The cylinders will be fabricated items with cast iron liners, I have some ideas in my head as to how I'm going to do this and end up with a solution that is better than a casting in terms of steam flow.
I'm giving serious consideration to the slot and tab method of frame construction, if anyone has done this would love to hear from you!
The slot and tab method is alien to me, if I build something I want to be able to take it apart again, this is a bit difficult if you have welded the frame stretchers into the frame plates, but then I'm a traditionist, and imperialist to boot!
Hi, There is also a 2nd Sweet William build on the home machinist build log page: www.chaski.org/homemachinist/viewtopic.php?f=45&t=92038 It's mine but I've got a new family so have little time or money so progress is slow. I love the Sweet Pea but wanted a 7 1/4" gauge engine so I went with the Sweet William.
The first engine linked to above is mine. As I noted there, I did my wheels as CNC steel blanks instead of castings because the price to ship the castings to the USA was cost prohibitive. I looked at alternatives but didn't like spoked wheels, and no other vendor in the USA had solid-disc wheels for sale separately.
The cost estimates for the wheels varied but I obtained a reasonable price. The machinist actually wanted to cut the treads at the same time for no additional cost but I wanted to do some of the machining myself. If you know someone with a CNC machine, you might get a great deal. Just bring over a plate of cookies or something!
I don't plan to purchase many castings for the engine. I have so far purchased horns, suspension springs, and buffer stocks. I will purchase cylinder castings but probably not too much else. Metal is metal. I would rather spend more time in the shop then cash to have something mailed to me.
Thanks for posting, reading your recent post updates promoted my recent question on wheel clearance.
I've been working this week on the cylinder drawings, hope to upload a tentative picture this evening. I was going to try and fabricate these but have decide cutting them from solid will be much easier, will most likely use MS for this as they are lined anyway.
I've been looking at the wheels and I have came up with a solution that will give me what I want without having to outsource machining to a CNC shop, will put it into CAD over the next few days.
My hornblocks are just going to be plain MS bar riveted in place on the inside of the frame with the Axlebox ruining on the frame face. The grove being offset to give the correct face to face distance. I'm using cast iron stock for the Axlebox so can't ever imagine wearing the frame away.
The only casting I can imagine needing at this moment is the base of the chimney, as I can't think of a way to machine this.
Well cylinder development is on hold until I can come up with a sauce of cast iron sq bar large enough. Hacking them out of 200mm round is something I don't have the machinery to do, even if it isl cheaper than castings!!
In the mean time, I have sent the frame drawings to the laser cutters. Ordered steel for the stretcher brackets and horn blocks. For the axles I have ordered a length of EN36 this should harden suitably for the needle roller bearings to run on. Also sourced some Ali/bronze in sheet form to build up the horn guides with.
Progress!! Hurrah all be it just ordering, really looking forward to cutting metal in the next few weeks!
hi sean, ive made cast iron cylinders out of meehanite square stock. there are suppliers in the UK who will send you a few chunks. otherwise make some patterns and make them oversize and reduced bore and get them cast locally specifying you want high grade close grained stuff perhaps with a bit of nickel added? there must be someone in NZ who makes ferrous castings! otherwise have you thought of fabricating them or machining from solid out of bronze? you could even make the blocks out of steel and silver solder bronze plates on the top for the port faces and fit bronze or cast iron liners? my first loco had steel cylinder covers. although i no longer have the loco ive never had any complaints from the friend i sold it to of rust inside the cylinders (or more particularly on the covers). otherwise buy the castings - the suppliers deserve a bit of support, and the cost isnt too bad when you think how long it takes most of us to build a loco, and the cost of making a copper boiler! cheers, julian
I have found a company locally who can do me a set of cylinders cast to my patterns (without cores) for $265 nz stressed relived, there is a company in oz can supply me a set for $490 Ozzie from there patterns. I could do steel cylinders with cast iron liners and bronze Ali faces for less than $100 nz.
Will just wait and see when I get to that point, there is possibly a way of getting free delivery on the ones from oz in march next year so watch this space