smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Nov 28, 2014 8:12:06 GMT
Black Friday, whatever that is?!?!
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Post by ejparrott on Nov 28, 2014 9:39:39 GMT
Payday!
I'm going looking for a new monitor....
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Dec 29, 2014 20:48:46 GMT
Had a bit of productivity over Christmas! I managed to get some more horn guide castings as I didn't like he look of the steel ones. Waiting for some 3/32 rivets to fasten them in, hopefully they'll be here tomorrow or Wednesday along with the saddle casting, axlepump and eccentric strap castings
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Post by GWR 101 on Dec 29, 2014 23:49:33 GMT
Ahh now axle pumps, not sure if you have seen the previous debates regarding these but if you decide to fit one (I am) the general advice seemed to be to use a smaller bore size than the 3/8" shown on the drawing. I am opting for 5/16" but as small as a 1/4" was suggested as being suitable. Regards Paul
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Post by Roger on Dec 29, 2014 23:50:32 GMT
That's good news then. I'm not sure why castings are used for eccentric straps to be honest, they are just as easily made from bar stock which is cheap enough for a short length and the quality of the material is more likely to be good. I'm guessing that in times past, these materials couldn't be easily found, but in the age of the internet and eBay it's not a problem.
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Dec 30, 2014 13:05:32 GMT
What is the advantage of using a small diameter bored pump Paul? Now you've mentioned it Roger I've actually stopped and thought "Why the bloody hell have I bought them?" When as you say, I could have made them from bar stock... What a plonker! She's really starting to come together now which is good! The next main bit will be crankpins and coupling rods, then onto the dreaded cylinders I guess
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Post by GWR 101 on Dec 30, 2014 20:21:14 GMT
Hi Dan sorry for the delay I have been at the club site most of the day out side and its good to get in for a warm. I have just done a quick search and can't find the thread so apologies if I get this wrong. If I recall there was a view expressed that axle pumps are not used so much these days because of the improvement in the operation of injectors. There was also a view that axle pumps could result in "uneven running", this resulted in a mixed reaction both pro and anti camps. Because Juliet drawings show a 3/8" bore pump this was considered to be capable of over delivery and so a smaller bore size was proposed which I assume would require less HP to drive it. I hope this helps I just mentioned it as you had mentioned it was on your "next to make list" and hopefully I have not re-ignited a well worked subject. Regards Paul
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mrmoo
Active Member
Posts: 32
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Post by mrmoo on Dec 30, 2014 20:24:49 GMT
Apologies for semi hijacking the thread but a big Thank You to baggo for the revised gear pdf. Also I have enjoyed reading all the info on this, having just aquired a juliet it all helps!
Cheers, ben
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Dec 31, 2014 0:13:53 GMT
Hi Paul, I see your point now. I would like to install a pump but maybe a smaller ram diameter as you are doing, so not to over compensate. Dan
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Post by Deleted on Dec 31, 2014 2:56:00 GMT
I wonder if someone could devise a form of "De-clutching" the drive such that it's not mechanically connected when it's not needed ??
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Post by RGR 60130 on Dec 31, 2014 8:58:33 GMT
I wonder if someone could devise a form of "De-clutching" the drive such that it's not mechanically connected when it's not needed ?? Last year I drew out an arrangement for a variable delivery pump that can be taken off stroke completely when not required. Apart from not taking any power when out of use, the plumbing will be simpler as a bypass valve isn't required. I've got a couple of bits made but at the moment I'm sidetracked with the hotrod. If it works I'll post a drawing. Reg Edit - Alan, if you want a clutch then hark back to your 50 years before the mast in an open topped shirt and the dog clutches found on windlasses and winches. A reach rod to a bell crank would operate it fine.
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Post by Deleted on Dec 31, 2014 9:33:15 GMT
Quote}---"your 50 years before the mast in an open topped shirt"....That would be a Square Rig crew member, whilst I was in Fore and Aft attire !!........Dog clutch eh ??......Good thinking there BUT we need to engage whilst moving SO.... maybe a simple form of a plate clutch that's held in the "on" position by a spring??.( Steel and Bronze plates ??)........with the bell crank and rods having an over-throw to positive-lock when disengaged ?? PS}-- I've got the dreaded LURGI so won't be out to play tomorrow............YEURGH !!! KOFF----KOFF etc. .
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uuu
Elder Statesman
your message here...
Posts: 2,816
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Post by uuu on Dec 31, 2014 10:27:41 GMT
An electro magnetic clutch?
Wilf
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Post by GWR 101 on Dec 31, 2014 12:39:00 GMT
Just a thought would it not be possible to have something in the connection between the eccentric strap and the ram, surely this must have been considered in the past. Regards Paul
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Dec 31, 2014 14:22:13 GMT
Does pushing a bit of water round a few pipes significantly affect a lump of metal that is difficult for a man to lift?
I would wager a few pounds off our bellies would be more noticeable for the loco's workload!
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Post by Roger on Dec 31, 2014 22:41:31 GMT
Just a thought would it not be possible to have something in the connection between the eccentric strap and the ram, surely this must have been considered in the past. Regards Paul Surely when the bypass valve is open, there's negligible resistance to movement of the ram?
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Post by GWR 101 on Jan 1, 2015 1:01:24 GMT
Roger I did wonder about that but "hands up" I have no practical experience. And as I already have the eccentric mounted on the axle and wish to also drive the lubricator off it I didn't want to build a clutch into that area. Regards Paul
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dc309
Seasoned Member
Posts: 146
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Post by dc309 on Jan 2, 2015 22:31:55 GMT
Good progress made today Horns finally finished and axleboxes and axles installed.
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Post by Jim on Jan 2, 2015 23:23:05 GMT
Just a thought would it not be possible to have something in the connection between the eccentric strap and the ram, surely this must have been considered in the past. Regards Paul Surely when the bypass valve is open, there's negligible resistance to movement of the ram? On my 3" Burrell there is no hint of resistance worth considering while the pump is working on bypass. Jim
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Post by Roger on Jan 3, 2015 0:11:39 GMT
Surely when the bypass valve is open, there's negligible resistance to movement of the ram? On my 3" Burrell there is no hint of resistance worth considering while the pump is working on bypass. Jim That makes sense to me Jim. As long as the bypass tubing and valve have a large enough bore, the losses are going to be tiny.
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