Atlas Diesels - P48

Larry,

While I'm a big fan of Atlas O Master Line, truth be told, converting the GP60 or any Atlas, MTH, or Lionel locomotive to P:48 would be a labor of love. You would need to be very dedicated and determined. It would be time consuming to alter the "solid block" power trucks narrow enough to fit with P:48 wheel sets. Northwest Short Line could certainly outfit the axles with P:48 40 inch wheels. Protocraft also has diesel wheels that have an even better profile, but I think you would have to do your own machining to get them on and fitting right. The power block would be the issue along with narrowing the frames, which I think a few people on the forum have accomplished so they will know better than I about the headaches. Since the truck frames are un-equalized, it would almost be better to start from scratch with a set of brass frames if they can be found.

Now the good news is this. If you are looking for the P:48 prototype look without as much hassle, NWSL has P:48 wheels and wheel sets that can fit right onto our Ow5 axles and trucks. I have struggled with this issue for some time, and have experimented with trucks and axles. What I have found is that Ow5 trucks fitted with .115 tread wheels operate just fine on well laid and constructed trackwork. I'm talking pre-fab track here, although turnouts must be hand built as I don't think any existing pre-made products will allow the narrow wheels to pass without dropping into the relative wide areas of the turnout.

A compromise that I like is the .135 wheels that NWSL makes for traction vehicles (trolleys). The wider tread operates a little better on trackwork that is less than the standard needed to operate .115 tread wheels. The big deal, as you know, is that if you have a home layout and want others to operate their trains on your track, P:48 makes that impossible, and vice versa. Too much beautiful O Scale equipment has been manufactured over too long a period of time to the Ow5 standard. So many people own so many of these great models by Overland, PSC, PRB, etc. that they aren't going to be converted. Time and money is a prohibiting factor, along with the risk of permanently damaging a expensive and scarce locomotive or freight/passenger car.

This has all been hashed out before so many times and although some look to P:48 to succeed Ow5, but I don't really see this happening because of the afore mentioned reasons, but there is nothing stopping a modeler from having trucks and wheelsets that provide the look of P:48, without the worry, hassle, work, and expense of doing many complete conversions and building P:48 trackwork. The field is wide open for a small manufacturer to provide "drop in" parts  to help ease the process of using more prototypical profiled wheels and closer to prototype truck width on our Ow5 gauged trains and I know of at least one person on the O Scale Modelers group on Yahoo that is doing just that with 3-D copy machines.  Hope this helps. There is no one best answer here other than I would go with the option that gives you the most flexibility while retaining the look that you're hoping to create.  It would have been great if O Scale had emerged out of its beginnings with the correct track and wheel gauge, but that's all in the firth and here we are, Ow5 dominating 99% of our trains and more of same being produced all the time. Good luck!............and let the controversy begin.....again.....sigh..........

Mike Caddell    Arvada, Colorado

The Atlas 2R SW8 switchers are a breeze to convert to P:48.  Using Jay Criswell's (Right-'O-Way) conversion wheel set kits, it takes about 10 minutes and you're in business.

The 3R units are a bit more complicated as you have to devise electrical pickups.

Nwsl has the drop in wheelsets for the sw8/9.  Jay can make the equivalent for the mp15dc using the axle gears from the existing Atlas wheelsets if you send them to him (he can do the same for the sw8/9 if you wish).

Jay also has a replacement gear cover for the sw8/9 trucks that both relocates the sideframes to reflect the reduction in wheel profile and addresses the cracking at the corners of the stock plastic covers.

I believe later versions of the sw trucks, and all the mp trucks, have a cover consisting of a metal frame with a plastic insert for pickup roller electrical isolation.  So these units don't require replacement, and therefor adjustment of sideframes and brake shoes will need to be solved differently.

Jay also is testing an equivalent replacement for Sunset diesels.  Basically any non-two motor drive can be converted in the same manner.

I agree that converting a two-motor drive would be a question of clearances for the truck block.

Btw, not that they are readily available at this time, but the mp15dc 9'-0" Blomberg truck  could be combined with a single motor to retrofit F units and gp's.  Food for though if one could find donor trucks and didn't mind getting their hands dirty a little bit.

Jim

Thanks all for the insight.

Larry

I think this was an Atlas (maybe a GP60).  I basically gutted it and installed my drive with a Faulhaber gear head motor.  The video is a little sketchy.  The jerking was caused by me changing the momentum and later holding the model to see what kind of amps it would draw at full power with the wheels spinning (about 1/4 amp).  You'll see a few of the axles extending through the side frames.  This was done so the owner could install rotating bearing caps.  Way more work than I would want to do on a normal basis.  One of the most difficult issues was boring the side frames for ball bearings.  The axles on the factory drive don't extend into the side frame and there were no holes or dimples to start from.  Very careful measuring.  Get it wrong and the axles won't be in the center of where the journal should be.  Once boring incorrectly it would be very difficult to correct.  You'll also note, the sound doesn't match the speed and power being applied.  The decoder hadn't been adjusted yet.  These motors draw so little current the factory settings don't even realize the thing is running.

http://s601.photobucket.com/us...zpsqxcjp9z2.mp4.html

By the way, Protocraft no longer offers the diesel wheels (actually, steam either).  All are now part of Right-O'-Way.  Norm wanted to focus on the decals, importing cars, and working on his layout.

Jay

Jay, Hope the Right-O'-Way line prospers under your lead!

Best,

Simon

Simon, me too!

Thank you for the thought.

Jay

One question and an observation...

The Atlas MP-15DC... I always thought this had the same running gear as the SW-8 with different truck sides.  Does it use a different Blomberg truck with a "standard" wheelbase and axle spacing?  (i.e., correct for an F3, GP7, etc.)?  If so this would require different castings for the truck frame / gear "cassettes."

Also: Jay you have posted some inspirational photos over the years, I've learned tons by viewing them.  But Photobucket is so encrusted with pop-ups now, I never was able to get your content to load.  Is there any way you can upload the photo as an attachment on this forum, or move your content to a more secure site for sharing?

Ted,

Thank you for the compliments.  Always nice to enlarge the ego when we can.

I can try to post directly to the forum but what I sent was a video and it may exceed the file size.

The hardest part now is going to be trying to find it on my computer.

Jay

How about this one?  It's not an Atlas, MTH, or Lionel but It's what I've been working on this weekend.  OMI AS-616 painted in SP Black Widow by John Ford.  I dumped the original junk drive while also converting it to P:48.

Thanks!!  Very nice work as usual.  Is that white metal high-low gear tower part of the original drive?  Also, I hope the crew clears that heavy snow packed onto the running boards before starting their run!  

Ted,

Yes it is.  I don't normally use them but this one had a high enough ratio that it worked out fine with the greahead motor and 1:1 gearboxes on the axles.  I often times try to get rid of the tank drive but because of the way this model was built and then modified by John Ford the tank drive was the only way to go.

The snow keeps the conductor in the caboose where he belongs.

Jay

Ted Sowirka posted:

One question and an observation...

The Atlas MP-15DC... I always thought this had the same running gear as the SW-8 with different truck sides.  Does it use a different Blomberg truck with a "standard" wheelbase and axle spacing?  (i.e., correct for an F-3, GP7, etc.)?  If so this would require different castings for the truck frame / gear "cassettes."

Ted,

The two switchers have the same style of drives, with single motor to worms, idlers down to axle gears.  Typical of what is found in HO and N.

That being said, the two truck gear cassettes are not the same.  The SW gear case (AAR type A//Flexicoil) has an 8'-0" axle spacing, while the MP gear case (Blomberg) has a 9'-0" axle spacing.  The Blomberg gear case is incrementally longer, and has an extra pair of idlers between the worm and the axle gears, to account for the longer wheelbase.  The axle gears on the MP trucks are slightly smaller in diameter than those for the SW.  Mounting locations for the side frames also vary slightly between the two, which I believe is an attempt to hide the mounting behind some solid part of the side frame on each type.

Otherwise, the trucks are nearly identical.  They both have a peg that extends through the frame, held in place with an "e" or "c" clip, depending on your choice of nomenclature.  Both are the same height overall.  They are effectively interchangeable, which is how I can take a pair of SW trucks and swap them to a cut-down MP frame for an SW1500 kitbash.  One thing to note, is that the telescoping drive shafts are different diameters.  As long as you keep appropriate motors and trucks together though, there isn't a problem.

SW truck on the left, mp/Blomberg on the right - p48 wheels in both.  The SW truck has NWSL drop-in wheels while the MP has wheel sets converted by Jay as referenced in my post above.  Jay's have a better profile, dished on both sides, but it's mostly evident on the back side of the wheel.  You can see the bushings for the idler gears on the gear box sides (I don't have the gears in the SW truck, so the holes are empty), with a worm gear and two idlers for the SW, versus the worm gear and four idlers for the MP truck.  The SW truck also has the replacement p48 gear box cover from Jay, as mentioned above.  You can also see the difference in mounting tab positions for the truck side frames between the two types of trucks.

Here are the wheelsets.  NWSL for the SW on the left, Jay's wheels and axle with Atlas gear and bushings for the MP on the right.  Note the difference in diameter of the axle gears.

I hope this clearly identifies the differences between the two trucks. 

Jim

Jim,

Good job.  I planned on responding but you proved, once again, procrastination is a wonderful tool!

Jay

Standard Atlas gear box cover/side frame position vs. Jay's replacement cover for p48 (there is a version for 5'-0" gauge as well).  With the replacement covers, the brake shoes are positioned over the middle of the tread.  There is still a large gap between the face of the wheel and the back side of the side frame, because the Atlas side frame is very thin to accommodate 3-rail wheels.  The only alternative to fix that would be to laminate styrene or similar to the backside of the side frame to close the gap, or come up with an entirely new side frame.

It's interesting to note that many people say they can't discern the difference in gauge between standard O scale 5'-0" and p48 4'-8 1/2", or it's not enough to bother, which are both valid observations.  However, the difference in side frame positioning is vastly more evident due to the narrow p48 treads versus .172" 3-rail treads.  

That being said, I could see doing 5'-0" gauge with .115" treads to take advantage of commercially available track products.  NWSL offers .115" treads in both gauges.  Jay can fabricate wheelsets in one gauge as easily as the other.  However, I plan to hand lay my track and switches, so I figured I might as well just do the correct gauge from the start.

Jim,

FWIW, I probably have somewhere in the vicinity of 20,000 P:48 wheels.....just saying!

Jay

John,

Drop in conversions for the Atlas engines?  Other than the SW-8/9 or maybe the MP, probably not.  Guess I'd have to look at one first.

Jay

Wow Jim, this is a GREAT insight into the Atlas trucks, exactly what I was looking for.  Since other folks might use these trucks for repowering projects, maybe we should "sticky" this thread?   (I'm burning it to .pdf for my own reference.)  Thanks so much for taking the time to post that info!!

No problem Ted.  I had the pictures handy from a post elsewhere.  I just had to find them on my computer.

Not really specific to Atlas...actually most of these are for Red Caboose GP-9 conversions (P:48 & Ow5).  Now the fun begins! All the tedious prep work is done. Get to start assembling drives again! Party time!

Okay, not Atlas or Red Caboose.  Hoping my propensity for thread drift will meet with everyone's approval.  if not, too late.

Sometimes it's better to be lucky than good! For many of us luck is all we have. What am I ranting about now? A rather brave fellow sent me a, basically new, C&LS RS-11 to have it converted to P:48. Because of the value on this thing I was somewhat hesitant to do it but told him I'd take a look and let him know if it was doable. Okay you ask, what's the lucky part? A year ago, or so, when Norm & I were talking about bringing in a new run of 40" wheels, I asked him to have some made for 3mm axles (for the newer OMI models). All well and good, haven't sold one wheel yet. Turns out Henry used 3mm axles. These will be a simple pressed fit. All wheels insulated! Not a problem, so are the new ones. Only thing left to do is decide if were want to narrow the trucks. If not we reuse Henry's. If so, we figure it out and make new axles. Piece-O-Cake!!