[ny_racer_xxx]

Hello, I'm looking into building a G0704 CNC...
I really don't want to make a hobby out of building the thing, I would like to get it setup and building parts fairly quickly.
That being said, I've been all over Hoss' site, really good info!!! I'm looking for as complete as a kit I can get for the conversion. I've seen the direct mount stuff on ebay, but I really like that German belt drive setup.

Has anybody used that Machine Warehouse BF20 belt drive kit on a Grizz mill?
I'm wondering if the ball screws are the correct length as the specs for the BF20L show 700mm for the bed length which is roughly 27-1/2" and the Grizz is listed at 26-5/8"?

Thanks,
CR

[DRock]

For a "no fuss" conversion where you buy the mill, ballscrews, pre-assembled electronics box, motors and mounts it is going to run you around ~$4,000 if not more when you add in all the tooling.

If this number doesn't scare you then order everything up and have fun!

[ny_racer_xxx]

For a "no fuss" conversion where you buy the mill, ballscrews, pre-assembled electronics box, motors and mounts it is going to run you around ~$4,000 if not more when you add in all the tooling.

If this number doesn't scare you then order everything up and have fun!

$4000 isn't too far off from doing all by myself, what I saw for turkey was $4900 from Midwest MMW G0704 CNC Mill

Looking at the pricing from Hoss' site, all the electronics from $500 to $800, plus the ebay mounts, is $650, and ball screws about $300.

On the low end $1450 on the high end $1750 plus $1200 for the machine, you're looking at $3k in parts and a whole lot of time getting everything sorted, if it were $4k for a tested machine, it would be a bargain!!!

What I was curious about is that kit from machine tool warehouse. For $1200 clams, it comes with mounts, motors and ball screws, only thing left is the breakout board and drivers.... It also looks like a better setup....

CR

[DRock]

I meant $4k for the basic parts and you doing the conversion yourself.

I would buy a pre-built controller box and then that kit from machine tool warehouse and you should be up and running fairly quickly.

[ny_racer_xxx]

Screw that!!! for $4k in parts, I wouldn't even think about it, I would spend the extra money and have it turkey!!!

Any idea if the ball screws are the same?

[DRock]

The ball screws are Rotons which are the same ones a lot of people use but I believe they are not as good as the linearmotions2008 eBay screws.

The $4,900 turnkey is a pretty good deal but it depends what electronics come with it...if it is the digital stuff then it is definitely worth it.

What are you looking to do with the machine...production or just personal stuff?

[ny_racer_xxx]

Mainly prototype work, some small batches, maybe a dozen or so pieces at a time....
I have an old Atlas lathe I use all the time, and I have a vertical attachment that's PIA, but I get done what I need to, I was thinking of picking up a manual knee mill and came across all this stuff. I might just pick up the mill and not convert it, but having the CNC option really opens up being able to do much more complex pieces.
Basically it's impossible to get small runs done of anything around here (NY), I have a waterjet guy that's pretty reasonable, but it's $300 a lot, that's about all the support I have. Everything else, I make by hand, one at a time.

I thought that kit looked pretty complete, add the break board and drivers and pretty much done, it is what it is, nothing worth working with is cheap...

CR

[Fastest1]

Why do you think there is a difference? I use Chai's screws and they are fine for my needs. Of course there is some backlash but there will be ways of minimizing that too, bigger balls, lubrication, tight bolts on all mounting points, alignment, preload on thrust or AC bearings. If the ability to machine right away is important, 4-6 grand would be a good deal for a turnkey machine. Sure you can do it cheaper (if you know what you are doing and have the other machines to assist). If my goal was to machine buying a Tormach or even a Haas would have been cheaper. Instead I have learned many things about machines, electronics, CAD, CAM, set up, fixtures and much more that I cant quantify just yet and maybe never will. The journey has been fun so far and I dont have to do it for a living. In fact most of my reasons for ever needing a mill much less a CNC mill are long gone (needed motorcycle parts during roadracing in the 90's). I will be ready if the time comes again LOL in the over 50's class!

The ball screws are Rotons which are the same ones a lot of people use but I believe they are not as good as the linearmotions2008 eBay screws.

The $4,900 turnkey is a pretty good deal but it depends what electronics come with it...if it is the digital stuff then it is definitely worth it.

What are you looking to do with the machine...production or just personal stuff?

[DRock]

I read somewhere on here that the linear error of Chai's screws were less than the Roton's and that is what I meant by that. Whether or not they actually are remains to be seen...it sure wouldn't be the first time a Chinese manufacturer/vendor either lied or misrepresented the truth.

I am not saying Chai is lying either, just that he doesn't make the screws himself so I am sure the specs are provided to him from the actual manufacturer.

If you don't have a need to go CNC right away I would get the G0704 if you are concerned with how much room it will take up. If you have a big space you can put a Bridgeport that would definitely be the route to go.

[Fastest1]

At the moment I dont know. I have my machine set up preliminarily and have tried to calibrate the axis with varied results but then again many items could still be loose, not falling off loose. I did reinstall a new Z ballscrew from Chai yesterday, I greased the screw prior to installation, tightned all bolts in the mounts, gibs, oldhams, including each and every fastener in that particular assembly. I couldnt really measure the backlash with my .001 gauge, the very first step in either direction creates movement on my indicator. Not a full .001th of movement on the indicator but a nudge. I will measure more accurately after all of my trial fitting and modifications. It did give me a good feeling. I have been using the chemically damaged screws for set up and verification and was getting around .006-.012 of backlash. In that case I had oiled not greased the screw and the fasteners were not confirmed tight just snugged for fitting. Same with the gibs.