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Post by 3405jimmy on Aug 29, 2014 12:59:28 GMT
Will
EN8 is fine your could use EN24 if your fifteen and you want the tyres to outlast you.
Where to get it; go for thick section pipe stockists. You can usually find something close to the inner and outer diameter you want. Get them to cut a few slices for you. If you wish you can then rough to size leave the inner diameter about a thou per inch tight.
Then wap it in the oven at gas mark nine wait till it turns blue and you can throw it on from last week.
The image below is a ten inch tyre which as you can see has expanded by at least a 1/32.
mg src="" alt="1o" wheel"]Don’t waste your breaths worrying about Loctite will squeeze out does it need pining will it catch Ebola or any other peripheral issues that come from over complicating a very very simple answer.
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dfh
Hi-poster
Posts: 197
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Post by dfh on Aug 29, 2014 15:34:40 GMT
it is a myth that the Loctite is pushed out when used in a pressed fit so no undercut is neccessary. I think this largely depends on the fit. On the sorts of very high precision assembly we used to repair, there was always an undercut for the Loctite and the fits were so close to retain concentricity that there was no visible Loctite on the locating areas. I don't think you'll have much Loctite left in a joint where there's a press fit, although Cast Iron would probably have enough texture in the surface to retain some. I think undercuts are considered by most to be best practice because they take the chance out of the equation. Improving the strength of the assembly Taken from Henkel web site. With press- and slip- fits, Loctite Retaining Compounds can either provide the same strength assembly with less interference or greater strength with the same interference. For example, with the proper use of Loctite Retaining Compounds: Press-fit strengths can be doubled (steel:steel) Slip fits can exceed heavy press/shrink strength (steel:steel) Slip fits can equal press-fit strength (steel:aluminum:bronze) Allowing looser tolerances lowers costs, produces less distortion, and eases assembly With the use of Loctite Retaining Compounds, slip fits can often replace press fits; thus, close control of interference between pins and collars is unnecessary. Concern about concentricity, parallelism, and roundness is reduced or eliminated. Easier assembly: If bonding slip-fits are used, press fitting is not needed. If press-fits are used, less interference is required, and lower assembly forces can be used. The result is fewer bent pins and lower hub stresses. Fewer rejects from distortion: Since slip-fits go together easily, rejects due to distortion and galling are eliminated when bonding slip-fits with Loctite Retaining Compounds. Fewer field failures: Assembly induced stresses, inherent in press-fits, are absent from slip-fit designs. Thus, bonding slip-fits with Loctite Retaining Compounds improves the fatigue life of the assembly and reduces field failures.
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Post by Roger on Aug 29, 2014 15:59:18 GMT
That all makes perfect sense to me within the remit of what they're selling. What it doesn't do of course it give you concentricity, only a mechanical fit can do that either by pressing or having a precision fit. If all you want to do is hold something on firmly then they're right, just leave more clearance and bond it on. If you need closer concentricity than that it doesn't help. I don't doubt that some Loctite will get carried into a press fit and improve the strength. How much I'd want to rely on that when I'm not sure how much has remained after pressing is open to debate. Personally, if I want to rely on some sort of glue in the joint, I like to make sure there's a place for it so I know what I'm getting. These products are presented to us as a panacea for all sorts of situations and they are best looked at bearing in mind they are trying to sell us something. As always, I like to figure things out for myself, and that's the logic that leads me to prefer undercuts where I rely on it.
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dfh
Hi-poster
Posts: 197
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Post by dfh on Aug 29, 2014 17:12:00 GMT
That all makes perfect sense to me within the remit of what they're selling. What it doesn't do of course it give you concentricity, only a mechanical fit can do that either by pressing or having a precision fit. If all you want to do is hold something on firmly then they're right, just leave more clearance and bond it on. If you need closer concentricity than that it doesn't help. I don't doubt that some Loctite will get carried into a press fit and improve the strength. How much I'd want to rely on that when I'm not sure how much has remained after pressing is open to debate. Personally, if I want to rely on some sort of glue in the joint, I like to make sure there's a place for it so I know what I'm getting. These products are presented to us as a panacea for all sorts of situations and they are best looked at bearing in mind they are trying to sell us something. As always, I like to figure things out for myself, and that's the logic that leads me to prefer undercuts where I rely on it. If its good enough for OEM's I would have thought that is quite an endorcement, you cant get any more concentric than a press fit and loctite will give a tighter fit than without
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Post by Roger on Aug 29, 2014 18:03:06 GMT
It's excellent stuff and I've used it for years. It certainly improves the strength of joints. I've used it extensively when making special hand tools. It's brilliant when you just want to cross drill a shaft and make a 'T' bar handle, I just glue it in.
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Post by The Red Baron on Aug 30, 2014 20:11:33 GMT
I was once told by a Henkel rep that Loctite isn't a 'glue'. It works by EXPANDING in the absence of air thus turning a slip fit into an effective interference fit. It also works best on highly polished shafts and reamed holes. It does NOT need any clearance or undercuts for it to 'get a hold' in. A few microns is plenty for it to work correctly. Indeed I have seen an interference fit get stuck so tightly before it was pressed fully home that the whole job was a write off and despite the vast amount of money HM Government were spending on the whole project this decision was not taken lightly. As it is a cyanoacrylate material it CAN also set like superglue although this is just a side effect and is NOT its primary function.
Manfred
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Post by Roger on Aug 30, 2014 22:52:59 GMT
You're dead right about things going off when you're assembling them, the finer the clearance the quicker it acts. You have to crack on and get it on when you use it on things like that. You can destroy the bond if you get it hot, it goes chewy if you get it hot enough though.
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Post by Rex Hanman on Aug 31, 2014 7:59:27 GMT
You can destroy the bond if you get it hot, it goes chewy if you get it hot enough though. Once you have got it apart, what do you have to do to put it together again? Presumably everything needs to be cleaned again rather than just adding more loctite. Are there special cleaning solvents? Are they a close second to printer fluid as the most expensive liquid on the planet? Just curious as I have never used loctite.
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Aug 31, 2014 8:05:51 GMT
hi rex, you have to chip/scrape every little bit off thoroughly. cheers, julian
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Post by Rex Hanman on Aug 31, 2014 8:13:24 GMT
hi rex, you have to chip/scrape every little bit off thoroughly. cheers, julian Bu**er that!
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Post by Roger on Aug 31, 2014 8:21:23 GMT
It's not as bad as it sounds, once it's been made hot, it does come off reasonably easily.
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Post by The Red Baron on Aug 31, 2014 18:39:50 GMT
Trouble was, this assembly had several delicate components and any heat would have ruined the whole thing. The fitter who chose to pause to light a fag halfway through the job was rapidly 'promoted' to a 'special project' - counting washers right down the bottom end of the plant and well away from the critical stuff!
Manfred
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Post by Deleted on Aug 31, 2014 20:31:07 GMT
---------ours used to get 1 month "Gardening leave"
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Post by cplmickey on Sept 3, 2014 20:40:55 GMT
hi rex, you have to chip/scrape every little bit off thoroughly. cheers, julian But it ends up like a white powder so easily scrapes off or polishes up with a bit of emery. Unless you're dealing with some incredibly fiddly part it takes a few seconds. No problem at all.
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Post by Deleted on Sept 3, 2014 21:32:07 GMT
hi rex, you have to chip/scrape every little bit off thoroughly. cheers, julian But it ends up like a white powder so easily scrapes off or polishes up with a bit of emery. Unless you're dealing with some incredibly fiddly part it takes a few seconds. No problem at all. Maybe a light bead blast ??
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Post by gingerneer on Sept 24, 2014 9:37:53 GMT
Hi Guys Thank you for all the reply's. Apart from stripping the loco down i have not managed much. As promised a photo of the damaged flanges. Time to get the wheels of the axles and order some steel for the tires IMAG0284 by tapdieuk, on Flickr
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Post by Deleted on Sept 24, 2014 10:55:25 GMT
wow.. that's some damage you have there Will... caused by derailment perhaps?
Pete
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Sept 24, 2014 11:13:24 GMT
i agree with pete - wow! that's a lot more than what i would describe as a "chip" to a flange!
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Post by Deleted on Sept 24, 2014 11:42:20 GMT
The flanges look too thin and there's not much of a radius between the flange and the tread so they probably would be very weak.
John
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Post by gingerneer on Sept 24, 2014 13:56:32 GMT
Yes i did understate the damage. I don't believe the engine has steamed, it might have run on air. From the damage to the buffer beams it looks like i has fallen/dropped as some point. The general oily swarf covered and rust look makes me think that its been stashed under a bench a long time. I won't go in to all the faults (but as John has pointed out the flanges are hopeless and all the back to backs are different). On the plus side, someone has machined the cylinder block well.
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