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Re: 3/4" Scale J1e

Posted: Wed Feb 06, 2019 2:12 am
by Steamchris
Hey Jack,

no worry about it, every model engineer makes mistakes from time to time...we're no machines. That makes us human beeing. To help and to find out of this situation is the art...and you did it. By the way , like always very beautyful work.

All the best,
Chris

Re: 3/4" Scale J1e

Posted: Wed Feb 06, 2019 8:29 am
by Pontiacguy1
They say good machinists make very few mistakes, but the best machinists know how to cover and/or correct their mistakes without scrapping the part!

Re: 3/4" Scale J1e

Posted: Wed Feb 06, 2019 5:20 pm
by Harold_V
Without delving in to the concept that one is "very good", I can attest that it is unusual for a seasoned machinist to make mistakes. When I was at the height of my working career, I had 26 years of experience behind me and could almost guarantee that a job would be accomplished without error.

Here's a picture of a part, an electronics chassis, with numerous features, all done on a manual mill, no DRO. Five thou tolerance on locations, with features within features.
chassis top.jpg
chassis bottom.jpg
These parts were made in quantities (long before reliable CNC's were the norm). The part shown was a spare, made in case one in the lot was scrapped.

It took years to achieve that level of competence, keeping in mind that machines were operated for hours on end, daily. It would be unusual for the home shop type to be able to duplicate that level of performance, and that includes me, as, having been away from machining for years, the skill has faded. It's hard to achieve, and is gone quickly if not exercised daily.

Edit: As a matter of perspective, the chassis, made from ¼" aluminum plate, is displayed standing on a pair of sweat 1¼" copper pipe couplers.

H

Re: 3/4" Scale J1e

Posted: Wed Feb 06, 2019 6:59 pm
by Asteamhead
Harold,
We (hobby) modelers can hardly match with such precision industrial products made by very scilled mechanics! :oops:
The way I found (and which I recommend to other modellers) was to make simple tools :idea: before starting production! Means a little patience ...
And to use a turntable whenever possible to achieve precision drills!
Please see some examples (photos taken during making of my A - now CNC at all!)
Just my two cents.
Asteamhead

Re: 3/4" Scale J1e

Posted: Thu Feb 07, 2019 2:27 am
by Harold_V
Asteamhead,
I have often been overly impressed by the creativity and exceptional results that are achieved by novice machinists. They have an advantage in that they often aren't concerned with the speed in which a part is machined, so they are afforded the luxury of taking as much time as might be needed to complete an operation. As you alluded, building fixtures is very much a part of that, too.

It makes sense to make shop aid fixtures, even for a one-off item, assuming it is troublesome without doing so. That was common practice for me, even when building tooling. How a part is held, and how operations are sequenced are often critical to success. It's really disconcerting to take a cut, then realize that you just removed the material that would have been useful for an operation. Armed with that thought, wise machinists make a part mentally before moving any metal. That helps avoid doing stupid things (which we are all prone to do, including seasoned machinists).

As usual, your work never ceases to amaze me. Beautiful stuff! I really enjoy seeing the work of a person with pride in craftsmanship.
H

Re: 3/4" Scale J1e

Posted: Thu Feb 07, 2019 10:56 pm
by JBodenmann
Hello My Friends
Pontiacguy is correct, a good builder, or the ones that actually finish things must be good at wiggling out of a tight spot. And to Harold, I admire you skill, to become a real machinist and not just a parts loader takes a lot of time and experience. And hopefully a knowledgable old cat looking over your shoulder and guiding you when you are starting out. Fortunately I had a few mentors that I could always tap on the shoulder and ask, how do you...or where do you...or why do you.... And to Asteamhead, thanks for the cool photos and all of your fine work that we can admire here on the board. Thanks for contributing everyone. Here is the beautiful little lead truck after a bit of clean up. Whoever built it did a very nice job. The brake cylinder is 5/8" bore and is too big. It won't fit under the driver brake cylinders so masters will be made and a smaller brake cylinder investment cast. Probably 1/2" bore. Then we have a couple shots of the pilot. This has been getting some attention. One of the drawings has a vague reference to the coupler support pin keeper, but no more. I looked and looked at photos but couldn't really find anything useful, although I could tell that there was something there. Why are most New York Cetral Hudson photos of the engineers side? So I shot off an E Mail to Tom Gerbracht asking if he had any info on this pin keeper thingie. He wrote that really cool book, Know Thy Hudsons, so I figured if anyone knew it would be him. Later that evening I was checking my E mails and guess what. There were three pages of drawings, pin keeper, general arrangement, and the chain arrangement. That is one of the wonderful aspects of our hobby, all the people that are willing to help one another and share information. I was able to accurately model something that hasn't existed for more that fifty years, how cool is that. Thanks Tom. The little wedge that holds the coupler support pin in place is .045" thick and .110" wide and .437" long overall. The tricky part was milling the slot in the pilot that it drops into. The tiny little bolt that holds the end of the chain is #00-90. Thats the smallest bolt commercially available. I may have to have a go at making some #000-120 bolts. I have that dap and die. These sizes used to seem really small but once you get used to them they are no problem. Too much fun!
Jack

Re: 3/4" Scale J1e

Posted: Sun Feb 10, 2019 11:16 pm
by Greg_Lewis
I don't make mistakes. I just make lots of "practice parts" and do lots of "research and development". :wink:

JBodenmann wrote:
Thu Feb 07, 2019 10:56 pm
...
That is one of the wonderful aspects of our hobby, all the people that are willing to help one another and share information.
...
And I think part of that is that, at least here in America, there are no competitions or trophies involved. When I was in another hobby, as soon as prizes and trophies started to be awarded the whole atmosphere changed and folks were less interested in sharing their tricks and techniques.

Re: 3/4" Scale J1e

Posted: Mon Feb 11, 2019 12:55 pm
by Bill Shields
Jack: I had the same problem with the pilot truck brake cylinder on my J1 -> no clearance.

When I got to looking about making it smaller, found that I needed additional clearance for curves, and ended up making a much smaller cylinder.

That was 35 years ago, and I don't remember exactly the size cylinder I ended up using as a silver soldered fabrication...but it took 2 tries before I got it right what with curve radius and spring motion being somewhat unknown until I took it 'out to the track'.

Re: 3/4" Scale J1e

Posted: Tue Feb 12, 2019 10:59 am
by JBodenmann
Hello My Friends
Thanks for the info Bill. You are correct in that there isn't much room under there for the brake cylinder. I have a 5/8" bore cylinder and it won't fit. I am thinking of a 1/2" bore cylinder but will make a crude wood mock up and see if it will work. I have thought about modifying the lead truck casting to lower the cylinder but that is a last resort as it's a beautiful casting. Can you post some photos of your Hudson? Is it 3/4" scale? I'm sure everyone would like to see it.
Jack

Re: 3/4" Scale J1e

Posted: Sun Feb 17, 2019 9:48 pm
by JBodenmann
Hello My Friends
It's been snowing quite a bit here lately so it has been a great time to hang out in the nice cozy shop. Focus has been on the front end. The pilot, smoke box, and engine truck. The engine truck brake gigging has been a lot of fun. Some delightful little puzzles like the brake head, shoe, and key which we have here. The top photo is the start of the brake head. I only had to make the master for the head as the shoe and key are from the arch bar truck. The brake beams were quite a fiddle. They have curves going in several directions and a gaggle of little gussets. Three different types of solder were used. First silver solder was used on the two live beams to fix the screw up I made. As you know silver solder has a very high melting point. Then stay bright solder was used to stick the gussets on one side. This melts at about 440 F. Normally these are the only two solders I would use. But because of my screw up, a third solder operation was needed. So I tried something new, it's called TIX solder and melts at 200 F. I had never used it before and it worked great. It allowed me to solder the gussets on the second side without disturbing the gussets on the other side. Now the brake beams are getting some body work. Primer, a little filler, sanding more primer...They are starting to look pretty good. There are four of them and they are all different. Then there is the part that bolts to the ends of the two live brake beams . This holds the push rod yoke in place and uses two #0-80 bolts and has a key that fits into a slot in the end of the brake beam. I'll post some better photos of this once the castings come back from the foundry and It all starts going together.

Re: 3/4" Scale J1e

Posted: Sun Feb 17, 2019 9:56 pm
by Bill Shields
It looks like this (or did 35 years ago when I completed it.

It's mostly Langworthy 3/4" but I had to trash quite a few of the castings and work from scratch..the cylinders being the biggest problem.

Made a sandwich, welded it up one section at a time.
finished hudson001-small.jpg
finished hudson002 small.jpg
finished fabricated cylinders.jpg
hudson cylinder sandwich.jpg

Re: 3/4" Scale J1e

Posted: Sun Feb 17, 2019 10:27 pm
by JBodenmann
Hey Bill that engine is a real beauty! Do you run it much? Those cylinders look like they were a real challenge.
Here is some more. The top photo is the push rod yoke. The push rod which is .090" steel will pass through the push rod yoke and will have #3-56 lock nuts on each side of the yoke. This fits to the outer ends of the live beams. The other end of the push rods has a clevis and will link to the outer ends of the dead beams. Then we have a tiny little brake cylinder. This will finish out to 1/2" bore and will have a teflon cup seal on the piston. The piping to the brake cylinder will be 1/16". Patrick sells some beautiful 1/16" tees and elbows. It will have a proper hollow piston rod with loose push rod and retainer pin and cotter. The air pressure for the brake system will be no more than thirty PSI. as I don't want to have the wheels locking up and sliding. The bottom photo shows the new smoke box and front ring. Andy Romer gave me this piece of brass tube, and the disc for the smoke box ring was purchased from Mcmaster. There is a smoke box ring in there, you just can't see it yet :D .Brian Keim sent me some ultra cool Okadee smoke box hinges and marker lamps. The Hudson came with a smoke stack, but it's a hideous lump, and will make a good paper weight. A master will be made and a new stack will be cast along with the auxiliary stack. Fortunately the CD of drawings from the New York Central historical has most of this little baloney, but not all. I haven't been able to find any info on the trailing truck brakes. Only the rear driver brake equalizer which linked to the pull rod to the trailing truck brakes. The search is on! Having too much fun here.
See you in the funny pages...
Jack