Northern 4-8-4 Build 3/4”

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bushav
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Joined: Wed Aug 24, 2022 2:23 pm
Location: Bainbridge GA

Northern 4-8-4 Build 3/4”

Post by bushav »

Not a mistaken post! I’m also building a Northern along with the Pacific build. As the regulars here realize, I saved these two projects by purchasing them from a car museum that had received them and didn’t know what to do with them.

This Northern had zero documentation. However, this week one of our forum members contacted me with good news! He (I’ll not disclose his name without permission but you guys probably already will know) is the guy to go to for info on Carl Hoffman designs. Through my pictures he identified that my chassis follows the Hoffmann plans. To the best of his knowledge two Hoffman Northerns were completed. Confirming his suspicions that more could have been started, mine is just such a partial completion. Now that I know what I have, and this friend has supplied me with some dimensions I need, it’s off to the races!

I feel honored to know the pedigree of this locomotive even though the original builder is still a mystery. As both the Northern and Pacific projects were being built in parallel I plan on continuing that way. This is going to be a fun journey!
F9F6DE10-57A0-47C0-A5DD-53D47A89FD02_rotated.jpg
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Last edited by rmac on Sun Sep 25, 2022 12:06 pm, edited 1 time in total.
Reason: Photo Orientation
New to live steam
Building 3/4” 4-8-4 Northern &
1” 4-6-2 Pacific
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bushav
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Location: Bainbridge GA

Re: Northern 4-8-4 Build 3/4”

Post by bushav »

I placed an order for some steel and taps/dies last night. I've already received hex rod for making the small bolts and nuts needed. Mostly still studying and making a game plan. In case anyone is interested in how the Carl Hoffman chassis squeezed in the extra set of drivers (from a 4-6-4 to a 4-8-4) here are some pictures. It appears that the guide yoke was altered from the plans. According to the plans the guide yoke should face outwards but mine faces inwards. The front section of the link bracket (a casting) was shortened and the guide yoke was silver soldered in instead of being mounted with screws. From the back forwards the link bracket measures to specs until you get past the rocker pivot and then the measurements start deviating.
Guide Yoke drawing
Guide Yoke drawing
Actual Guide Yoke for stretch conversion
Actual Guide Yoke for stretch conversion
New to live steam
Building 3/4” 4-8-4 Northern &
1” 4-6-2 Pacific
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Bill Shields
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Re: Northern 4-8-4 Build 3/4”

Post by Bill Shields »

some of those castings look a lot like my Langworthy Hudson....
Too many things going on to bother listing them.
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Dick_Morris
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Re: Northern 4-8-4 Build 3/4”

Post by Dick_Morris »

I've already received hex rod for making the small bolts and nuts needed.
Since you're fairly new to this, I hope this isn't a dumb question. Do you know that scale miniature bolts, nuts, and washers are available from Godshall's?" (https://godshallscustommachining.com/co ... all?page=5)

Quality and service is good, although it was reported that he was recently involved in a accident and that may affect his orders.

Laying in an assortment of hardware and putting them in little plastic boxes was one of my better investments. Having the necessary hardware on hand helps makes it easier for me to make big parts without having to deal with the little ones.

If you need hex 00 or 000 bolts they are available from J.I. Morris (no connection). They aren't true to scale, but at that size it's hard to tell.
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bushav
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Re: Northern 4-8-4 Build 3/4”

Post by bushav »

Dick_Morris wrote: Wed Sep 28, 2022 12:56 am
I've already received hex rod for making the small bolts and nuts needed.
Since you're fairly new to this, I hope this isn't a dumb question. Do you know that scale miniature bolts, nuts, and washers are available from Godshall's?" (https://godshallscustommachining.com/co ... all?page=5)

Quality and service is good, although it was reported that he was recently involved in a accident and that may affect his orders.

Laying in an assortment of hardware and putting them in little plastic boxes was one of my better investments. Having the necessary hardware on hand helps makes it easier for me to make big parts without having to deal with the little ones.

If you need hex 00 or 000 bolts they are available from J.I. Morris (no connection). They aren't true to scale, but at that size it's hard to tell.
Nothings dumb when it’s offered as helpful info! I have seen the Godshall’s website and the unfortunate accident report. I’m thinking I better be set up with the proper taps and dies as a matter of principal. It appears most of the support this hobby gets is from people doing it out of love of trains. As such it appears I should be prepared to dig myself out of a jam while waiting on deliveries. So many of the vendors show “out of stock” on many of their items.

Where do you get your tiny cotter pins? I need some. Finished two couplers yesterday.

Lane
New to live steam
Building 3/4” 4-8-4 Northern &
1” 4-6-2 Pacific
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rmac
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Re: Northern 4-8-4 Build 3/4”

Post by rmac »

bushav wrote: Wed Sep 28, 2022 6:40 am Where do you get your tiny cotter pins? I need some. Finished two couplers yesterday.
One guy here makes them himself:

http://www.chaski.org/homemachinist/vie ... 39#p439239
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Bill Shields
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Re: Northern 4-8-4 Build 3/4”

Post by Bill Shields »

McMaster Carr

Keep a running list and order appropriately
Too many things going on to bother listing them.
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JBodenmann
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Re: Northern 4-8-4 Build 3/4”

Post by JBodenmann »

Hello My Friends
Your Northern will be a fun project. 3/4" scale is a delight to build, it's both big enough, and small enough... I have always considered it as "The Model Builders Scale". As to fasteners, #00-90 through #2-56 Model bolts and nuts are are available from JI Morris - Swiss Turn. American Model Engineer-(Godshalls) I hope I spelled that right. Have #0-80 through #10-32. For 3/4" scale #00-90 through #5-40, should probably do. I use brass model bolts for most things. I use steel where needed. The cost of fasteners is often overlooked when building an engine. When I returned to building engines for a living after having just done it for myself for quite a few years, I had been using fasteners from my stash. When I went to re stock all the plastic boxes I spent over $2000.00. Two grand...that seems like a lot. There were sizes 0-80, through #10-32. This included nuts and washers in both brass and steel. Everything under #6 I ordered a hundred of each. Over #6 just 25 each. Now I didn't order all lengths, I still had plenty of many sizes. Ouch, but you have to have them. For hobby purposes I would buy 25 of the needed sizes. You don't need to buy them all at once. It's very nice to be able to just go to the stash and get what you want, when you want it. We are fortunate to have suppliers like American Model engineer. There are hundreds of fasteners on a scale model, and the thought of having to make them all makes my hair hurt. 🤪
Happy Model Building
Jack
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Bill Shields
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Re: Northern 4-8-4 Build 3/4”

Post by Bill Shields »

Or burn..hair on fire
Too many things going on to bother listing them.
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bushav
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Location: Bainbridge GA

Re: Northern 4-8-4 Build 3/4”

Post by bushav »

Good info. It seems my comment that I’ve ordered appropriate taps and dies has been misconstrued as “I’m fabricating all my fasteners”.
New to live steam
Building 3/4” 4-8-4 Northern &
1” 4-6-2 Pacific
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Dick_Morris
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Re: Northern 4-8-4 Build 3/4”

Post by Dick_Morris »

Actually, I keyed in on, "I've already received hex rod for making the small bolts and nuts needed."
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bushav
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Re: Northern 4-8-4 Build 3/4”

Post by bushav »

I finished up the second coupler today and started on the cylinders. The previous owner machined the cylinder castings. This has made it a little nerve racking as I have to make a lot of measurements and assumptions. For instance the valve bores are .686 instead of .625 as indicated on the plans. I built the first valve spool with the dimensions indicated on the plans and just enlarged the diameter to fit the valve bore. It took three tries but I finally got a perfect fit in the bore. The plans don’t show any rings on the spool. I wasn’t sure how that would work but I added air and manipulated the valve by hand. It is airtight and chug chugs like a locomotive when I move it back and forth. Sounds pretty neat.
Valve spool.
Valve spool.
Fits perfect on third try!
Fits perfect on third try!
New to live steam
Building 3/4” 4-8-4 Northern &
1” 4-6-2 Pacific
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