BR Standard Class 6 - Clan MacGregor

[Ressaldar]

They have more presence than a certain well-known manufacturer's wheels.

Plus they still aren't a whole lot dearer.

 

Do you use his crankpins, and if so, what are THEY like?

 

Hi Jeff,

 

I did use the JPL crankpins, they are very good, especially with the spigot already present to solder the return crank onto, in this case on the centre wheel. They also enable you to get a good tight 'fix' onto the wheel, so no worries about coming loose.

 

cheers

 

Mike

[JeffP]

I have his leaflet from telford, but it makes no mention of a front crankpin for outside valvegear locos? How did that go?

[Ressaldar]

Hi Jeff,

 

I just put a 'countersink' in the leading wheel to take a bit more of the plain (bearing) surface of the pin and thinned the face of the coupling rod boss and the crankpin face to get it behind the slidebar, worked ok for me.

 

 

cruel close-up

 

 

finished article

 

I hope that this helps.

 

cheers

 

Mike

[JeffP]

Yep, thanks.

[PAD]

They have more presence than a certain well-known manufacturer's wheels.

Plus they still aren't a whole lot dearer.

 

Can't say I agree with that Jeff, in terms of how the wheels look. In fact the cast wheels look too "grainy" to me, compared to the pic. of Canadian Pacific, suggesting the cast appearance does not scale down. I have no idea when it comes to cost. However, when it comes to ease of use, a certain well-known manufacturer's wheels cannot be beaten. You can if you wish add talcum powder to the paint for the wheels to simulate that cast look, although I have never tried it. However, I believe that some of the BFB wheels used on Bullied pacifics were fabricated not cast. Each to his own thought.

 

Apologies to NGtrains for going off message in his thread.

[JeffP]

AFAIK, they were cast by Redpath Dorman Long in Scunthorpe.

[Arthur]

By Firth Brown in Scunthorpe, BFB, Bulleid Firth Brown.

[ngtrains.com]

Apologies to NGtrains for going off message in his thread.

 

and I am still non the wiser on which bearings I shall use! I am unanimous on knowing I don't want to build a Bullied

[PAD]

and I am still non the wiser on which bearings I shall use! I am unanimous on knowing I don't want to build a Bullied

I see no reason why you cannot use wiper pick ups on the uninsulated as well as I insulated wheels. In which case keep it simple and use plain brass bearings. Roller bearings on a model of this size seems like over engineering and I personally cannot see the benefit. Hope you come to a decision soon as I will be very interested to see how the Clan compares to Duke. Once again apologies for the digression on the wheels Bulleid wheels.

[ngtrains.com]

PAD thanks for the comments.

 

I am sure I have mentioned this before but you may be disappointed at the lack of speed with this build. It might even rival JeffP for its procrastination although it won't be due to a lack of activity just that the activity will be otherwise directed. The Clan is a "for me" job rather than one for a customer. I don't feel comfortable with doing a blow by blow account of building a customers loco but as I have taken an order to build one of our Double Fairlie kits today I may post some stage photos of its build in another topic.

 

I am still tempted with fitting roller bearings because whilst the engine might spend the majority of its life stood still looking pretty its may also do silly things like run for seven hours a day for seven days of the week on an automated display layout.

 

Whilst at Guildex I looked at the various bearing hornblock combos and have decided to make my own. This may seem an odd thing to do but away from the Clan I have several other projects going to need sprung bearings and the cost of buying them in would be prohibitive and whilst I realise this could turn the topic into one of those despised of articles that goes "and then I turned a widget in my lathe" like everybody has one I do have a CNC mill and the CAD program to create the design and G code so for me it makes sense to use the parts. The time will be consumed in getting the first one right but then I can leave the mill to get on with them on its own. Its quite good at that. (Thing is though the mill is a bit busy at the moment making cylinder draincocks for 2ft gauge engines)

 

Along with the rollers I think I will fit plungers both sides to ensure there is an electrical path other than through the bearings.

 

I think I had probably made my mind up before I asked. My Dad always used to reckon that by the time I ever asked him for advise about anything I had already made my mind up and it was just a case of running it by him so I could further justify my decision by claiming to have discussed it

[PAD]

Take your point about running 7 days a week. I have no experience of that. Who knows maybe plain bearings would wear out after a few weeks of that. It still seems an overly complex and time consuming way to do it. But then again it's your model and if you enjoy doing it that way the who am I, or anyone else to criticise. Good luck on the build with whatever method you go with. Cheers, Peter.

[JeffP]

By Firth Brown in Scunthorpe, BFB, Bulleid Firth Brown.

Quite right, my bad.

[ozzyo]

Hello Paul,

 

why are you worried about the electricity going through the bearings B.R. don't on the 25kv locos. Or is the motor casing live to the axle and misses out the bearings? One way or another it has to go to earth somehow.  Or do they have plunger pick-ups rubbing on the back of the wheels?

 

All I would do is see what the resistance is like from the outer ring of the bearing to the inner ring, if it's high add a return path. It does not have to be to the wheels why not use some 10 -15 thou P/B wire rubbing on the axles. Most modern motors with a good gearbox will only draw about 1amp. A Hall? that I built would run drawing about 0.5 amp and would wheel slip drawing about 0.85 amp. IIRC the loco had plunger pick-ups on all driving wheels.

 

As it look like your going to make your own horn guides and axle box's. Why not make the axle box's (or should that be bearing box's) out of one of the engineering plastics like Acetal or Delrin (have a look on the Direct Plastics web site for more info.). If you make the bearing box's out of something like one of these you will not have any worries about electricity and roller bearings. For picking up the power tender one side engine the other (for small plugs have a look on the Technobots web site under connectors and headers).

 

Back to the roller bearings, as you will know for a roller bearing to work at its best both of the rings have to be fixed. So the one problem that I can see is how do you allow any side play on the middle axle?

Do you;

A] allow the axle to slide in the bearing? Not that good when you see what I have just said.

B] allow the bearing blocks more side play, say 0.5mm each way. This would allow the bearing blocks, bearings and axle to move as one unit.

C] fit plain bearings on the centre axle.

 

As it looks like your going to make your own bearing blocks etc. I think that I would look at option B.

 

OzzyO.     

[pH]

The latest photo of 72005 I can find was taken in '63 and it certainly didn't have AWS then so I'm sure you are right.

 

I know this has been settled for a couple of weeks, but just for confirmation, here's a picture of 72005 on the scrap line at Kingmoor in May 1965 - no AWS: http://www.flickr.com/photos/80572914@N06/7388734684/in/photolist-cfVcpj-do3aNb-dmVQoV-b66HVP-do3cDA-dDBNPf-do34xn/lightbox/

[ngtrains.com]

I know this has been settled for a couple of weeks, but just for confirmation, here's a picture of 72005 on the scrap line at Kingmoor in May 1965 - no AWS: http://www.flickr.com/photos/80572914@N06/7388734684/in/photolist-cfVcpj-do3aNb-dmVQoV-b66HVP-do3cDA-dDBNPf-do34xn/lightbox/

 

Thanks pH for the link to the photo on the scrap line. It does confirm what we knew in that 72005 went to scrap having dodged the AWS queue but I wonder did you click to the next image?

 

It shows Clan Macgregor in  a dated photo with a speedo passing the junction signal box as it approaches Carstairs Station on the morning of 1 August 1964. So now we know it got its speedo between April 59 and August 64 which is somewhat better than the "not by May 56" the RCTS managed in their books on the BR standards

[ngtrains.com]

why are you worried about the electricity going through the bearings B.R. don't on the 25kv locos. Or is the motor casing live to the axle and misses out the bearings? One way or another it has to go to earth somehow.  Or do they have plunger pick-ups rubbing on the back of the wheels?

 

Ozzyo,

 

You're getting into the territory of my old day job dealing with traction electrics there so I can answer that. Electric loco's and units which use the rail at the current return do indeed have the equivalent of plunger pickups to prevent the current going through the bearings. Its often in the form of a brush and slip ring on the axle. Similarly you will see bonding straps between the bogie and the body and across sections of the suspension as its not wise to rely on springs, air bags or metalastic bushes to convey the current.  Also if the loco has resilient wheels as the 86's had (to try and stop them wrecking the track they also had multiple bonding straps on each wheel between the wheel centre and the tyre.

 

I do remember there being an epic fuss when one ran into some debris but was allowed to run on after a cursory look see. A  more detailed inspection found that only one of the thirty two (I think its four per wheel - memory failure) tyre to wheel centre straps had survived. The consequence could have been deadly. Without the straps tying the return path, body and frame down to earth (effectively sitting on insulated wheels) there is a good chance that the body would come close to being at 25Kv. That is until the driver stepped from the engine to ground!

 

Thanks for the bearing suggestions. I will come back to them later but I have to go and do some work now

[RedgateModels]

You would have been familiar with the delights of UNIal then Paul?

 

UNIal MSDS asessment.pdf

[billbedford]

By Firth Brown in Scunthorpe, BFB, Bulleid Firth Brown.

Firth Brown in Sheffield, and it's Beaumont Firth Brown on the patents. Thomas Beaumont was the works manager of Firth Brown's Atlas Works.

[JeffP]

Firth Brown in Sheffield, and it's Beaumont Firth Brown on the patents. Thomas Beaumont was the works manager of Firth Brown's Atlas Works.

And yet my memory tells me that they WERE cast here in Scunny. Or so I was told as a boy.