a newbie's take on the A3 switcher

[Kim]

Well, Pogo, I have no doubt you'll make it!  The valve train is a challenge, no doubt, but no more so than all the other parts you've already completed. Just take it one part at a time, as you've been doing, and it will get done.  You're doing an amazing job!  Keep it up!

Kim

[Pogo_proptie]

ouff, did not touch anything because of work.. today i started to assemble the loco frame with wheels wanting to put the side rods and NOTHING turns.. not even with only one rod.. i have no idea where to even begin.

i think i mixed and matched my wheel bearing with my sloppiness.. don't know if it's enough to make it jam up like that...  no sense in doing anything for a while..

GUH

POGO

[Pogo_proptie]

kinda solved in a weird way. nothing was working, i was doubting everything and i flipped the front axel box left to right (should be symmetrical so no difference  but  ) anyway it's now turning in an acceptable way so i will stamp marks on the box to make them handed. and keep on trucking until next catastrophe

 

POGO

[Kim]

Excellent!  Glad you got it things moving again. 

Yes, it's best to mark everything and never assume anything is interchangeable.  Get things working in one position and don't move them!  (or at least put them back in the same place  )

Kim

[crueby]

Its amazing how  little a difference  in bearings and blocks it takes to make things bind. I try to remember to number stamp sets of parts. Don't  always remember,  but I  try.

[Pogo_proptie]

yeah big crisis averted but i realise that i should have assembled thing more as i build.  i was just keeping a big pile because. anyway i need to paint later so why bother.. but now i have probably a week to take just to fiddle things cuz nothing runs as smooth as i wish. but at least i'm not back to making 4 bearings and all the side rods.. 

[Pogo_proptie]

A lot of fuzzing around with bushing clearance and I am happy to offer this proto chooching

<a href="https://www.youtube.com/watch?v=YBb3WA-p89o" target="_blank">http://www.youtube.com/watch?v=YBb3WA-p89o</a>

Side and main rods and piston are in. No tight spot i am smiling ear to ear. Next is combination lever 

[crueby]

Excellent!!  Is it supposed to go "chugg chugg" rather than "cackle cackle"?   

[Kim]

That's beautiful!   
Runs back and forth very smoothly!  Congrats on getting it all working!

On to the next parts 

Kim

[RReid]

Very nice, a major milestone passed. Congratulations!

[Pogo_proptie]

Another brainfart  i just realised the big bracket was made with 1/16 sheet instead of 1/8.. i feel so dumb. But hey...at least i didnt remake the guide bar longer because somehow they were too short  hoo wait. Yeah i did that instead of figuring it out.. and then i checked quinns video and even asked her why her model seemed thicker than mine and blamed the macro lense for the illusion.. crazy to see the brain makes whatever to convince yourself that it's all good when in fact it's a mistake from the very 1st step.

[PaulR]

That seems really smooth... and you obviously enjoyed it 

[Pogo_proptie]

oof.. reality check time..

while making part was going well.. now i needed to assemble everything proper in order to measure the eccentric rods.. and oh boy did my ass get kicked..

absolutely nothing is smooth regarding the expansion links.. i'm honestly not sure what i can even do at this point to make it work. the combination lever wants to hit the guide rails, and whatever i measure with the tiny jig is close to 3mm too short from nominal.. i was so close to putting air in this thing and now i feel like i lost any chance of having it work.. anyway.. i'll probably redo the expansion from scracth because i don't think my little pivot soldered perfectly but  rest was ok (well it seemed like that).

end of rant that shit is really hard.

POGO 

[Kim]

Yeah, the expansion links were a challenge, for sure.  It took some fettling to get those running smoothly.  And EVERYTHING around the crosshead guide rails was challenging.  I had to take it all apart and reassemble it piece by piece several times to find the areas that were binding.  And of course, I filed off the wrong area thinking I was helping, then had to go back and Loctite in a shim to make up for my over-exuberant filing!  But in the end, I got there.

Take heart.  I'm confident you'll get there too.

Kim

[Pogo_proptie]

okay, sunday morning, i have my cofffee and the book with me and sketchup open and i'm checking everything and you know the handle on the expansion link (that looks like florida)  well i some how misread or messed up my trig to locate that and that's going in the trash. too bad the fit for the link blocks was lovely i think. at least i know i can stop looking for a way to make this work and just start over most of that. also i don't like my soldering job on the axles of the trunnion and de soldering them will probably leave residu hard to get out.. i'm not sure,

yesterday i actually 3d printed two trunion as per the print just pushed new little axel in there and it was a bit better. cool little experiment.

also real life is catching up so that will have to wait a couple weeks

see ya

POGO