|
Post by toolman1951 on Oct 26, 2007 11:26:59 GMT -5
I thought about the same concept. One thing nice about a gas/electric system is that you don't have to worry about batteries running down. I'll got a 5000 watts gas power generator I don't use much. I wonder how you can change the AC to DC without getting expensive and complicated?
|
|
|
Post by bowdidge on Nov 28, 2007 0:00:02 GMT -5
I'm building an A3 in 3/4" scale. I started a year ago, but most of my intense work's been in the last few months. I'm currently finishing the tender. My big milestone today was testing whether the tank was watertight. I ended up finding a couple places that needed resoldering, but it's looking close. Now, I just need to finish some handrails, make the side sheets, and get the pump working, and I'll be done.
As I've mentioned elsewhere, I'm doing this on a Sherline lathe with a milling column. This is almost too small, but I'm finding ways to make things work. For those concerned about cost, I think I've spent less than $500 on materials; the sheet brass and copper was easily the most expensive stock.
Robert
|
|
|
Post by Harlock on Nov 28, 2007 2:33:48 GMT -5
Congratulations Bowdidge, do post pictures when you get the chance.
I did a little work on the A3 today, slowly trying to get back into it after some time off to deal with many other things.
Cheers,
--Mike
|
|
|
Post by bowdidge on Feb 6, 2008 2:33:58 GMT -5
|
|
|
Post by phutcheson on Feb 6, 2008 4:02:00 GMT -5
Robert,
Thanks for sharing ...
Impressive work well done.
What are your next steps (besides the pump)?
What are the issues with pump?
I hope to get back on my A3 soon, I'm just finishing the steps, then machining the hand rails, mounting etc. Then will start the pump and the connections.
Keep up the the photos
Pat H
|
|
|
Post by bowdidge on Feb 6, 2008 13:42:06 GMT -5
> What are the issues with pump?
I'm testing the pump by connecting a water pressure gauge to the pump output with a length of tubing. I can't get the gauge to stay above 20 psi (though it does go higher as I pump.) I'd previously had problems with the check valves not checking; that problem got solved by finally getting correct-sized ball bearings. Now, I see water coming out around the piston, so I suspect the piston's too small for the pump's bore.
Robert
|
|
|
Post by phutcheson on Feb 6, 2008 16:27:33 GMT -5
Robert,
There is a very good thread that describes pump issues back in 2005 named "Pumps that won't pump". Although the article talks about the axle pump it also applies to the tender pump. The article goes into good detail about the various dimensions and O-rings issues.
It might give you an insight on what to look for and how to fix it.
Also it would be a good idea to start a new thread on your pump issue so that all could follow through.
I certainly would like to know your outcome as I will be making the pump body very soon. I have stock for the plunger and the o-rings.
Good luck and keep us posted...
Pat H
|
|
|
Post by siggy on Feb 6, 2008 18:42:01 GMT -5
Robert B.,
If you have water squirting out the back of the plunger then your o-ring isn't sealing correctly. This could be due to a number of issues such as having the o-ring bore dia. too large, o-ring shoulder cut too deep into the body such that the retainer doesn't properly capture the o-ring, improperly sized o-ring, etc. The plunger itself is spec'd at least .004 undersize to the plunger bore so clearly, that isn't the sealing surface. If the bore turns out to be too large you can probably re-size to a larger o-ring to get a good seal. Parker has a wealth of engineering data on o-ring fits on their website that you can use to get a proper fit.
When I tested my pump I was able to peg the largest pressure gauge I have, which is 800 psi, so you can be confident that when you solve your leak problem the pump will be capable of producing enough pressure!
Robert
|
|
jackg
Gandy Dancer
Posts: 1
|
Post by jackg on Feb 28, 2008 17:28:54 GMT -5
Hi, Im Jack from Rhode Island, Ive been reading the A3 book and ordered some stock, starting soon in 3/4 scale, I got some .097 copper, not .079 as the book calls for, I cannot think of any good reason why this wouldnt work out, except the fact that it could be a bit tougher to work. what is everybody using for tube stock?? Ive already comitted to the drivers from Friends..... heres what im working with, HF 9x20 lathe old old south bend 10 in lathe with back gears HF miller 1 1/2 hp Unimat SL with milling attachment and milling table Waiting on my 8" rotary table from HF, been since xmas and its backordered tooling tooling tooling, muuuussttt have tooooling...... LOL $$$$$ Jack
|
|
|
Post by Harlock on Feb 28, 2008 18:18:53 GMT -5
Amazing how you can spend just as much on tooling as on the machine itself.
Welcome to the group.
--M
|
|
|
Post by waumbek09 on Apr 27, 2008 15:30:57 GMT -5
Just finished the second chucking of all the A3 tender wheels and am trying to find out what sort of paint to use after I've machined the treads. My machinery: Emco Maxmat V10-p Van Norman #12 milling machine old sears drill press that's surprisingly nice. Sheldon shaper older Maximat V10 that needs to be brought back from the dead.
|
|
|
Post by Harlock on Apr 29, 2008 10:36:41 GMT -5
Hey good to see you on here. Welcome welcome. It's a fairly quiet board but there's a critical mass of A3 builders. Most of us are going in slow motion but we're going...
|
|
|
Post by pkastagehand on Apr 29, 2008 11:41:05 GMT -5
Yes, welcome. Slow going is definitely the word. I've been at it almost 3 years now (or is it 4?) in fits and starts and I just about have the tender finished to the point of painting. I have the plumbing and its fittings and a bit of the hand pump left. Hope to get a photo up soon.
Nothing much happened for a long time until I bought more materials. Daughter in college and price of copper/brass had me on hold for a bit.
Paul
|
|
|
Post by hervcram on Mar 13, 2009 21:19:11 GMT -5
Fellow members. I am considering building a model of Heisler #1225 an 18 ton narrow gauge locomotive in 2.5 inch scale. I have the book The Heisler loomotive by Benjamin Kline and am going to purhase building the heisler by Kozo Hiraoka. Using Kozo's upscaling method can this be done? If so what pitfalls should I watch out for?
|
|
dwb
Gandy Dancer
Posts: 3
|
Post by dwb on Jul 3, 2009 6:43:09 GMT -5
New to the group, I've been working on a hiesler for about 4 years. I'll be setting the boiler on the engine for the first time this weekend (hope it fits
|
|