Another newcomer's question re wagon suspension

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Will L
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Re: Another newcomer's question re wagon suspension

Postby Will L » Fri Feb 07, 2020 1:13 pm

davebradwell wrote:...it leaves me wondering if a parallel brg wouldn't be easier in the long run with the difficulties in defining, manufacturing and inspecting cones with blunt ends.


I've wondered about that, but given the improvement in running we get from pinpoint bearings (I'm old enough to remember before they became common) I rather doubt we'll be going there. Not only that but as sprung system is very likely to allow parallel bearing to get out of line I wouldn't be surprised to find they didn't perform well. That said I have been considering their use for the middle wheel on a 6 wheel coach chassis.

I do think this thread has lost sight of the key work "Newcomer" in the thread title. What such a person needs to know is
  1. There is an issue here which they need to be aware of.
  2. That sprung axles do need vertical W irons while compensated and rigid chassis ain't so fussy.
  3. If you want a vertical W iron, then choosing a bearing axle combination that fits, including washers if necessary, is a perfectly valid solution.
  4. That actauly you can do this on a trail and error basis just in case a high precision measuring device doesn't happen to be available.
  5. That a small but detectable degree of slop is not a problem, while jamming the pin points hard into the end of the bearings can be.
  6. That to avoid distorting the W irons when putting a set of wheels in, a triangular grove filed across face of one bearing will make life much easier. See the end of the CLAG article on this topic (again). Actually this slot has only to be in the bottom edge of the bearing face which is quite possible to archive (hold the file at an angle). The bottom slope of the bearing is only there to stop the wheels dropping out, just enough to achieve that will do.

Daddyman
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Re: Another newcomer's question re wagon suspension

Postby Daddyman » Fri Feb 07, 2020 5:29 pm

Will L wrote: I do think this thread has lost sight of the key work "Newcomer" in the thread title.


No don't worry, I'm still here and the advice I got was useful. Re point 1, yes, the issue was that I didn't know there was an issue. My standard fix from now on will be to use BB spring units with the low-profile bearings. Point 2 is not relevant as I'll always spring. The need for point 3 is obviated by the use of BB plus low-profile bearings. Re point 4, there is no need for any measuring if one always uses the same components. Point 5: good to hear. Point 6: I may experiment with this.
Thanks!

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Neil Smith
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Re: Another newcomer's question re wagon suspension

Postby Neil Smith » Fri Feb 07, 2020 8:42 pm

From another newcomer.. I feel I learned from this too. But.. One small confusion. At some points in this thread there was reference to W Irons. At others Axleguards. The RCH drawings that Tim produced suggest that they might be one and the same. Or maybe not. Can someone clear this up for me please?
All the best
Neil

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Noel
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Re: Another newcomer's question re wagon suspension

Postby Noel » Fri Feb 07, 2020 8:55 pm

They're the same thing. Axleguards is the official description, sometimes called "W irons" from the shape visible below the solebar.
Regards
Noel

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Neil Smith
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Re: Another newcomer's question re wagon suspension

Postby Neil Smith » Fri Feb 07, 2020 9:03 pm

Thank you Noel I thought so. But the terms kept switching depending on who was posting!


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