K-27? lets hope so

Hi Guys,

Malcom, your question got me curious, so grabbed the book and took a look.
No stretchers (cross members) between the drive wheels. Seemed odd to my eyes too, but ya have to think Baldwins had it sorted.
Began thumbing forward and found chapter 9 "The Link Supports and Crosshead Guides" pg141. There's a photo of the finished unit on that page and one of it fitted on pg148. Question answered maybe??

For those without the book. These supports and guides either side of the engine are mounted to a pair of steel plates. One above and in front of and one behind drive wheel pair No2. They have silver soldered feet which bolt to the tops of the main frames. These should act as cross members. Hope this helps.

Malcome, latest crop of parts look great, every bit as good as Kozo's in the book. I'd be right chuffed with those.

Thank you all

Brett:thats a great find thank you :-)

Malc

Hi,

Here is all I have on the prototype frame:

https://www.dropbox.com/scl/fo/4ec6qv21c02gflrfxvfgi/AKvqLxmYtIQO45I7Be-BRPo?rlkey=arr4yg6louez2xlj3c4evs4iq&st=c0ctvori&dl=0

Hi

They answer my question nicely about stretchers, thank you.

I hope you dont mind but i have downloaded them to look at offline, although never at the skill level to incorporate some of this detail it still wonderful to study and who knows if this one works maybe the next one will be better, especially after seeing some of the k-27 & k-36 models on you tube

thank you very much

Quote from: PJPickardHi,

Here is all I have on the prototype frame:

https://www.dropbox.com/scl/fo/4ec6qv21c02gflrfxvfgi/AKvqLxmYtIQO45I7Be-BRPo?rlkey=arr4yg6louez2xlj3c4evs4iq&st=c0ctvori&dl=0

Well, now I'm home and have access to my book.  But it looks like you've got the answer to your question.

As Fj45 says, there are several cross members between the two sides of the frame, but none right at the wheels.  The closest cross member seems to be the one that is effectively made by the  Link Supports and Crosshead Guides (Ch 9, pg 141).

Kim

Beginning to appreciate the effort and time it takes to get things right just the setting up and checking and rechecking time and time again to be sure.

So major step today with first ever silver solder job, it was rear frames and extremely pleased how it went as very worried about it but the solder flowed nice and they are now pickling.

Broke a few taps getting to this point but that's my learning curve, all holes threaded in the frames now so time to paint them up for protection. One thing important that i learnt which is worth a mention for new builders and that is that i was cold chemical blackening my parts and they came out nice but a bit of research has pointed out that it would destroy solder joints or badly affect them at least, so its etch primer and stove paint for me on the rear frames :-)

Malc

Glad its progressing well (and learning lots).
For tapping, I broke a lot fewer taps after getting a tapping holder, like this one (there are many types and brands, this is just one example)https://littlemachineshop.com/products/hand-tapper-mini?_pos=1&_sid=36f04fe61&_ss=r
Also learned to back out/clear chips frequently, especially on blind holes, and to use oil when tapping. And that taps do wear out, when they start being harder to cut with, they are about worn out and will break. And also that steel needs a slightly larger hole than brass... Probably other stuff too! 

I have used taps when young mechanic so it was the back and forth that made the success in the end for me here, i was trying to be clever and brought some machine taps thinking this would be the way to go, how wrong i was for me it was back to the old taps and back and forth :-D oh and a look at a holder might help thanks

Quote from: cruebyGlad its progressing well (and learning lots).
For tapping, I broke a lot fewer taps after getting a tapping holder, like this one (there are many types and brands, this is just one example)https://littlemachineshop.com/products/hand-tapper-mini?_pos=1&_sid=36f04fe61&_ss=r
Also learned to back out/clear chips frequently, especially on blind holes, and to use oil when tapping. And that taps do wear out, when they start being harder to cut with, they are about worn out and will break. And also that steel needs a slightly larger hole than brass... Probably other stuff too! 

Quote from: bernienufcOne thing important that i learnt which is worth a mention for new builders and that is that i was cold chemical blackening my parts and they came out nice but a bit of research has pointed out that it would destroy solder joints or badly affect them at least, so its etch primer and stove paint for me on the rear frames :-)

I had not heard this about chemical blackening.  I understood it to be only creating a surface oxide layer and that it wouldn't negatively affect a hard-soldered joint.  I assume that's what you're talking about, right?  Silver solder?  Not soft solder?

Where did you see this? I'd love to learn if I'm wrong here. Thanks!

Kim

I am pretty sure that the detrimental chemical interaction is with soft solder, not silver solder.

Gene

Gents
My profuse apologies as you are both correct.
I know in my mind that i read somewhere that it affected silver solder as well as soft solder becasue i so remember being very disappointed that i could not blacken all the frames to match, but with that said i cannot find where i read it so found the statement from Gateros to back up your comments.
Again thank you for picking that up and sorry, next time i'll zip it :-D
I think this bit was maybe in my reading
' Most cold blacking kits use an acidic activator (often containing phosphoric acid or bifluorides). If the silver solder joint has any microscopic porosity, the acid can become trapped. If not meticulously neutralised and sealed with a high-quality dewatering oil, this trapped acid can lead to rapid bleeding and galvanic corrosion right at the joint line.'

Correction for my post.

'While the solution will rapidly turn the S275 carbon steel a deep, uniform black, it treats the silver solder alloy completely differently. Because cold blackening kits rely on a copper-selenium redox reaction designed specifically for iron and low-alloy steels, the silver-rich joint will either resist the chemical entirely or turn an uneven, patchy greyish-brown colour' -Gateros Plating

I am pretty sure that the detrimental chemical interaction is with soft solder, not silver solder.

Gene

I assume that's what you're talking about, right?  Silver solder?  Not soft solder?
Where did you see this? I'd love to learn if I'm wrong here. Thanks!
Kim 

i'm having a big moment here, seriously contemplating what to do now.
I have made a number of mistakes some due to dyscalculia some for some reason i cant put my finger on.
I have been meticulous with these rear frames checking rechecking and checking again till i'm blue in the face because i know what i am like, i even wrote on them LH RH Inside Outside, i scribed lines ready for the soldering parts and still i got one on the wrong side, ok so i de-soldered it and found i de-soldered the wrong one so now have done both to realise that as i had machined down the correct sizes there is nowhere to lay the solder on to re-apply them, i am really really down about this because if i tried so hard on these parts and got them so wrong it does not look good for the future.
time for some time out i think to revaluate myself and capability
cheers rant over

Thanks for the clarification on the chemical blackening. Much appreciated!

I'm sorry to hear you're having such a time with those rear frame pieces. It can be quite frustrating and demoralizing to find you've done something wrong when you've been SO careful to do everything 'right'!  I can relate completely.  On the A3 Switcher, there were several major subassemblies I had to completely redo.  For example, the whole U-shaped coal bin on the tender.  There is a LOT of work and a lot of metal involved in that.  I worked hard on it and was very careful, yet when I went to try and place it on the base, it was so cockeyed that it would have warped everything around it to try and get it to fit.  I struggled with it for a while, then after sleeping on it, decided to redo the whole assembly.  I'm glad I did, because the second time it came out MUCH better. I was able to watch for the steps that caused it to get out of square and did a much better job of it.  Sad as it was, once I got past it, I was really glad I did.

Not that I'm telling you you have to start over.  I'm just relating a story (one of MANY) where I was in a similar predicament and felt hopelessly lost and out of my depth.

Back to your situation at hand.  I went combing through Kozo's K-27 book to see if I could figure out what part you were working on.  If I'm understanding it right, you're talking about the part he calls "Frame Back Sections" on page 55 of Vol 1?  Fig 3-14 shows the extra pieces you silver-solder onto the main frame piece.  And I see he has you do it BEFORE you machine it to shape.  But it seems that you could drill and tap a couple of spots to hold a new piece in place for soldering?  And if you can't reuse the little soldered on pieces, it seems that they aren't that big, and it shouldn't break the bank to cut a couple of new small plates to solder in place?  You could cut those a little oversized on the side that will hang out over the top and edge of the frame piece.  That would give you an edge to set solder, possibly? Then mill or file those edges down to match the rest of the frame.

That's just one idea.  I'm sure after sleeping on it, you'll come up with a plan that will work for you.  I do encourage you NOT to give up. You've doe a lot of beautiful work on this.  Don't let a little setback like this stop you from having fun with the rest of this wonderful project! 

(How's that for a bit of cheerleading?  )

Really though.  We've all been through this.  It isn't easy, but then, if it was easy, it wouldn't be so rewarding, would it?

Best of luck in figuring out how to proceed.  I'm certain you'll get it figured out!
Kim

Quote from: bernienufci'm having a big moment here, seriously contemplating what to do now.
I have made a number of mistakes some due to dyscalculia some for some reason i cant put my finger on.
I have been meticulous with these rear frames checking rechecking and checking again till i'm blue in the face because i know what i am like, i even wrote on them LH RH Inside Outside, i scribed lines ready for the soldering parts and still i got one on the wrong side, ok so i de-soldered it and found i de-soldered the wrong one so now have done both to realise that as i had machined down the correct sizes there is nowhere to lay the solder on to re-apply them, i am really really down about this because if i tried so hard on these parts and got them so wrong it does not look good for the future.
time for some time out i think to revaluate myself and capability
cheers rant over

I suffer from the same dyscalculia' as you do (I think we all do!), in fact just 2 days ago I made an error on my build which I measured numerous times, drew out and took what I thought was every precautiuon ............ but no, it was out. I know exactly how frustrating it can be to put all that effort in and find it's has gone awry. Hopefully after some time out you'll get back to it with a fresh pair of eyes 

Thank you Kim for the encouragement it really makes a difference and thank you Sanjay its amazing that i don't feel so bad knowing that someone else is going through a similar thing, i found that i swap numbers like 20.105 would become 20.501 no matter how many times i checked it so i don't feel so alone so to say :-)

Kim, i did put some bolts though and nice tip i found (yes i'll put this one out there) chalk on the threads to stop the solder sticking to them which worked :-), i only had the one ledge for the solder so when i redid it the solder went right the way through the piece (yes Kim your are correct with the piece i am doing), i was amazed and felt not all was bad, so once again a recovery that i am happy with so time me to take a kicking and knuckle down as you are all right its what we are here for :-D

thanks again