The old topic is over 120 days , so as recommended I've opened a new topic. I have one on the Sonic Prairies and it is an excellent runner, so I bought another.

The new model stops on certain areas (especially one point)  and the wheels spin, before moving off, which needs a higher speed.

Hopefully Rails will accept it for replacement , but for interest why does the model stop and the wheels spin? None of my other models act this way.

That would sound like something physically catching externally.
Maybe something hanging low underneath such as a loose bolt or the brake rigging catching on something on the track.

Quote from: PLD on May 27, 2025, 07:02:50 PMThat would sound like something physically catching externally.
Maybe something hanging low underneath such as a loose bolt or the brake rigging catching on something on the track.

Some models apparently have issues with the pony truck springs being too strong preventing driving wheels from getting proper traction, adjusting the spring length apparently cures the problem.

All the above said, mine runs very nicely with no such issues.

Roy

Yes probably it  is the front and rear springs lifting the driving wheels of the track
The trucks just pull out be carefull not to loose the springs  I cut about 3 or 4 links of each spring ,while you have removed the trucks check the wheel back to backs they might be catching on the frogs which is stopping the loco in the first place . other members have I believe removed the springs altogether with no bad effects ,but I left the shortened spring in so that they still lightly press the trucks down on the track as they also pick up current which helps to stop the locos stalling .
  but still shorten the springs anyway  as it will improve the haulage capacity of the loco ,mine pulls 10 Peco tanks with no slipping at all .
When the model came out we were testing our models at the club my one needed the spring shortened so did 2 other members but 3 members locos were fine without the need to shorten the springs ,So as the springs are so tiny it does depend on how they were made some stronger than others .
Bob
Bob

Thanks for the replies.

 The first Prairie is excellent, but the new model has the problem. With arthritis and two left thumbs , it's going back and hope for a better replacement.


Regards


Geoff

Quite right, too. If the problem is with the loco we shouldn't have to mess with them

I have commented previously on the Sonic Large Prairie tanks, All I'll add is that last Monday I used my pair to double-head a 13 coach train of Farish Hawksworth stock. I had no problems at all. I then ran one of the locos on an 8 coach train of the same stock - no problem, though I suspect that 9 coaches may have been its limit: this loco had both of the pony truck springs removed. My other loco has had the springs shortened and it was comfortable with 7 coaches, although it did manage 8, on the 180 32" radius curves at either end of the layout it was slipping, though it did not stall.

I am very satisfied with the performance of these models. In "real life", in GWR/BR(WR) service, these locomotives were normally loaded to a maximum of 8 or 9 coaches, particularly on the Birmingham suburban services. The 61xx locos, of which Sonic makes a single example, had higher boiler pressure, and were originally allocated to Old Oak Common and Southall Sheds for the Paddington suburban services. Both the 5101 Class and 61XX Class were ousted by the dreaded DMUs in the late 1950s and the 1960s. Both classes were then spread further afield around the Western Region: some, from new, were used as bankers, pushing heavy east-bound coal trains up the 1-in-100 out of the Severn Tunnel to Patchway.

As my end-to-end layout's platforms will only accommodate a six coach train, (plus a "Hall", "Manor" or a 5MT) I am very satisfied with the Sonic prairies' performance, and will use them on 4 and 5 coach trains.