Speedy axle boxes

[Peter Simpson 2Participant @petersimpson2]

[Peter Simpson 2Participant @petersimpson2]

I have made the frames for my 5″ gauge Speedy. I intend to fit cast iron horn blocks. Would it be realistic to make the split axle boxes out of cast iron square bar. Would BMS axles run ok face to face with cast iron. or should Gun Metal be used.

Any assistance would be appriciated.

[Sub MandrelParticipant @submandrel]

I’m interested in the answers to this too. I was planning the unusual mix of cast iron axleboxes in gunmettal horns and fitted with oilite bushes.

 

Neil

[mgjParticipant @mgj]

Yes – why not. We run cast pistons in cast bores – though the heat etc does have some metalurgical effects that means that though it sounds similar, actually one is comparing apples and pears.

 

Grease will solve the problem!

 

Stub mandrell – Sweet Pea uses gunmetal hornblocks with cast iron axleboxes as standard. I added bronze bushes for the axles, and just pressed them in. Sweet Pea /Metre Maid is not known for having undue wear on the axle assemblies. Depending a bit on the ashpan arrangements, it might be worth rigging some sort of cover or deflector to keep the grit away from rotating bits?

Edited By mgj on 06/12/2011 22:49:44

[michael howarth 1Participant @michaelhowarth1]

I am about to start a Martin Evans design Gresley V2 2-6-2 in Gauge 1 and I am also contemplating axlebox materials. The frames are 3/32 steel and the axleboxes slide directly into the frames ie no hornblocks. The design specifies gunmetal axleboxes but as I don’t have any I have been wondering about hard brass with a gunmetal/bronze bearing press fitted as per mgj above. My Greenly books mention the use of hard brass in this gauge. I have also wondered about using mild steel axleboxes with a similar press fit bearing. This size of loco. is of course not a passenger puller. Any thoughts?

[Peter Simpson 2Participant @petersimpson2]

Hi Guy’s Thanks for the feedback. I assume that if one uses gun metal bushes in the cast iron axle box. The construction of the axle box would need to be a one piece construction. The original “Speedy” drawing show a split axle box with a keeper and a felt oil pad. Fabricating a solid cast iron axle box then pressing in a gun metal bearing would my easier and considerably cheaper in material costs. Lubrication would require a hole to be drilled vertically through the axle box and the bearing bush.

[John BaguleyParticipant @johnbaguley78655]

Cast iron makes an excellent bearing material on it’s own. You don’t really need to put a bush in it. Should work fine with steel axles.

 

John

[Adrian Parker 1Participant @adrianparker1]

Personally I would make a steel axlebox with an “oilite” bush in it. I would not make it split – too much like hard work! An alternative to the bush would be to use the roller bearings available from Polly which Nevil Evans specified for his Grange.

 

If you have a self centring 4 Jaw chuck another wizard wheeze is to make the axlebox square making the boring operation very simple.

 

Adrian

[michael howarth 1Participant @michaelhowarth1]

Adrian….I like the sound of the steel axlebox/pressed bearing combination, both for ease of construction and cost…….. but if it is that simple I wonder why there is such a strong adherence to the cast iron/gunmetal way of doing things?

 

Mick

[Sub MandrelParticipant @submandrel]

Thanks MGJ – this is an electric ‘diesel’ so grit isn’t an issue. The reason for oilite is to simplify lubrication.

 

Neil

[mgjParticipant @mgj]

Ah – yes. electricity that makes a difference.

 

Why did I use bronze – because I had it, and because if it wears out then I have an easily split – able axle box – the centres of the axles are relievd. If it ever came to it I’d use split shell bearings in a split axlebox. Steel or cast iron makes no difference. .

 

If i hadn’t had bronze, I wouldn’t have bothered. If I’d had some ball bearings of the right size I’d have used those, and if I’d thought about it enough, I’d have sent off to someone for some needle rollers or oilite. As it was drawn bronze was there, and if kept lubricated it will see me out – but then so would oilite or rollers.

 

Take your pick – does it it matter as long as its kept lubricated..

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