Understanding the drawings
Speedy Builder5 | 12/09/2021 19:18:46 |
2878 forum posts 248 photos | Has anyone got an accurate drawing of the main body and cones of his horizontal injector for 5" Gauge loco. The script that I am using indicates that the1/4" water inlet and overflow will just burst the sides of the main block however the drawing (NTS) shows a clearance of about 0.040". On page 3 it states that the second cone (0.213" long) "....drill through number 63. An accurate hole is required-use a number 62 drill as a pilot." In my book, a 62 drill is larger than the 63. In another script, another author says "drill through number 56" I am just a little bit confused!! Bob |
Simon Collier | 12/09/2021 21:59:40 |
![]() 525 forum posts 65 photos | If you are building injectors for the first time, get Derek Brown's book. It can't be recommended highly enough. |
Paul Lousick | 12/09/2021 23:58:42 |
2276 forum posts 801 photos | Recommend Derek Brown's book |
Stewart Hart | 13/09/2021 08:39:40 |
![]() 674 forum posts 357 photos | Hi Bob I'm a good friend of Peters and he's seen this post and he's asked me to reply I've successfully made Peters Injectors so I'm a little confused what what drawing your using if you check your personal messages I've sent you a contact email address so that I can send you a copy of Peters drawings Regarding Dags book you will find the bodies of Peters Injectors far simpler and easier to make and regarding the cone sizes and proportions Peters are very similar to Dags, but with all due respect to Dag some of his methods are overcomplicated Peters method of sizing the cones is simpler. Stew |
Stewart Hart | 13/09/2021 08:44:16 |
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Weary | 13/09/2021 11:23:57 |
421 forum posts 1 photos | How and where can I get hold of Peter Cauley's injector drawings and/or manufacturing descriptions please? I'm especially interested in the vertical injector. I have tried searching t'net & and the ME index without success. Phil Edited By Weary on 13/09/2021 11:42:21 |
Dave Wootton | 14/09/2021 16:29:19 |
505 forum posts 99 photos | I too would be interested in Peter Cauley's injector design information, as I'd like to have a go at making injectors. I did make some to Laurie Lawrences design years ago, but I'm afraid they didn't work very well untill the late Jim Ewins took them away and breathed life into them. Well three out of the six were saveable! I won't even mention the one I tried to the LBSC design, known as old reliable- you could rely on it never to work! I'm also interested in a vertical injector, so any leads would be much appreciated.
Dave I am aware of the injector book mentioned above. Edited By Dave Wootton on 14/09/2021 16:30:19 |
Speedy Builder5 | 14/09/2021 19:52:32 |
2878 forum posts 248 photos | This post will give you an idea:
Edited By Speedy Builder5 on 14/09/2021 19:53:30 |
Dave Wootton | 15/09/2021 10:58:45 |
505 forum posts 99 photos | Speedy Builder 5 thank you for the above link, I hadn't seen that - very interesting, Stew has kindly been in touch, always good to see another approach to something. Dave
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Speedy Builder5 | 15/09/2021 20:47:13 |
2878 forum posts 248 photos | I am not here to criticise, but to help and with apologies to Pete and Stuart. Following the explication and drawings, I found the following may be helpful : When inserting the combining cone, I inserted the delivery side first (from the steam side) using the setting tool, then insert the steam side cone checking the gap between them with a Number 63 drill poked down the ball chamber as you go. From Stuart Hart’s link (On the MADMODDER site) :- 1/ The cross section for the injector shows a delivery cone of 6 degrees - this should be 9 degrees ?? 2/ “Face the length down so that the gap between the body is 0.094" measured with a No 63 drill, and set the saddle dial at zero, this is important. “….. This should read:- The body is 0.037” (0.94mm) measured with a No 63 drill ….. 3/ Making the steam cone, "Now I say this only once ........ then face off by a further 0.0015" …… This should read ……. a further 0.015” (0.38mm). From Peter Cauley’s series :- Page 3, item 5 “ An accurate hole is required - use a No 62 drill as a pilot” should read No 64 drill perhaps ??
Steam Cone Manufacture and setting Page 4, Its not wrong, but I scratched my head to understand item1 (perhaps I am a bit thick!) 1- Chuck a length of 5/16” dia brass and face the end. Machine a 1/2” length (with a square shoulder) to be a sliding fit into the injector body. Reduce the gap between the shoulder and the body to 0.037”. I read it, and again and obviously got fixated into finding this gap… until it dawned on me. Slide the steam side of the injector body onto the cone and Reduce the gap between the shoulder and the injector body to 0.037”. All I need now is a boiler to test it with - Fingers crossed! Bob |
Dave Wootton | 15/09/2021 21:52:48 |
505 forum posts 99 photos | Bob I've got a copy of the drawings and instructions now thanks to Stew, will have a good look , I'll have a go at some when next I get bogged down on my loco. Out of interest I was doing some googling today and found a short series of articles of tips on making injectors on the Maidstone Model engineering societies website, in their newsletters archive starting in spring 1975. They were written by Fred LaRoche who was a fellow club member some years ago, Fred made injectors on a semi commercial basis,using cast bodies, I've got a few of his and they work very well. All done on a ancient Little John lathe with a top speed of about 750 RPM! Good luck with the injectors. Dave |
Stewart Hart | 16/09/2021 07:49:41 |
![]() 674 forum posts 357 photos | Thanks for your heads up Bob, It's not easy to spot your own mistakes it needs someone with the diligence to read closely, I'll revise things accordingly. Bean in touch with Peter and he's extremely pleased that we have people prepared to give his design a go, and would like to know how you get on so please bring us up to date on your injector builds.
Stew |
Stewart Hart | 16/09/2021 09:38:59 |
![]() 674 forum posts 357 photos | Just been in contact with Peter he confirms the sizes he uses for the smaller injectors for 5" G are as follows:- Stew I see we have some corrections in the computer articles Don’t know how they have cropped up the sizes should be for working pressure 80 to 100lbs sq ins Steam cone inlet angle 13 degree Outlet angle 9 degree Throat no 56 drill 0.046" dia Combination cone 9 Degree Throat no 63 drill 0.037" dia Del cone 13 Degree ( not 12 has pointed out in forum ) Throat no 68 drill 0.031" dia Steam cone insertion 0.037" annular gap 0.0075" Can you sort them out please:- they are the sizes I use for my small injectors Pete Hope this hasn't caused to much confusion Stew |
Speedy Builder5 | 20/09/2021 18:23:49 |
2878 forum posts 248 photos | Here is my first attempt at one of Peter's injectors for 5" gauge loco. The 'D' bit tapers seem to work OK. They did need quite a push to make them cut. Drilling the small cone holes - snapped a couple of the number 65 drills before discovering that I was drilling PB102. A change to a softer bronze made things easier, pecking the drill every 1/16" more or less. Just need a boiler to see if it will work. Ps I marked the body to indicate steam flow. |
Stewart Hart | 21/09/2021 06:52:18 |
![]() 674 forum posts 357 photos | If you had to push hard on the D bits it indicates they are blunt sharpen them up by rubbing the flat along a smooth hand stone they should be sectioned just a couple of thou over the centre line. Stew |
Stewart Hart | 21/09/2021 07:55:23 |
![]() 674 forum posts 357 photos | Hi Bob Just been in contact with Peter and he points out that the overflows shouldn't be threaded with a pipe connection, it needs it to be a free flow a short pipe. Stew
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Speedy Builder5 | 21/09/2021 10:33:11 |
2878 forum posts 248 photos | Thanks Stew, I only threaded it in case it needed extending, which I could do with pipe larger than the overflow pipe I guess. The bore of the pipe is 3/16" as to plan. I need to make a I need to make a check valve which follows the injector now - Always something to do! Bob |
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