Brown & Sharpe 618 Spindle Bearings Question

Hi There

I've a B&S 618 Micromaster surface grinder over here in the UK.

The spindle bearings are getting noisy and need replacing, it's a great machine and gets a lot of use. I was wondering if anyone here knows either the bearing sizes/type or a bearing manufacturer name and part number for replacement bearings.

The machine is fitted with a two bearing Orflex type spindle.

Thanks in advance
John

All sorted now!
It turns out the bearings are a matched pair of very high quality metric (62mmx35mmx14mm) angular contact bearings. I was quoted $750 +$250 for shipping for a pair from the USA and managed to find a set of German made ********* bearings here in the UK for £149.34 + £7.50 for shipping, I've just fitted them and they seem perfect

B&S 618 Spindle bearings needed and some questions about the spindle

I am also in need of spindle bearings and I have a couple of questions. I have a new to me 618 whos spindle is very noisy and surface finishes are chattery. So I do want to replace the bearings. I have the spindle out, a parts diagram, and a few questions.
1. Does anyone have a part number and supplier of the ********* bearings quoted above? Ive searched no joy on that. Im a hobbist so I do not need the most expensive bearings. Northland tool quoted me $2100 for me to ship it to them to replace the bearings. Ahhh! I can not afford that.
2. Is the motor rotor pressed onto the spindle shaft? I removed the rotor nut and the rotor would not budge. I assume its pressed on but before I go putting force on it... Id like to know.

3. On the front of the spindle, the ball bearing retaining nut, is that a left or right thread. I have the spanner and tried both ways, and some heat, and it wont move. So unless I absolutely know which direction the thread is, Im not putting any more force on it. And by the same token, is the rear spindle ball bearing retaining nut a left or right thread.


Thanks so much for your help. Long time lurker. First post!
Mike

$2100 sounds very cheap compared to what you are fixing to do, take it apart yourself. You need some kind of holding fixture to clamp the rotor and backoff that lock nut. Be sure to witness mark the two some how so you can reassemble it with the two aligned to each other. You will probably have to press the shaft out of the rotor. The ends of the spindle housing should have the same cover threaded on, they should right handed threads. Try not to add anymore "Bubba marks" to the spanner wrench holes. Looks like the front bearings are toast, the spindle looks like it has turned blue from bearing melt down. Looks like this spindle has been into before. Once you get i apart, the spindle needs to be set up on vee blocks and a tenths reading indicator used to determine runout of the spindle. IF that spindle did see that kind of high heat, Runout may be too much for installing new bearings. Could be toast!!! I know that's not what you want to hear, just saying. Ken

4GSR said:

$2100 sounds very cheap compared to what you are fixing to do, take it apart yourself. You need some kind of holding fixture to clamp the rotor and backoff that lock nut. Be sure to witness mark the two some how so you can reassemble it with the two aligned to each other. You will probably have to press the shaft out of the rotor. The ends of the spindle housing should have the same cover threaded on, they should right handed threads. Try not to add anymore "Bubba marks" to the spanner wrench holes. Looks like the front bearings are toast, the spindle looks like it has turned blue from bearing melt down. Looks like this spindle has been into before. Once you get i apart, the spindle needs to be set up on vee blocks and a tenths reading indicator used to determine runout of the spindle. IF that spindle did see that kind of high heat, Runout may be too much for installing new bearings. Could be toast!!! I know that's not what you want to hear, just saying. Ken

Click to expand...

Ken thanks for the response.
I was able to get the rotor nut off pretty easily. I can press it out.
There was no discernible runout on the shaft on the machine. A tenth or 2 (ten thousands)measured on the machine. There was no measurable play in the spindle at all on the machine.
The darkness is from me heating it to remove the bearing cover. I can certainly measure the shaft once removed.
Thanks very much for your info. You answered several questions.

Now I need a bearing part number and a source at prices i can afford.
Best,
Mike

My 612 machine carries a bearing number of 7007. That would be basic number of 2mm7007xxxxx. Probably a DU arrangement? You will need two pairs of bearings. I would suggest getting the spindle completely apart to verify that the numbers are correct. Those bearings are too expensive to take a chance on my numbers. Shop around for pricing. I just rebuilt three spindles for KO Lee T & C grinder that I have. Make sure to get the proper grease, don't just use any old grease. I selected a Mobile SHC100 grease. It's a red-pinkish looking in color recommended for spindle bearings. I put my rebuilt spindle in the lathe and run it at about 1000 RPM for about thirty minutes to let the bearings seat and the grease distribute good before mounting and putting full RPM to the spindle. Also, if it heats up in the lathe, you will know something was not right, and will require tearing back down. Should not heat up any at all if properly rebuilt. Be sure to clean thoroughly and polish all surfaces of the spindle with super fine steel wool or scotch brite. Don't take off any material, just trying to get rid of any residue left from the previous install. Make sure the bearing caps and any locknuts screw on without wrenching. You should not have to use a torch to heat up anything to reinstall. Before going back together, think about the steps to take to reassemble. Make sure to orientate the bearings back to back or what ever the book says. Last, make sure to get the "high" marks on the bearings are all in line with each other. A magic marker works good for this!
Don't rush it! take your time and work clean with clean tools. Do all of this, you should come out good without having to rebalancing. Ken

The front spindle bearing cap IS A Left hand thread. After I cleaned it up there stamped in plain view, was LH
I was able to press the rotor off the shaft. It is a taper fit. The rear bearing cap came off no problem and is right hand. The front, took a lot of heat and finally broke loose.
Bearings are coming off and out no problem. I stopped for the day. Bearings have 7007 on them. I can not find any other markings of brand, part number, or orientation.
Bearings are not sealed, are completely dry. Im considering cleaning them up and re-greasing. Nothing to loose trying that really. I can clean them up, inspect them for wear, re-grease them, and see if the noise and chatter marks improve or not before I drop real money on bearings.
I sure would like to find a part number supplier with reasonable prices.
Also Ken, you mentioned a DU configuration on the bearings. After reading multiple bearing manufacturer sites, I can not find a DU arrangement. Here is a good short list of options NSK provides.

Update..
I removed both pairs of bearings. One set showed the vee markings of orientation.

One pair was ********* and not much for numbers. BUT, the other pair had plenty of markings. YEAH! RHP 7007 TADU EP7 Super Precision Ball Bearings 35mm ID 62mm OD 14mm W

And, somehow, I found an ebayer with NOS of these bearings. I was able to snag 2 pairs for $150. WOW. Fantastic. Hopefully I can figure out the high markings on them and hopefully there are VEE marks on them. The ones I removed from the spindle did not have the VEE marks on the bearings that I could see. The ********* ones did have the vee marks as shown in the photo.

I put the shaft on the lathe (between centers) and cleaned it up with some Scotchbrite and wd40. Its in real good shape. As is the spindle sleeve both seen here.


The spindle also has in it, according to the parts manual, a "friction seal washer". One of mine is fine barely, one is so brittle it broke apart. Its paper thin, made of some kind of fiber product I think. Does anyone know what this material is or what or where it can be procured? Oh and I did talk to Bourn & Koch who purchased Brown & Sharpe. They want stupid money, $90 each, for these little rigid paper thin fiber washers.


And as a side note, each time I have called Bourn & Koch for parts, the prices exceed any sense of reasonableness. Paper gasket for a hydraulic valve $150each. I needed about 8 of them. ARGH! I was easily able to make them out of paper gasket material and it works just fine.

Thanks
Mike

Eek. Hope you didn't trash that spindle. Not sure what the original hardness was but I bet it's a good bit softer now. Don't think I'd recommend using a drill for match marks either. Bye bye balance.

eKretz said:

Don't think I'd recommend using a drill for match marks either. Bye bye balance.

Click to expand...

Yes. Agreed. That was dumb. My punch was not leaving a mark. I touched it with a new carbide drill bit, and then regretted it.

Here's a set of bearings on ebay. Just search for "7007 bearing" and you will get almost 400 hits, but not all of them are super precision bearings.

NACHI 7007CYDU/GL PRECISION BEARINGS - DUPLEX SET, JAPAN MAKE-BRAND NEW IN BOX. | eBay

https://pulsar.ebay.com/plsr/clk/0/...OGiClvF+ADmDGIDyuEaILJiIoS6LNYqAw6QAQVqxBis"}


The DU I mentioned is the bearing arrangement. You won't find this in the bearing number, it would be mentioned in their technical manual.

Every bearing manufacture will have it's own designations for this bearing. The "7007" would be the common base number among manufactures. And it is super precision bearings that you are looking for.

If the balls in the bearing do not have a mirror finish and I mean mirror finish, they are bad and need to be replaced.

Update:
I installed the new spindle bearings and ran them on the lathe to break them in per manufacturer instructions. The change in sound (quiet) and surface finish is night and day. Clearly they were bad. Since I had never even stood next to a surface grinder before, I was not familiar with what the sound should be. I still have a tiny bit of chatter on the surface finish, and this could be quite a number of things which Ill have to go through one at a time. Im 80% happy on this improvement. Im confident there is opportunity for improvement on the surface finish.

I also made this simple grinder wheel balancer. 3 pieces of steel flat plate, tig rod on the top rails, 3 point leveling screws on the base, some bushings to fit the arbor, 1/2 drill rod as an axle. Works well I think. First wheel to try and balance has so many holes drilled in it to try and balance it, I quit to reassess if it is actually a decent design or not.

Anyway, thanks so much for the folks here who chimed in to help on the spindle bearings. Excellent advice all around.