Desktop block bearings. Machine wouldn't move in the X axis.

[Bud Meade]

Decided I had nothing to lose by taking them off and seeing what was going on with them.

Turns out that lack of maintenance by the OP (ME) led to a build up of gunk. Used brake cleaner to clean them all up. Used the same to clean up the track. Used sewing machine oil (similar to 3 in 1) and oiled the bearings and lightly oiled the track and then wiped it off with a clean cloth to leave a thin film.

20210905_133616.jpg

On one end there is a small chrome nut that looks like it has a very small spring loaded opening. I assume this is where one would add oil? Are there special oiling devices that would fit something that small?

Surprised on how quiet the machine is when moving..

Life is good.

Glad I found and fixed this before putting it up for sale. Never want to sell something only to have the buyer have a problem.

[scottp55]

Bud,
This subject came up years ago when the 5.5"Z retrofit kit came out, and a lot of questions came out when Z bearing block bearings fell out.
Turns out a lot of people had been using WD40 on the rails and it degraded the factory grease.
(happened when I got back the second Desktop from up North and did his Z upgrade, and turned out he'd ignored my advice on WD

The felt wipers on the ends of bearing blocks are key.
Every 30-40 hrs of cutting, center machine(for X,Y) and wipe rails clean with light oil(sewing is good,and been using 3-1 for 5 yrs), then drop 2-3 drops oil on upper rail,
and a saturated paper towel on underside. Then I make radio button 1 0,0 and radio button 5 at 24,18 and go button 1 and then 5 about 6 times....then wipe excess off!!
Felt wipers Need to be moist to clean debris off completely!
On Z rails, got to max height/clean rails...with bit out go as low as you can, wipe rails...3-4 drops on each channel(and let it roll down channel) then raise and lower 6 times and get
all excess off. That's all the maintenance to do.

A mandolin Desktop owner asked about the grease fitting, and Brady Watson(was a Shopbot Technician/Guru at the time) explained that those bearing blocks were also used in wet environments(thus the fitting), and nothing needed to be done in dry environment except keep felts moist(he said it could actually be Bad for the factory grease).

Have to admit on the Northern Desktop where WD had eliminated factory grease,I used to have a high end bicycle shop and had sealed bearing grease(Phil Wood N/A now)..
and gave the bearings a light coat(and no problems in 5 yrs).

A little worried about that brake cleaner taking out all factory grease...NOT up on quality greases now as I still have Campagnolo lithium and Phil Wood.
Maybe someone else could recommend a top quality grease?
MAYBE just weekly oiling of felts will be good enough for the bearings? (If so I'd say weekly oiling is now a Must)

Hope this was any help Bud.
scott

[Bud Meade]

Thanks Scott, as always a detail explanation and helpful advice.

Wonder what kid of grease the factory used? I would think white lithium would be a good choice in that application but that's just a WAG with no basis.

[scottp55]

Hey Bud,
I looked for pics of when I did my Z-retrofit, but apparently didn't take any of the insides of bearing blocks
IF failing memory serves, it did not look like a yellow/white lithium grease..it was sort of a clear translucent(?) and Not a whole lot of it(not Packed).

Like I mentioned,I worked high end bicycle shops for 9 yrs. Bearing remind me of headset races, and on best non-sealed ones we used Campagnolo Lithium,
BUT we repacked pretty much every year...and not much grease at all remained before we cleaned and repacked.
The translucent green Phil Wood we started using on non Campagnola was quite visible the next year in comparison on top end other brands.
Sorry I can't help you there.

OH...one other tip from Brady on the bearing blocks,
Vac or wipe off rails regularly..do Not use 90psi air, as it can drive contaminants beyond the felt wipers!
Unfortunately I space that occasionally, but at least now I keep the nozzle Away from the machine quite a bit(especially the blocks).
Z-blocks are a PITA, but paper towel wrapped toothbrush, and 3-1 oil with extendable nozzle helps...and it's Worth it!

Have fun with your new Max!
scott

[don]

Hi Scott,

I've purchased an early (I think 2011) desktop, I think I'm the 3rd owner.
Both block bearings on the right side of the Y rail were bad, So I ordered 2 new and have replaced them.
I'm thinking about take the rest of the bearings blocks off (one at a time) and clean the rest of them.
I just looked at the rest of these bearing blocks and none have felt wipers on either end of the bearing blocks.
Is this a feature on the new machines?
What kind of felt would you suggest and whats the best way to attach them?
I also appreciate your Desktop Jigs and Clamps, thread, very informative Thank you.

I just sold a 2004 PRT a few months back so I'm not new to ShopBot just a different machine.

Thanks any info/guidance on the felt would be greatly appreciated.

Don

[scottp55]

Hmm....NO idea why I called them "Felts"....must heard someone call them that when I was a rank newbie

Just went out and looked at mine after toothbrushing fine dust off that made them LOOK like felt

Found Max's thread....and Nate's(Shopbot Tech replies verbatim)....and then Brady's reference to the actual blocks and the page # that's pertinent here;
http://www.talkshopbot.com/forum/sho...rease-fittings

Sorry about that!
Even looks like greasing my Z bearing blocks was a mistake(but 6 yrs(5?)) and no problems.
Must have been felt wipers made for bigger machines rails now that I think of it maybe??

Quite a few people downsizing once sheets get heavier and traveling(not right now) gets attractive.
Think you'll love the old unibody Desktop!
Does it have the 5.5Z retrofit?
That's a wonderful upgrade!!

scott

[don]

Thanks Scott,

Quite a few people downsizing once sheets get heavier and traveling(not right now) gets attractive.
Think you'll love the old unibody Desktop!
Does it have the 5.5Z retrofit?
That's a wonderful upgrade!!

scott

No it does not have the Z upgrade..... yet!
I do remember them putting felt on the rollers the larger machines.

How does the Desktop do with aluminum?
Been making hitch covers on the Old PRT but haven't made the first cut on this 2011 Desktop

These were the first two.
Don't look at the sloppy paint work. I've changed my process since.

[scottp55]

Sorry Don,
Trying to cut Tiny Harleys (60 of them) and attend Vectric's Virtual UGM at the same time
Never cut Aluminum on purpose(coupla clamps won though)...pretty sure others have on the Desktop.
Only metal cut was IBM Tin 99.999999% (as in tin can/tin soldiers) for a VCarved inlay.
Came out nice, but sharp chips got into wheelchair tire rubber and ripped my hands up for weeks....so I avoid metal
Sorry I can't help with that, but Google search of forum should yield stuff...Desktop isn't a milling machine, BUT should be tight enough for most stuff.
Enjoy the machine!!
scott