Monday, July 29, 2013

Improved running quality of Eureka Models HUB Set cars

I posted a while back on adjusting the running quality of Eureka Models HUB cars. At the time I also had to make some adjustments to several old Shinohara Code 70 points in Wollar station yard, the cars tracking well through the other Peco Code 75 and hand built points on the layout.

Since then I have had a number of derailments on a Code 100 Shinohara point in one of my staging yards.

I decided to have another look at the cars and the offending point.

I removed each bogie from the cars along with the wheel sets, this allowed the metal bearing plates to be slid out of the bogie.

The issue with the wheel sets is that the wheels need to be regauged with the back to back dimension being on or below the minimum. I had previously adjusted the back to back to the maximum possible allowed by the metal bearing plates but I felt that the back to back measurement needed to be just a little more.

I decided to centre punch the pressed cone bearing in the plate and used an adjustable automatic centre punch. Some experimentation was required to get the right amount of penetration so I started with one turn of the centre punch adjustment and ending up with two turns. If you decide to try this then you will need to determine the required adjustment on your own centre punch. Using a normal centre punch and a small hammer could give variable results.

I did one bogie at a time and adjusted the back to back of the wheel sets with my wheel and track gauge (see picture). My track and wheel gauge is a very old one produced by AMRA and is to the AMRA Standards but a NMRA gauge would also work, failing that a digital vernier calliper would give the same result.

When refitting the bogies I tightened the bogie screws and then backed them off 3/4 of a turn but noticed that the bogie didn't rock smoothly and would catch slightly. I checked and decided that there wasn't enough clearance between the bogie mounting post and the hole in the bogie. I used my number drills to find the size of the hole in the bogie then a used the next larger number drill (No. 28) to slightly expand the hole, this then allowed the bogie to rock easily.

After adjusting the bogies and wheel sets I still had occasional derailments on that old Code 100 Shinohara point in the staging yard so a careful study of the point was in order.

I found that the wheels were riding up over the check rail on the curved track of the point and this was caused by the gap between check rail and the running rail being about 1.5mm instead of 1mm.

I removed the plastic spikes holding the check rail between the check rail and the running rail, this allowed me to move the check rail towards the running rail and it was glued in place with a 1mm gap.

All running issues are now solved although wheels do drop into the frogs of the Shinohara points.

I should point out that other items of rolling stock and even locomotives have had tracking issues over the Shinohara points and I might have to replace them. I am pondering over replacement or modification as the problem is that the architecture of a Shinohara point is not the same as say, an equivalent size Peco Code 75 point, so simple replacement is not possible. Hand built points would be the best solution of course.

The lesson from all this is not to assume that all track work and points are perfect or even the same and if you are having issues with a variety of rolling stock then have a good look at your track work.


Argyle said...

Hi Ray,

I have been toying around with the idea of using a centre punch to increase the space between the wheel bearing pin points. One of the reasons that I haven't done so is the inability to get a definite measurable increase in the bearing depth. The automatic centre punch hadn't crossed my mind.

Did you measure the change in bearing depth? What BTB did you end up using? I think that about 14.7 to 14.8 mm would be ideal.

As an aside (of sorts) there are quite a lot of derailments with HUB sets (and some other recent Aussie outline rolling stock) on Peco code 100 points on the Argyle layout in Goulburn. This occurs on double curved points and also on medium and large radius points on the straight section!!

I have taken some careful measurements with a digital vernier caliper and have found that the gauge through the point blade area can be up to 17.3mm. No wonder these vehicles get the wobbles.

Happy tracking,


Ray P said...


It isn't that easy to measure the bearing depth so I used the gauge and also ran and ran the HUB set until I was satisfied that they ran well.

I just now measured the back to backs on a HUB car and they are between 14.42 and 14.49mm, so a target of 14.45mm would be OK.

I have a copy of the AMRA standards and they quote the minimum as 14.4mm and the maximum as 14.50mm so It appears that what I adjusted to complies with the AMRA standard.

I am not going to get into any discussion of AMRA versus NMRA standards, I know which one works better.

In regard to the through the point gauge measurement, If you have a back to back of 14.45 then the distance from the outer wheel face to the opposite flange would be 17.47mm so the wheel shouldn't drop in between the track gauge.

The drop at frogs though is related to the architecture of the point check rails and not so easy to eliminate without making your own points.

Ray P