[TT350]

Hi guys it’s time for a new set.

They started whining a few days ago and they got so loud that I couldn’t stand being in the shop with it running.

I took the spindle out of the machine and disassembled it and got the part # off them and was going to order a good set of high grade American bearings until I saw the price, about $550.00 a pair and there’s two pair.

It has 7007’s up top and 7008’s on the bottom.

I’m right in the middle of a job so I a set of put 6007’s and 6008’s back in the spindle for now.

The 6007 and 6008’s are a garden variety seal ball bearings that have the same dimensions.

They are rated for 7000 rpm but are not intended
as a “spindle” bearing but they will get my by for now.


Where can I get a good deal on the 7007’s and 8’s?

[300sniper]

i guess the american bearings are a lot more expensive than the factory ones. the whole spindle cartridge from tormach is $564.

out of curiosity, would you be able to guess approximately how many hours are on your machine? i want to know if i need to start putting funds aside for when i need to replace the bearings.

[TT350]

I looked today it's 840hr's

[BlueFin]

I looked today it's 840hr's

Is there a timer in the control software somewhere that tells you that? Also I would probably just buy a new spindle and bolt it in instead of mess with it, I wonder if Tormach has a core service established?

[METALTEK]

Try Motion Industries. I have had great luck with getting a good price on bearings. You will need to be a business to buy but that is simple enough.

http://www.motionindustries.com/moti...mii/index.html

Jaime

[TT350]

This type of bearing is in the mid 5's even from them.

I'LL try to get a screen shot and a path to the timer today.

[mayhugh1]

TT350,
Check with Tormach. Their replacement lower bearing (part no. 30303) is $95 and the upper (part no. 30316) is $61.60. - Terry

[keen]

Hi TT350

I think you were following my thread on my spindle bearings - (faulty assembly).

I made up a sprung preload and my spindle runs a lot cooler now - yet is still great on heavy machining. I think the bearings will last a lot longer with this setup.

[philbur]

Hi Keen,

One of the primary criteria for a precision machine tool spindle is rigidity. The key word being precision. Bearing preload increases rigidity but shortens the bearing life. Of course if you are satisfied with the lower ridgidity (precision) that's find, but at the end of the day nothing is for nothing.

Phil

Hi TT350

I think you were following my thread on my spindle bearings - (faulty assembly).

I made up a sprung preload and my spindle runs a lot cooler now - yet is still great on heavy machining. I think the bearings will last a lot longer with this setup.

[keen]

In principle you are correct Phil."All things being equal"

But with the tormach spindle bearings so far apart - the preload varies greatly (from heavy to nil is quite likely) - with spindle temp change. - ( Which is less with sprung preload) - this was discussed at length in the original thread or perhaps it was some similiar thread about that time..

[philbur]

Hi again Keen,

Do you have a general arrangement sketch of the layout of the bearings inside the housing/on the spindle shaft etc. I'm curious as to how the preload is applied with two pair of AC bearings at each end of the shaft. I'm unable to guess/draw an arrangement that looks right based on the exploded view from the manual.

Phil

In principle you are correct Phil."All things being equal"

But with the tormach spindle bearings so far apart - the preload varies greatly (from heavy to nil is quite likely) - with spindle temp change. - ( Which is less with sprung preload) - this was discussed at length in the original thread or perhaps it was some similiar thread about that time..

[TT350]

Well it has some L-cheapos sealed bearings in it now, so far so good we’ll see how well
they do over time.

I took the original ones apart and the races look perfect but the ball are not shiny there a little dull, I think this is the source of the noise.

I can buy precision balls from McMaster for about $10.00.

I’m going to rebuild the old ones and see what happens.

I done a little digging and the guys that rebuild spindles do more than just put bearing
in and send it back.

They check it for run out and regrind tool holder bore and balance it.

Now back up and look at the overall pitcher, $1100.00 for a good set of angular
contact matched set of duplex bearings.

I think it is like putting a deer hunting scope on a bb gun.

If I take it this far I going to put a 5 hp motor on it and set it up where I can get 10,000
rpm out of the spindle.
For now a $40.00 set of bearings are doing the work.
I’ll keep you guys posted.

[keen]

TT350 - I tried new balls in mine also - but they were still noisy - a lot of work - there only needs to be tiny damage or wear to the race. why dont you buy replacement tormach bearings - they are fine.

[keen]

hi Phil. Pics below. The disc spring is under the adjustment nut on top of the top bearings on the spindle - also included for TT350 is a pic of the grease - really good stuff.

[philbur]

They are a matched pair so I think if you use new balls they are no longer a matched pair.

Phil

TT350 - I tried new balls in mine also - but they were still noisy - a lot of work - there only needs to be tiny damage or wear to the race. why dont you buy replacement tormach bearings - they are fine.

[levelzero]

TT350,
Check with Tormach. Their replacement lower bearing (part no. 30303) is $95 and the upper (part no. 30316) is $61.60. - Terry

When ordering do you need 1 or 2 of each?

[levelzero]

Quoted from the document.

Upper bearings are PN 30316 and are provided as a matched set. Lower bearings are PN 30303
and are also provided as a set. Order both part numbers to get a full set of 4 bearings.

[philbur]

If you are going to rebuild your spindle it might be worthwhile getting some advice from Tormach. Bearing preload is critical, getting it wrong can be expensive before you even know you got it wrong. Bearings with excessive preload can die very quickly.

Just a thought

Phil

Quoted from the document.

Upper bearings are PN 30316 and are provided as a matched set. Lower bearings are PN 30303
and are also provided as a set. Order both part numbers to get a full set of 4 bearings.

[levelzero]

Speaking with them today the instruction I got were .... snug and not too much grease in the bearings.

[TT350]

My sealed L-cheap-os are doing a good job, We'll see how long thay'll last.