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Sweet William axleboxes

stuartcompton

Joined: 1-01-70

Topics: 4

Replies: 10

Posted: Mon 18th Feb 2013, 9:01am
Sweet William axleboxes

I'm considering the incorporation of sealed ball-bearing axleboxes in my 'Sweet William' build, so as to reduce friction, eliminate grit, etc from bearing areas, in a manner similar to the SRS 'Stafford'. Does anyone have experience of this they could share, ie bearing sizes, etc, before I dive in and cut metal?
 

Replies To This Post

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Mon 18th Feb 2013, 11:16am

Stuart, go for it - modern technology is there to be used and should be used. Use a metric size bearing (so that you can be sure of obtaining new ones if you ever need to) and use the 2RS designation (rubber seals). Unfortunately, plain axleboxes tend not (in ball bearing terms) to have much spare meat in them so you might have to reduce the axle size a little to suit the bearing. You'll probablt fit two in side by side. If you're at all unsure, let me know the axle diameter and width/thickness of the axlebox and I'll draw something up for you.
Regards
Peter
 

stuartcompton

Joined: 1-01-70

Topics: 4

Replies: 10

Posted: Mon 18th Feb 2013, 12:11pm

Peter, many thanks for your input. I agree entirely with your sentiments that technology is there to be used. As I've not yet ordered the mainframes I guess there's an argument for reworking the axleboxes to allow the inclusion of ball-bearings and opening the gap in the frames slightly. I'm not averse to fabricating new axleboxes from solid (or having new castings made) and having frames cut to suit if it results in a better end product. I've a good portion of the design modelled in SolidWorks so don't have an issue with creating the necessary files for cutting new frames and reworking the axleboxes. Thanks again for your input and generous offer. Stu.
 

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Mon 18th Feb 2013, 12:34pm

Stuart, assuming a 20mm diameter axle journal, pairs of 6004-2RS's side by side would seem to do well. That's 42mm O/D by 12mm thick, so the pair would fit into a 1" thick axlebox. Great to hear you've thought about this before cutting metal - so you can make the axleboxes big enough to fit them in. Alternatively, (and you may not like this) use take up bearings with the bolt shackle cut off - that way you get someone else to make the axlebox for you, and the bearing's self aligning. Thicken up the frames to 10.5mm at the guides and use ST20's for the same axle diameter, with a 76mm axlebox slot. You can get the whole unit for about a tenner each carriage paid on ebay.
Peter
 

stuartcompton

Joined: 1-01-70

Topics: 4

Replies: 10

Posted: Mon 18th Feb 2013, 4:14pm

Peter, thanks for the further input. I far prefer your initial suggestion of pairs of 6004-2RS side-by-side. What I need to do is sit down with the drgs and consider what alterations to the axleboxes and frames are deemed necessary to accomodate the bearings. At that point I'll post up my thoughts for your comment, if that is ok? Cheers. Stu.
Ps. I was taught a long time ago that you enter the workshop with a clear plan in mind - a little extra thought can save much time in the long run.
 

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Mon 18th Feb 2013, 7:41pm

Stuart, all good with me. And your PS - 100% correct. I spend a significant amount of time planning how I can make the most effective use of what little workshop time I can get. It's a very valuable investment - occasionally I even get to finish something!!!
 

stuartcompton

Joined: 1-01-70

Topics: 4

Replies: 10

Posted: Mon 18th Feb 2013, 9:45pm

Peter, browsing through BearingShopUK's site reveals further options. Given that I reduce the journal od from 1.125in (28.58mm) to 1in (25.4mm) - not an unreasonable reduction I think - then not only do standard ball-bearings (6005-2RS (25id x 47od x 12w), 6205-2RS (25x52x15), 6305-2RS (25x62x17)) show possibilities (with or without an axlebox/mainframe rework) but also the thin-section 61805-2RS (25x37x7) and 61905-2RS (25x42x9) appear worthy of consideration given their reduced od. I wonder if a pair of the thin-section bearings, spaced across the 1.5in (38.1mm) thick axlebox (ie flush with inner and outer axlebox faces) would provide maximum axlebox stability and clearance for the lower spring caps to be inserted whilst allowing standard mainframes and axlebox castings to be used? Out with the CAD next to confirm (or otherwise) my thoughts. Stu.
 

stuartcompton

Joined: 1-01-70

Topics: 4

Replies: 10

Posted: Tue 19th Feb 2013, 6:56am

Peter, further to yesterday's discussion I CADed up a standard 'Sweet William' axlebox last night and added the required bores on either face for a pair of 61905-2RS (25x42x9) thin-section bearings. There appears to be adequate clearance all round and the two 1/4in dia x 3/8in deep bores for the lower spring caps also remain clear, so it would seem that this is a valid path forward, given that both stock mainframes and axleboxes can be utilised. The only areas of compromise are the reduction in the axle journal dia from 1.125in to 25mm, but given that this is the approximate dimension (25.4mm) shown on the drgs for the wheel bore it should still be of adequate section, and a further slight reduction in dia, perhaps to 23mm, in order to create a land for the wheel to be located against. My apologies for the mix of units - metric bearings, imperial drgs (just need to throw in some American decimal imperial for a full house...). Any thoughts? Stu.
 

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Tue 19th Feb 2013, 9:16am

Stu, Sounds like you're there - no big changes needed, and it all works OK - as long as you can easily get those bearings then you're away. Good luck!!
Units - they're just a way of measuring, as long as it makes sense to you, that's fine. I often mix imperial and metric, whichever's easier for the job in hand!!
Peter
 

stuartcompton

Joined: 1-01-70

Topics: 4

Replies: 10

Posted: Tue 19th Feb 2013, 10:55am

Peter, thanks for the encouragement. The bearings appear to be a stock line so acquisition shouldn't be an issue. As and when the axleboxes are machined and fitted out I'll try to remember to post up a couple of images. Thanks again. Stu.
 
 
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