Using SBR12 as ballscrew end support

[Lovre]

Hi guys,

Could I use as a cheap solution this linear bearing as my end support for ballscrew?

Its like 10 usd compared to at least 50 per axis...

At least to get machine to work, and then I could upgrade it with milled parts on same machine ;)

[njhussey]

You're going to need at least one end fixed to stop play in the leadscrew from the cutting forces. You could use a pillow block and 12mm ID bearing as your other support, I'd not recommend an SBR12 as it's not designed for that use.

What machining have you asked for on the ballscrews, or have you not ordered them yet?

[Lovre]

I did order them, but machining I'm gonna do locally. At least that was the plan...

[njhussey]

The problem going down the "cheap" route is that it always costs you more in the end, either through having to buy cheap and then the proper stuff later or in ruined work as it's not up to the task.

If you're going to get the ends machined, what you going to get them machined for? The cheap solution or the proper more expensive one?

Have you asked Chai (linearmotionbearings2008 on ebay) how much the ends are?

Even if you use a quick and dirty solution to tide you over you'll be surprised at how little difference there will be in total cost.

[Lovre]

Well I'll try... But certanly it will be round 200 usd for alk 3 axis... And thats really a lot for budget ;(

[njhussey]

Go down either the pillow block and double angular contact bearing route or get some shaft supports and 2 single AC bearings then, will be cheaper. Trouble is you'll get the ballscrews machined for this solution and unless you design it carefully you'll have to either get them re-machined or new ball screws as the machining won't be correct for your "propper" solution.

[wilfy]

this just kind of back up the theory of getting everything done at once really..
but you should really listen to everyone about contacting chai as in my quote for parts 3 sets of bf/bk blocks are priced at 87 usd... so even with shipping and the fact that this is likely reduced due to placing a $800+ order i fail to see how that can get even remotely close to 200usd

[Lovre]

Ok guys ... You convinced me :)

I'll try chai :)

[Lovre]

So I found some supplier that will provide this for around 120 USD !

Thanks

[wilfy]

see thats a big difference and i'm sure you'll be happy you didnt cut corners to get a part like this

[Lovre]

Now... Anybody has drawings for end machining? And some assemblly instructions?

[njhussey]

Whoever you're getting the ends from will provide you these I'm sure, or at the very least a data sheet so you can draw them. Also what type, size of ends you using and what type of drawing DXF, STP, SKP etc. etc......more info needed ;)

Also Google is your friend for finding drawings, you can bet your bottom dollar that you're not the first wanting these drawings so someone somewhere will have already drawn them and have them to share.

[wilfy]

http://www.mycncuk.com/forums/linear-rotary-motion/4826-machined-ballscrews.html


this thread basicly answers your questions..