Well here goes... Aluminium frame router design

[Boyan Silyavski]

Are all pieces there assembled like that?




So if the whole bearings are moving in the housing, then shim the OD of the bearings. If only the ID of the bearings are moving, then shim only the ID. When shimming, dont shim between them, but outside in both cases.

If not freely rotating, then something is not right. It must be something simple, so just check again

[CharlieRam]

It's all there apart from the lock washer, do I need one?

[CharlieRam]

Heres a little video of what I mean, if the screw is pushed upto the sleeve, the seal starts to spin. I'm wondering if the spacer O/D is catching on the seal and when it is butted upto the bearing face it is dragging it round? Also I'm still not sure how freely the screw should move, I was expecting it to spin a little like a roller skate bearing, it seems to have resistence even without tightening the nut. The spacers are different lengths but if I put them the other way round the outer one would be too short and be inside of the seal, the way they are now both sides protrude from the seals.
Any help and advice greatly appreciated.
Cheers, Charlie

[njhussey]

Here's a pic of mine, the spacer goes beyond the seal to keep the face of the machined shoulder away from the seal.

[CharlieRam]

It's been a while so heres a little update.. been working on the Z axis and also repairing my mill in the meantime as I stripped the plastic gear on my Chester champion.

But it's not moving very freely, I have clocked the rails up within 0,01 and put it all together including the ballnut and tried to push it up the rails, I could just about move it but it didn't feel very nice, I took the plate off and greased the carriages, and tried the rails on there own. one felt lovely and smooth but the other felt notchy on one of the carriages. So I carefully removed the rail and it appears as though I have a ball bearing missing!

Would this cause a notchy/stiff feel in the carriage or have I got other problems? I measured one of the ball bearings and it was 3.98mm so am I right in assuming 4mm. This is the first time the rail has been off so it must of been missing when I got the rails and if it hadn't been for the notchy feel I wouldn't of taken it off so please no telling me off for removing it :-P

Cheers, Charlie

[mekanik]

Hi Charlie
When you get the carriage cleaned and running smooth, bolt the rails to your Z plate with the carriages installed but not bolted to matting face, offer the carriage/rail assembly up to your other plate and check the matting face with feelers to see if both plates are flat, one or both of the plates might be twisted or something.
Regards
Mike

[CharlieRam]

I've got to get the carriage running smooth first, I tried both carriages on each rail, one of the rails is perfect but on the other rail I have one notchy carriage, that is when i discovered what looks like a ball bearing missing, just wondering if anyone else has had a problem, I can buy some 4mm ball bearings and see if it makes a difference, it definitely doesn't feel right though.
PS. I did remove the rails from the Z axis to check I wasn't twisting it.

[Lee Roberts]

Could do with the exact size ball mate, shouldn't really round it to 4 mil like that.

What you using to measure it?

I'll have a look in a mo as I've got loads of different size ball bearings, can send you some if you want.

Pop a ball out of a good unit and use it to check the dodgy one, let us know

.Me

[CharlieRam]

I used a mic, but only a quick check and I may of been a bit over on the pressure, I was more bothered about dropping it in the swarf! I will measure a good one tommorow and get back to you, cheers. Do you think having one ball missing could cause the notchy tight fit? I'm thinking about removing all the balls and giving it a good clean incase the missing ball is actually in bits causing the notchy feel. Good idea or not? It doesn't look too hard, just a bit time consuming.

[Lee Roberts]

I used a mic, but only a quick check and I may of been a bit over on the pressure, I was more bothered about dropping it in the swarf! I will measure a good one tommorow and get back to you, cheers. Do you think having one ball missing could cause the notchy tight fit? I'm thinking about removing all the balls and giving it a good clean incase the missing ball is actually in bits causing the notchy feel. Good idea or not? It doesn't look too hard, just a bit time consuming.

OK nps.

Well yeah I would seems silly not to at this stage, like you say not difficult just a time thing, may as well do it now and rule it out then revisit.

I doubt it's a ball gone to bits in there, more likely to be something else got in, check the returns and any paths the balls take for damage, lumps and bumps things like that.

I just rebuilt two ball nuts for someone and on one of the nuts, a plastic return was just a little bit snug as the balls passed through it, the symptoms where a slight judder/nock as the nut was spinning on the screw.

If you know what brand/make and model we may be able to look up the right size ball.

.Me