JasonB | 03/02/2017 15:25:43 |
![]() 25215 forum posts 3105 photos 1 articles | |
Brian Abbott | 03/02/2017 17:51:14 |
![]() 523 forum posts 95 photos | Thanks Jason, just wanted so see how you had bent the draw strap round the corner into the draw bar. i've done mine the same. Thanks again
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Brian Abbott | 28/02/2017 17:06:43 |
![]() 523 forum posts 95 photos | Hello.. This is a sketch of the by pass valve on the Minnie i am building. Unsure of the angle of the pipe cones, in the past i have just used the drill angle which seems to work ok, is this right ? Thanks.
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JasonB | 28/02/2017 17:54:08 |
![]() 25215 forum posts 3105 photos 1 articles | Should be 60degree inclusive, easily done with a centre drill and will then match off the shelf nipples/ferrules |
Brian Abbott | 01/03/2017 16:50:50 |
![]() 523 forum posts 95 photos | Thanks Jason. |
Brian Abbott | 01/03/2017 20:46:18 |
![]() 523 forum posts 95 photos | Hello Jason, Can you remember what diameter pipe you ran from the by pass valve, was it 1/8" OD ? |
JasonB | 01/03/2017 20:49:03 |
![]() 25215 forum posts 3105 photos 1 articles | No can't remember. But just had a look and its all plumbed in 1/8" |
Brian Abbott | 01/03/2017 21:18:23 |
![]() 523 forum posts 95 photos | Ok, thanks Jason. |
Brian Abbott | 09/04/2017 07:57:56 |
![]() 523 forum posts 95 photos | Hello again. I am in the process of machining the cylinder on my minnie. The gap is no more than a paper thickness in on corner so not much. Should I try and file them in together or will the gasket sort things out. Thanks. Brian |
JasonB | 09/04/2017 09:50:10 |
![]() 25215 forum posts 3105 photos 1 articles | You may find that as you tighten the bolts the boiler shell will pull back into shape if its is only a small rocking that you are getting. |
Brian Abbott | 10/04/2017 19:09:36 |
![]() 523 forum posts 95 photos | Thanks Jason, glad you said that. Sorry for not getting back to you sooner, |
Brian Abbott | 19/04/2017 16:35:37 |
![]() 523 forum posts 95 photos | Hello All.. Can anyone tell me what the pocket is for on the underside of the Minnie cylinder block ? The book calls it a sort of steam dome and according to google this is to prevent water entering the cylinder, is this correct ? Thanks.
Edited By Brian Abbott on 19/04/2017 16:51:27 |
JasonB | 19/04/2017 18:15:11 |
![]() 25215 forum posts 3105 photos 1 articles | You will find it on most traction engines, it does indeed act a bit like a steam dome allowing steam to be drawn off higher above the top of the boiler barrel and therefor the water level which reduces the risk of priming. |
Brian Abbott | 20/04/2017 11:43:33 |
![]() 523 forum posts 95 photos | Thanks Jason. One last thing ( for now anyway The drawing calls for the bore to be. 0.625" and also for the piston to be 0.625" Does the piston need to be a really good slide fit or should i have a little clearance ? I have not noticed in the book what size o rings to order, i will have another look. Thanks. |
JasonB | 20/04/2017 13:11:15 |
![]() 25215 forum posts 3105 photos 1 articles | Good sliding fit, I think I have the O ring sizes somewhere, will have alook tonight. Think I got them in a set for the minnie from Reeves when I made mine. |
Brian Abbott | 20/04/2017 13:25:27 |
![]() 523 forum posts 95 photos | Thanks Jason. Fingers cross i have the bore exactly true and perpendicular to the face that mounts the front flange
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Brian Abbott | 23/04/2017 21:01:15 |
![]() 523 forum posts 95 photos | Hello, When i turned the liner on my minnie cylinder i left it about .001" undersize. On rechecking now its fitted i have a slight taper, measures 0.624" at one end to 0.625" at the other. Very annoying, the finish is really good and the plan was to give it a quick polish to remove the last little bit. Do you think lapping would true this up ? Thanks.
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Neil Wyatt | 23/04/2017 23:17:43 |
![]() 19226 forum posts 749 photos 86 articles | How are you measuring it Brian? I'm assuming something like a bore gauge than measuring over it with a calipers or micrometer. Unless you use something that reads to a tenth of a thou. The actual taper could be well below a thou but just happens to straddle the line betwee 0.624 and 0.625. On the other hand it could be nearly 2 thou, but that would probably appear obvious. As long as your piston doesn't jam at one end or slop at the other, the o-ring should cope with a taper of about a thou. Neil |
Brian Abbott | 23/04/2017 23:46:52 |
![]() 523 forum posts 95 photos | Hello Neil, thanks for the reply. I think i will turn a gauge to pass though the bore to see exactly what is happening and if there is an issue maybe i could try and pierce of 1200 grit paper on a split mandrel to lighly polish the bore ? Jason..did you have any luck findind the o-ring size for the piston ? The closest i can find is a BS111 which has an id of 0.424" and an od of 0.630" Thanks |
Neil Wyatt | 24/04/2017 08:25:19 |
![]() 19226 forum posts 749 photos 86 articles | BS111 is the correct size for a 5/8" / 0.625" nominal bore. They have to be oversized by a few thou as they should be compressed when you insert them - that's why they can accommodate slight tapers. Neil |
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