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Post by simplyloco on Jan 14, 2023 17:54:21 GMT
Looking good. But - and I hate it when people do this, but I'm going to do it anyway - I'd have had more clamps. There, I've said it. I just get really nervous about things (the work or the cutter) moving during milling, so I'm a belt-and-braces man. Wilf Hi Wilf. It didn't move as there are two 10mm bolts holding it down, and any twist is prevented by the dowels in the bed. Do not worry...  John |
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Post by simplyloco on Jan 16, 2023 17:53:53 GMT
Completed the bedplate today.
Unfortunately, unless I can work a minor miracle, it is now a piece of scrap metal! My dodgy eyesight again... I machined the slots for the main bearings OK, and drilled the holes in all the right places, but when I machined the columns to size, the holes didn't look right, and I found an offset error in two of the main bearing columns that is just too great to 'adjust'! I could try plugging the bad holes and 'adjusting' things, but I should really fabricate a new bedplate, it'll be far quicker and easier to make! This bit was going great: spot on!  So was this, doing the columns and gaps.  You can see the errors. The holes are in the right place but the column isn't! 
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Post by chris vine on Jan 16, 2023 19:31:48 GMT
Hi John, is it the holes in the tops of the bearing pedestals that you don’t like?
I think you can plug them with a threaded stud and loctite. Or add a sliver of aluminium on the sides.
Other than that the casting looks grand and will take you days to reproduce.
My other solution would to split the differences and disguise the problem with several small adjustments to columns, caps etc. I have often done this!!
C
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Post by simplyloco on Jan 16, 2023 19:45:35 GMT
Hi John, is it the holes in the tops of the bearing pedestals that you don’t like? I think you can plug them with a threaded stud and loctite. Or add a sliver of aluminium on the sides. Other than that the casting looks grand and will take you days to reproduce. My other solution would to split the differences and disguise the problem with several small adjustments to columns, caps etc. I have often done this!! C Hi Chris. After a good look at it over a soothing Gin and Tonic it looks like I can save it! I'll plug/retap the relevant holes as you suggest, and adjust the web on the crank at one end to take care of the 0.75mm column position error. I'll use the main bearing caps as the drill templates. That should do the trick! |
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Post by ettingtonliam on Jan 16, 2023 19:47:07 GMT
Sorry, don't follow what it is thats wrong. I'd be surprised if a little hole plugging and redrilling couldn't correct things.
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Post by simplyloco on Jan 16, 2023 19:54:24 GMT
Sorry, don't follow what it is thats wrong. I'd be surprised if a little hole plugging and redrilling couldn't correct things. Not only are some holes out of position, the RH end columns are 0.75mm too far to the right. I can fix it. |
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Post by chris vine on Jan 16, 2023 22:19:18 GMT
Phew!!
It’s amazing how a soothing G&T gives a better perspective on life - and castings 🚂🚂🚂
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tony9f
Seasoned Member
Posts: 115
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Post by tony9f on Jan 16, 2023 22:25:48 GMT
Hi John,
I wouldn't beat yourself up about it too much, you're making good progress and I can't see anything there that is not recoverable. Any discrepancy in the bearing pedestals could be compensated for when machining the main bearing blocks. At the end of the day you can make the bearing pedestals any way you want if it solves the problem.
I made loads of alterations to mine as you have seen with a view to embodying full size marine practise and it looks OK so far. I'm sure you'll find a solution to it.
Tony
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Post by simplyloco on Jan 17, 2023 17:02:26 GMT
I've taken some very good advice and the bedplate is now ready to be redrilled. I'll use the yet to be made bearing caps as templates foir the holes. I can adjust the main bearing blocks to compensate for the error, so I can sleep easy again! 😇 Thanks again for the inputs. Plugs coated in Loctite and banged in!  Filed off nearly flush using the biggest file in my armoury. It was easier than setting up the mill to skim it.  Finished with wet and dry on the surface plate. I'm gonna do some lathe work now, I don't make many mistakes on lathes...  |
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dalboy
E-xcellent poster
Posts: 235
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Post by dalboy on Jan 17, 2023 17:41:17 GMT
Getting there even with the hiccups. Just out of interest are the plugs the same type of material as the casting.
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Post by simplyloco on Jan 17, 2023 17:42:59 GMT
Getting there even with the hiccups. Just out of interest are the plugs the same type of material as the casting. Soft alloy rod sitting in the rack. I hope so!  |
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Post by simplyloco on Sept 19, 2023 9:03:30 GMT
Hi folks. I'm getting fed up with talking to myself so here's a pic or two of my Triple Expansion engine. Not bad progress after just ten months but the details are quite taxing!! I gave it a new bedplate, as the original was past fixing!    |
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Post by steamer5 on Sept 19, 2023 9:19:41 GMT
Hi John,
You have been busy! Looking great!
Talking to yourself is fine…… unless you start loosing the arguments!
Cheers Kerrin
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Post by ettingtonliam on Sept 19, 2023 13:52:40 GMT
Talking to yourself? We've been quite happily chatting to you and admiring your work over on the modelenginemaker site!
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mbrown
Elder Statesman
Posts: 1,786
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Post by mbrown on Sept 19, 2023 14:06:20 GMT
But good to see you back on these pages, nonetheless....!
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Post by dhamblin on Sept 19, 2023 17:29:32 GMT
That is looking rather splendid. Also welcome back  Regards, Dan |
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Post by simplyloco on Sept 20, 2023 13:54:14 GMT
Some plumbing: Connecting the IP and LP cylinders.
My little home made bender came into its own when I needed some tight bends in some 5/16" copper pipe. However, I had to fill the pipe with solder to prevent collapse on the wanted bend radius. Some pics.  Fill the tube with solder - no flux required!  The solder runs straight out of the pipe leaving no residues.  Fluxed and a ring of 0.4mm silver solder at each end. I used a 20mm nozzle to get the heat in!  After 10 minutes in the acid you can see that the joint has taken.  I'm happy with this. The other side will probably be done in situ with a high temp solder such as Comsol. 
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Post by simplyloco on Sept 23, 2023 17:31:58 GMT
Steam Stop Valve HandwheelJust a few pics to show how I make accurate square holes in small handwheels. I do not possess any broaches....  I used a newish square needle file with a maximum AF dimension of 0.092", which by a happy coincidence is the wanted size of the square hole! The drilled hole in the handwheel is 3/32". I mounted the file in the tailstock chuck, splashed lubricant on it, and pecked at the hole for about five minutes. It helps to have a nice big lever operated tailstock... however, the file can be mounted in a holder in the tool post.  Snug as a bug in a rug! 
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Post by simplyloco on Sept 26, 2023 9:56:30 GMT
I might just finish this by Christmas! If I get around to finishing the valve gear that is...  
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Post by simplyloco on Sept 30, 2023 17:36:16 GMT
Reversing Levers and LinksMore fiddly stuff! I was trundling along quite happily today until I 'overdid' the fork link! GRRR! Some pics Here's the little monsters, part machined. I made a spare but didn't need it! They will be held in the 3 jaw chuck on loctited shafts.  Isn't Loctite Retainer wonderful?  I had to change the insert once as I forgot to run the lathe in reverse!  Reversing levers and crossbars.   Reversing crank, bearing bolt and fork link. Spot the not so deliberate mistake! 
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