Constructing the Martin Lewis Little Engines Northern Tender
Moderator: Harold_V
Constructing the Martin Lewis Little Engines Northern Tender
Off again on another project. This time it is the start of tender construction for the (old) Martin Lewis Little Engines Northern.
No detailed description this time, only some photos as construction proceeds.
At the rate I work 2-3 years may see an end to the building. Maybe.
The construction articles said the equalizer pieces could easily be bent up from 3/16" square CR steel. Martin must know something about bending which I don't. What a disaster. Went with milling them out from 3/16" HR plate. The hard way as usual.
No detailed description this time, only some photos as construction proceeds.
At the rate I work 2-3 years may see an end to the building. Maybe.
The construction articles said the equalizer pieces could easily be bent up from 3/16" square CR steel. Martin must know something about bending which I don't. What a disaster. Went with milling them out from 3/16" HR plate. The hard way as usual.
Last edited by Carrdo on Mon Aug 10, 2015 3:36 pm, edited 2 times in total.
Re: Not much to show for two weeks of machining
Perhaps he used a former in an arbor press? Anyway, you got the right end result.
Dan Watson
Chattanooga, TN
Chattanooga, TN
Re: Not much to show for two weeks of machining
Could you tell us a little history of the locomotive Don?
It looks like it is a well made model.
Sadly too many locomotives reach this state and then the original builder loses their health and are unable to complete the models.
Keith
It looks like it is a well made model.
Sadly too many locomotives reach this state and then the original builder loses their health and are unable to complete the models.
Keith
Constructing the Martin Lewis Little Engines Northern Tender
Hi Keith,
The truth is I don't know the history to this locomotive myself and would like to find out more if someone here in southern Ontario might know.
Purchased the locomotive in 1990 almost in its present state. The model had already passed through a few hands and the person selling it just knew that it was a distant family member who constructed it.
The interesting thing about this locomotive is it has a very unusual boiler - I will take some better pictures of the firebox end but here it is like a Yarrow type marine boiler. There is a large single 2 -1/2" dia. crown tube and two smaller 1-1/4" dia.bottom tubes arranged in a triangle with a number of 1" dia. downcomer pipes joining the top and bottom tubes to form a rigid triangle shaped combustion chamber.
The boiler is not very well made (all of the brazing is suspect) so I will have to make a decision on that at some point.
I have seen a few very similar (but more sophisticated and not exactly like this one) Yarrow type marine designs for model steam locomotive boilers published in the Model Engineer over the years but I don't know how well or if they performed. I don't think one could use coal; it would have to be propane if anything.
The chassis is definitely a Martin Lewis Little Engines old northern as its design and all of the castings are exactly as shown in the Martin Lewis 1930's Model Craftsman construction articles for the Hudson/Northern - which I have as a soft cover book).
I do not have all of the castings needed to complete the tender so I am looking at making parts from the solid or fabricating some of the tender parts. For example, on the tender underframe, Martin showed two design methods; one a built up underframe assembly using miniature channel sections or, as an alternative, he did offer a complete tender underframe casting.
Miniature steel channel (which is what I want) in the size shown on the Lewis drawings (3/4" high by 5/16" or 3/8" wide) is extremely difficult to come by so I plan on making it (the hard way again). On the internet, I found a supplier in Florida who lists it but I don't think it practical to ship 6' long pieces up here.
The locomotive chassis itself is very well built but has been left unfinished where not needed- as per the full size prototypes. Someone certainly knew what they were doing and did the machine work correctly. It appears that whoever did it may have had limited access to machine tools leading me to suspect that the locomotive could be quite old. It has ball bearings on all of the axles as per the Lewis design. The entire chassis movement is extremely smooth with no binding or shake anywhere.
The truth is I don't know the history to this locomotive myself and would like to find out more if someone here in southern Ontario might know.
Purchased the locomotive in 1990 almost in its present state. The model had already passed through a few hands and the person selling it just knew that it was a distant family member who constructed it.
The interesting thing about this locomotive is it has a very unusual boiler - I will take some better pictures of the firebox end but here it is like a Yarrow type marine boiler. There is a large single 2 -1/2" dia. crown tube and two smaller 1-1/4" dia.bottom tubes arranged in a triangle with a number of 1" dia. downcomer pipes joining the top and bottom tubes to form a rigid triangle shaped combustion chamber.
The boiler is not very well made (all of the brazing is suspect) so I will have to make a decision on that at some point.
I have seen a few very similar (but more sophisticated and not exactly like this one) Yarrow type marine designs for model steam locomotive boilers published in the Model Engineer over the years but I don't know how well or if they performed. I don't think one could use coal; it would have to be propane if anything.
The chassis is definitely a Martin Lewis Little Engines old northern as its design and all of the castings are exactly as shown in the Martin Lewis 1930's Model Craftsman construction articles for the Hudson/Northern - which I have as a soft cover book).
I do not have all of the castings needed to complete the tender so I am looking at making parts from the solid or fabricating some of the tender parts. For example, on the tender underframe, Martin showed two design methods; one a built up underframe assembly using miniature channel sections or, as an alternative, he did offer a complete tender underframe casting.
Miniature steel channel (which is what I want) in the size shown on the Lewis drawings (3/4" high by 5/16" or 3/8" wide) is extremely difficult to come by so I plan on making it (the hard way again). On the internet, I found a supplier in Florida who lists it but I don't think it practical to ship 6' long pieces up here.
The locomotive chassis itself is very well built but has been left unfinished where not needed- as per the full size prototypes. Someone certainly knew what they were doing and did the machine work correctly. It appears that whoever did it may have had limited access to machine tools leading me to suspect that the locomotive could be quite old. It has ball bearings on all of the axles as per the Lewis design. The entire chassis movement is extremely smooth with no binding or shake anywhere.
Last edited by Carrdo on Mon Aug 10, 2015 3:37 pm, edited 2 times in total.
Constructing the Martin Lewis Little Engines Northern Tender
The first equalizer sub assembly.
Will now disappear for some time while I leisurely complete the remaining 7 units.
Will now disappear for some time while I leisurely complete the remaining 7 units.
Last edited by Carrdo on Mon Aug 10, 2015 3:38 pm, edited 1 time in total.
Constructing the Martin Lewis Little Engines Northern Tender
Since the story of my life to date has been searching for "unobtainium" in small quantities, I did find a source for miniature structural steel channel right here in Toronto.
North York Iron and Steel has it in stock so now I have a lifetime supply (2, 20' long lengths of 3/4" high by 3/8" flange width by 1/8" web thickness).
It also helps if you know the correct terminology to use i.e. A-36 Carbon Steel Channel, Bar Mill Sizes as this is how it was listed.
Apparently it is used a lot in the movie industry.
North York Iron and Steel has it in stock so now I have a lifetime supply (2, 20' long lengths of 3/4" high by 3/8" flange width by 1/8" web thickness).
It also helps if you know the correct terminology to use i.e. A-36 Carbon Steel Channel, Bar Mill Sizes as this is how it was listed.
Apparently it is used a lot in the movie industry.
Last edited by Carrdo on Mon Aug 10, 2015 3:39 pm, edited 1 time in total.
Constructing the Martin Lewis Little Engines Northern Tender
A shot of "unobtainium".
To be used in the built up/fabricated tender underframe.
To be used in the built up/fabricated tender underframe.
Last edited by Carrdo on Mon Aug 10, 2015 3:40 pm, edited 1 time in total.
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Re: Not much to show for two weeks of machining
Good to now on the channel...one of the hobby suppliers should take note and stock this.
Paul
Paul
Constructing the Martin Lewis Little Engines Northern Tender
Hi Paul,
I am not sure what I have was just a "find" and this size is not produced anymore.
The channel pieces looked like they had been sitting there for 40 years and most of it was badly surface rusted. Picked the best couple of pieces from the pile but still had to do a lot of cleanup before the photo was taken.
The supplier certainly had a lot of it (at least a ton - 200, 20 ft. lengths) but it certainly didn't look like anything which had been in demand recently.
I am not sure what I have was just a "find" and this size is not produced anymore.
The channel pieces looked like they had been sitting there for 40 years and most of it was badly surface rusted. Picked the best couple of pieces from the pile but still had to do a lot of cleanup before the photo was taken.
The supplier certainly had a lot of it (at least a ton - 200, 20 ft. lengths) but it certainly didn't look like anything which had been in demand recently.
Last edited by Carrdo on Mon Aug 10, 2015 3:40 pm, edited 1 time in total.
Constructing the Martin Lewis Little Engines Northern Tender
I'm not yet there Dave!!
Am certain Dave will have the Frontenac Society's Hudson sorted out before I finish these equalizers.
Am certain Dave will have the Frontenac Society's Hudson sorted out before I finish these equalizers.
Last edited by Carrdo on Mon Aug 10, 2015 3:41 pm, edited 1 time in total.
Constructing the Martin Lewis Little Engines Northern Tender
Without comment.
Last edited by Carrdo on Mon Aug 10, 2015 3:41 pm, edited 1 time in total.
Constructing the Martin Lewis Little Engines Northern Tender
Well, in the end I am machining some short channel pieces from the solid for the tender 6 wheel trucks as I discovered Martin specifies 3/4" high by 5/16" deep channel here (one really has to look at the print under a microscope to see that there are channel sections shown), a size which I will never find.
Could have cut down my existing miniature channel stock but decided to save it all for this and future tender underframes.
Thank goodness for the newer carbides and rougher end mills as there is a lot of material to rough out. I run my carbide cutting tools at slower speeds, depth of cut and feeds than industry due to limitations on the mill but so far am surprised they are giving just as good a finish as HSS and are not complaining at all.
Not much to say other than it is a lot of dog work just to get to this stage. I leave everything 0.015" oversize when roughing. This is a good exercise in squaring work and keeping everything straight and parallel. I mark one end of the channel blanks so they go back in the mill vise the same way every time.
Could have cut down my existing miniature channel stock but decided to save it all for this and future tender underframes.
Thank goodness for the newer carbides and rougher end mills as there is a lot of material to rough out. I run my carbide cutting tools at slower speeds, depth of cut and feeds than industry due to limitations on the mill but so far am surprised they are giving just as good a finish as HSS and are not complaining at all.
Not much to say other than it is a lot of dog work just to get to this stage. I leave everything 0.015" oversize when roughing. This is a good exercise in squaring work and keeping everything straight and parallel. I mark one end of the channel blanks so they go back in the mill vise the same way every time.
Last edited by Carrdo on Mon Aug 10, 2015 3:42 pm, edited 1 time in total.