[madbee]

Chalky, did you know what motor they were using for their Z-axis on the G0704-type mill? I did a quick search but could not find any references to this mod. Thanks for any info / links if you have it handy. My shoulder hurts just thinking about this !!

No problems with 50lb loads on the fully extended x axis, but I gotta agree that the height of the z axis handwheel is probably the only poor design feature on the G0704. I guess that you can motorise it as some people have already done.

[chalky]

Yes it was a windscreen wiper motor. Not sure I can find the website again but I'll have a look tomorrow.

[machinechick]

A guy on homeshop machinist moved the handle due to a shoulder injury. the thread was entitled "power head adjustment-chinese mill". He just ended up putting a chain and chainpulley arrangement on it. Someone on the yahoo Lathemaster group mounted a dc gear motor on the top of the column via a direct connect coupler and left the handle on for fine adjustment. The pitch of the leadscrew isn't as tiny as the X3 so if you don't have a torn rotator cuff or something it shouldn't be a problem physically. However if you try and rapid the head manually and dont have your table secured to the floor properly you can end up rocking the whole table a little due to the "lever action" of the handle being on the top of the column. I adjusted the z leadscrew nut and gib on the tight side and no longer notice that. Just to keep this all in perspective, I'm only 5' 5" and weigh about 115 lbs. and have no problem with the z-axis control where it is.

[madbee]

Thanks for the info Chalky and Machinechick,

I Googled "windscreen wiper" and "z-axis" and that led to a few links. I just needed a clue. I am going to also look for the thread for "power head adjustment-chinese mill". My right shoulder is fubar. I don't have my mill yet so I wasn't sure if it will be an issue. BTW, called Grizzly today and they are now saying it's due on Feb 12.

Yes it was a windscreen wiper motor. Not sure I can find the website again but I'll have a look tomorrow.

[iandh]

Funny, I thought I was going to get made fun of for crying about the z-axis handwheel position and instead I get another person with bad shoulder.

I like the idea of sticking a DC gearmotor on there actually... I have a spare baldor laying around from a project.

I'm 6'4", but the problem is that I built my worktables at 43" so that they would be elbow resting height to make working easy on my shoulders and back. That makes the z-crank on the G0463 perfect height, but on this machine not so much.

I got my G0463 for $700 still in the packing grease, so it's going to be pretty hard for me to justify replacing. I can see how this machine looks a tad nicer, but TBH I'm pretty happy with the X3 for what it is. As I mentioned above, the only thing I really miss having is the tapered gibs.

[madbee]

iandh, I am 6'2" but still see this as something that needs to be addressed. Being tall, I recently helped someone hang a poster high on the wall (without thinking) and my shoulder was sore for months! I found an old Makita cordless drill I had sitting around and am thinking about using that for my Z-axis. Just not sure if this will be strong enough or if I will need a counter-weight or if I need to mess with the bearings (read that somewhere)? Grizzly is now saying March 9th for the G0704 Mills. Not good.

Funny, I thought I was going to get made fun of for crying about the z-axis handwheel position and instead I get another person with bad shoulder.

[Enraged]

Has anyone received their G0704 yet? Im quite interested in buying one of these for a CNC conversion, but I would liek some first hand opinions of the machine first.

[madbee]

I don't think anyone has this Grizzly mill yet. I was told they are still waiting for their first shipment. There are several similar models that some people have and I believe have been around for years.

[hoss2006]

I was one of the first to order the G0704, should put me near the top of the list for the first batch.
I'll post as soon as it arrives, or is on the way.
Good things come to those who wait.
Plenty of prep work to do anyway so I don't mind a delay or two.
Hoss

[ellik]

It's not exactly the same machine but almost, the table is smaller.

http://www.cnczone.com/forums/showthread.php?t=97057

As far I can see its a very solid machine and well built. The only issue I run into so far is how to CNC the Z-Axis without upgrading to a ball screw. Using the crank on the side is an option but not ideal.



I got the X and Y motor mounts designed and will check how my 305oz steppers from the X2 perform on it before I decided on what motors to get. The Z motor needs to be 900-1200oz, the spindle head is very heavy.

I was one of the first to order the G0704, should put me near the top of the list for the first batch.
I'll post as soon as it arrives, or is on the way.
Good things come to those who wait.
Plenty of prep work to do anyway so I don't mind a delay or two.
Hoss

[machinechick]

On the Lathemaster group site on yahoo a guy put a dc gear motor on top of the column with a direct connect and left the hand wheel for fine tuning. He told me he put a torque wrench on the top nut set at 3 foot pounds(I have my gib pretty tight and think it might be a little more) and it didn't click. Also, for all you guys waiting I think Lathemaster has these in stock you just have to come off some more cash! Three or four more vendors have them in Canada with various tapers in the spindle and there's another vendor in the US but it's with a MT2 taper which I know would horrify most of you Bigdog metal works has it too, but with a MT3. Probably the one with the best build quality, with real hand scraping etc. is the one with the MT2 from the Euro-brother Top Tech Machine factory in China, that's Optimum Machine in Germany's factory, and the machine I personally own. Mine is accurate as h.... The only one with an Imperial leadscrew though appears to be from Lathemaster the rest have metric. The versions with the R8 are all made by Weiss as far as I've heard. The big dog one is made by Real Bull, the castings look a little heavier on that one, the listed weight is more too.

[hoss2006]

I plan to direct drive the Z screw (ballscrew) or use a pulley/belt with the motor
hanging behind the column for lower overall height.
Replacing the top plate with a longer one to mount the motor looks like a simple solution.
Using a backlash laden hand crank won't be an option.
Hoss

[ellik]

Hoss.

I assume you will upgrade to a ballscrew?

[Enraged]

that top plate looks like it would be easy to replace when changing over to a ballscrew. I'm thinking about servos, so hanging the servo behind the column would be ideal, plus it would keep the bearing plate/motor mount design fairly simple.

I was originally considering a Novakon NM135, but I'm leaning more towards a CNC conversion now that this mill is becoming available.

[ellik]

When removing the top plate of the column I noticed there is only one thrust bearing, and a brass bushing on the other side. Would be interesting to know if the other BF20 style mills are the same way.

[LongRat]

My Weiss WMD30LV/BF30 had one thrust bearing and one bushing just as you describe. I would think they are probably all the same.

[madbee]

That 3 ft-lb torque really helps quantify things. BTW, the Grizzly is the 20LV with a different column, the Lathemaster is based on the 25LV (a bigger mill?). I asked Grizzly a couple of weeks ago and they tell me they have true-inch screws, but their .02 graduations might imply otherwise. We'll see.

I think Lathemaster has these in stock you just have to come off some more cash!.......The only one with an Imperial leadscrew though appears to be from Lathemaster the rest have metric.

[hoss2006]

Hoss.

I assume you will upgrade to a ballscrew?

Yep, ballscrews all around for me.
already have some here with some nuts.
My x and y will be opposite of yours, I need it to fit on my cart.
Want the table up front as much as possible without the motor in the way.
Hoss

[ellik]

I thought about mounting the Y in the back but it would require allot of modifications to the base and column, something my X2 cant handle

[Enraged]

I'm curious about spindle upgrading, as Grizzly lists the speeds as 50-2250rpm, while Optimum lists 90-3000rpm. Novakon has 6000 rpm on their 135/145 and Tormach has 10,000 in their 770. What would it take to upgrade to those speeds, new higher quality bearings and a new motor setup?

Did some searching, looks like the spindle bearings (if they match the Optimum) are 32005 X/Q, I have attached a PDF of SKFs info on the bearing. It's been a few years since I studied bearings so I'll have to go through my old textbooks SKF lists reference and limiting speed as 11k and 14k rpm. I can see removing the gearing from this mill and running a belt drive, just like people do to the X3.