My N&W class A 1239 (gauge 5", 1 in 10 scale)
Moderator: Harold_V
- Bill Shields
- Posts: 10581
- Joined: Fri Dec 21, 2007 4:57 am
- Location: 39.367, -75.765
- Contact:
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
That's a hot water faucet...
Too many things going on to bother listing them.
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello friends of the N&W,
Today was fine to me for I could assamble all the parts to built a complete tender truck for the first time . Just the right wheel sets are still missing. Will be built soon, too.
The cross bars are bolted rather than welded in favour of better access (for adding in the brake rigging!).
The equilisation will allow the axles to move about a generous + / - 5 mm (1/5 of an "). Springs will ad about 2 mm at full load then.
The trucks are intended to turn around the outer cross bar (the big bore) rather than the center . Thus the wide lateral travel of the long tender ends in curves will be reduced for better connection to locomotive and train. Vertical load will be transferred by means of a central cross bar and sliding plates as common, yet.
Best regards
Asteamhead
Today was fine to me for I could assamble all the parts to built a complete tender truck for the first time . Just the right wheel sets are still missing. Will be built soon, too.
The cross bars are bolted rather than welded in favour of better access (for adding in the brake rigging!).
The equilisation will allow the axles to move about a generous + / - 5 mm (1/5 of an "). Springs will ad about 2 mm at full load then.
The trucks are intended to turn around the outer cross bar (the big bore) rather than the center . Thus the wide lateral travel of the long tender ends in curves will be reduced for better connection to locomotive and train. Vertical load will be transferred by means of a central cross bar and sliding plates as common, yet.
Best regards
Asteamhead
N&W class A 1239 tender trucks
Very, very nice.
I like the offset support too.
The equalization will be interesting when in service because of the eccentric vertical load on the truck.
It may behave more like a 4-wheel truck with an idler axle. Time and experience on the track will tell.
I like the offset support too.
The equalization will be interesting when in service because of the eccentric vertical load on the truck.
It may behave more like a 4-wheel truck with an idler axle. Time and experience on the track will tell.
- Dick_Morris
- Posts: 2851
- Joined: Sat Jan 04, 2003 2:09 pm
- Location: Anchorage, AK
- JBodenmann
- Posts: 3865
- Joined: Sun Oct 26, 2003 1:37 pm
- Location: Tehachapi, California
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello My Friends
Very nice and ultra cool Asteamhead.
Jack
Very nice and ultra cool Asteamhead.
Jack
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Andy, Dick and Jack,
Thank you all!
Andy, you are right, the equilization will be supportet by just 4 points to the truck frame. The total load will be distributed to all 6 wheels equaliy, yet.
The people from Roanoke found this construction superior to the standard Commonwealth design at higher speeds. Hope they were right
The center axle-boxes will get a bit more lateral play to improve running around sharp curves (of about 30 feet radius).
In the meantime I started milling the 12 axle boxes, more to come soon.
Best regards by
Asteamhead
Thank you all!
Andy, you are right, the equilization will be supportet by just 4 points to the truck frame. The total load will be distributed to all 6 wheels equaliy, yet.
The people from Roanoke found this construction superior to the standard Commonwealth design at higher speeds. Hope they were right
The center axle-boxes will get a bit more lateral play to improve running around sharp curves (of about 30 feet radius).
In the meantime I started milling the 12 axle boxes, more to come soon.
Best regards by
Asteamhead
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello friends,
Time to show some progress. First, all the 12 axle boxes were turned, milled and tested by use of some tools in several steps from raw rings of bronze. Starting with the fit for the ball bearings of 32 mm diameter and the front surface , they were turned and centered again. Thus the rear (inside) fit for the sealing was turned as was the rear side.
Next I milled the two sliding plates in two steps, related to the finished bore and front surface . The final precision cuts were milled after some testing and adjusting the position of the parts in the vice. Thus the gap between the truck insides and the axle boxes could be achieved precisely at 2 x 0.1 mm (1 / 256 ") to insure for a slight glide without sticking. (The prototype drawing asked for 2 x 1 / 16 ").
The fits for the pair of ball bearings to be pressed onto the axles are intended as very slight press fits to insure easy assembly.
The next steps will be milling the bottom first and then the top head finally. For all other surfaces are finished and rectangular that will be a more easy job . A lot of chips could be saved by means of a shovel
Not to damage the finished surfaces by the vice, very thin plates of aluminium (taken from Märklin metall) worked best.
More to come soon.
Asteamhead
Time to show some progress. First, all the 12 axle boxes were turned, milled and tested by use of some tools in several steps from raw rings of bronze. Starting with the fit for the ball bearings of 32 mm diameter and the front surface , they were turned and centered again. Thus the rear (inside) fit for the sealing was turned as was the rear side.
Next I milled the two sliding plates in two steps, related to the finished bore and front surface . The final precision cuts were milled after some testing and adjusting the position of the parts in the vice. Thus the gap between the truck insides and the axle boxes could be achieved precisely at 2 x 0.1 mm (1 / 256 ") to insure for a slight glide without sticking. (The prototype drawing asked for 2 x 1 / 16 ").
The fits for the pair of ball bearings to be pressed onto the axles are intended as very slight press fits to insure easy assembly.
The next steps will be milling the bottom first and then the top head finally. For all other surfaces are finished and rectangular that will be a more easy job . A lot of chips could be saved by means of a shovel
Not to damage the finished surfaces by the vice, very thin plates of aluminium (taken from Märklin metall) worked best.
More to come soon.
Asteamhead
- Attachments
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello friends,
Time again to report some progress. Now, the axle boxes are completed. The axles are turned with precise fits for both the wheels and the pair of ball bearings. I decided to construct slide fits (- 2 to 3 µm) for the outer races and medium press fits (+ 1 to 1.5 µm) for the inner races on the axles.
This will allow removing the axles (with the ball bearings) out of the axle boxes in case of repairs with just little force . The ball bearings may then be removed from the open shaft, if necessary. The wheel set is hold together as a unit by means of nuts on the axle and the covers at the outsides. Following the construction of the N&W, the axle boxes got just one edge each at the inside .
Sorry, but there are no photos of the wheel sets yet, for assembly will be the very last step. Some dimensions are to be checked very carefully before the bearings may be pressed on
The brake rigging will be added in a bit later. Such a lot of parts to be constructed lasered, welded and milled!
Best regards
Asteamhead
Time again to report some progress. Now, the axle boxes are completed. The axles are turned with precise fits for both the wheels and the pair of ball bearings. I decided to construct slide fits (- 2 to 3 µm) for the outer races and medium press fits (+ 1 to 1.5 µm) for the inner races on the axles.
This will allow removing the axles (with the ball bearings) out of the axle boxes in case of repairs with just little force . The ball bearings may then be removed from the open shaft, if necessary. The wheel set is hold together as a unit by means of nuts on the axle and the covers at the outsides. Following the construction of the N&W, the axle boxes got just one edge each at the inside .
Sorry, but there are no photos of the wheel sets yet, for assembly will be the very last step. Some dimensions are to be checked very carefully before the bearings may be pressed on
The brake rigging will be added in a bit later. Such a lot of parts to be constructed lasered, welded and milled!
Best regards
Asteamhead
- Attachments
Last edited by rmac on Sun May 22, 2022 8:48 pm, edited 1 time in total.
Reason: Photo Orientation
Reason: Photo Orientation
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello friends,
I´m so sorry for I used wrong nos. :
The used fits were 10 times bigger than written in my last post of coarse, meaning more standard - 20 to 30 µm resp. + 10 to 15 µm.
The press fit for the wheels by the way is + 20 to 25 µm (about 1 / 1000 of the shaft diameter).
The smallest precise fit for the bearings was made last (step 4) in favor of better turning the bigger diameters as long as the axle is more rugged. The cosmetic turn of slight tappers to the center will be done after the wheels are pressed on for the same reason.
Be careful making sure, the axle will not be warmed up when turning the final cut. Otherwise the final diameter might not be precise but a bit smaller
All the best
asteamhead
I´m so sorry for I used wrong nos. :
The used fits were 10 times bigger than written in my last post of coarse, meaning more standard - 20 to 30 µm resp. + 10 to 15 µm.
The press fit for the wheels by the way is + 20 to 25 µm (about 1 / 1000 of the shaft diameter).
The smallest precise fit for the bearings was made last (step 4) in favor of better turning the bigger diameters as long as the axle is more rugged. The cosmetic turn of slight tappers to the center will be done after the wheels are pressed on for the same reason.
Be careful making sure, the axle will not be warmed up when turning the final cut. Otherwise the final diameter might not be precise but a bit smaller
All the best
asteamhead
Last edited by rmac on Sun May 22, 2022 8:47 pm, edited 1 time in total.
Reason: Photo Orientation
Reason: Photo Orientation
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello friends,
Some more photos how I built the SKF cover plates of the axle boxes. Maybe helpfull to other modelers?
The (sand-) casted covers made of bronze needed some final precision work. They are sealed by means of an O-ring and hold the outer race of the ball bearing in position. Like the prototype a small thread may be used to add grease for the bearings once a year.
A simple tool to hold the raw covers safely centered in the chuck was milled on the turntable first:idea:
Drills were made by means of a turntable, too at the identical positions as were used drilling the axle boxes before. Thus all covers may be mounted on any axle box
When all jobs are done, the small shaft will be cut off on the lathe using the tool for centering again.
Best regards
asteamhead
Some more photos how I built the SKF cover plates of the axle boxes. Maybe helpfull to other modelers?
The (sand-) casted covers made of bronze needed some final precision work. They are sealed by means of an O-ring and hold the outer race of the ball bearing in position. Like the prototype a small thread may be used to add grease for the bearings once a year.
A simple tool to hold the raw covers safely centered in the chuck was milled on the turntable first:idea:
Drills were made by means of a turntable, too at the identical positions as were used drilling the axle boxes before. Thus all covers may be mounted on any axle box
When all jobs are done, the small shaft will be cut off on the lathe using the tool for centering again.
Best regards
asteamhead
- Attachments
-
- Posts: 582
- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Hello friends,
All parts are done, just 2 leaf springs are missing yet. The axles were finished by turning the tappered shafts before the covers were mounted.
The first truck is ready for use now . A load test by about 300 pounds showed some spring action but very low side motion for good stability.
A closer load test by means of a press will follow to test maximum load and load distribution on each axle under less optimum conditions.
The complete clasp brake rigging of mostly lasered levers is still under construction, It will be built in a second step to achieve a working air brake.
All the best by
asteamhead
All parts are done, just 2 leaf springs are missing yet. The axles were finished by turning the tappered shafts before the covers were mounted.
The first truck is ready for use now . A load test by about 300 pounds showed some spring action but very low side motion for good stability.
A closer load test by means of a press will follow to test maximum load and load distribution on each axle under less optimum conditions.
The complete clasp brake rigging of mostly lasered levers is still under construction, It will be built in a second step to achieve a working air brake.
All the best by
asteamhead
Re: My N&W class A 1239 (gauge 5", 1 in 10 scale)
Well done!
RussN
RussN