UP HK-50-3 Ballast Hopper


David North
 

Thanks Dennis,

I really appreciate your comments and suggestions.

I’m planning to scratchbuild some coal hoppers and would not have thought about many of the things you have mentioned until I was too far along in the building process to easily (if at all) remedy the issues.

Can’t thank you enough.

Cheers

Dave


Tim O'Connor
 


This one does not. That is the point.



On 1/26/2022 4:47 PM, rdgbuff56 via groups.io wrote:
Some 100 ton coal hoppers have wheelsets that extend further than ends.

Francis a. Pehowic, Jr.

On Wednesday, January 26, 2022, 04:41:21 PM EST, Dennis Storzek <dennis@...> wrote:


On Tue, Jan 25, 2022 at 02:31 PM, Allen Montgomery wrote:
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book.
I don't know exactly how to broach this subject without hurting feelings, but with 3D printers leading a lot more people to try to design model railroad equipment, it needs to be discussed. While the printed body looks really fine, the misplaced trucks make it look like an ore car. Those of us who have done this work know that until everybody migrates to P:87, there are going to have to be compromises made, and choosing the right compromise is part of the art.

First off, identify the proper trucks to design for. If those are 100 ton trucks with 36" wheels, they are seven inches longer than the proper trucks; 4" in the wheelbase, and 3" more in the extra diameter of the wheels. Here is a link to an older version of the same design car: CBQ220145

Note the relationship of the trucks to the features on the body; The wheels don't extend past the end sill, few prototypes do (only ore cars) and the truck bolster is back under the full height side sheet, since that's where the body bolster, that transfers the weight of the car to the truck, is located. This relationship is the same on all hopper cars, with very few exceptions.

Even with the proper trucks on this car, however, there are likely to be problems. Our commonly used wheels, even the Code 88 wheels, have deeper flanges than the prototype, so the truck is still about two or three inches too long, In addition, we expect our models to go around curves that would derail the prototype. This is where the designer needs to get creative. My suggestion would be to put the truck king pin where it belongs, then shorten the discharge gate by whatever is needed to gain adequate truck swing. There is no real visual "landmark" on the body above the end frame of the discharge chute, so there will be nothing that looks wrong, and the slight variation from the prototype will never be noticed.

Dennis Storzek


--
Tim O'Connor
Sterling, Massachusetts


Richard Townsend
 

I agree with Dennis. I think what he suggests is a more appropriate compromise. 

Richard Townsend
Lincoln City, OR


-----Original Message-----
From: Dennis Storzek <dennis@...>
To: main@RealSTMFC.groups.io
Sent: Wed, Jan 26, 2022 1:41 pm
Subject: Re: [RealSTMFC] UP HK-50-3 Ballast Hopper

On Tue, Jan 25, 2022 at 02:31 PM, Allen Montgomery wrote:
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book.
I don't know exactly how to broach this subject without hurting feelings, but with 3D printers leading a lot more people to try to design model railroad equipment, it needs to be discussed. While the printed body looks really fine, the misplaced trucks make it look like an ore car. Those of us who have done this work know that until everybody migrates to P:87, there are going to have to be compromises made, and choosing the right compromise is part of the art.

First off, identify the proper trucks to design for. If those are 100 ton trucks with 36" wheels, they are seven inches longer than the proper trucks; 4" in the wheelbase, and 3" more in the extra diameter of the wheels. Here is a link to an older version of the same design car: CBQ220145

Note the relationship of the trucks to the features on the body; The wheels don't extend past the end sill, few prototypes do (only ore cars) and the truck bolster is back under the full height side sheet, since that's where the body bolster, that transfers the weight of the car to the truck, is located. This relationship is the same on all hopper cars, with very few exceptions.

Even with the proper trucks on this car, however, there are likely to be problems. Our commonly used wheels, even the Code 88 wheels, have deeper flanges than the prototype, so the truck is still about two or three inches too long, In addition, we expect our models to go around curves that would derail the prototype. This is where the designer needs to get creative. My suggestion would be to put the truck king pin where it belongs, then shorten the discharge gate by whatever is needed to gain adequate truck swing. There is no real visual "landmark" on the body above the end frame of the discharge chute, so there will be nothing that looks wrong, and the slight variation from the prototype will never be noticed.

Dennis Storzek


rdgbuff56
 

Some 100 ton coal hoppers have wheelsets that extend further than ends.

Francis a. Pehowic, Jr.

On Wednesday, January 26, 2022, 04:41:21 PM EST, Dennis Storzek <dennis@...> wrote:


On Tue, Jan 25, 2022 at 02:31 PM, Allen Montgomery wrote:
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book.
I don't know exactly how to broach this subject without hurting feelings, but with 3D printers leading a lot more people to try to design model railroad equipment, it needs to be discussed. While the printed body looks really fine, the misplaced trucks make it look like an ore car. Those of us who have done this work know that until everybody migrates to P:87, there are going to have to be compromises made, and choosing the right compromise is part of the art.

First off, identify the proper trucks to design for. If those are 100 ton trucks with 36" wheels, they are seven inches longer than the proper trucks; 4" in the wheelbase, and 3" more in the extra diameter of the wheels. Here is a link to an older version of the same design car: CBQ220145

Note the relationship of the trucks to the features on the body; The wheels don't extend past the end sill, few prototypes do (only ore cars) and the truck bolster is back under the full height side sheet, since that's where the body bolster, that transfers the weight of the car to the truck, is located. This relationship is the same on all hopper cars, with very few exceptions.

Even with the proper trucks on this car, however, there are likely to be problems. Our commonly used wheels, even the Code 88 wheels, have deeper flanges than the prototype, so the truck is still about two or three inches too long, In addition, we expect our models to go around curves that would derail the prototype. This is where the designer needs to get creative. My suggestion would be to put the truck king pin where it belongs, then shorten the discharge gate by whatever is needed to gain adequate truck swing. There is no real visual "landmark" on the body above the end frame of the discharge chute, so there will be nothing that looks wrong, and the slight variation from the prototype will never be noticed.

Dennis Storzek


Dennis Storzek
 

On Tue, Jan 25, 2022 at 02:31 PM, Allen Montgomery wrote:
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book.
I don't know exactly how to broach this subject without hurting feelings, but with 3D printers leading a lot more people to try to design model railroad equipment, it needs to be discussed. While the printed body looks really fine, the misplaced trucks make it look like an ore car. Those of us who have done this work know that until everybody migrates to P:87, there are going to have to be compromises made, and choosing the right compromise is part of the art.

First off, identify the proper trucks to design for. If those are 100 ton trucks with 36" wheels, they are seven inches longer than the proper trucks; 4" in the wheelbase, and 3" more in the extra diameter of the wheels. Here is a link to an older version of the same design car: CBQ220145

Note the relationship of the trucks to the features on the body; The wheels don't extend past the end sill, few prototypes do (only ore cars) and the truck bolster is back under the full height side sheet, since that's where the body bolster, that transfers the weight of the car to the truck, is located. This relationship is the same on all hopper cars, with very few exceptions.

Even with the proper trucks on this car, however, there are likely to be problems. Our commonly used wheels, even the Code 88 wheels, have deeper flanges than the prototype, so the truck is still about two or three inches too long, In addition, we expect our models to go around curves that would derail the prototype. This is where the designer needs to get creative. My suggestion would be to put the truck king pin where it belongs, then shorten the discharge gate by whatever is needed to gain adequate truck swing. There is no real visual "landmark" on the body above the end frame of the discharge chute, so there will be nothing that looks wrong, and the slight variation from the prototype will never be noticed.

Dennis Storzek


Dick Harley
 


FWIW, The California State RR Museum Library has the General Design drawing for that class.

https://csrm.andornot.com/en/permalink/techdrawing32274


Tim is right about the trucks.

Cheers,
Dick Harley
Laguna Beach,  CA


Tony Thompson
 

Allen Montgomery wrote:

I believe I am done with the fine tuning of this 3D resin printed car. I spent yesterday adding the final under frame details that I can make out in the pictures. I know I missed a few things that are obscured by shadow in the black and white photos.
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book. The final weight with hardware means I will have to add a little less than two ounces per car. I've been patiently waiting for some Tamiya primer for 3 months now and I regret I was not able to give this a coat to cut down on the resin shine and let the details pop.
Now it's time to find a decal set that will work for this car. Any suggestions?

Allen, the model looks excellent. It is almost a dead ringer for the H-70-2 class on Southern Pacific. Any chance some of the bodies will be for sale or trade?

Tony Thompson



Tim O'Connor
 


Unfortunate about the trucks, but you may have used 100 ton trucks, which have a 5-10 wheelbase.
A 50 ton truck has a 5-6 wheelbase with 33" wheels.

Tim O'Connor


On 1/25/2022 5:30 PM, Allen Montgomery via groups.io wrote:
I believe I am done with the fine tuning of this 3D resin printed car. I spent yesterday adding the final under frame details that I can make out in the pictures. I know I missed a few things that are obscured by shadow in the black and white photos.
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book. The final weight with hardware means I will have to add a little less than two ounces per car. I've been patiently waiting for some Tamiya primer for 3 months now and I regret I was not able to give this a coat to cut down on the resin shine and let the details pop.
Now it's time to find a decal set that will work for this car. Any suggestions?

Allen Montgomery

Attachments:



--
Tim O'Connor
Sterling, Massachusetts


Allen Montgomery
 

I believe I am done with the fine tuning of this 3D resin printed car. I spent yesterday adding the final under frame details that I can make out in the pictures. I know I missed a few things that are obscured by shadow in the black and white photos.
The second picture shows the amount of overhang of the wheel sets as I had to move them out to gain some room for the trucks to pivot. That was the one thing I had to change from the drawing in Terry Metcalfe's book. The final weight with hardware means I will have to add a little less than two ounces per car. I've been patiently waiting for some Tamiya primer for 3 months now and I regret I was not able to give this a coat to cut down on the resin shine and let the details pop.
Now it's time to find a decal set that will work for this car. Any suggestions?

Allen Montgomery