Chris's N Scale Crew Speeder build

[narrowminded]

Thanks for those links, Chris.  They are helpful.

Now, I'm home and got those bodies today!  These kinds of things are just cool.   Love it!  They are the longer and wider version.  The length was added at the rear and just projects back beyond the running boards.  I don't actually need that length but some might for some of the chassis' out there.

Something I vowed I wouldn't do is attached here because I just couldn't stand not trying it out.   The chassis is my 44" wheelbase test unit that I've been endurance and performance testing components in so is too short, too tall, and wider than necessary for this application.  The chassis I make for this will have an appropriate, much longer wheelbase and a much lower profile in the exposed access openings, level with the floor (I'm pretty sure) , and with the motor mostly under a doghouse in the cab with operator room at each side.  It may have to extend back into the opening a small amount but I won't know that for sure until I get the actual drawing going.  I'm also weighing other body types that will use a similar configuration attempting to keep the chassis variations as broadly applicable as possible. 

Also, @nkalanaga, I think you may have been right about this body width being acceptable in Nn3 as well as N and that's what you're seeing here, Z track (Nn3).  A wheel swap is all it takes to go one way or the other, N to Nn3.  All performance, heights off the rail, etc. remain the same with either one, just the track gauge changes.  Anybody else have any comments on that?  I would welcome them.

Thanks so very much Chris and here's what it looks like, sorta'

[Chris333]

Hey that is cool   

I can put the original regular sized body back up if you would want that instead.  How do the molded on hand rails look?

And I took the speeder basic body and made a HOn30 railbus out of it.
With a Kato 8 wheel chassis:

With the Kato 4 wheel chassis:

[narrowminded]

Well, there's another one to do.   Have you done that in N scale as well?

On this body, I think I like the width for N scale but the length is not necessary and I think it might look better without the overhang in the back.  Would it be a lot of trouble to leave the width but go back to the original length?  Also, the roof in this longer version looks like it could use just a little more length (.01"/ .02".  It has almost no overhang in either direction, fore or aft, and doesn't quite sit tight up against the alignment ribs front or rear, either.  I considered it might be me in my glue up but the front and rear fit pretty snug to the sides and were very square.  If you shorten the sides back up I guess the roof gets shortened too but it might still be worth a look to make sure it's not something that would carry.  I don't know how much you want to mess with this but I do think it will make a pretty nice looking and running model on my chassis.   

Also, they printed this with the print lines running front to rear so there's no discernible vertical board lines.  It looks like there are boards but they appear horizontal.  That's not controllable, or is it?   It's still a neat, fun, little model no matter what.

[Chris333]

I took the board lines out on the N scale model. In HO they were only .005" wide and deep, updated to .008" deep. I still can imagine how small this is in N.

I didn't order one for myself, but I might if I can add it to another order. I was getting into this thing where I was uploading and ordering a new model before the last one even showed up in the mail... wasting money just wanting to see what it looked like. So now I'm trying to cut back on Shapeways crack. 

Heck that railbus I just showed has 7 different revisions just today since it came in the mail. If I ordered the new one now I might come up with 7 more changes tomorrow. 

But yeah I can cut the rear add-on and mess with the roof. I'll try later today.

As for the build lines you see anything to do with how it is printed is between you and Shapeways and I've never tried to contact them. Do you try a light coat of primer? Those build lines might disappear.

[narrowminded]

Thanks Chris.  I don't know for sure on the handrails but I suspect they'll be OK.  Not sure what else you could do as the vertical roof supports around those openings just don't have anywhere to drill while maintaining enough strength for even gentle handling.  In fact, those might help the strength of what is there which isn't much. 

As far as the build lines, I didn't paint it yet but I suspect they'll show.  Just washed in the ultrasonic with mineral spirits and then dish soap.  I don't have any Bestine which is what all the cool kids seem to be using.   Later today I may prime it but I want to leave the possibility of needing to machine some details when it's time to mount the actual chassis that's made for this type model so may just leave it alone until I do the new one.  I still have the other body untouched so I can work it while flat if needed.  That's what I SHOULD do.  But I can get distracted.  I've seen me do it.  BTW, this thing IS tiny! 

As far as the lines, if I could get them to print it with the lines vertical that would probably make a reasonable representation of vertical boards all by itself.  We'll see.  

The 24" wheels seem very right and at least for now I'm leaving the springs out.  As you said before, they will be pretty hard to see at this size.  How do you feel about doing the dual gauge thing?  Does it look OK or would you chuck the idea for one or the other? 

If you build one for yourself would you like to do it on one of my chassis?  A good time to try one out and with all of the work you've put in this I might be able to get you a deal on one.   I think you'd like it.

[nkalanaga]

I'll admit that I probably won't buy one, as it's definitely out of my era, but if it can easily be made for either N or Nn3, I'd make both available.  You'll increase your potential market at very little extra effort or expense.

[narrowminded]

I'll admit that I probably won't buy one, as it's definitely out of my era, but if it can easily be made for either N or Nn3, I'd make both available.  You'll increase your potential market at very little extra effort or expense.

As long as the body is wide enough to accommodate both, which this is, it's just the price of a set of wheels.  My biggest concern wasn't so much the saleability but just the appearance, if it looked OK.  I'm thinking it does but maybe a coat of paint will make the suitability more apparent. 

[Ed Kapuscinski]

This thread is really making me think that this may finally be the PRR model that @chicken45 beats @dougnelson with in the PRR modelers room.

[Chris333]

So to update the drawing. You want:

The rear side back extensions removed.

The roof interlock tabs to be exactly the size of the opening for a tighter fit.

Front and rear roof overhang extended out more.

Anything else?

[narrowminded]

So to update the drawing. You want:

The rear side back extensions removed.

The roof interlock tabs to be exactly the size of the opening for a tighter fit.

Front and rear roof overhang extended out more.

Anything else?

WOW!  Above and beyond!

That all sounds good with the possible exception of tightening up the interlock tabs.  A little short (which is what they are now) might actually be helpful in case the front or rear sit a little tighter.  That might cause more trouble than help.  The problem was the roof length being just short of the front and rear faces.  If that was lengthened, maybe .010", it could be positioned fore or aft to center it. 

The only other item that might be easier to deal with is the crank mount might be better as a saddle that would accept a tube sleeve for the crank.  I'm actually fooling with that now and after drilling it .008" and very well centered, it crumbled through anyway.  I'm filing this one off and using a piece of tube glued to the now flattened triangle support.  That could also be done at anytime if that would be any trouble to change.  I'm using .008" wire for the crank.  That makes it a little over 1 1/4" scale but any less, even if I had it, I fear would be pointless.  This is the modeling stuff that I'm new to, making these calls at this scale.  Because I have it, I'm using this one for practice. 

Thanks, Chris. 

[Chris333]

interlock tabs

You mean under the roof?

I can't even believe the crank tube printed, in HO it is small!  I can just turn it into a small block with a hole in it.

[narrowminded]

You mean under the roof?

I can't even believe the crank tube printed, in HO it is small!  I can just turn it into a small block with a hole in it.

It did print at .020" diameter.  I drilled that .008".  It basically crumbled lengthwise when I inserted the wire crank.  

If there was a saddle that a brass tube could set in I think that could be as good as it gets and make aligning the tube piece for gluing painless.  That's what I'm doing now to fix it.  I used a piece of .3mm x .5mm tubing and glued it to the original vee section after filing it flat.  That will work.  If you thought a printed block with a little more meat (.025"/ .035"... more?) and a .010" hole would look OK and print OK, that would be great.  And simpler.

Under the roof there are lenthwise steps for alignment and I thought you were talking about those when you mentioned "interlock tabs" and making them "exactly the size of the opening".  I was suggesting just leave them as they were, not lengthening them, if that's what you were talking about doing.  The relationship of those tabs to the body were fine, had room to shift slightly forward or back which is actually no problem and maybe desirable, affording some tolerance.  It was the actual roof length that was just a tad too short. 

[chicken45]

This thread is really making me think that this may finally be the PRR model that @chicken45 beats @dougnelson with in the PRR modelers room.

Nah- Doug has to do it first so I can see which rivets he missed, and add them to my model.

[narrowminded]

I took a few photos to show some progress with the mockup.  It is sitting on a Z track piece and has the Z/ Nn3 wheels in place. 

I machined a radiator cap that pins into .010" hole in radiator top that I found after close scrutiny.  Cap is basically 3 1/4" diameter x 1 1/2" high (.020" x .010") with a 2 1/2" x 3/4" high neck (.016" x .005") and a .010" extended locator pin for gluing in to radiator hole. 

Also filed and fit a .3 x .5 mm brass tube piece for the crank which is from .008" phosphor bronze wire (didn't have steel) and actually can be cranked.    I did that because I could and also figuring I may need to replace or repair that thing some day  and it will be easier to pull the unglued wire out than to try to deal with a glued in .008" wire job.  I just kinked the end at about 30 degrees and then slid it through the .3mm (.012") tube with the kink springing enough as it passed through, popping down and being sufficiently bent to hold the crank positively while spinning quite freely in the tube.  It can be removed with a pair of tweezers.

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Edit add:  There are a few things that strike me as I look at this. 

The crank is from .008" wire which is nominally 1 1/4" and probably pretty prototypical.  But for modeling purposes I wonder if .010" or closer to 1 5/8" might be the better choice just for seeing it.  I can make it either way but would appreciate folks thoughts on this. 

The rad cap also seems like it could stand a little more size but I may leave it alone.  It's already probably at the larger end of the prototypical size as guessed with the greatest of care with a thoroughly furrowed brow and a very serious look, approaching stern.  (And measurements from a Ford F-150.)

I like the wheel size.

I think the body width can pass for Nn3 but would also appreciate opinions on that.

[Chris333]

Ok I updated the model file at Shapeways. It looks like the same page, but the file is updated. If you zoom in on the 3D image you can see the bulked up area around the hand crank.
https://www.shapeways.com/product/469DUF56F/prr-speeder-7-n-scale-bulked-up?optionId=62999751

I also shortened it .100", but left the width the same.

The roof is now .010" longer at each end. (.020" total)

There is .0154" gap wiggle room fit for the roof to the body.