Herbert B Pillar Drill: Lubrication

[garrardgfgParticipant @garrardgfg]

I have a Herbert B Pillar Drill and wonder if anyone out there knows what lubricants are recommended for it. It has three ‘grease’ nipples:

One on the right which I assume lubricates the rack on the drill handle

Two on the front which I assume lubricated the quill and bearings.

Does the rack take a lithium grease and the bearings a medium heavy oil (like my BCA Jig Borer), or are all three supposed to have grease, or conversely oil ? and if so of what grade? As a Myford owner, I’m very aware that ‘grease’ nipples are not necessarily what they appear to be!  Any advice or comments would be most welcome.

I’m also curious what the other three holes on the front of the drill were for. These have always been blanked off on my machine (two with large headed screws and one with a Allan bolt). On pictures I’ver seen these always seem to be blanked off although on one picture on the internet the lower one has been used to mount a home made swarf shield, However, I wondered if anyone knew what the original purpose was?

[gerry maddenParticipant @gerrymadden53711]

I have completely stripped and rebuilt one of these nice little machines recently. It only had the slow-speed pulley when I got it, but other than being in a sorry state, it was largely intact and original.

Despite being a good design, this drill does have some anomalies around its bearings and lubrication.

The motor bearings in mine were original (1960s Hoffmann). These were of ‘open’ type and would have been ‘greased up’ on assembly. This would have been a right messy thing to do because of the internal end-cover arrangement. There is then no facility to relubricate these motor bearings, so its effectively sealed-for-life.

As a contrast, an excess of grease nipples have been fitted to the spindle head.  As you mention, the one of the right feeds into two ball bearings that support the operating lever. Use of two bearings here is a luxury. To give them a relubrication facility as well is quite honestly a little bit OTT. The other two nipples, as you surmise, each feed the pair of quill drive bearings and the spindle bearings.

Regarding the spindle bearings, from everything I have seen, these were always double shielded types which would have had their own controlled-volume grease charge. As this drill unit can run very fast, (up to 18k RPM) it makes no sense to have a relube facility on these bearings. Forcing grease extra grease into double shielded bearings, surrounding them with more grease to stop them purging the excess, then running at high speed is courting disaster.

My quill drive unit contained two open type self-aligning bearings mounted almost side-by-side. (Why this type was used I do not know.) They are significantly bigger than the spindle bearings and therefore at substantially more risk from overheating from uncontrolled greasing. Putting a grease nipple here is just inviting serious trouble.

When I stripped my ‘B’s head, every cavity was chocka-block with grease which was oozing out of every orifice. Some people seem to think that grease just disappears with time. It doesn’t significantly, so eventually, every cc that’s fed in will come out, somewhere. The three units in the head, handle, spindle and quill drive all interconnect too. So if you feed enough grease into say just the quill drive, you will eventually lubricate the handle bearings too!

In my rebuild, I have put ‘sealed-for-life’ bearings in all positions except the handle. The grease inside these bearings will handle the maximum speeds with ease. They will not need any additional grease to be added and will almost certainly out-last me.

The handle bearings were not replaced. I just washed them out and fed them with a few drops of high viscosity oil to produce a nice viscous damped action. I have, as you see in the picture, refitted the three grease nipples. This is just for completeness. I will never use them.

As regards original Herbert guidance on the matter I have trawled the net and can’t find any operators manual, only spare parts guides. I have however seen a picture of a very early ‘B’ which seemed to be fitted with drip-feed oilers! This would actually be a very safe way to lubricate these bearings but unfortunately would make the machine rather messy in use. The nipples fitted to most machines could therefore, as you suggest, have been intended for oil rather than grease.

My feeling though is that Herberts would have subsequently “recommended” grease lubrication (just because it’s a bit more ‘modern’) but would have included strict limits/restrictions on the amount, the type and the frequency. They would have probably suggested things like ‘a No.3 consistency’ (for vertical shafts) ‘Lithium based’ and ‘2 ccs per year’. However, these might have been reasonable for a machine being used for say 5 hours a day, 5 days a week, but in all honesty aren’t really that relevant for intermittent/occasional duty, especially if one doesn’t make use of the 18k RPM speeds.

What you should do now really depends on what’s already in your drill’s bearings. If as was the case with mine, they are already stuffed with lubricants of unknown parentage, I certainly wouldn’t add more. I would either leave as is OR clean it all out and start afresh with oil or new sealed-for-life bearings. It all depends on whether you need another project or not.

As for what all those miscellaneous holes are on the front, I only wish I new!  I can only assume it was for some sort of attachment, but I cannot think what.

Gerry

 

 

 

 

 

 

[BazyleParticipant @bazyle]

Such high speed bearings would not be intended for grease but a relatively thin oil which would easily escape hence needing a replenishing point. It is unfortunate that we call these multi-use items ‘grease nipples’. The Alexander Die-sinker spindle does specify Vaseline for the high speed magneto bearings probably because it is consistent and liquifies at a very low temperature.

[garrardgfgParticipant @garrardgfg]

Thanks for your comments on lubrication and Gerry for your pictures of your restored Herbert. I also chased back all the previous posts on Herbert’s, the parts catalogue is very interesting and clearly suggests the quill bearings are sealed.

I bought my Herbert about 30 years ago in London from a guy who cleared workshops and factories. I actually went for something else, but noticed he had three (what I now know to be ) Herbert’s and other bits that he said had come out of a British Aerospace factory. He was just collecting stuff together as he had a stall at the Model Engineering Exhibition (the one in Jan in London). He was reluctant to sell of his MEE stock, but let me chose one of the high speed drills. I took the only one with a 240V motor and apart from cleaning it up, giving it a coat of paint, fitting a new switch and a drill chuck I haven’t done anything to it apart from use it. I don’t think I have ever lubricated it (what an admission!) and recently out of guilt thought maybe I should!

With your comments I had a look to see what lubrication was in the nipples and casting, working on the supposition that if it was from BAe it had probably been looked after! I was surprised to see the nipples were dry and as Gerry noted there is a huge space behind the nipples in the casting which was also empty. With a long screwdriver I did manage to get a scraping of grease off the spindle. It looks to me very like a medium lithium grease. I also found traces of a similar grease on the cavity walls / rack behind the third nipple (also clean). I noted Gerry’s guess in a previous post that he thought Herbert’s would recommend Shell Alvania R3 or equivalent for use on a minimalist basis. What I saw traces of could well be something similar. But what I can’t get my head around is the huge size of the cavity that connects to the nipples, and Gerry notes the two cavities are interconnected, so it would take a huge amount of grease to fill and as noted packed grease is not good for high speed bearings. I can’t see that putting a small squirt of grease (or oil) into the nipples will have any benefit to the running surfaces as it wouldn’t have the velocity to carry it across the cavity. Anything you put in would, I suspect, eventually just pool at the bottom of the casting and drain out the bearing / casting interface. So I’m tempted to ‘do nothing’ on the quill bearings and assume they are fine, but may try a bit of grease on the rack to salve my conscience and because its not such a deep space.

I suppose I should strip it and do as Gerry has done, However, everything I’m touching at the moment is turning into a project and I really don’t want another one at the moment, particularly  when its not broken!. If anyone has any other comments on this strategy or could reassure me that the nipples do do something then I would love to hear from you!

The other posts on the Herbert quill and motor pulleys for speed changing made me go and have a much closely look at my setup. I had always thought my drill was a single speed  drill as it had no speed change plate (although I now see there is a hole for a rivet in the correct place for something). The 240v motor I’m now pretty sure is a replacement, possibly a GEC washing machine motor (so not sure how this stacks up with the BAe origin!). At the motor pulley closer inspection shows that it looks to have the original cone spindle with a pulley with two sheaves, a c63mm diameter upper one and a 38.7mm diameter lower one. But as it was set up only the larger sheave was obvious as the other was hidden by the casting. I then got very excited when I saw there appeared to be two sheaves on the head 19mm upper and 27.2mm lower diameter. My belt size is ½ inch (12.7mm). So I assumed it was a two speed machine. I reset the motor pulley height and adjusted the belt tension but found that the upper 19mm diameter sheave isn’t deep enough to fit the belt (its only 9mm, whereas the 27.2mm sheave is c12mm). The belt on the upper sheave therefore runs part on the sheave and part on the nuts holding the pulley in place, so not good. I’ve therefore returned it to as it was (ie using the 63mm motor:27.2mm head sheaves). However, I wondered if I was using the wrong belt size (1/2 inch), should it be c9mm diameter? or alternatively has the upper sheave been shortened at some point?. Any measurement from others would be most welcome.

Also, There is no evidence that the machine had an intermediary B pulley which others and many plates illustrate. All I have is the height adjusting spindle, is that there the other pulleys are mounted?. Were some machines just supplied as two speed?

Many thanks for your help.

[gerry maddenParticipant @gerrymadden53711]

@ Bazyle, sorry I’m not quite sure what you mean in your comment but all the standard format bearings on the ‘B’ will be operating comfortably within the makers ‘limiting speeds’ for grease, when the drill is running at its maximum of 18000RPM.

In the case of the largest bearing on the spindle drive unit, (6201 in my case), the typical Catalogue limiting speed for grease lube is typically quoted as 22000 RPM. This figure would of course be factored down if heavy loads were present, but this is not really applicable in the case of drill. The catalogue figures do however expect that the appropriate care is taken with respect to the quantity, and type of grease that’s applied. So yes, oil lube would be satisfactory, but so too should grease.

I was interested to read your comment about Vaseline in Magneto type bearings. Along long time ago I do recall reading old Hoffmann Test Centre reports in my lunch breaks which indicated that Vaseline was in fact a very poor lubricant. Most oils have a unique characteristic called a ‘pressure viscosity coefficient’. This is a characteristic which causes the oil to turn instantaneously to a glass-like material under the high contact pressures encountered in rolling element bearings. By turning to ‘glass’ metallic interaction and wear is prevented, regardless of the load. Vaseline, if my memory is correct, doesn’t really do this. So even though it looks like a grease, its use would actually result in more friction, wear, temperature and noise, depending on the precise operating conditions.

@garrardgfg… Im away at the moment but when I return I will come back to you on pulleys and belts.

Gerry

[amdjokParticipant @amdjok]

You could diy some plant hangers and use the rocks to hold them.

 

snaptube vidmate

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