Ready Steady Eddy

**EddyCurrent** · 11-03-2014

Yes I think you are correct about the double row bearings, I was looking at those yesterday. Getting the nut set right on the BK type is a bit of a fiddle to say the least.

**JAZZCNC** · 12-03-2014

You make me laugh you lot.!! . . . . Your quite happy to pay peanuts for the parts but then whinge and whine when they aren't top quality.!
WTF do you expect when You couldn't even buy one decent Angular contact bearing in this country for the price payed for both Blocks with bearings.

I strip, grease and shim every BK/BF bearing. It Takes minutes to do and other than that they are mostly fine considering the price payed.

Yes I could make my own better but unless chasing true Zero Backlash like Jonathan mentions then I'd just be wasting time and money because the BK/BF blocks when fettled work perfectly fine for any normal router machine.

**EddyCurrent** · 12-03-2014

Originally Posted by JAZZCNC

You make me laugh you lot.!! . . . . Your quite happy to pay peanuts for the parts but then whinge and whine when they aren't top quality.!

Totaly wrong, I don't expect top quality but I do expect 'fit for purpose'

**JAZZCNC** · 12-03-2014

Originally Posted by EddyCurrent

Totaly wrong, I don't expect top quality but I do expect 'fit for purpose'

I know what you mean but come on it's 10min job at tops and it's not difficult or hard. There has to be some affect of cheap prices and If folks have the abilty to build the machine in first place then in the grand scheme it's a drop in the ocean to fettle these bearings.

Getting all anal about bearing's and whether one came from China and other Japan is mostly pointless unless your chasing very tight tolorences because your own workman ship will introduce a lot more error than a couple of cheap or mismatched bearings ever will.!! . . . . . End of the day it's a router for cutting Wood and provided the bearings are greased and shimmed to remove lateral movement then they last for years.! . . . I've just after 5yrs changed my bearings, yes I've adjusted and greased them couple of times in that period but that's just normal service like any machine needs.

**EddyCurrent** · 12-03-2014

Well, not even that, I just want to buy them and fit them knowing they will work as expected, is that asking too much ? I don't think so.

Anyway I stripped the Y axis ball screw out and laid it on a flat surface, sure enough it was bent about half way. Using a feeler gauge I slid it along underneath to find the bend position, then I put it in a vice with wooden jaws, put a pipe over the other bit and 'leaned' against it until it was straight. Now it's about right however the ball nut is a bit crunchy, I pumped some grease in and the metal particles that came out was alarming, it's still a bit rough and sticks now again so I see no alternative than to strip it out and clean, that's assuming it will go back together.

**JAZZCNC** · 12-03-2014

Originally Posted by EddyCurrent

Well, not even that, I just want to buy them and fit them knowing they will work as expected, is that asking too much ? I don't think so.

Well you need to dig deep then and pay the price.! . . . Can't expect to pay £15-20 for something that cost's £80-100 over here and not have something to complain about.!! . . . BUT I suspect we'll have to agree to disagree.

**EddyCurrent** · 17-03-2014

Been away for a few days, got back and now the PC graphics card has gone ! more expense.

Took the ball nut off like I mentioned earlier, emptied the contents into an old but clean washing up bowl I use for occasions like this.
The ball nut has 3 ball circuits and each ball measured about 3.15mm in diameter, maybe they are 1/8" inch ? anyway the number of balls that came out was 53 so right away you know there is something amiss. Before removing the ball nut the problem was that it felt like it was dragging and looking at grease patterns on the ball screw it looked like the centre ball circuit was stuck because the grease was being totally removed from the ball screw in those threads.

I watched this video on how to repack the ball nut and it was no problem putting it back together.
Linearmotionbearings C7 Ballnut Flipping and Repacking - YouTube

He explains in the video that 16 balls should be in each circuit which leaves a gap, I found that 17 balls left a similar gap so that's what I put back in and it's now nice and smooth running.

Edit: 10/12/2014 It was later confirmed that the correct number of balls for a 1605 or 1610 ball screw is 17 balls per circuit 51 total. (so that's good news for me !)

So the problem was too many balls in the ball nut so that they were jamming instead of rotating.

**Wobblycogs** · 17-03-2014

No one wants jammy balls!

Interesting video, thanks for the link.

**Neale** · 17-03-2014

Eddy - I'm looking to build a steel-framed machine and yours looks like a great candidate for stealing the design! I am looking for a slightly larger cutting area although I don't think enough to make any significant difference. Before I start, do you have thoughts on what you might do differently if you did it again?

**EddyCurrent** · 17-03-2014

The only thing I would do different would be to make sure the ground was level that the welding was going to take place and I would not weld the 10mm plates to the bottom of the top beams because it warped them like a banana, I would bolt them to the beams instead with a thicker plate inside to beef up the 3mm wall thickness of the box section.