Search found 830 matches

by Curtis_F
Thu May 15, 2014 9:13 pm
Forum: Live Steam
Topic: Marshall (Hackworth) Valve Gear Design?
Replies: 6
Views: 2254

Re: Marshall (Hackworth) Valve Gear Design?

Several published designs in the U.K. feature Hackworth valve gear, all narrow gauge, the most popular being the 5"g 'Sweet Pea' and 7 1/4"g 'Sweet William'. There is a construction manual (I got one on Amazon a few months ago) to accompany the drawings for this loco. Another is Ken Swan's 'Wren' i...
by Curtis_F
Thu May 15, 2014 9:46 am
Forum: Live Steam
Topic: Marshall (Hackworth) Valve Gear Design?
Replies: 6
Views: 2254

Marshall (Hackworth) Valve Gear Design?

Good day, I know almost nothing about Marshall (or Hackworth) Valve gear, and now want to use it on a personal project, so I need to do some research! Paul Pickard remembers an article in Model Engineer from the 70s that talked about it, can someone tell me which issue? Are there any books or other ...
by Curtis_F
Tue May 13, 2014 5:08 pm
Forum: Live Steam
Topic: Theory behind cylinder bore size
Replies: 5
Views: 1747

Re: Theory behind cylinder bore size

What are the advantages to a smaller bore? Less steam consumption? Less "slippary" drivers? More power? When power exceeds traction the wheels slip. When traction exceeds power the wheels stall. Traction is a DIRECT function of weight on the wheels. The more weight you have the more traction you ha...
by Curtis_F
Fri May 09, 2014 8:06 pm
Forum: Live Steam
Topic: Rivets v solder on larger boilers
Replies: 8
Views: 1875

Re: Rivets v solder on larger boilers

Welcome to the board, it's good to see someone enthusiastic. For hobby boiler information in general I would recommend getting the Australian Model Boiler Code: http://www.aals.asn.au/AMBSC/AMBSC.htm For the size of boiler your talking about, 18" dia. x 24" long, you are much better off going with a...
by Curtis_F
Sun Apr 27, 2014 4:36 pm
Forum: Live Steam
Topic: Question regarding eccentric throw
Replies: 8
Views: 1738

Re: Question regarding eccentric throw

the stroke will be twice the throw Thank you for pointing out my error about the Crank Throw. I've gone back and fixed my description. However, contrary to that logic, "Eccentric Throw" is the Eccentric Offset x 2. An eccentric with 1/4" offset gives 1/2" of Throw. If there are no mitigating factor...
by Curtis_F
Sun Apr 27, 2014 11:43 am
Forum: Live Steam
Topic: Question regarding eccentric throw
Replies: 8
Views: 1738

Re: Question regarding eccentric throw

Bill, I have the feeling I'm misinterpreting the question, but ya' gotta start somewhere: Crank Shaft Throw is 1/2 the stroke of the engine. If the throw of the crank is 1" then the piston will travel 2" for ever rotation of the Crank Shaft. Eccentric Throw is directly related to travel of the Valve...
by Curtis_F
Thu Apr 10, 2014 5:18 pm
Forum: Live Steam
Topic: Steel Shell, Copper Tubes?
Replies: 36
Views: 4619

Re: Steel Shell, Copper Tubes?

Often, the tube ends are procerred (if spelled correctly), by a sort of flaring, rolling process on the outside of the boiler's end. I'm troubled by the fact that I see no constraint placed on the tube's insertion through the end (what are those ends called again?) Primary Seal: When a Tube is Roll...
by Curtis_F
Wed Apr 09, 2014 8:13 am
Forum: Live Steam
Topic: Tapered Pins and Bolts
Replies: 16
Views: 2847

Re: Tapered Pins and Bolts

Do you have the other ALCO drawings for the frame bolts? Tim, I've looked through the ALCO standards books and that page really is it for dimensional information about bolts themselves. The other pages and bits of info scattered about deal with stuff like: If the loco has X tractive effort, then fo...
by Curtis_F
Tue Apr 08, 2014 1:49 am
Forum: Live Steam
Topic: Tapered Pins and Bolts
Replies: 16
Views: 2847

Re: Tapered Pins and Bolts

Not sure I understand the concept of "tapered bolts" completely. The unthreaded shank being tapered? If that, then the part being clamped by the bolt would have no clearance within the hole, thus preventing movement. On a locomotive there are Rough Bolts, Straight Fitted Bolts, and Taper Fitted Bol...
by Curtis_F
Thu Apr 03, 2014 10:44 am
Forum: Live Steam
Topic: How to start Walschaerts Design as a beginner?
Replies: 50
Views: 7499

Re: How to start Walschaerts Design as a beginner?

This forums own LSGOD has built several 1-1/2" scale engines with the valve gear 100% scaled and they work fine. Generally they're over-bored due to scale being linear and weight being cubic, so he runs them at reduced pressure (70-80 psi), but they run great! Though in general I tend to agree that ...
by Curtis_F
Tue Mar 04, 2014 2:41 am
Forum: Live Steam
Topic: 3D Printed Big Boy
Replies: 12
Views: 2814

Re: 3D Printed Big Boy

Yep he's using a spaghetti printer. he should kickstart a campaign to pay for a proper model from Shapeways or similar vendor. A higher resolution printer would only get a better surface finish, it won't fill in all the missing detail. I've looked at most all of his STL files and it's clear he, rig...
by Curtis_F
Mon Mar 03, 2014 6:36 pm
Forum: Live Steam
Topic: 3D Printed Big Boy
Replies: 12
Views: 2814

Re: 3D Printed Big Boy

While still very impressive, he cut a lot of corners when he 3D modeled the locomotive. It's designed to be 3D printed. The files wouldn't be useful for a live steamer or historical reference. I have about 40 hours into a "full size" 3D model of a Southern Pacific MT4/MT5 cast steel frame and guess ...