Hi, I'm not sure if this have been asked. I did a search and didn't come up with anything (although I should've shorten the search...) anyways, I'm wondering what some of you guys think is the best CNC kit for a X2 that doesn't require modifying the X2 itself (as in drilling and tapping new holes). I know some of you will say build it yourself but I'm a newbie and I wanna get a feel of how a conversion is done before attempting to design something on my own.

Thanks.

I looked at Hoss2006 post and he did an excellent job.

There is CNC fusion - Looks nice and well done also.

KDN tools - I just recieved mine today. Ground screws and ball nuts. Ken claims backlash at less than .001. So I spent the extra money. I have to re-assemble my mill now so I cannot speak to the accuracy of the claim.

Smitty

cnc fusion kit requires 1 hole to be drilled and tapped. pretty easy to do though. if you are going to ballscrews, go with preloaded.

KDN tools - I just recieved mine today. Ground screws and ball nuts. Ken claims backlash at less than .001. So I spent the extra money. I have to re-assemble my mill now so I cannot speak to the accuracy of the claim.

I was just looking at their site. I see where they offer rolled, and "precision rolled" ballscrews for their X2 kit, but I didn't see where they had ground screws. Is this something you had to request custom?

I was just looking at their site. I see where they offer rolled, and "precision rolled" ballscrews for their X2 kit, but I didn't see where they had ground screws. Is this something you had to request custom?

My Mistake;

They offer the precision rolled. How 'bout they just look really nice. Haven't taken them out of the shipping tubes yet. Maybe this week.

Smitty

So is ball screws better? Has anyone use cncfusion? Do they know if the backlash is a problem.

i went with KDNs kit...second one I have purchased from them and their service and quality is awesome! and yes when I got my preloaded ball screws they are very accurate...I am very happy with them and have no problem reccommending them at all.

So is ball screws better? Has anyone use cncfusion? Do they know if the backlash is a problem.
yes its better
no i havent
any slack, loose, wobble you can get on cnc is a problem

There was a whole thread on cold fusion conversion, I believe it has to do with using a clamp to set pre-load. I believe they have since changed there design to use a nut to pre-load. This eliminated one (1) source of the backlash.

From my research most of the rolled screws will have .003-.005 backlash. Than any mounting issues would make it worse. The KDN claim is alot less than that.

I just went and bought the one I felt would deliever. I don't have the time to worry about this that and the other, design, make, check, do over (which I'm quite good at). Seems the second/third/ninth time I do something it comes out quite well.

Smitty

I keep reading about preloading of ballnut. Can someone explain what this is all about. Thanks. I am in the process of converting my mill also and willbe ordering some ballscrews and ballnut. I would like to have preloaded ballnut but what do they mean?

I thought it had something to do with them loading the ballnut onto the ballscrew. Cos doing it myself will be difficult.

Easy to think about this way. When you move the handle on a manual mill, you are putting the nut under a "load" in relation to the screw. You can stop, and start again, and as long as you are going in the same direction you continue to have a load on the nut and therefore no backlash. However, as soon as you start moving the handle the other direction, you remove the load from the nut on one side and start applying it to the other. This transition is where the backlash occurs. Now if you have a nut that has a "load" in both directions without moving anything at all, then you have a "pre-loaded" nut. In principle, the transition from moving in one direction to the other never removes the load, and therefore you have no backlash. The one caveat is that the force you put on the nut cannot exceed the pre-load. If it does, then you will be back to the same situation as before, and the potential of backlash will be there again.

That is the principle of pre-load, but there are various ways of making it work. One way is to use two ball nuts screwed together in such a way that they create a load on each other. This is what you find in more "high-end" system. The amount of pre-load is adjustable depending on how tightly you have the nuts screwed together so you can set it based on the characteristics of the machine. Another way is to use slightly larger balls in the raceway of a single nut. This is a little tricky and tends to be a trial and error sort of thing. Because the balls are a little too big, the nut squeezes them in on the screw creating the load. This method is common for the smaller conversion kits, but isn't adjustable like the two nut approach. However, it is also a lot less expensive to implement, and doesn't limit the travel as much as having two ball nuts might. (Something important on the smaller machines many of us are converting.)

http://62.75.219.46/shop_cfg/metall/KG-Mutter.jpg

There is a third option. This ballnut uses the same principal as the oversized ball option, but instead of making the balls bigger, you compress the casing. I have tested these and there is less then 0.01mm of backlash in it (0,00039").

Sorry not trying to hijack this thread.

Thanks for the info. If I just get the non-preloaded ballnut from homeshopcnc (cos they are cheaper), when used with the ballscrew, will there be significant backlash that I will be concern about? I mean 0.01mm for preloaded ballnut is real small. So small I probably won't be concern at all.

If non-preloaded nut produces say 0.1mm of backlash. Again, thats real small for most of what I need to do. Or can I also achieve 0.01mm with non-preloaded ballnut? Thanks.

Cotang,
If you're looking at the cncfusion kit,
Richard put together several step by step tutorials for installing the kit.
Watch here on Youtube (http://www.youtube.com/watch?v=ZMh_imajn4Q).

Sorry not trying to hijack this thread.

If non-preloaded nut produces say 0.1mm of backlash. Again, thats real small for most of what I need to do. Thanks.

I understand your train of thought, but it is not good.
Yes a lot of jobs have a tolerance greater than .1mm.
The real issue here is that while you are cutting the table is flopping back and forth .1mm. Lets assume that if you are lucky and do not simply just keeping breaking your end mills off. Your cut finish will be a horid gouged up mess. Harmonics will be nasty to listen to. Machine life will be reduced by at least 50%.

I have seen springs or weights used as preload devices to try and keep the load always on one side of the nut.
On a manual mill where cuts are linear the table locks are used effectively to stabilize unwanted movement.

On a lightweight machine such as we are talking about all these issues are huge because they do not have the mass to keep themselves stable.

If you are using cheap screws I suggest at least double nutting it.

Just a few thoughts.

Hi Darebee,

Thanks for the advice. Between the non preload and preloaded ballnut, how much difference in terms of backlash between the two.

i know that cncfusion makes a kit for that mill, i dont have one that size, i have the one for an x3, and its a really nice kit... i'll let you all know it goes once i get it installed... i will say this much, excelent email support, i've been asking them questions for about a week before i ordered, and ever since, and its been a pleasure conversing with them...

"i know that cncfusion makes a kit for that mill, i dont have one that size, i have the one for an x3, and its a really nice kit... i'll let you all know it goes once i get it installed... i will say this much, excelent email support, i've been asking them questions for about a week before i ordered, and ever since, and its been a pleasure conversing with them..."



Please do, I'd like to see. :wave: What are you using for motors (steppers/servos)?

http://62.75.219.46/shop_cfg/metall/KG-Mutter.jpg

There is a third option. This ballnut uses the same principal as the oversized ball option, but instead of making the balls bigger, you compress the casing. I have tested these and there is less then 0.01mm of backlash in it (0,00039"). Isel? I have 2 of those and have yet to mount them....Typing here isn't helping :D

i'm going to be using 500oz bipolar steppers.. mostely cause its what i've got right now... i bought the motors for another project thats been put on hold, so i'm gonna bolt em up on my x3.. maby down the road i'll get more appropriately sized motors.. i'm thinking that the 500's are a bit big for the x and y...

non preload has backlash of about .005 to .015 or so while preloaded ball nut will be about 0.001 or 0.002. definitely worth the extra cost .

I have x2 early kit. it had some backlash issue on the Y due to ball screw itself moving, but latest version is good in that regard . I just got the deluxe x3 kit and should be really good.

non preload has backlash of about .005 to .015 or so while preloaded ball nut will be about 0.001 or 0.002. definitely worth the extra cost

Still waiting for my X2 cncfusion kit. Spent the extra $40/axis to have the nuts preloaded (fitted with larger balls). If the backlash comes in at .002 or less it will be a pleasant surprise. Non-preloaded just didn't look like a viable option. As pointed out by project5k, Michael is a genuine pleasure to correspond with.

Also looked at the kdn kit. Looks very nice but didn't fit the budget.

About those Isel (?) ballnuts, how is the compression done? Is it built into the nut or do you need to build an external clamp of some kind? The website seems a bit short on information. What's the cost $$?

edit-> To partly answer my own questions
http://www.gimbal.com.au/content.aspx?name=cnc-mill-ballnut-carriers

Doubt if anything that bulky would fit under an X2 :( Might be worth looking into for a larger mill.

I have the KDN kit for my X2 and would highly suggest using them. They use a 5/8 ball screw and over sized nuts, great support and quality parts. IMO your equipment should be at least one order of magnitude better then the tolerance you are tying to maintain.

About those Isel (?) ballnuts, how is the compression done? Is it built into the nut or do you need to build an external clamp of some kind? The website seems a bit short on information. What's the cost $$?

edit-> To partly answer my own questions
http://www.gimbal.com.au/content.aspx?name=cnc-mill-ballnut-carriers

Doubt if anything that bulky would fit under an X2 :( Might be worth looking into for a larger mill. I dont think the genuine isel carrier is that bulky!

have a look at this mill , 4th and 5th axis also , for price you can't beat it

how accurate do you want things mmmmmmm don't know about that ??

This DEEPGROOVE1 CNC Mill is a very rigid and precise machine It is based on the famous Taig 2019cr cnc ready mill

http://www.deepgroove1.com/cnc%20mill.htm

New 4th or 5thAxis Axis Trunnion Table and Industrial Rapid Changer with 3ER-16 Tool Holders

http://www.hightechsystemsllc.com/index_files/Page320.htm

I have the CNC fusion kit somewhere in the archives I gave a review of my install and what problems I had. For the most part the kit has been better tan I had ever hoped it to be. Now if my X2 didnt have a dip in the top the mill would be better for it. Someday I will have it ground to perfection. I am using a jig so the dip is not an issue right now. As far as the kit goes it was everything I could have hoped for. Preloaded ball screws full kit is what I bought.

GB