X2 Conversion using the CNC-Fusion kit #4 - Four quick questions

[CNC74]

Hi all,


I know this is probably burried on page 50 of another post and my "Jedi search" capabilities need some work so please forgive me if these questions have been covered. I would really love to slam dunk this build but am stuck on a few things that are jamming my progress meter.

Here are the details:
I am converting a Harbor Freight X2 mini mill using the CNC-Fusion CNC kit #4 with the ball screws. I have run into three major road blocks at this point and would greatly apreciate any help.

#1. While installing the Y axis rod in the base I noticed that the block that protrudes upward from the base replacing the brass part that the rod travels thru is sticking up to far beond the top plate and this is blocking the installation of the X axis rod. I have read that there were variances in the thickness of the base but this is like a half inch protrusion sticking up. (Any reason why I shouldnt grind the excess metal off the top of the part?)


#2. I noticed that the front of the Y axis rod is not keyed. This makes no sense. The installation calls for tightening the hew screw on the lovejoy coupler to it. If I clamp down on the Y axis circular rod it just going to come lose in very short order. (Should I grind a flat spot onto the Y axis rod to mate it wilth the lovejoy adaptor?)

#3. While trying to install the Y axis I accidenally unscrewed the ball screws too far and my bearings came out. What is the proper proceedure for getting the bearings back into the ball screws? Also how many bearings need to be in them? I think I lost three of them and if I need to replace them where is a good place to buy them?

#4. Is the tention bar on the left side of the Z axis of any use in this setup?


I have sat on this build for a year with all my parts sitting in a box and now that I have the time I would really love to get this thing going but I want to do things right. Any help and pointers are greatly apreciated!!!!!!!!


Regards,
CNC74

[hoss2006]

I can answer a few,
If the lovejoy uses setscrews and not clamps, then a flat would do you well.
Newer helicals use a clamping action that would hold very well without a flat.
My buddy Richard has a video showing how he loaded balls back into the ballnut.
Check out his other videos on installing the cncfusion kit.
The tension bar is almost always tossed for CNC, it limits the travels and isn't necessary.
Hoss

"http://www.youtube.com/watch?v=cPOhAjmPADM"]YouTube- 34: Nook Ballnut loading

[kawazuki]

1. Yep - grind it down!
2. Yep - grind a flat on there!
3. Amazingly EVERYONE seems to do this - the video is ok!
4. No it is not needed and if left will reduce your usable Z axis.

Enjoy the new, mess making machine

[alex781]

#2 I found a method that increases the clamping force of a set screw without grinding a flat, don't know if it's a known thing but it works well on my mini mill. Very simply, put a piece of crumpled copper wire in the threaded hole between the axle and the set screw and tighten down hard. It doesn't leave any marks either.

[CNC74]

First off, THANKS A TON for your quick responses to my issues. I really appreciat it!!

I have another question though,

I lost some bearings from the ball screws in the install process and am trying to find out what size they are and where is the best or fastest place to get them from?

I am so excited to start cutting and making stuff!

[hoss2006]

Email Michael at cncfusion for some replacements or mike them and order some from
Toolsupply on Ebay.
I got some in a few days.
Hoss

[CNC74]

Hello all,

I am making forward progress but as always time is short and due dilegence takes lots of it.

New questions:

1. What is the proper tool for tightening the nut on the end of the right side of the X axis on the CNC Fusion ball screw? (Its a circle with four notches in it.)

2. The X axis ballscrew rod is too long (or so it seems) and required washers between the End piece and the nut that secures the ballscrew to the right side X axis mounting block. I seem to have a good bit of play even with three washers compensating for the difference and am wondering why this is so far off (About 1/4" too long). Any ideas?

3. How tight should the axis be when turning them manually? I can turn them by hand by twisting the ball nuts on each axis but its a bit tight. I am trying to aviod any possibility of burning out my stepper motors and get thigs right the first time around. Can someone give a description of how much tention is "normal" when turning by hand?

4. One the topic of turning the ballscrews, there is a "grinding noise" when going from one end to the other of Z X & Y axises and they seem to "bind" and become tough to turn but do turn and the issue goes away once it passes that point in its travel from one end to the other. Any ideas?

5. Where can I get some good looking (colored) hand cranks to attach to my dual shaft steppers? ( I have the one from the original parts that I reporpused for the Z axis but would like to get three nice one that match each other.

6. Tooling questions... Do I need a "collect holder"? What size collects do I need? (R8?) Is getting a collet collection the right move? I see that "Econo" has "cheap" collects other stuff is thier a recomended collection to go with?

7. I bought an endmill collection from H/F some tine back and am reading that the quality of the endmills are of the highest importance. Are the H/F endmills garbage? If so please recomend a good small set to start with.

8. Can someone recomend a good dial test indicator to use with the X2?

9. Can someone recomend a good "MIC"?

Thank you all for you support and insight. I am bent on getting this thing dialed in correctly before moving forward.

Regards,
CNC74

[CNC74]

I posted the following video to show some of the issues I described in the last post.

"http://www.youtube.com/watch?v=dkn966MQAAI"]YouTube- Harbor Freight X2 Mini Mill - CNC Fusion Kit #4 w/Ballscrews - X axis ball screw issue


Regards,
CNC74

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[hoss2006]

1. no need to buy a tool, just use a flat blade screwdriver.
2.could have just been a machining booboo, add more washers or a 1/4 spacer to the block.
3.you should be able to turn them with your fingers though not real easily with power off. the motors will give you the telltale stalling buzz if they encounter something too tight.
4.use plenty of oil, they should "wear in" after a while and get quieter. it would be highly
unlikely that you're missing balls in all 3 nuts.
5.http://www.littlemachineshop.com/pro...First=G&Last=I
6,7,8,9. Check out LMS's recommendations for tooling with convenient links to buy from them.
Good endmills can run $20+ a pop but you can learn with the cheap stuff just don't expect good results. Maritool and MSCDirect is where I get mine.
A good test indicator and mic would be a Starrett or Brown and Sharpe but the Mitituyo's are pretty good for less.
You only have to buy GOOD tools once if you take care of them.
I've had my Starrett's for 20 years.
Hoss

[jalessi]

CNC74,

Sherline makes several types of good quality hand-wheels.

http://www.sherlineipd.com/handwhls.htm

Jeff...

[CNC74]

Guys,

Thanks for you help thus far!!


I know... Total green horn questions!!!


I'll be "getting chippy with it" soon becuase of all your help.


Thanks to you all!!

-CNC74

[Quazar]

I've seen it stated several times that it is not worth putting handwheels on a CNC conversion. The main reason is that the ballscrews do not offer enough resistance to back-driving, so cutting forces tend to make it much harder for the operator to control the feed by hand. At the very least, you'll have to lock-off any axis that you are not holding steady by hand.

Also, they are useless (and can even get in the way) during CNC cuts. On the plus side, they look really cool turning by themselves during a CNC cut. I had planned to put them on my CNC conversion too, but after seeing this mentioned several times, I decided to leave them off.

Cheers,
- Dean