Author Topic: a newbie's take on the A3 switcher  (Read 5697 times)

Offline Mike R

  • Full Member
  • ****
  • Posts: 169
  • Ottawa, ON
Re: a newbie's take on the A3 switcher
« Reply #45 on: March 27, 2024, 09:19:47 PM »
Agree with Kim, a little oil and the truck should be fine.  They should free up with some running. 

Mike

Offline Pogo_proptie

  • Full Member
  • ****
  • Posts: 28
Re: a newbie's take on the A3 switcher
« Reply #46 on: April 24, 2024, 11:57:23 PM »
hey guys i need your help for this mini update.

before i cut 40 $ of copper i want to run my numbers by those who did it. 

the plan is a bit weird to me.

do you think that the layout is ok for the 2 intersecting radii with the flat front part




on the second one i showed the way i THINK it's supposed to be but I am not sure at all if it's the correct way to offset the center of the 1.23 Radius thank you.

and boy do i have a nice skateboard to show you later ;)

POGO

Offline Pogo_proptie

  • Full Member
  • ****
  • Posts: 28
Re: a newbie's take on the A3 switcher
« Reply #47 on: May 05, 2024, 06:31:04 PM »
time for an update. i'm having so much fun the past weeks and trying stuff i never did.

looks like i forgot to document the frame but hey.. it's mostly DRO magic



now the floor was much more stressful and, according to quinn the biggest piece in the whole build.

so i started to try and get it to dimension AND square. wich is quite easier said than done on el cheapo mills with not enough travel to do it all in one setup.



i believe i did very good in the end, (certainly close enought to the book's tolerance wich seem to be carefull filling).



to do the whole i have only enough Y travel to do it in halves so with carefull edge finding and not rushing the inversion i did patern without mistakes.


with the floor on this thing is SO RIGID, it feels like those patio tiles made of cement when  I hold it.

next was the oak former.

fresh out the router.

and the fun part started with a lot of anealing and a lot more beating. (those corners are very difficult to flatten)

here it is before the ''surgery''


and just after



a bit of filing and plumbing solder later i had this.



and now i have this



i can measure 10 thou diff to the front of the floor so I am calling this a very good and i am extremly pleased with the progress.. the heavier it gets the more satisfying the roll is.

i just came back from my brass supplier with enough material to make it all the way to the loco frames and bumpers. probably enought stuff to last until holidays until the next trip to the metal shop.


thanks for watching

Pogo

Offline crueby

  • Full Member
  • *****
  • Posts: 18987
  • Rochester NY
Re: a newbie's take on the A3 switcher
« Reply #48 on: May 05, 2024, 06:38:53 PM »
Beautiful tender parts! The sides formed out great!  Are you using brass for the frame and floor? Looks like it in the pictures, but that could be lighting. If so, nice to see someone else who likes it that much!   :popcorn: :popcorn:

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 8107
  • Portland, Oregon, USA
Re: a newbie's take on the A3 switcher
« Reply #49 on: May 05, 2024, 07:19:16 PM »
Beautiful work on the chassis and formed sides, Pogo!  Great work!  :popcorn: :popcorn:
t really is fun to see it all come together from a pile of bar stock, isn't it?

And Chris, just so you know - it's not that I don't love working with brass, because I do.  I just don't like paying for brass!  :Lol:

Nice update, Pogo, keep them coming!
Kim

Offline Pogo_proptie

  • Full Member
  • ****
  • Posts: 28
Re: a newbie's take on the A3 switcher
« Reply #50 on: June 12, 2024, 02:34:29 PM »
hey group.

not dead just not posting much but progress is happening..

i do have a question on the front plate and the riveting.

how did you prevent the piece going all banana

this is my 1st one and i foresee a lot of grief fitting that flat with a big curve





let me know if you have some tricks/ideas

sorry for the big picture made this in a hurry .

thanks as always

POGO

Offline crueby

  • Full Member
  • *****
  • Posts: 18987
  • Rochester NY
Re: a newbie's take on the A3 switcher
« Reply #51 on: June 12, 2024, 03:02:15 PM »
Looks like typical brass turned Bananium when one side is cut away. It gets stresses on the surfaces when they roll it in the factory, and cutting one side away makes it warp the other way. Solution is to degrease it then bake it in the oven at 500f for an hour and let it cool. That relaxes the stresses so it takes no or at least very little warp. I do that on all my brass and bronze stock that will be cut lengthwise. Bars to be turned on the lathe doesn't  need it since all sides are taken away evenly. This does not anneal or soften the metal, just stress relieves it. This recipe does not work on steel, each alliy has a different temperature  and time requirement.


Hope that helps!  The piece you have already hopefully  can be bent back straight enough!


Chris

Offline Pogo_proptie

  • Full Member
  • ****
  • Posts: 28
Re: a newbie's take on the A3 switcher
« Reply #52 on: June 12, 2024, 03:21:43 PM »
just wanna know if this is the correct phenomena crueby. the banana appeared when i punched the rivet, not when i cut it.. will cooking it as you say help anyway?

Offline internal_fire

  • Full Member
  • ****
  • Posts: 205
  • Punta Gorda, FL
Re: a newbie's take on the A3 switcher
« Reply #53 on: June 12, 2024, 03:31:49 PM »
just wanna know if this is the correct phenomena crueby. the banana appeared when i punched the rivet, not when i cut it.. will cooking it as you say help anyway?

I think this is a different cause and effect. Almost any flat strip will curl somewhat when it is formed by pounding on one side. Indeed, that is a standard technique for making curved surfaces.

Just gently straighten it back by hand. A sheet roller could also be used if you have one.

You can "minimize" this effect by pounding on a hard substrate, not wood, for example.

Gene

Offline crueby

  • Full Member
  • *****
  • Posts: 18987
  • Rochester NY
Re: a newbie's take on the A3 switcher
« Reply #54 on: June 12, 2024, 03:44:46 PM »
just wanna know if this is the correct phenomena crueby. the banana appeared when i punched the rivet, not when i cut it.. will cooking it as you say help anyway?
Ah - sorry, I misunderstood the picture and thought your were milling on one side.  Gene is right, punching through or any hammering on one side will deform the thin stock, and stress relieving it wont help that. I wonder if drilling rather than punching the holes would give better results? Use a spot drill first to make the dimples for the final drill to locate in and resist skating on the surface. When drilling really thin stuff I'll clamp it between two blocks so the drill doesnt grab and lift the sheet.

Offline Admiral_dk

  • Full Member
  • *****
  • Posts: 3834
  • S°ften - Denmark
Re: a newbie's take on the A3 switcher
« Reply #55 on: June 12, 2024, 05:04:39 PM »
Are we talking about punching Holes or punching Rivets ?

If it is Rivets - I believe that a bunch here have made a 'Plier' for doing this so you don't have the problem.

Per       :cheers:

Online Kim

  • Global Moderator
  • Full Member
  • *****
  • Posts: 8107
  • Portland, Oregon, USA
Re: a newbie's take on the A3 switcher
« Reply #56 on: June 12, 2024, 05:12:43 PM »
Hey Pogo,
Yeah, I remember having a little bit of bending like that when making the rivet patterns on the long thin parts.  I just gently curved them back to mostly flatish and it all seemed to work out fine.  I don't think you're doing anything wrong.  Like Gene and others have said, this is what happens when you're working on one side only of a thin sheet like this.  I'd be careful of trying to flatten it with a roller though as you're likely to flatten out the rivets you spent so much time and care putting it!

Kim

Offline Pogo_proptie

  • Full Member
  • ****
  • Posts: 28
Re: a newbie's take on the A3 switcher
« Reply #57 on: June 12, 2024, 06:52:55 PM »
good news hitting the top side of the banana on my vice's anvil with my copper hammer made it 80% flat.. so now its shallow enough that fixturing it wont be difficult i think.. now its credit card flexible i'd say..

suck a cool thing to learn.. love those old school technique..

thanks for the help folks. a bit update coming if i can finish the big tank panels

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal