7mm US model dabblings

Big Train James

Western Thunderer
I didn't bother with fixing plates like Jim nor internal structures/supports (neat idea that) or the bending break lines, I'd worry abut that detail once the basic shape could be replicated reasonably consistently.
I'm not sure the internal structures are truly necessary, at least not for one of these shorter tanks. In fact, from the "structural" aspect, I put them in more to support the form of the tank during printing. Again, they may not be necessary, but I'm not disappointed with the results.

The other benefit, which is intended, is to create compartments within the tank. The original modified Atlas tank was diecast, and it was going to be attached to the frame with a brass bracket. The resulting assembly added a nice amount of weight to the chassis, but that would be lost by switching to the printed tank. Once the end sheets are attached, I can fill the outboard compartments with lead shot and copious amounts of glue to recapture some of that weight. The middle section is also separated so that I can place a keep-alive device there. It's not evident in the above photos, but I've included a small conduit as part of the printed form, to contain the keep-alive wiring as it runs up past the motor.

Not certain what you mean by "fixing plates", but if it's the thickened pads on the back of the end sheets, those are more about adding thickness to the end sheet print to try and prevent warping. Oddly, despite only covering the two distinct areas, the strategy did seem to manage warping compared to the previous test prints. The end sheets are really positioned by the four pins, and then the rest of the end sheet will be laminated to the core with a suitable adhesive.

Regarding the question about internal ribs manifesting on the exterior of the tank due to surface area change, I did experience that to a degree on one of the test prints. There isn't a shift in the print, so no distinct line or edge at that point, more so a very subtle crease. However, other test prints at a different orientation resolved that situation.
 
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Big Train James

Western Thunderer
Atwater is an old manufacturer of O scale trains. Think cast bronze type bodies, or something similar. I don't know when they came on the scene, but it might be post WWII at the latest? I know they did F units, but I'm not sure what other models they offered. However, those old drive trains often found their way into other models, Central Locomotive Works and All-Nation are common examples of this. Bullet proof drives really, and at the time the parts were readily available.

Page 5 of this thread, about halfway down the page, will get you a view of an Atwater F unit. All things considered, given when they were made, the units aren't half bad.
 

mickoo

Western Thunderer
Presuming I'm understanding the pictures correctly, I'm wondering why you aren't making the tank core the full length, and making the end piece sit down inside the tank core, rather than having the end of the tank core combined with the tank end sheet? By combining the end of the core with the end sheet, you get that joint and gap in the surface of the core, that is meant to represent a continuous piece. By making the end sheet smaller and setting it inside the end of the core, it makes the joint between surfaces at the logical point where surfaces are perpendicular to each other. The mounting brackets could still be printed as part of the end sheet, with proper allowance to clear and wrap up and around the end of the core. I fully understand that it may take several iterations to get the fit of the two parts just right, but it can of course be done. One thing I did was print only a small length of fuel tank, just the end with the end sheet mounting pin locations, so that I didn't waste time or resin doing the full tank.

The end of the tank core would need to have a thin edge to represent the end of the sheet, but it will be a very small amount, and if doubled to roughly ¾" prototype wall thickness, will meet or exceed the .3mm model wall thickness that seems to be a good standard minimum.
That's a fair point, one I hadn't considered but I still think it'll have issues which I'll discuss shortly.

The reason for the full tank test shot as opposed to just a short end section test shot like yours was that the full tank was the primary printing concern, there's little point having ends that fit perfectly if you cannot effectively print the full tank core later. It turns out you can print the full length, just and it's not without issues over that length, it might be better if it was angled slightly, say 15° off vertical like the EMD frame front I'm doing right now.

There is no yaw angle on this run, I've tried two with yaw and one without and both give good results, lack of yaw makes supports to a few underside edges unnecessary, therefore lack of yaw is simply down to laziness in support removal and post clean up.

Image2.jpg

I don't know why this happens but angled long sections seem to have a better surface finish and are more engineeringly true than a pure vertical one.

Back to the fuel tank, it can be orientated just one way, vertically, primarily because that's the only way it'll fit in the machine and secondarily because that's the best orientation for an object like this (my experience). My initial test shot was purely vertical, were I to do another then I'd angle it over so that the belly begins to face the build plate. That would also help with the sight glasses and pads on the top and they would become better defined.

The potential issue with doing the inset ends is the thin rib around the outside, 0.3 mm is a good figure but you'd not get good enough, or big enough supports along that thin edge to support the rest of the mass as it gets printed.

Image.jpg

This view from below shows the original supports (white dots), I added the thin columns to the base in CAD as a way to try and make the edge more robust and limit puddling on the lower faces, turns out it was a waste of time, they're not needed and solved nothing.

If I opt for an inset end (I think it has more merit and mileage than my initial plug end attempt) and a thin ridge, then the main core supports will have to be moved from the outer edge and into the inner recess (red dotted line), that'd work and you could add bigger supports to take the weight and peel forces. The problem then is that face then puddles and support removal is difficult, especially as you need a reasonably flat face to secure the insert to. The outer skirt (thin ridge) would need to be overly long, maybe extend by 1-2 mm, this will move the puddling and support deformation away from the final cut back face once the ridge is trimmed back.

Regarding the tank end support brackets, I'd not design them to wrap up and over the rim, that is one way of doing it but I'd prefer to keep them solid and more robust and in line with the tank end face. Then I'd just trim notches in the rim at the top where the brackets could slot into, that joint doesn't have to have NASA tolerances as it's near hard up against the engine frame and nigh on impossible to see even at low angles. Less so if you fit the tank hard up against the frame floor, which I wouldn't do as that does not leave the characteristic gap between the two seen on real engines.

Why I care about that gap and not below floor drive shafts is one of those conflicting levels of detail I often come across.

I may well also add two longitudinal baffle plates like yours, you're right they probably add nothing visually or structurally but they may do long term, it might also help my really long tank and reduce some of the small intolerance's along it's length.

Fixing plates are your two longitudinal risers each side of the centre section, I'm presuming they are fixing plates due to the four holes which I suspect are for fixing to the chassis. I haven't even begun to think how to add fixing plates or even securing my tank to the model, primarily because right now, it can't be printed well enough for my needs.

If the core and ends won't print well enough then no need to stress over how to fit it :cool:
 

SimonT

Western Thunderer
Mick,
my first shot at printing this tank would be to make it solid with threee or four longitudinal circular hollows through the length of the tank. I would print it on the back with a longitudinal incline of 20-25 degrees and a roll of about 5-10degrees about the longtudinal axis. I would do away with the recesses at the end and print a large land on the mating face with a single plug type aligner to mate into the tank portion. I learnt from the boys with the £500000 machine to keep wall thicknesses to 4mm; I can get way with 3mm on my Form.
Simon
 

mickoo

Western Thunderer
Mick,
my first shot at printing this tank would be to make it solid with threee or four longitudinal circular hollows through the length of the tank. I would print it on the back with a longitudinal incline of 20-25 degrees and a roll of about 5-10degrees about the longtudinal axis. I would do away with the recesses at the end and print a large land on the mating face with a single plug type aligner to mate into the tank portion. I learnt from the boys with the £500000 machine to keep wall thicknesses to 4mm; I can get way with 3mm on my Form.
Simon
Tanks too big to orientate much below 50° above horizontal, 40° off vertical, it's just a massive thing :p

Your angles for pitch and roll match what I've found and I get away with 2 mm thick walls on the cab front, nose and sub base panels; but I might try a test shot of 3 mm on the sub base modules as that will increase the surface area and hopefully spread the peel forces over a wider area and maybe reduce bowing.

I can't wholly visualise your tank end explanation, but I'll work on that and mull it over as the day goes on.

It'd be nice to resolve this as most RTR models need new tanks in one guise or another, even if it's just a length adjustment to suit capacities that are Railroad specific, but more often as not it'll be for shape and generic form which can be way out.

EMD tanks generally fall into three types, I'm avoiding Gen 1 as they have their own anorak closet all to themselves.

Gen 2 and later Dash-2 follow the same format, a outer skin formed with a bending brake to give the distinctive lines along the side and with end plates welded onto the outer end.

This BNSF SD40-2 shows a typical EMD tank with ribbed lines.

IMG_3820.jpg

A close up of the plate welded to the end and giving a raised edge, in this case a CSX SD70M

Img_2183.jpg

At some point EMD must have changed the method of forming the tank skin as none of the three CSX SD70M's I got up close and personal to at Mulberry FL showed any evidence of longitudinal bending brake lines.

Img_2181.jpg

During the SD70 production the tank changed shape and construction, the shoulders became higher, the sides deeper and overall they look bulkier.

IMG_3246.jpg

Again they do not appear to have the bending brake fold lines and appear to be rolled smoother, certainly on all the ones I got up close with.

More importantly they changed the design of the end plates, no longer a larger flange plate welded to the end they are recessed in part with the skin.

IMG_4526.jpg

The extended flange is not full circumference but only the base, sides and a small part of the top at the shoulders, for the rest of the joint it is flush with the skin, well not quite as the upper skin is overlaid onto the sides/base skin with a lap joint and is thus slightly higher than the end plate.

This tank was also fitted to the ATSF SD75M and SD75I but the ACe has a whole new different angular type. I've not thoroughly checked the 80, 90, 9043 or MACs and some of these appear to have a variation of the above where the top skin covers all of the top, shoulder and down the side by about 4-6".

The tank I was trying to replicate was the 70M with inset end plate, though I do need to do the older more rounder variant with wider end plates for several models, in which case, Jim's methodology may well be the best.
 

SimonT

Western Thunderer
P:rint in two halves with an aligning device? My boiler parts came out agreeably circular and the same size with little finishing required.

The ends.
Capture.JPG
A square/rectangular section dowel and hole would give alignment. Support structure onto the area outside of the alignement dowel.

There is a change in section as the yellow loco tank is slab sided.
 

mickoo

Western Thunderer
Two halves would give more space in the work area and greater flexibility with orientation :thumbs: It should also reduce the mass/peel forces and hopefully give a better/uniform profile for the full length. I'd use an aligning device like the Garratt bunker, a profiled plug fitting into rebates in the two halves.

Your flat plate end is similar to Jim's and perfect for the older Gen 2 tanks with the plate welded to the end, it might not work so well when that end plate is inset into the end of the tank, however, it does trigger a different thought process/rabbit warren.

I found the hobby printer to be quite poor with regards to circular sections, unless they were printed flat, any angle would induce some ovaling. The Form doesn't seem to suffer as bad and the Garratt bunker was agreeable circular though in some EMD noise test shots, the headlight openings are not perfectly circular, but you have to look really hard to see it and some of that is also down to resin holding/puddling/gripping in/to the lower surfaces.
 

Dangerous Davies

Western Thunderer
I have to admit to dropping a bollock with my statement that the truck bolster centres on my model were a scale 35', they are 203mm or 32', as stated by Overseer above. I have attached a couple of shots of the body, one bogie and the drive motor. Yes, it does need some work. Also attached is a pdf giving the overall specifications of the GP35.
The photo of the truck and gearbox shows an aluminium frame which has a rounded end, possibly designed to fit under an F-Unit body. This would tie up with Big Train James' comment above that many Atwater chassis were repurposed. I believe that the F Unit has 30' between truck bolsters so the intermediate motor carrying platform would need to be longer.

Thanks again to all for your help.

Dave
 

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Big Train James

Western Thunderer
The reason for the full tank test shot as opposed to just a short end section test shot like yours was that the full tank was the primary printing concern, there's little point having ends that fit perfectly if you cannot effectively print the full tank core later. It turns out you can print the full length, just and it's not without issues over that length, it might be better if it was angled slightly, say 15° off vertical like the EMD frame front I'm doing right now.
I wasn't suggesting one or the other for testing, but rather both. Because you are 100% correct on the full tank print having its own issues......
tank fail 002.jpg

It's a nice bit of sculpture. :shit::eek::confused:

The potential issue with doing the inset ends is the thin rib around the outside, 0.3 mm is a good figure but you'd not get good enough, or big enough supports along that thin edge to support the rest of the mass as it gets printed......

.........If I opt for an inset end (I think it has more merit and mileage than my initial plug end attempt) and a thin ridge, then the main core supports will have to be moved from the outer edge and into the inner recess (red dotted line), that'd work and you could add bigger supports to take the weight and peel forces. The problem then is that face then puddles and support removal is difficult, especially as you need a reasonably flat face to secure the insert to. The outer skirt (thin ridge) would need to be overly long, maybe extend by 1-2 mm, this will move the puddling and support deformation away from the final cut back face once the ridge is trimmed back.
Is there a reason you're not including an end panel on the tank core? If I had to guess , I'd go with accounting for getting a big Tang Band speaker in there through the end. But I would consider adding an inset end closure panel to the core, at least on one end. You could then support the extended edge with very thin support contact points, while applying heavy supports to the end panel surface to support the mass of the overall model. If you do add a panel, I'd suggest including some drain holes as you see on my tank core, as I had excess resin pool inside the center section of the tank. It didn't cure, but it was a potential mess when I took the build plate off the machine and had a bunch of resin dump out unexpectedly.

If you don't add the end panel, then I would do the heavy support as you say, along the red edge, but I would also add supports further up into the tank body. There shouldn't be any need to clean up the pips on any internal surfaces away from mating edges.

On Simon's suggestion to make the tank solid with 3 or 4 hollows down the length, I think many of us will want to put something electronics related in the tank, so need it to be an empty shell.

Regarding the gap between fuel tank and bottom of frame, I too would aim to recreate that effect. On a frame from scratch, I would be attaching the tank to the frame in much the same manner as the prototype, suspended by the end brackets only. It can't be done that way on the switcher project though, since I'm starting from the Atlas frame. The area where the tank would hang from is almost fully occupied by the motor, so there aren't really any available fixing points. The solution is the fixing plates you noted, they will slide up inside the frame alongside the motor, and be screwed through the side. It's not the most ideal solution, and I lose the gap effect, but I don't have any other option on this particular build.

tank fit 001.jpg
tank fit 002.jpg
tank fit 004.jpg

Last thought, for now, is that I would consider splitting the fuel tank down the middle lengthwise rather than side to side. Doing it this way doesn't give you as much flexibility with respect to orientation, but it does give some additional wiggle room. Perhaps more importantly, it makes the seam between halves either hidden between the tank and frame, or on the very lowest point underneath the loco, which will be invisible from all but the lowest viewing angle. It also gives you a lot of readily accessible surface area for supporting the print.
 

Big Train James

Western Thunderer
Dave, definitely a gp35 body there. It could be something like a Kemtron brass import, or even a kit built Central Locomotive Works body. Although if CLW, it would more logically have a CLW drive underneath. But modelers swapped things around on a fairly regular basis back in that era, half a model found at a show mated to a different half found at another show.
 

mickoo

Western Thunderer
Overall I'm really pleased with this big slab of front end, it's the most accurate and well defined engineering shape I've produced to date.

There is a high chance I won't end up going down this route and opt for a complete etched brass footplate and then fit the 3D prints on top, I may still keep the 3D coupler pocket and small section of frame behind the steps as a bolt on piece though.

The current plan in play right now is to have a brass bed under the 3D chassis, it'll cover all of the base and wrap around the enlarged centre profile, there are also slots in the side cills that will grip the edges of the brass sheet, aiding alignment and reinforcing that fragile area.

Under that will come the big pure metal rolling chassis with thick flanges and risers, a drawing would explain it better and I'll do a colored in one later.

The latest rendition popped out of the printer today, it ran all night and has, for me, my first Form known issue failure. This if nothing else is why you model sub parts, if this had been a big detailed print it'd have been in the bin now, luckily it is salvageable.

IMG_0711.jpg

Right across the whole piece is a ridge roughly mid centre of the nose access opening, on this side it's a slight trough, on the backside it's a ridge.

IMG_0712.jpg

By my calculations this happened around 05:30 this morning so I didn't witness what happened, however it's more as likely to be the Form3 stupid inability to calculate resin levels, I'll explain.

When the Form first initialise a run it'll fill the tank so the float switch sensor makes, it's a binary switch so not clever enough to calculate the exact level, also being binary it has hysteresis, such that you might just be 5% above the refill level. This means that at some point during the print the float switch will make and Form will want to top up, it's not smart enough to do it on the fly so it stops the print, raises the part out of the vat and then goes through it's fill cycle. In my case my tank is empty so it will have tried to fill the tank for at least 20 minutes before giving up and carrying on.

The problem now is that the tank is still 35°c and the print is much cooler and the last few layers have hardened off, thus the next few layers are not rendered at the same density as that which has cooled and you get a ridge in the print.

There are ways around this and if I think about it, and remember the tank is empty, will top up manually from a back up bottle, more than enough to do the full print, so the ridge is partially down to my forgetfulness.

However the bit that really ticks of Form users is the companies inability to sort the issue out, it's not hard math, if the tank switch is made then you know you have more than 400ml of resin in the vat...the vats on the Form are huge and hungry and take a lot of resin to fill first time around.

Form also knows exactly how much resin the print is going to take, it tells you this in the slicer so you can bill your clients, it's reasonably accurate to two decimal places, so the part above might be 178.34 ml with 2000 layers at the start of the print.

Now imagine the float switch trips after the first 500 layers, it should be able to calculate it's used 44.58 ml and it knows that if the switch was on and then switched off the level will logically be 400 ml, simple math will tell it that the remaining layers will consume 133.75 ml so why stop, just keep going.

One argument (long and twisty on the feedback forums) even goes one further, when you start you know you have >400 ml, you know the part volume before you start, if it's <400 ml then just bloody print it, you could add a margin of safety in, say 200 ml but the net result is that it's all calculable so why isn't form doing it.

You can get away with stopping a print for a few minutes, much more and you'll get visible lines, if you're quick you can open the door (stops machine) and gloop in 1-200 ml real fast, do it in one corner so it spreads into the tank and warms as it goes, it'll soon get mixed when the next few layers print.

Still, it is what it was so no need to get hissy with it, just work with/around it in future.

The revised tread pattern came out well, it actually looks bigger in the images than it does by eye, I already knew the tread repetition from my handy trips to the real deal.

IMG_4443.jpg

This is an ATSF FP45 which has the same tread plate as all Gen 2 engines, it also has the same sub base doors and many other common parts, handy as one of these may well be in the build pile though I'm focusing on SP models only right now.

At a rough guess the tread repetition is 45 mm but the best I can manage on the print is 84 mm, so roughly 50% density.

IMG_0713.jpg

It's a compromise but one that I'm happy to live with right now, I might be able to get to 75% density if I drop to 25 microns, but then a piece like this would take near 30 hours and whilst it's doing that, it can't do anything else more productive.
 

mickoo

Western Thunderer
I wasn't suggesting one or the other for testing, but rather both. Because you are 100% correct on the full tank print having its own issues......
View attachment 154469

It's a nice bit of sculpture. :shit::eek::confused:


Is there a reason you're not including an end panel on the tank core? If I had to guess , I'd go with accounting for getting a big Tang Band speaker in there through the end. But I would consider adding an inset end closure panel to the core, at least on one end. You could then support the extended edge with very thin support contact points, while applying heavy supports to the end panel surface to support the mass of the overall model. If you do add a panel, I'd suggest including some drain holes as you see on my tank core, as I had excess resin pool inside the center section of the tank. It didn't cure, but it was a potential mess when I took the build plate off the machine and had a bunch of resin dump out unexpectedly.

If you don't add the end panel, then I would do the heavy support as you say, along the red edge, but I would also add supports further up into the tank body. There shouldn't be any need to clean up the pips on any internal surfaces away from mating edges.

On Simon's suggestion to make the tank solid with 3 or 4 hollows down the length, I think many of us will want to put something electronics related in the tank, so need it to be an empty shell.

Regarding the gap between fuel tank and bottom of frame, I too would aim to recreate that effect. On a frame from scratch, I would be attaching the tank to the frame in much the same manner as the prototype, suspended by the end brackets only. It can't be done that way on the switcher project though, since I'm starting from the Atlas frame. The area where the tank would hang from is almost fully occupied by the motor, so there aren't really any available fixing points. The solution is the fixing plates you noted, they will slide up inside the frame alongside the motor, and be screwed through the side. It's not the most ideal solution, and I lose the gap effect, but I don't have any other option on this particular build.

View attachment 154473
View attachment 154474
View attachment 154475

Last thought, for now, is that I would consider splitting the fuel tank down the middle lengthwise rather than side to side. Doing it this way doesn't give you as much flexibility with respect to orientation, but it does give some additional wiggle room. Perhaps more importantly, it makes the seam between halves either hidden between the tank and frame, or on the very lowest point underneath the loco, which will be invisible from all but the lowest viewing angle. It also gives you a lot of readily accessible surface area for supporting the print.
From experience I never add supports to a visual surface, unless it's an area that has no detail and can be sanded perfectly smooth, that kind of negates adding plates to one or both ends of a tank, one of them at some point will need supports adding.

You might be able to get away with it if you could angle the tank lower into the 20-25° zone Simon mentioned, then you could put all the supports along the bottom, but even then that surface will be a rippled/puddled disaster zone.

I hadn't fully considered speaker placement but it'd go in through the top so that opening would need revising at some point.

Splitting down the middle is a nice idea but if you had the ends in place, then you'd get a joint right down the middle of the end plate, if you had separate end plates then it'd certainly be a consideration.

Ironically for the SD70 inset end type of tank it's not the core that's the issue, it's getting the inset ends in neatly and retaining the thin ridge around the edge that's the problem, I of course may be overthinking the problem or not seeing the wood for the tree's, either way I'll park that tank for a later/wetter day and work up one I do need for the current project; one just like yours, which is very nice BTW, mine is just a lot longer.

Your test tank is groovy, I've not had one that bad, there's some serious warping going on there but the support base area is reasonably flat, with waves like that I would of expected the base to have warped to match, quite odd really.
 

Big Train James

Western Thunderer
In all cases, I would be suggesting separate end sheets plugged in some way into the core. The core end panel I'm advocating for would not be a finsihed surface, but rather an internal hidden surface that provides support area, has no detail, and be free to sand if necessary. Agree that the starting goal should always be to find a way to support prints on a non-visible final surface or edge.

Splitting the tank lengthwise, the intent was always to cap the ends with the separate finished end sheets.

My tank is also warped in the XY plane, if you will. The two outside faces aren't even remotely parallel to each other, as a result one end is narrower than the other, and both end surfaces curve over their widths. At first I thought I had scaled the end sheet incorrectly, because it was too wide for the mating end of the core.
 

mickoo

Western Thunderer
In all cases, I would be suggesting separate end sheets plugged in some way into the core. The core end panel I'm advocating for would not be a finsihed surface, but rather an internal hidden surface that provides support area, has no detail, and be free to sand if necessary. Agree that the starting goal should always be to find a way to support prints on a non-visible final surface or edge.

Splitting the tank lengthwise, the intent was always to cap the ends with the separate finished end sheets.

My tank is also warped in the XY plane, if you will. The two outside faces aren't even remotely parallel to each other, as a result one end is narrower than the other, and both end surfaces curve over their widths. At first I thought I had scaled the end sheet incorrectly, because it was too wide for the mating end of the core.
Copy that :thumbs:

If your tank has warped then the angle may have been too shallow? Try a more end on vertical way like mine, try kicking it off the vertical by 20-25°, add a skirt to compensate for the warping which may naturally occur at the base where the supports are, my hobby printer was a witch for that, the Form seems more reliable in that aspect. Skirts are good as they have a smaller surface area to get flat and true, much easier to get a circular skirt level than a big slab face, unless you chuck it up in a 4 jaw and skim it.

I've even seen folks make sacrificial rings/castle walls around their work to try and spread the peeling for the first few layers to prevent warping, it seamed to help but drank resin at the same time which will only be binned in the end.
 

SimonT

Western Thunderer
My approach to having a correct outside shape and a speaker slot in one of these tanks would be to put all effort into getting the shape correct and then mechanically remove the slot. Remember, KISS rules!
 
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GrahamMc

Western Thunderer
as I recently acquired an Elegoo Mars 3 printer. That's another story though.
Hi James, thank you for your contributions, they're very informative.
I know there are a couple of us looking at buying a Mars 3 so if you have the time I'm sure we'd be grateful if you could share any advice you have about them with us. You're 'That's another story though' comment makes me wonder if there's things I should know before buying one. Might be better on this other thread, it would save clogging up Mickoo's excellent thread.
Thank you,
Graham.
 

JasonD

Western Thunderer
FWIW Dave, the power trucks and motor in your pics are the same as those in my All-Nation NW2 switcher which, along with an F3A, came from an even older line, maybe Atwater. Yes, I've read who it was, but - oh, I've forgotten. I picked up another basket case NW2 a while ago, but it had a single power truck from the 40s and deserves better. You never know....

Bodyshell? The obvious answer hasn't revealed itself yet. The fan tops and exhaust look like KTM castings, but nothing else doe... those handrail stanchions are quite nic.... who put bits of angle on the frame to locate the bodyshell? Wasn't it U...aaaarrggh!
Jason
 

Big Train James

Western Thunderer
Hi James, thank you for your contributions, they're very informative.
I know there are a couple of us looking at buying a Mars 3 so if you have the time I'm sure we'd be grateful if you could share any advice you have about them with us. You're 'That's another story though' comment makes me wonder if there's things I should know before buying one. Might be better on this other thread, it would save clogging up Mickoo's excellent thread.
Thank you,
Graham.
Hi Graham,
The "That's another story though" comment was meant simply to note that the current discussion at the moment was about wheel profiles, gauge, and sideframe positioning, rather than about 3d printing. Nothing dire or dramatic was intended.

That being said, I will take your suggestion and add my thoughts to the 3d printing thread.
Jim
 
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