No, NO! Lee--I wasn't referring to your comments--but some folks carried
them into outer space. Your queries below are very applicable to our
hobby where scratch builders need this info. (sorry I can't help!) We
have to be very technical at times--my concern is keeping the technical
stuff within our hobby.--That's all.--Wait--How DARE you appologise
SaltyChief --you add so much to our group-- your humor too-besides. I'm an
old codger, as you no doubt recognize! I sold construction and industrial
air compressors during my career which makes me think I'm smart--UGH!
Tally Ho
Geoff.
>Geoff,
>
>I hope your not holding me too responsible for getting too technical since I
>started this, but there really was a point I wanted to address and learn
>about.
>
>Namely,
>
>If I start out to design a model Loco, what formula (if there is one), can I
>apply to calculate how much steam pressure I need to generate, on what size
>piston, to move x amount of weight?
>
>(Since it's obvious that models need PROPORTIONATELY more steam pressure to
>work than prototypes. I wasn't sure everyone would even agree with this at
>first...)
>
>Charles Dockstader's software (which you can get from Vance Bass's site)
>does a great job of demonstrating valve gear layout and modifications, but
>the pressure issue is not one I've seen specifically addressed anywhere.
>
>Jim Curry posted the answer I was looking for.
>
>AND...
>
>I thank EVERYONE for their input on this, including the digression into
>measuring systems.
>
>Thanks,
>
>Lee
>
>-----Original Message-----
>From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
>Behalf Of Geoff Spenceley
>Sent: Tuesday, February 15, 2000 9:46 AM
>To: Multiple recipients of sslivesteam
>Subject: Re: Nightmare Units
>
>
>Clark Lord and Pete Foley hit the nail on the head concerning bars/kg/cm2.
>Of course Clark usually does hit the nail on the head--squarely!! For our
>hobby, there is nothing complicated about the conversion. Multiply 14.7
>(or even 15) by the reading on the kg/cm2 and you have psi. or vice versa.
>The gauges on my air compressor have dual readings and when comparing them
>with the 14.7 multiplier the amount of error is far too small to worry
>about. The inaccuracy of the gauges in our hobby is probably much greater.
>We are not launching a shuttle using critical pressures, and frankly, to
>resort to mathematical formulas is needless.
>Since I have owned locos with metric and psi gauges for years I almost
>automatically read them either way (practice!)
>
>It seems to me that some members of our group like to get very technical on
>some subjects reaching far beyond the requirements of our little engines.
>The subject matter goes back and forth and gets beaten to death . It is my
>belief that some of these discussions go beyond the main interests of our
>hobby! Let's keep to the "nuts and bolts"-that's where my metric etc
>nightmare lies!
>
>Now I realise some members enjoy getting into "Cal-Tech" discussions beyond
>the requirements of our locos--perhaps we should have an
>sslivesteam@colegroup. hitec.com as addtional forum!
>
>Stay the course,
>
>Geoff
>
>
>I think of bars or kg/cm2 as atmospheres. Loosely translated, multiply
>>the bar reading by 15 (really 14.7 psi on a standard day at sea level).
>>
>>Therefore when you see 4 kg/cm2 it's around 60 psi or 3 kg/cm2 is around
>>45 psi and so on. Close enough for live steamers out running at the
>>track. If you need exact numbers then you will have to do the math.
>>
>>Clark.
>>
>>Peter Foley wrote:
>>>
>>> At 02:51 PM 00-02-14 -0500, you wrote:
>>>
>>> >Let's stick with the real world and use PSI.
>>>
>>> I think you need to re-think this one, Bill. North America, and to a
>>> lesser extent the UK, is/are the last bastion(s) where this terminology
>is
>>> in regular use. The rest of the world use 'bars' or kg/cm2, or some
>other
>>> expression that is SI based (metric to the non-initiated). I'm afraid
>that
>>> it will be us who will eventually have to catch up with the rest of the
>>>world.
>>>
>>> regards,
>>>
>>> pf
>
>
>
>
