KenC Posted March 8, 2023 Author Share Posted March 8, 2023 David thats great news, though I don't require one just yet. What I am on the scout for is either 1) A new OS 46FX back plate so that I can remount my dislocated needle valve. 2) An also fits needle valve bracket. It seems that a few other manufacturers created needle valve mounting that was a captive bracket attached to the rear plate by its own mounting screws. Either of these options will be much appreciated if found. Quote Link to comment Share on other sites More sharing options...
David Foley Posted March 8, 2023 Share Posted March 8, 2023 The Mk1 AX has a rear mounted needle on a bracket. So if you can find one, problem solved. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted March 9, 2023 Share Posted March 9, 2023 It's not a big job making an aluminum needle support for an engine, It's winter where you are, so put the heating on in the garage it will be quicker making one up than writing pages on the forum looking for one. Quote Link to comment Share on other sites More sharing options...
KenC Posted March 9, 2023 Author Share Posted March 9, 2023 Hi David, thanks for your message, the original bracket was built into the rear plate of the engine with its shape and depth quite critical to the engine. When it broke off ( something they do with alarming regularity) I was left with the needle and its housing plus a small bit of the aluminium where it joins the plate. If I were to find a suitable solution it would have to be able to act as a housing for the original needle and support its tuning functions , plus if it was a bracket match the hole positions of the top two screws of the back plate...... I most probably would need to use longer screws for the assembly . If as suggested I were to try and make one , I would be faced with not just making a small triangular flat plate ( quite easy) but creating a way to join this to the existing needle housing ( not much spare bracket to attach to ) and for me building the composite needle assembly in a truly functioning unit , is out of the question. So I sit here annoying all by typing pages. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted March 9, 2023 Share Posted March 9, 2023 is the main needle valve unit ok? no reason it couldn't be mounted on a firewall, instead of a backplate bracket. Quote Link to comment Share on other sites More sharing options...
KenC Posted March 9, 2023 Author Share Posted March 9, 2023 Nigel you have read my thoughts and actions. I took the lid off and Aldi Stackers can and cut a strip 1/4" wide and 3" long . I have two screws that I can screw this strap to the bulkhead and hold the needle valve body captive. Still would prefer a more native solution if it is out there. Quote Link to comment Share on other sites More sharing options...
Caveman Posted March 9, 2023 Share Posted March 9, 2023 Hi Ken, the ASP remote needle is separate from the backplate and but is otherwise very similar to the OS on which it is based. A version of this could be made from thin brass or similar to hold the remains of the OS needle valve. Split the needle valve and body at the arrow and sandwich them onto the mount - job done. I have some KS brass sheet 0.025" thick which I would consider suitable and it's readily available and easy to work. Mount it on the back of the motor using the original screws - I don't think an extra 0.025" of thickness will matter. GDB 2 Quote Link to comment Share on other sites More sharing options...
Richard Wills 2 Posted March 9, 2023 Share Posted March 9, 2023 The 46AX parts that would work are OS needle valve 24681900 Mounting bracket 24682930. This is discontinued but would be very easy to make if you can't find one. Quote Link to comment Share on other sites More sharing options...
KenC Posted March 9, 2023 Author Share Posted March 9, 2023 Caveman thank you for the very encouraging and informative post, I have been concerned about two aspects of that process. Firstly by increasing the "gap" and extending the needle seat, I was worried that it might become difficult to tune the engine if the needle seat was altered. Secondly the extra thickness in respect of a secure fit of the rear plate bolts. Your mention of the brass, and its minimal thickness is interesting. I shall visit a local model shop on Friday and see what they have. Thank you for your effort. Quote Link to comment Share on other sites More sharing options...
Caveman Posted March 9, 2023 Share Posted March 9, 2023 Ken, I too wondered if the needle would screw in further to accommodate the extra thickness, so conducted a trial, before posting 😉, with the photographed setup. No problem at all, the needle had plenty of extra thread. GDB 1 Quote Link to comment Share on other sites More sharing options...
KenC Posted March 9, 2023 Author Share Posted March 9, 2023 Thank you very much for the tremendous effort you must have put into helping , and trialing your advice too ! Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 10, 2023 Share Posted March 10, 2023 (edited) Hi Ken. Cavemans suggestion is good way to go if your up to the fabrication . As an alternative if you look at the Force engine advert at top of the page the engine on the right has a rear needle valve. I have looked on line and bracket is available at around £4.75. This will save making the bracket . There is also a rear NV bracket available from OS for their LA range that would fit. I have a friend who had a couple of OS NV put by for me but won't see him until the end if the month if it can wait that long. You may have to fettle the holes if spacing is not correct but suspect the 46 will have very similar spacing for screws as the OS. Your NV might screw into that bracket or if unsuitable then a force NV will solve the problem . Edited March 10, 2023 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted March 10, 2023 Share Posted March 10, 2023 Is that because it's a rip off David? Quote Link to comment Share on other sites More sharing options...
David Foley Posted March 10, 2023 Share Posted March 10, 2023 Pretty much. I think ASP are modeled on the OS FSR series engines Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 11, 2023 Share Posted March 11, 2023 10 hours ago, David Foley said: Pretty much. I think ASP are modeled on the OS FSR series engines ASP/SC modeled later engines on the OS FX , in fact so good were the copies that most parts were interchangeable inc piston an l8ner sets. Sadly no longer available. I think the force engines will be a handy source for some bits like the rear NV assembly . As they become available on the second hand scene we will know if a y other bits can be used. Quote Link to comment Share on other sites More sharing options...
aidan mcatamney Posted May 27, 2023 Share Posted May 27, 2023 I've just bought this engine test stand to break in a brand new OS 46FX that has been sitting in its box for the last 12 years. Looking forward to getting it running. Quote Link to comment Share on other sites More sharing options...
KenC Posted May 27, 2023 Author Share Posted May 27, 2023 As this old thread has returned, I mention for the info of others that might try, that the Force bracket does fit the back of the OS 46 FX. That however is where the joy ended, because the OS needle when offered to the hole in the Force bracket, is too wide. Yes I did try and drill it out, and just at the point of being large enough the metal gave way. The vibrations during flying would have split this as there was not enough residual to be viable. Looks like the final result for 46 FX owners is to buy the entire Force 46 bracket and needle valve assembly , which comes ordered as about 5 separate pieces. Still nice to have an alternative. Thanks to Engine Doc for drawing attention to this idea. Quote Link to comment Share on other sites More sharing options...
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