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Just another modeller
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QUOTE (Nthusiast @ 6 Jul 2008, 02:34) <{POST_SNAPBACK}>Just bought one of these (metronet pathfinder), inserted a dcc decoder and put on the layout:

Great looking model. Smooth running with moderate noise level. Bi-directional lighting is really nice. Weathering needed on this model in my opinion.

Areas of potential improvement:

The model is too light. This means traction is not great and an imperfect layout can cause the loco to stall relatively easily. Electrical pick up will also eventually suffer from lack of weight.

Electrical pickup: only 4 axles out of the 6 are used for electrical pickup: very silly as adding the other two would be very easy and provide improvement for power pickup. The lack of weight will not help. I wish they would add lead to the boggies.

Wheels: slightly shallow. My loco cannot go through one of the peco points on my layout as the point is right at the end of a curve and the front wheel of the rear truck is 'climbing' on the needle of the point as it enters (the needles are cut downward at the tip so that the very end of the tip is about 1.5mm or so below the rail level). Having a slightly deeper wheel flange (like on my Kato locos for eg) would prevent that happening.

Great model overall but please add weight and put the extra pickups as this would then produce a truly great and reliable runner. Deeper wheel flanges would provide extra reliability on the track particularly as these long 6 wheel boggies are always struggling to cope with tight curves and imperfect layouts.

***Picking the tip of the frog isn't a factor caused by flanges. It is an issue with the wheel back to back or the point itself.

(1) Japanese made N isn't done to global standards and Kato have a narrow back to back compared to worldwide standards. The Dapol will almost certainly be set slightly wider. This doesn't make the Dapol wrong, but emphasises that parts of your points are not doing the job properly. (see 3 below)

(2) dropping the tip of the frog as you mention is unwise and goes against everything most modellers try to achieve - the objective is to have the wheel tread properly supported as far as possible, and dropping the frog tip increases the effective gap at the common crossing area and prevents this.

(3) The REAL problem with your points is that the "check rails" on your points aren't doing their job at all. They are designed to do exactly what their name describes on the real railway, and need to do the same on a model.

PECO are hopeless and have no idea about the reality of point design so they always place them too far away from the rail so they do not "check" the wheels and stop them picking the frog point.

You can fix this by adding appx 10 thou of styrene glued inside the check rail face (and shaped to match the check rail properly) so the gap is more correct and effectively narrowed between rail and check rail. This will keep the wheelset slightly more to the left and right of the frog as appropriate (correct name of that area of the point = common crossing). If the check rails are right and the back to back also right then your problem will disappear.

I can say definately that larger flanges will NOT help tracking - correct wheel profiles and accuracy of track design will... Big flanges are an abomination on models - certainly they tend to be the most jarring thing on the look of small scale models, totally destroying the look and realism of many otherwise fine models.

Richard
DCCconcepts
 

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Just another modeller
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QUOTE (Nthusiast @ 7 Jul 2008, 05:26) <{POST_SNAPBACK}>Thks David for the tip. Here is the photo showing the tip of the peco blade:
http://farm4.static.flickr.com/3076/264205...1d87411.jpg?v=0

As the wheel comes at an angle (coming out of a curve) the shallow flange on the Dapol 66 gets onto the indicated slope and climbs it causing derailment. Slightly deeper flanges on kato stock goes fine through it.

I'll try Alastair's suggestion of narrowing the centre axle B2B.

having dropped the tip of the blade so far lets it ride ON the blade end and derail - however its already done so try filing the top edge to a knife sharpness from the BACK of the blade not the face and then gently twisting the blade a tiny bit over the last 15mm or so so it lies very snugly against the stock rail...

You could also add a check rail on the track very close to that particular point so it holds the wheels over more to stop it "picking" the end of the blade - the prototype does this on any similar situation. Make the check rail from any offcut of rail....

Richard
DCCconcepts
 
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