Re: Rotating Ballnut - design ideas
This is not an ideal setup for a normal machine, even for a heavy duty one. Its better to use the normal angular contact bearings, which are more than enough for the job by any
means.
Now i know more having run my machine a couple of years daily and having made the kit for a couple of people.
I already sait it there #122 , and couple of posts after that.
Not only there is absolutely no gain but there will be loss, using these bearings.
Now if you are constructing a lathe head, then go with them :pirate:
Re: Rotating Ballnut - design ideas
+1 The advantage of roller bearings is the huge radial load they can take, in this case the axial is more significant I think. However there are one or two sizes of tapered rollers that are easily available at a very attractive price which might swing it ;-)
Re: Rotating Ballnut - design ideas
Quote:
Originally Posted by
Voicecoil
+1 The advantage of roller bearings is the huge radial load they can take, in this case the axial is more significant I think. However there are one or two sizes of tapered rollers that are easily available at a very attractive price which might swing it ;-)
If you will be milling steel using 3 inch cutters yes, not in a 3m woodworking machine case scenario. But don't listen to me, put that bearings there cause they are cheap.And see what happens.
Re: Rotating Ballnut - design ideas
Quote:
Originally Posted by
Boyan Silyavski
If you will be milling steel using 3 inch cutters yes, not in a 3m woodworking machine case scenario. But don't listen to me, put that bearings there cause they are cheap.And see what happens.
I agree with Boyan and we Both have experience of using rotating ballnut design, so you might want to listen. That design and those bearings are not good for this application because of things which have been stated. They will work ok, but they won't last ok, the forces are in all the wrong places so between this and the heat generated because these ballnuts are being run in ways they where not designed to run it will impact the life and performance.
But you could say what do we know.? In which case go for it.!
Re: Rotating Ballnut - design ideas
Well, this one was bugging me today, so I did some digging and the good Mr NTN came up with the info.
edit I guess it's friction/heat that's the issue?? OK angular contacts may not have the load capacity of rollers, but usually have lower coefficient of friction (1.2....2) than tapered rollers (1.7....2.5). I did see that there's been some recent advances in roller bearings pushed on by trying to get better efficiency in automotive, but they don't seem to be generally available at a nice price
1 Attachment(s)
Re: Rotating Ballnut - design ideas
Attachment 28168
What do you think of that design for a 16mm ballscrew? Maybe the pulley should go on the right between the bearing and locknut so I can use a smaller pulley.
The bearings are double row 3805 2RS 25x37x10 spaced 35mm apart.
It is just a copy of the Fenergy angetriebene Mutter and I will probably buy that one anyways.
I just extended the spacing of the bearings and didn't copy other stuff that well.
https://www.google.com/search?q=fene...h=566&biw=1280
Re: Rotating Ballnut - design ideas
Quote:
Originally Posted by
Heavyweather
Attachment 28168
What do you think of that design for a 16mm ballscrew? Maybe the pulley should go on the right between the bearing and locknut so I can use a smaller pulley.
The bearings are double row 3805 2RS 25x37x10 spaced 35mm apart.
Why do you need a rotating ballnut for a 16xx screw? This should say it all. Did you read anything at all from that thread and the forum?
Re: Rotating Ballnut - design ideas
Quote:
Originally Posted by
Boyan Silyavski
Why do you need a rotating ballnut for a 16xx screw? This should say it all. Did you read anything at all from that thread and the forum?
Several times the last 6 or so years.
Why not? I got a 2m belt on belt drive now and 2m 2005 screws but the 16mm is cheaper and easier to do.
Plenty of machines that use it up to 3m (https://www.cnc-aus-holz.at/index.ph...6525#post16525) and some that sell it, some mostly/only the 16mm.
https://team-haase-shop.de/maschinenelemente.html
https://www.ems-moederl.de/ws45.html
(Uses 2 on Y and one on X)
https://schulze-leistungselektronik....ne-kus-mutter/
https://schulze-leistungselektronik....ne-kus-mutter/
http://cnc.a-ueberbach.de/?s=angetriebene%20mutter
Re: Rotating Ballnut - design ideas
Quote:
Originally Posted by
Heavyweather
Just because someone else uses it doesn't mean it's good or should be used, not every one who builds a CNC is good at it or as the experience to know better.!! . . .For instance one of those guys built his machine from wood which says it all really.!
Also just because a company as designed and sells a product doesn't automaticly make it a good product. I've experienced many products from suppliers like Haase that seem to look good only to find in practise they have some serious flaws, whether that be instantly obvious at time of fitting or appear over time in use.
With some experience of rotating ballnuts then I see such issues occuring over time with this narrow unbalanced design, but you take your chances and time will tell.
My point in this post is to say don't be fooled by what your seeing and reading, because most of those singing the praises are the designers and often those that have bought them won't admit they have issues or even have the experience to know they have issues or what the issues are over time.! . .Often blaming other areas of the machine when things do start going wonky.!
Re: Rotating Ballnut - design ideas
You probably didn't understand the name of the site where the bamboo machine is shown.
I don't see anything wrong with combining wood with a 3m screw driven nut. The nut is a proven design running in EMS machines for years.
What's wrong with 16mm screws?