it shipped over to the UK - exchange rates are really good at the moment (1.87:1 at the time of writing).

[leejsmith]

Originally Posted by |kbn|

sorry to go off topic, but what about cheap non-cnc mills? Are there any in the $1500 range that would be adequate for making waterblocks and over stuff?
Im in the UK so the price would be more like £1000 with exchange rates... but stuff always costs more over here, probalby be £1500 for what you can get for $1500...

kb have you looked on ebay.co.uk ? they have some cnc and none cnc mills on at the moment.

also look at http://www.west-point.co.uk/

and this http://homeandworkshop.co.uk/othrmill.htm are the ones bladerunner used to make his awsome blocks.

Lee

[whtsui]

Originally Posted by JFettig

oh man, what he is doing is nothing compared to what its capable of, It could do a profile of your face 3d and all. no rotary tables needed. with rotary tables you can machine some really crazy stuff too, all the way around parts, on 4 sides or whatever, really cool stuff. and with 2 rotary tables now thats some insane stuff, thats where you get to the 5 axis machines. maybe someday I did see a 5 axis taig.............


yeah, what he did with that thing is some very basic cnc opperations, G1 linear interpolation, G2/3 would make the curves I bet that thing only uses those codes and G0(Rapids) lets just say theres Gs up over 100


Heres some cnc stuff of mine:
http://jfettig.wc101.com/cnc/


Jon

Hi Jfettig,

It is quite impressive to see your converted mini mill in action. I am considering to build a low cost CNC milling machine using the low cost Grizzly or HF mini mill. From the photo, it appears your mill is one of those models. I wonder if you can share your construction knowledge with me? Just a few questions to ask:

- What is the torque of the stepper motors used in your machine? Would 140 Oz-Inch is enough?

- I am curious how you installed a ball screw to control the Z axis? These low cost milling machines use a rack and pinion drive mechanism which can't be converted to CNC.

Thanks,

Tommy

[JFettig]

Yup, I got mine from homier.com

140 oz is not nearly enough, you need between 300 and 400 for best results.
The Z axis ballscrew is mounted to the top of the column and supported at the bottom, the ballnuts mount to the side of the head. The rack and pinion is completely gone.

Jon

[whtsui]

Originally Posted by JFettig

Yup, I got mine from homier.com

140 oz is not nearly enough, you need between 300 and 400 for best results.
The Z axis ballscrew is mounted to the top of the column and supported at the bottom, the ballnuts mount to the side of the head. The rack and pinion is completely gone.

Jon

Too bad, I just bought 4 PowerMax II from eBay. I was planning to buy a Sherline mill and convert it to CNC. After doing some research, I found out the accessories for Grizzly mini mill are much cheaper than Sherline's.
Going back to the z axis mod. Can you tell me the model and the spec of the ball screw and ball nut that you use? A few close up pictures of the ball nut mount would be nice.

I found a website selling Grizzly mill CNC conversion plan for $50.
http://www.stirlingsteele.com/millplans.html

Thanks,

Tommy

[chewyboy]

a couple of things in no specific order

the grizzly mini-mill is the same one that you can get from homier and harbor-freight. the main difference is the cost, the other difference is the color and the collet included, besides that there really is no difference. so save yourself some $$$ and dont buy the grizzly one and get either the homier mini-mill
homier mini mill
or the one from harbor freight, i cant find it on thier site right now but i know they have them in thier stores, and online too, just not sure where :P
as for the vertical ballscrew, i would suggest rockford ballscrew. give them a call, tell them what you need. you will need the screw and a nut (2 nuts if you want to do it better to stop backlash) anyway click on the about us there and either call them up or e-mail them and they should be able to help you out.

hope that helps out some.

Originally Posted by whtsui

Too bad, I just bought 4 PowerMax II from eBay. I was planning to buy a Sherline mill and convert it to CNC. After doing some research, I found out the accessories for Grizzly mini mill are much cheaper than Sherline's.
Going back to the z axis mod. Can you tell me the model and the spec of the ball screw and ball nut that you use? A few close up pictures of the ball nut mount would be nice.

I found a website selling Grizzly mill CNC conversion plan for $50.
http://www.stirlingsteele.com/millplans.html

Thanks,

Tommy

[JFettig]

I got my ballscrews and nuts from reidtool.com thompson signaw I think they were called the 5/8" diameter .2" lead screws/nuts. I bought all non preloaded nuts and preloaded the Z axis because there wasnt room even after milling the bed for the X axis.

Those plans for that mill are very interesting how he has that set up, he is turning the nut on the Z axis rather than the screw, The one thing I dont like about it is it looks like it is using the stock x and y screws/nuts and it is using small steppers. you need at least 300oz/in for good performance.

Jon

[whtsui]

Originally Posted by JFettig

I got my ballscrews and nuts from reidtool.com thompson signaw I think they were called the 5/8" diameter .2" lead screws/nuts. I bought all non preloaded nuts and preloaded the Z axis because there wasnt room even after milling the bed for the X axis.

Those plans for that mill are very interesting how he has that set up, he is turning the nut on the Z axis rather than the screw, The one thing I dont like about it is it looks like it is using the stock x and y screws/nuts and it is using small steppers. you need at least 300oz/in for good performance.

Jon

I have checked some ball screws from Nook Industries and a few others,
but I found out typical ball screw accuracy is around +-.004in/foot. Is it still acceptable for CNC applications?

Sorry for asking dumb questions, what is "preloaded" means?


Tommy

[JFettig]

check out the thompson screws, That is typical for but that is in an entire foot. I thought that it was less but thats what you get from rolled screws. ground screws cost thousands.

Preloaded means the nuts push against eachother to get rid of any backlash, that way whenever the screw is turned the nut moves, no play.

Jon

[ToddTheFrog]

This looks like a happy medium!

http://www.cncmasters.com/CNC%20Jr%20Mill.htm

Todd

[JFettig]

Yes, that definately is a good one, I know someone who bought one and probably has it by now, next time I talk to him Ill have him post here


Jon

[CNC_accro]

I've some question for JFettig,

I too plan to buy the Hormier mini-mill to convert it to cnc. If you had to draw a cube over your machine, what would be the dimension? (I want to evaluate the space needed for the machine.

At what feed to machine go? with 300oz stepper motors

Thank's

[CNC_accro]

Ho!, and one more question... where did you get the motors. Any recommendation?

[JFettig]

Hey man, with steppers, I woudl say 3ft deep, 3ft wide and about 3.5-4ft tall.

Also, i just grabbed 26 steppers that I will be selling

If you havent already checked out cnczone, do so now!
cnczone.com

Jon