Got Peter Witt Streetcar: It does run on D-21 curves - well, sort of

Lee,

Based on many of your previous posts on streets and some of your diagrams about maneuvering around the two different size curves, could it simply be the length? And as a result it's binding up because of the wheel angle?

That is a great looking streetcar and I'll look forward to see what you come up with.

Terry

It sure looks BIG!!! I like it but will stick with my MTH PCC....it runs on small radius curves fine.

Yes, I am certain it would run better through D-21 curves, if, say, it had three inches taken out of its wheelbase.  I don't know if that will be possible until I take it apart.  I have to work all day tomorrow so it will be the weekend before I can spend some serious time on it.  

And AMCDave - it is big, you are right.  I was hoping it would be a bit smaller.  Probalby should get the mTH.

Lee,

That trolley sure looks nice running down your street. Do you use the curve to straight adaptors? Just wondering how much help they are. I fear that I'll never see a Peter Witt on my layout with the D-16 curves. However I am able to run the RK PCC through those curves; it does complain some but makes it.

Dave, How do you feel about the size of the RK PCC? I thought that it is a little too large (High) compared to 1/43 trucks and autos. I was looking at scale Birneys to use instead; but I am encouraged that someone else is running the RK on streets.

Boy, that thing looks gigantic compared to your other vehicles. I have no doubt in my mine that you will have that running like it should be,

Can you post a photo of how the drive is laid out? I'm thinking that one of those might be usable for another project the Apprentice and I are thinking about.

Also, the spec says "O-21" curves. I'm wondering if the D-21 streets curves are actually smaller than 21" diameter.

Getting it right Lee, no hill for a climber.

Lee, I think the second curve maybe an overhang issue.  I think the trolley is rubbing against something trackside.

The prototype was a long streetcar at 45 feet 11 inches and I believe the model is very close to scale. However, this length would result in relatively large overhangs on curves and generally streetcar tracks moved apart at curves which E-Z streets do not do. Any curves that do not separate are known as non-clearance curves and usually signed and noted in the rule book. Philadelphia still has one or two non-clearance curves, so there is a prototype.

The photo below shows the overhand on D21 curves and my car does run on D21 curves. Its a little slow in the curve at low power, but moves along normally at higher power with my 80 Watt power pack. Sorry about the poor light in this photo it was just taken a few minutes ago.  

There are already several threads about the Witt car and D21 curves also.

These streetcars were considerably larger than the Corgi old-look buses at 35 feet in length.  The Baltimore Peter Witt seats 61, the old look bus 45.

Watching the video you can see the trolley lift up (tilt) to the inside of the curve.  It almost comes to a stop when it peaks.

Jan

Matt, here is a link to photos that I took of mine when I disassembled it.

>> Peter Witt

Not having the car or the street, it occurred to me none the less, rather than the car, perhaps the flange way needs to be widened  in the street. It looks as if the wheel flanges are being lifted out of their slot so to speak. The contact of the flanges on a tight radius seem not to have the room to accommodate their angle of tracking. 

BTW: The prototype had the same issues with flange size in regard to street trackage and flange ways..the interurban cars had deeper flanges than the streetcars and this could cause damage when the interurban flanges would make contact with the rail rather than the wheels. I your case it might be they (the flange way) are simply not wide enough.

An update and comments:

pennsyfan: yes, I use straight-to-curve adapters everywhere.

AGHRMatt: I will post photos when I take it apart and shorten it: I looked at it this morning and it should be be too difficult.

Jan: yes, it does this on several of the curves.  It is not hitting any obstruction, it just seems to rise up and try, but not quite succeed, in de-railing.  

Here is a video of a Bang running through the same part of my layout.  It behaves somewhat the same way but actually runs a bit better.  BTW - it, too, is running on DC here. 

I wonder how the K-Line by Lionel trolleys - I think they part of the Superstreets items - run with regards to realistic slow speeds and on the 21 and 16" curves?

Paul

I think it would be interesting to compare flange depth and the wheel diameters as well as the distance between trucks...I think the street is the issue in relation to those. It might be easier to cut a deeper flange way then to reinvent the car.

The axle spacing on the trucks needs to be reduced, not the wheel base of the street car.

Matt:

Yes, in almost all measurements Superstreets curves are smaller than 21" in diameter.  I don’t have any E-Z streets to measure but from what I have read on here they are exactly the same diameter as Superstreets.  

So the real "specs" for a circle of Superstreets D-21 curves as actually measured are:

(a) Overall Diameter (from the outside of a section to the outside of the section across the circle from it) = 21½"

(b) Center rail to center rail = 19 1/8”

(c) Outside rail to outside rail = 20 3/8”

(d) Inside rail to inside rail = 17 7/8”  

So the “21” in D-21 comes from the outside diameter measurement.  That measurement is important when planning a layout because it tells you how much space to allow for the track.  However, what is much more important in this discussion is the diameter that the INSIDE wheel of a venicle on a curve has to negotiate.  As listed in (d) above, that diameter is only 17 7/8”.  So the advertised “21” quickly becomes less than 18, a difference of 15%!  Even the outside wheel on a D-21 curve sees a diameter less than 21”.  

That’s why we need wider radius curves, as well as switches!  

BTW the corresponding values for a D-16 circle are:

(a) 16¾”

(b) 14 3/8”

(c) 15 5/8”

(d) 13 1/8”

HTH,

Bill

Comments: 

WftTrains: I agree - given that manufacturers vary slightly in how they interpret the "27" in O-27 (center to center of outer to outer) - 'Streets D-21 track is probably best described as D-20 or D-19 curve.

Bobby Ogage: I don't see that the spacing on the trucks needs to be reduced that much.  Note the video of the BANG running on the same track - axle spacing on its trucks is about an inch farther apart than on the Peter Witt and it does fine.  Based on playing with it a bit this morning, the problem may just be that the trucks can't swivel quite enough - it looks to me like a silly mm more would make such difference - to really accommodate the D-21 curves.  

Regardless, I will take the thing apart this weekend and try widening the swivel angle, etc., and shorten it if that does not fix the problem, although I may not complete it if more work is needed than that, until next week.

I looked at these streetcars for my Superstreets loop but decided they looked oversized compared to the other streets vehicles I have. Maybe they aren't oversized but they just looked that way to me.

Instead I bought an Atlas Industrial Rail trolley which is much smaller and looked "right" on my streets loop.

One important revision needed to make even this smaller trolley run smoothly was to eliminate the "truck limiting screws" inside the chassis. This task is covered in an earlier thread. After the revision my trolley easily negotiates D16 curves with no hesitation.

Lee...I know you are aware of this type of revision as you commented about the screws in that thread. 

Maybe the streetcar has similar truck limiting screws?

Might be easier to fix than you think.

Mark

Hello Lee,

Have you tried  bit of conductive grease on the corners (LBG or other).  A bit messy, but if I'm not mistaken is probably prototypical.  As a kid, I remember the old streetcars squeeling around the tight turns at the end of the line, and how dirty the tracks were.

r0d

I wonder if any type of cruise could be added and/or if it would help.

Interesting comments.  I have learned the following:  at 12 v the car sprints but without 12 v it binds in the curves, even on 0-27 track.  Compared to the MTH PCC car it is a midget.  I am puzzled at the comments about it seeming large.  As far as a cruise board, adding that would take away from the ability to see inside the car.  Some sort of view block would be required and that would just ruin the charm.

The PCC car was, I think, roughly the same length (not sure about the other dimensions) - about 11.5 inches at 1/48 (50 feet scale).  The Peter Witt does look a bit large but then, apparently, it was a lot bigger than a city bus, for example. 

Does the gauge widen in curves?  

If not I think what we may have is track that was designed with nothing but very small vehicles in mind. My Western Hobbycraft and Atlas trolleys take the curves better than the WBB trolley.