Brass against brass

[WolfieParticipant @wolfie]

I have just realised that I have made both my slide bits and the thing that slides in them (terminology again!) out of brass. Is this likely to be a problem as I understand same metals against same can bind?

 

Edited By Wolfie on 28/12/2011 12:50:12

[WolfieParticipant @wolfie]

[SpringbokParticipant @springbok]

Wolfie it should not be to big a problem as I note oil holes, what gauge is it for this would suggest halfords cycle oil, I personaly used steel then casehardened for my 5″ Springbok, but it is intended for a lot of track use It really depends on how much you wish it to run it. If you are planning a lot of running change it otherwise should be ok, I tend to use a drop of brasso to finish linishing and some spirits to clean up.

 

happy new year

 

bob

[Ramon WilsonParticipant @ramonwilson3]

Hi Wolfie, similar metals can and do ‘pick up” and sometimes to a considerable degree

 

Brass is particularly bad in rotational situations and it may occur in yours though it does depend on fit. If well lubricated you may be okay but I would suggest the slide bars are re-made from steel or the crosshead. (Personally I’d do the slide bars)

 

You are doing well – keep it up.

 

BTW I thought our paths would cross last year at the Peterborough (plastic) model show as there were exhibits by a ‘Wolfie’. I looked you out but it appears there are two of you!

 

Regards – Ramon

 

[Ian S CParticipant @iansc]

Yes they don’t run together very well, although if they were two different types of brass it would help. If you changed one surface, ie., either the rails, or the bit that slides up and down for cast iron that would do it, or you could use cast iron for both surfaces as cast iron can be used together. On a Scotch yoke (don’t ask, its getting late), Iused thin strips of teflon for a steel crank pin to opperate on. Ian S C  ps., It also depends on how many hundreds of hours you want to run the motor before replacing worn parts.

Edited By Ian S C on 28/12/2011 13:20:34

[WolfieParticipant @wolfie]

Well I’m probably going to have to remake the crosshead anyway so I’ll do that in steel.

 

“BTW I thought our paths would cross last year at the Peterborough (plastic) model show as there were exhibits by a ‘Wolfie’. I looked you out but it appears there are two of you! “

 

Not that I’m aware of, I’m known throughout IPMS as Wolfie especially as I do articles for the modelling press under that name.

 

I don’t generally go that far south for regional shows apart from Gaydon and the Nationals at Telford. Furthest south I go is Huddersfield or maybe Newark

[WolfieParticipant @wolfie]

Whats linishing?

[Ramon WilsonParticipant @ramonwilson3]

Hi again Wolfie,

 

Last year at the PB show I noticed there were several exhibits on one stand (actually I think it was the PB stand itself but may be wrong) credited to ‘Wolfie’.

Putting two and two together and making three I assumed that it was likely to be you but it turned out that this one had no interest in model engineering but was however another ‘Wolfie’ who plastic models too – (there’s probably another Tug Wilson as well for that matter) (I’ve let my IPMS membership lapse since getting back to ME though I still do have a break on the plastic from time to time)

 

Linishing is using a power driven ‘belt sander’ to smooth metal. Generally ‘Belt sander’ in woodworking – ‘Linisher’ in metalworking. Metalworking belts are generally ok on wood but not always the other way round though most belts sold today are universal. Make sure though as metal soon makes short of belts that aren’t intended for it.

 

Ramon

 

PS just like to add that my little Rexon linisher is, tool for tool, probably the most used item in my workshop outside of mill and lathe – it’s like the fridge door, you just don’t realise just how often you open, or in this case use, it

Edited By Ramon Wilson on 28/12/2011 16:35:01

[SpringbokParticipant @springbok]

Sorry ramon as an old engineer there are many ways of linishing yes there are the very rough modern bits of kit but to get that perfect finish that will stand the test of time finish off as I suggest.

 

Bob

[Ramon WilsonParticipant @ramonwilson3]

Hi Bob, I confess I missed the connection to Wolfies question and your advice. As a ‘old engineer’ myself I certainly wasn’t suggesting a ‘linisher’ should be used for fine finishing of such components nor would I advocate it but can see how it infers.

Wrong ‘terminology mistake’ at this end to blame I guess it’s just not a term I would generally use for the task as described but that too is not to infer its use is incorrect

 

I can assure you though I most definitely don’t use mine for that kind of finishing but outside of that it is a much used piece of kit for deburring, roughing radii, quick chamfering etc before fine finishing with a file ’emery etc. when needed.

 

Regards – Ramon

 

 

[TerrydParticipant @terryd72465]

Hi all,

 

As I understood the term, linishing is a term meaning to generate (no precision) flat surfaces using a belt sander or grinder. When I worked with the ‘Fabrication Platers’ in my first apprentice department they used the term linisher to refer to a large air operated angle grinder. It was used for ‘linishing’ large fabrications to remove weld beads, spatter and other irregularities from the flat surfaces. In Wolfie’s case I think the term honing would be perhaps be more appropriate, no?

 

Regards,

 

Terry

[maurice bennieParticipant @mauricebennie99556]

Hi everyone a very happy new year , where can we of little knowledge who are lost, not understanding all these words such as CLACK valves SNIFTER valves etc. too many to think about. Could ,would some kind person tell where to find the meaning of them .

Perhaps compose a dictionary .

Best wishes Maurice.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Maurice, well to ease your mind a little, a clack valve is just a simple hinged flap that shuts off a liquid flow if/when it flows in the wrong direction, it can also be just a floating ball that does the same thing. A snifter valve is just as the name suggests, that is it sniffs a little air when required, to prevent a vacuum forming, it is usually associated with steam engines when the steam is cut off and the engine is allowed to coast and prevents dirt and ash to be sucked in by the pistons.

 

Regards Nick.

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

As rule how the bearing will last long: unlike material against each other as slider/rotating parts etc..

 

As the photo showed the brass against brass, i will prefer the trunk guide in brass replaced to steel or cast iron and the cross head in brass, bronze or cast iron.

 

Cast iron to cast iron no problem if well lubricated..but the cast iron can be brittle if too thin to stand against load.

 

You can make the trunk guide bar of cast iron from old brake disc, saw the four bar of brake disc and machine them nice in milling machine to true and nice trunk guide. And the cross head of same material as in brake disc.

[Sub MandrelParticipant @submandrel]

The original snifting valves were fitted to atmospheric engines. The problem was that they rapidly built up air in the cylinders which spoilt the vacuum. The snifting valve allowed the first rush of steam to expel air from the cylinder witha sound like a man clearing his nose.

 

Interestingly this is the other way round from what is now normally described as a snifting valve, as in Nick’s explanation.

 

Though I have read several explanations of this I still don’t know exactly how the snifting valve was controlled as it clearly must have some shut-off (as the piston rose) to stop all the steam escaping as well.

 

Neil

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