Fobco Star Bearing Replacement - Code Confusion!

[Dissolve]

Hello,

I've searched around the net and forum for all I can find on this subject but I've found too much conflicting information. I am currently undergoing restoration of a Fobco Star bench drill along with another Meddings drill simultaneously. I have stripped the drill down and de-greased everything awaiting a fresh coat of paint, some wire brushing and re-assembly with new bearings. Now, the drill has 4 bearings in total which I have sourced all the codes from as follows:

- One lower spindle bearing (115ACD Thrust 4 Hoffman)
- One bearing in the quill tube (115ACD)
- Two bearings in the head casting that are separated by a spacer (WG B Hoffman 59)

I've searched for thse codes and cannot for the life of me find out what I need to purchase for replacement! In the "Fobco refurb" Topic I found on here there is only mention that the Spindle and Quill bearing are "Angular Contact" bearings, and the thread here has entirely different codes than myself:

bearing-replacment-in-fobco-bench-drill-t11575.html

Would anyone be able to confirm what type of bearings I require and how I go about finding the correct size bearings?

Thanks!

 

[Cheshirechappie]

I'm not surprised you're confused! Hoffman became part of RHP (Ransomes, Hoffman and Pollard) some time in the 1960s, and RHP have since been taken over by (I think) the SKF conglomerate.

Two possible ways to solve this problem. The first (and probably the better) option is to contact Tony Griffiths at http://www.lathes.co.uk who may even be able to supply the right bearings - he holds the remaining Fobco spares. The second is to contact SKF customer services with the Hoffman spec, and ask if they can give you the modern spec number, or identify a modern equivalent. If you can measure the exact OD, ID and thickness and describe the rolling element, cage and sealing (if any) arrangement, that might help them.

Edit - Incorrect information! RHP are now owed by NSK - contact information for after-market bearings information here; http://www.nskeurope.com/cps/rde/xchg/e ... earch.html

 

[CHJ]

Cross reference for part numbers might help, can you measure bore as CC mentions, outer diameter and thickness of existing bearings?

This will at least give you sizes for fit, selecting a version with thrust enhancement may then be easier.

RHP 72--
R & M LJT--
HOFFMANN 1 - - ACD
POLLARD 1 - - GW

 

[Dissolve]

Cross reference for part numbers might help, can you measure bore as CC mentions, outer diameter and thickness of existing bearings?

This will at least give you sizes for fit, selecting a version with thrust enhancement may then be easier.

RHP 72--
R & M LJT--
HOFFMANN 1 - - ACD
POLLARD 1 - - GW

Hello, I'm afraid I don't fully understand what you mean here, I have however measured the bearings and they match up to these bearings:

http://www.ebay.co.uk/itm/R14-IMPERIAL- ... 4836176686

I'm going to fork out for SKF bearings for the spindle/quill bearings but I'm not sure how important the pulley bearings will be for the accuracy/running of the drill? I might be able to get away with cheaper alternatives for these.

When you say "selecting a version with thrustenchancement" what exactly do you mean? I'm unsure what 'Type" of bearings these are but they definitely match up to the dimensions of the one linked and they're open bearings, is there anything else I should take into consideration?

Thanks

 

[CHJ]

The list is the differing manufacture part designation (letter idents for similar spec. bearings to your Hoffman 1--ACD)

Pulley bearings should not need any thrust component so any decent pattern should do.

I do not know the specifics of the spindle bearings and how they are assembled but I would expect them to be a pattern that has a side thrust component on one side of the outer race to take increased side loads on the balls due to downward pressure when drilling.


If in doubt take your existing bearings to a local bearing supplier and they will match them with their nearest equivalent.

 

[gerrypb]

Hi Fobco users and restorers, this seems to be the latest post on Fobco problems so here goes with mine. I just got a Fobco from ebay that I thought was a Star, turn out to be a Universal 16 MT with the threaded nose on the spindle for 2MT collets. That is great although it has had a hard life and needs TLC. There is play in the quill, only 3 thou where the quill runs in the machined casting at the bottom but accentuated by loads of play where the 15mm top of the quill slides in and out of the drive pulley. This means that as the quill is lowered the play gets worse at the chuck as the whole assembly is rocking artound the machined lower part of the casting. How is the top of the quill supported in the drive pulley. There is no play in the drive pulley bearings and a barely measurable amount in the two opposed angular contact bearings that hold the spindle into the quill.
The machine is totally missing the handle and bar that fits in the hole across the head at the bottom in front of the quill, I presume this is for locking the quill, does anyone have one of these. It needs a new return spring and a belt which I can get from Lathes if and when Tony answers his emails.
I could also use a compound slide table of a rotary table if anyone has one surplus to needs.
Looking forward to lots of help. Gerry.

 

[beech1948]

Cross reference for part numbers might help, can you measure bore as CC mentions, outer diameter and thickness of existing bearings?

This will at least give you sizes for fit, selecting a version with thrust enhancement may then be easier.

RHP 72--
R & M LJT--
HOFFMANN 1 - - ACD
POLLARD 1 - - GW

Hello, I'm afraid I don't fully understand what you mean here, I have however measured the bearings and they match up to these bearings:

http://www.ebay.co.uk/itm/R14-IMPERIAL- ... 4836176686

I'm going to fork out for SKF bearings for the spindle/quill bearings but I'm not sure how important the pulley bearings will be for the accuracy/running of the drill? I might be able to get away with cheaper alternatives for these.

When you say "selecting a version with thrustenchancement" what exactly do you mean? I'm unsure what 'Type" of bearings these are but they definitely match up to the dimensions of the one linked and they're open bearings, is there anything else I should take into consideration?

Thanks

If I were you I would STOP now.

Quite a few bearings will have the same or very similar sizes. Thus your ebay purchase might look OK but be quite wrong.

The naming on the bearings will tell a knowledgeable person what type of bearing they are. I believe that Fobco used some angular style bearings as well as standard types.

Take the info you have + ID/OD and thickness or width and go visit a bearing shop or bearing factor. Also send an email to the bearingboys web site and ask for clarification. Both these places will have several books or system access of about 800 pages each which provide a tracking of original Hoffman bearing numbers through to each and every takeover upto modern day to provide a modern day replacement. Your id/od/thickness measurements merely confirm fit to the hole and not the type of bearing.

Clarification will come back as a recommended modern bearing with a choice of felt or steel shields which will broadly seal in the grease. Open bearings have no seal and so will need greasing during their lifetime. Grease can go "OFF" and separate the wax from the petroleum compounds so that your bearings are ruined if run for any time. It can be washed clean and an open bearing be refilled. Modern synthetic grease is much better. Never fill an open bearing more than 1/2 full of grease at maximum as that can simply overload the structure.

Bearings with felt or steel shields will already be filled with grease and be sealed for life. Some variations will include double steel shields for example.

Listen to the experts recommendations.

When you get a recommendation have a chat with the bearing supplier and either show or send pictures of the existing bearings.

Unfortunately a bearing is not just a bearing but a precision item which must be replaced with an absolutely correct replacement.

Thrust is the force applied against the sides of the bearings to either hold in place or provide a force to properly load the bearing during use. In a drill I would not expect this to be great and to probably be provided by a washer or spacer.

You did write down the sequence of bearings and washers removed...I hope.

If you think I am being pedantic thats OK but know that just picking up any old bearing of apparently the right size is a recipe for disaster.
Al

 

[sjalloq]

Posting to an old thread because it seems to have the most recent useful data in it. If only people would return to their question threads and post the answers.... (hammer)

So, what was the outcome here and did you manage to find a set of bearings that were the correct ones? I'm just starting to refurb a Fobco and have found lots of questions with not many answers.

I spoke to the people at the bearingboys.co.uk today and didn't come away too impressed. I sent them the following pictures of the pulley bearings and was told that they had 'no clue' as to what they were and to ask elsewhere. Can mark that one on the list of companies to avoid. :roll:

I'm assuming that any old generic open EE8/R14/KLNJ7/8 bearings will do here? I don't need to splurge £60 for the SKF ones when a £6 Far Eastern one wlll do - save the money for the quill bearings.

Thanks.

 

[marcros]

i have just logged on to ask whether i need to spend on branded bearings for my meddings, or whether cheap ones will do- i will await the awnser.

 

[beech1948]

Have a look here

http://simplybearings.co.uk/shop/Be...+Bearing+7/8x1-7/8x3/8+inch/product_info.html

Mod edit:- URL link corrected

 

[RobCee]

When I renovated my FobcoStar, I had a lot of fun finding the correct angular thrust bearings! Many suppliers were telling me that the ones I had were metric! I can't imagine that was the case, on a drill made back in the stone age...
I eventually found a very helpful bearing supplier in Scotland that understood the Hoffman range and the modern equivalents. It was too long ago to remember them now, I'm afraid, but if you search for Hoffman bearing suppliers, you should find someone knowledgeable.
I absolutely agree with the "don't guess and get them from ebay" concept - the angular thrust bearings are the critical precision component in your drill and getting them wrong will make the whole renovation process worthless.
The upper bearings are where you can go for something cheap, but you should expect to pay a sensible amount for the angular thrust bearing pair.

 

[sjalloq]

Just wanted to put some more information in this thread as I've finished my renovation now. I have the original Fobco Star that uses a spindle that is the same diameter along its length. The different spindles can be viewed about 3/4 down the page here: http://www.lathes.co.uk/fobco/

I bought my bearings from Midland Bearings and Eriks, both of whome were very helpful and cheaper that the regular internet stores. I tried Simply Bearings and the Bearing Boys but not only were the prices higher, I felt like I was talking to a kid on work experience when I asked any technical questions, not a seasoned pro with an depth of knowledge under their belt.

The pulley bearings I used were some no-name generic ones which were about £12 for 6. I had to buy 6 to get over the minimum order price of £10. These were the R14 EE8's I asked for help on above. The quill bearings were both SKF 7202BEP and are metric. They cost about £12 each.

Fitting them was fairly painful but I managed it in the end. The pulley bearings can just be knocked out from the bottom once the top circlip has been removed - I used an old screw driver as there wasn't a lot of room to get a tube in there. You then remove the bearings from the sleeve they sit on and retain the spacer. Fitting the new ones was a case of pressing in the bottom bearing first until it stopped on the lower circlip. The spacer goes in next followed by the top bearing. You want to be careful when you get to the last few mm of travel as you don't want it to jam so hard against the spacer that the bearings then don't turn freely. I tapped mine home with a length of mild steel tube that was the correct diameter. Then finally you need to press the sleeve through the inner races from the bottom. This requires quite a bit of force and you need to press on the inner races to avoid the force being transmitted through the balls. I came up with a threaded rod and tube settup in the photo below but it took a loooong time and was hard work due to the tight fit. If you have access to a pneumatic press then that might be a better idea.

The quill bearings were much easier and you can tap them out and press/tap home new ones. I fitted the lower bearing onto the spindle first so that the inner race butts aginst the stop. The top bearing was then pressed and tapped home against its stop in the top of the quill. From there it's another case of getting the correct sized piece of steel tube so that you can press the spindle up through the top bearing while putting pressure on the inner race. I used the only large clamps that I had available for this which were my Bessey K Body ones and they coped fine. Once the bearings are home you can fit the retaining nut, placing some pressure using your tube and clamp again in order to preload the bearings, before tightening the locking grub screw on the nut. The dismantling notes from lathes.co.uk states that a firm tap with a lump hammer should seat the bearings correctly and they should run smoothly. There should be no play in the bearings like there is when they are unloaded.

 

[marcros]

nice paint job by the look at it.

 

[sjalloq]

Thanks marcos, it's not too bad but you can see it was my first spray job when you look closely but perhaps I'm being picky. I'll put some more pics up on a project thread once the light improves - been raining all day today. I posted a finished pic in this post: post993855.html#p993855

 

[beech1948]

I wonder if there is someway to create a sticky thread which records the suppliers of things like bearings we have had good service and support from.

That has to be better than searching for angular bearings Scotland based on the info above.

Anyone agree.

 

[CHJ]

I wonder if there is someway to create a sticky thread which records the suppliers of things like bearings we have had good service and support from.

That has to be better than searching for angular bearings Scotland based on the info above.

Anyone agree.

one-stop-reference-links-t67853.html

 

[beech1948]

CHJ,

Thank you for the reminder.....that resource slipped my overworked mind.

The OP needs to add the Scottish bearing supplier I guess...I have no idea whom it is.

Looking at the classifications used in your message I wonder if they support the know how needed to rebuild machines ?

 

[alex21008]

Hi all,

Hope you don't mind me reviving this old thread! I've just become the proud owner of a Star and need some help/advice on refitting the spindle pulley shaft and bearings.

I was wondering if its possible to refit the shaft and bearings by tapping down from the top? Or is the only method by following Sjalloq's method in this thread, of seating the bearings first and then pressing the shaft onto the bearings, from the bottom?

Any advice would be much appreciated!!

Alex