Building Bernard Tekippe’s Precision Regulator

[Chris Raynerd 2]

On Chris Raynerd 2 Said:

[…]
More interesting, he shared an audio tape recording of Tekippe presenting. I think Steve may have also had a copy of this, and if he has, he will be able to contest that it was almost inaudible with background noise and echo. I have used some free AI tools to try and clean it up best and can and it is now definitely a good listen (pretty amazing how the software did this!).

[…]

An hour very well spent, listening to that !!

MichaelG.

[Chris Raynerd 2Participant @chrisraynerd2]

Glad you enjoyed it and could listen OK. I can assure you the original was very difficult to hear!

Chris

[Chris Raynerd 2Participant @chrisraynerd2]

After all the bearing discussion I went ahead and ordered some and they were not cheap. I placed them in white spirits as suggested by some and it seems to have ruined them ALL!

What had gone wrong? 😢

 

[John HaineParticipant @johnhaine32865]

Oh dear! Did they have rubber or plastic seals? Is that smeary stuff possibly grease that has been softened but not removed?  Swenson recommended several washes and a particular bearing make and type which presumably work well when washed.

[Andrew CrowParticipant @andrewcrow91475]

Hi Chris, as these look like metal sealed bearings the white spirit may not have washed out all the grease and what’s left looks like staining caused by a reaction between the white spirit and the grease. I can’t believe that white spirit would actually damage them.

Do they still revolve OK?

If “yes” try washing again with something like cigarette lighter fuel, it may need a bit longer soak to get the grease from behind the shields.

Andy.

[SillyOldDufferModerator @sillyoldduffer]

Well Chris, you were warned in my #794240!  “Best results in the experiment are achieved with de-lubricated steel bearings. Not a surprise, nor is it the answer! …”

My experience with washed bearings on a light Stirling Engine was initially good, but they only lasted a few hours run time – rapid wear.  If, as John says, the bearing contains a material like plastic, it might also be catastrophically attacked by the solvent.

A problem with web advice is well-meaning chaps try something and, because it worked for them, assume it’s universally good.   Dangerous, because their sample is far too small and the test far too short; they got lucky.  Industry take far more care, fund well organised research, and get large scale customer feedback.

As there are dozens of different types of bearing and many different materials used, going off-piste isn’t guaranteed unless exactly the same bearing is used.   Which is unlikely unless full details were provided.  And even then, there’s nothing to stop a manufacturer changing what’s inside his bearings.

Good news is the experiment proved conclusively that White Spirit can destroy bearings.  Now you can tell everyone authoritatively that the idea is unreliable!

Dave

 

 

 

 

 

[Russell EberhardtParticipant @russelleberhardt48058]

When I built my JW Regulator I used stainless steel bearings with two metal shields (not seals).  I washed them out in white spirit and then blow dried them.  They then gave reduced friction, as measured before and after by spinning a wheel mounted on them before and after and timing how long it took to stop.

I bought them from Arc Eurotrade for about a pound each.  Why do you need flanged bearings.  I machined the housings for just a light push fit.

Russell

[Michael GilliganParticipant @michaelgilligan61133]

Long experience of cleaning congealed grease from microscope mechanisms has convinced me that ‘PlusGasFormula A’ is an excellent solvent for same.

It would probably be worth trying.

MichaelG.

[Chris Raynerd 2Participant @chrisraynerd2]

Thanks everyone for your messages. It is very strange. Whist I do believe that some of the original discoloration was just lubricant that had not fully dissolved, it looks to have definitely attached the metal in some way! I’ve washed for 24 hours on alcohol and whilst they have cleaned up, there is no chance I dare use them as there are marks that won’t even scratch off. It similar patches are inside the bearing race then this will be a major problem. I’ll just have to cut my losses and go again.

@John, yes Swenson uses a supplier in Australia I believe. I therefore opted for the exact bearings tested by David Robertson and he also degreased his. They were from a UK supplier.

@Andrew Crow – yes I’ll give cig lighter fluid a go but honestly, there is like a brown oxidation on them. Maybe it is some sort of product of the reaction of the grease with the white spirit. The alcohol dries off quick with a blow of air and there is still a powdery residue that looks to have etched its way into the surface of the metal and not just on top. Even if it is on top, it’s hard enough to scratch off so no way I can risk just attempting to dissolve it away from behind the shield.

@Dave, yes the warning wise there but all in the name of fun and experimentation though, ey? That said, I’m £35 down so no longer feels so fun!

@Russell – I’ll look at what Arc have to offer. You are right in that I don’t need flanged and actually they would probably look neater not flanged. However I presumed a flange might get me a bit squared to the face should my bearing bore not be perfect. I think when I order again I will scrap the flange.

@Michael – thank you. I will buy this for use with the next lot! I’ll not be using white spirit again!

Chris

[Clive SteerParticipant @clivesteer55943]

Chris.

What size bearing are you using as I’ve loads of 1/8th inch bore, 1/4 inch OD flanged steel bearings that you could use to try different cleaning methods. They also run very free anyway.

[John HaineParticipant @johnhaine32865]

Chris, I admire your craftsmanship in the making, but I also think your videos are very good.  No superfluous verbiage, well lit and give a good idea of the processes you are using.

[gerry maddenParticipant @gerrymadden53711]

Hi Chris, its actually a good idea to use flanged bearings in this situation. As you deduce, it avoids the outer ring from sitting cocked in its housing. It also means you can slightly loosen you bore tolerance. But the inner rings / shaft are still a little vulnerable from two things. Firstly ensure that your shaft shoulders are square to the shaft by machining them in the same operation as the seating diameter. (Watch that deadly corner rad. too!) Secondly the shaft must be accurately square with the outer rings. Therefore machine the two housing together and make sure they stay in the same relative position after the frame is assembled. If you want smoothness and minimum friction, alignment accuracy needs to be in the order of 0.05 degrees.

Regarding your damaged bearings issue, one problem is that the manufacturers typically use in the order of 50 to 100 different greases to meet specific high-volume customer demand. Local stockists don’t usually care about what’s in the bearings they sell to you unless they are asked to supply a particular grease type. So basically there could be anything in your bearings from a simple mineral/lithium thickener type, to silicon, PFPE, diester and all manner of other stuff. Usually the grease type is marked somewhere on the packaging if the bearings are individually boxed. If yours have come from a multipack, there will not be traceability now. I would suspect that you may have suffered from an incompatibility issue.

Please keep in mind though that grease is a combination of oil and a thickener. Thickeners are not soluble, only the oil component is, so dipping them in a ‘solvent’ is not effective. You really need to at least remove the shields.

Alcohol is not great general purpose grease cleaner. It can contain water and/or absorb it from the atmosphere so I would be wary of using this this for bearings. My preference would be brake cleaner from an aerosol can, as it will be filtered to fine limits. The jet will also help blast the grease away, mechanically.

Finally, if you take shields out of small bearings they will be damaged and you cant put them back in. So try to get hold of bearings with what are known as ‘non-contact seals’. These are really shields but made in rubber like normal seals. They have a much finer labyrinth than shields though. However, the real beauty of non-contact seals is that, with care, you can pop them back in after cleaning the bearing. When re-fitting, make sure they are absolutely flat, then snap them in using a flat plate. Non contact seals have the designation in NSK language of V, as opposed to D for a contact seal. Other manufacturers may have other designations.

Gerry

 

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