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5" gauge Craven 25 Ton
http://bdca.org.uk/forumtwo/viewtopic.php?f=10&t=109		 Page 1 of 2
Author:  John Cafearo [ 23 May 2011, 23:22 ]
Post subject:  5" gauge Craven 25 Ton
Seeing David's gallery photo's of "my" crane, the Craven 25 ton at NRM, I thought it best send some piccies of my attempt.

I will dribble you a few piccie's once a week or so (don't want to get you too excited).

First off is the match truck or jib runner, made of wood and tied together with the correct tie rods, measuring 23.1/2" over the buffers.

Attachments:
Match wagon.jpg
Match wagon.jpg [ 90.59 KiB | Viewed 37751 times ]
match wagon 001.jpg
match wagon 001.jpg [ 87.95 KiB | Viewed 37751 times ]
match wagon 002.jpg
match wagon 002.jpg [ 107.83 KiB | Viewed 37751 times ]
match wagon 003.jpg
match wagon 003.jpg [ 103.32 KiB | Viewed 37751 times ]
match wagon 004.jpg
match wagon 004.jpg [ 99.3 KiB | Viewed 37751 times ]
Author:  Alex Chamberlain [ 09 Jun 2011, 17:10 ]
Post subject:  Re: 5" gauge Craven 25 Ton
John, The wagon is excellent!! really looks the part. you have to get some of the pictures of the crane on there.. the gear arrangement is fantastic!!
Author:  John Cafearo [ 21 Jul 2011, 23:43 ]
Post subject:  Re: 5" gauge Craven 25 Ton
Hi, next off was the jib, well you do don't you. 5" wide and 29" long, used 8ft of brass angle and no, I didn't count the rivets. Actually, after a spat with the next door neighbour, 1/16 copper rivets were renamed "Angelas", It's surprising how much pleasure one can get by bashing Angelas on the head with a 1lb ball pein hammer!!

Attachments:
crane jib 1.jpg
crane jib 1.jpg [ 116.83 KiB | Viewed 37676 times ]
Author:  Roger Cooke [ 22 Jul 2011, 11:04 ]
Post subject:  Re: 5" gauge Craven 25 Ton
John,

Stunning! Please keep the photos coming.

Roger.
Author:  John Cafearo [ 26 Jul 2011, 23:53 ]
Post subject:  Re: 5" gauge Craven 25 Ton
Hi, more bits. Sheaves and center top, hoist brake disc. John
Attachment:
sheaves and brake disc.jpg
sheaves and brake disc.jpg [ 168.18 KiB | Viewed 37659 times ]
Author:  John Cafearo [ 05 Aug 2011, 00:11 ]
Post subject:  Re: 5" gauge Craven 25 Ton
Hi, the biggest "gear" on the model. 8 3/4" dia. x 176 teeth plus the center pillar. It only just swung in the Myford gap. Having fallen foul of crane terminology, (see my intro), is it the "slew ring", or "base" ring, please let me know. There were some anxious moments as the last teeth were being cut in case I ended up with a half tooth!!! John

Attachments:
slew ring and pedestal.jpg
slew ring and pedestal.jpg [ 217.79 KiB | Viewed 37638 times ]
Author:  David Withers [ 05 Aug 2011, 08:34 ]
Post subject:  Re: 5" gauge Craven 25 Ton
John, that is impressive! But what else have we come to expect from you?

What in the way of machinery did you use to cut the gear teeth?
Presumably the gear and the pillar are separate components pressed or bonded together?

Please excuse any ignorance on my part as I'm not much of a machinist. [Though I do possess a gear tooth vernier... bought in a disposal sale several years ago simply because I liked the look and feel of it. :oops: ]

As to terminology, the gear you have made is the Slewing Ring. The Glossary on the main website describes this as "the large spur gear fixed to the carriage and used in conjunction with the Slewing Pinion to slew the superstructure".
Author:  John Cafearo [ 09 Aug 2011, 00:21 ]
Post subject:  Re: 5" gauge Craven 25 Ton
The slewing ring is cast iron and the centrer pillar is mild steel and they are bolted together with 4 fitted bolts. The two photos show how some of the other components were machined in the miller. There are 19 spur gears and 18 bevel or mitre gears on the model, 2 dog clutches and 1 taper clutch. 5 of the larger spur gears have "H" section spokes which caused a bit of head scratching.

Attachments:
cutting a dog clutch.jpg
cutting a dog clutch.jpg [ 128.35 KiB | Viewed 37618 times ]
cutting a bevel gear.jpg
cutting a bevel gear.jpg [ 134.55 KiB | Viewed 37618 times ]
Author:  Alex Chamberlain [ 09 Aug 2011, 21:10 ]
Post subject:  Re: 5" gauge Craven 25 Ton
Now that is cool!, I am not looking forward to making the gears for mine!!
Author:  John Cafearo [ 10 Aug 2011, 00:15 ]
Post subject:  Re: 5" gauge Craven 25 Ton
Hi Alex, easypeasy, but you will need a dividing head. The cutters I got from a second hand tool dealer at a model enginering exhibition. The Craven has two sizes of gear teeth, the ones for travelling are a larger tooth form than the crane gears. I have done both sizes but as the travelling gears are largely out of sight you could get away with the one size for all. Something to look forward to! John
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