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Point filing angles
http://fast-tracks.net/forums/viewtopic.php?f=4&t=977		 Page 1 of 1
Author:  bjviper [ Tue Feb 17, 2009 6:27 am ]
Post subject:  Point filing angles
Hi all,

Just wondering if the filing angles for the point blades differ between #6 #8 #10 etc.

Reason being I am building #6 turnouts with a longer distance between point blades and the frog (than designed by fast tracks). I currently have a #6 point form tool, however when filing the point blades, I have to manually file them to the required (shallower) angle.

I want to know if I could use a #8 or #10 point form tool to get shallower angle point blades.

Thanks,
Brendan
Author:  emccamey [ Tue Feb 17, 2009 9:59 am ]
Post subject:  Re: Point filing angles
Yes - Maybe - Sometimes. Are you constructing with one piece closure and points? Do you construct with hinged points? Hinged points are longer for 8-12 turnouts than for 5-7 trunouts and shorter still for the less than 5. With one piece closure-points the angles will be much shallower - pending where you fix the last fixed position that allows the beginning of the flex. A longer lead distance effectively makes for a larger turnout number at the points end. You gain in appearance - but running reliability may actually suffer if you are using one piece points with closure because the open flangeway side may actually become too narrow and pinch the wheel flange. With hinged points, you have the option of a fixed relationship of clearances. Still the longer points will need a shallower angle. You can continue to hand form the modification or you can order the larger point form tools. I've always needed to do some extra 'dress up' filing after the tool filing anyway.

-ed-
Author:  bjviper [ Tue Feb 17, 2009 4:43 pm ]
Post subject:  Re: Point filing angles
I'm using hinged points.
Author:  emccamey [ Tue Feb 17, 2009 5:23 pm ]
Post subject:  Re: Point filing angles
With hinged points - you don't have to have longer points - only the closure rails need be longer with more like a eased curvature. The points to stock rail fitting is based on the heal offset to the stock rail and the length. The heal offset is governed by wheel flange clearance minimum requirements. There's no need for longer points as you are not using the points to flex. But, if you want longer points - then yes, the shallower angle will need extra filing - and the point form tools do have a different angle for the #8 and #10 filing.

-ed-
Author:  bjviper [ Tue Feb 17, 2009 6:32 pm ]
Post subject:  Re: Point filing angles
Thanks for that. Looks like I might order a #8 or #10 tool, possibly both.

Here's a pic of the two points I've built so far. The bottom one is to the fast tracks #6 template, whilst the top one is to a NSWGR (Australian) #6 template and uses hinged point blades. I've tried to place them so that the frog V is aligned and to show the difference in length between the two. Also note these are my first and second attempt at handlaid track (respectively), and were made on paper templates, no jigs were used (except the point form tool).

Image

Ohh, and yes the blades on the top point are not fixed to a tie bar yet. I am still to decide what method I will use for this, most likely it will be some sort of simulated spacer like is used on the real thing (not a PCB sleeper).
Author:  emccamey [ Tue Feb 17, 2009 8:02 pm ]
Post subject:  Re: Point filing angles
The prototypical lead length is far more pleasing in appearance. Typical model geometry is compressed for space savings. It's reliable and a compromise. You are doing some fine work.

-ed-
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