PC.Vere Posted July 18, 2015 Author Share Posted July 18, 2015 Sorry, forgot this one! Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted July 18, 2015 Share Posted July 18, 2015 Too me, that's impressive! Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted July 18, 2015 Author Share Posted July 18, 2015 What is? - my honesty? I would call it 'taking a chance and having a go anyway' - mistakes are always good lessons (except when it's safety of course), Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted July 19, 2015 Author Share Posted July 19, 2015 Probably not a lot to say for a while as I have got my experiences up to date, the descriptions and pictures were more of a brief summary and don't show the details or the amount of work that actually went into it. I had to force myself to do it sometimes to see it through and chronicling it here means that I just have to see it through! I do realize that there are a lot of people who could put me to shame by doing the same thing perfectly and quickly but I would like to plod along at my own pace, also describe my progress as I go along. From now on it will be "suck it and see" - I'm open to suggestions from anyone who might know something about this stuff (either from experience or even just intuition). Please don't be surprised or offended if I don't use your idea though! Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 2, 2015 Author Share Posted August 2, 2015 Posted by John Olsen 1 on 17/07/2015 07:28:05: Hi Percy [Whereabouts in NZ are you? I could put you in touch with a guy here in Cambridge (NZ) who has built a number of model aero engines ..there is a thread on the Model Engineer website with photos. John] John, Thank you for the offers of help, but I am a bit of a 'do it when the spirit moves me' type - the typical absent minded muddler and experimenter really. You couldn't really call me a cutting edge foundryman or an aircraft modeller! however, but I want to build a Mills powered Veron Cardinal like my first flying model when I was 14 or so (all from scratch and with tools which I already have or can make) and in order to complete the circle before I finally kick the bucket! I haven't yet found the thread by the guy who is building the 12 cylinder engine (could you possibly post a link?) Thanks. Quote Link to comment Share on other sites More sharing options...
John Olsen 1 Posted August 2, 2015 Share Posted August 2, 2015 Hi again, Try **LINK** You might find it takes a couple of tries to lap a piston to fit the cylinder, but a few extra pistons is not a big deal. I still have a model I built when I was about 14, and it flies again too. I didn't build the engine but I did convert it to spark ignition. John Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 2, 2015 Author Share Posted August 2, 2015 Thanks John, I doubt I'll ever have the patience that this guy has and do not have enough equipment or expertise to attempt a project like that of course, but then he is a true engineer/modeller (which I am not) and time is not on my side! My main objective at the moment is to learn how to do a decent casting - I already know enough about machining for the job I am attempting (except lapping of course), but I will never attempt a project like that, I know my limits! Guess he has encountered the dreaded trial and error 'fine tuning' by now but it is a great credit to him to have actually got that far! Thanks again, for your help. Edited By PC.Vere on 02/08/2015 12:27:00 Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 11, 2015 Author Share Posted August 11, 2015 Took the existing Mills apart last night and although it looked in reasonable condition, I found that some previous owner had attacked the light alloy conrod with what seemed to have been a pair of long nosed pliers instead of easing it off the crankpin with his fingers - does look a little butchered! - don't think I can trust that rod anymore. Everything is very small and looks like quite a challenge on my equipment! - as casting is new to me, I'll have to learn by trial and error and at the moment I think I'll need to revise my techniques and use a much smaller crucible so my good tongs won't really be of much use! - I'll probably need to make a new, more suitable pair. Also I feel I'll need to use a hard mould, eg.the Co2/sodium silicate (waterglass) type, or even try a plaster / sand mould. A greensand mould (sand / bentonite clay) which I have used previously might be just a little too fragile for this particular job. All looks like fun and games . Edited By PC.Vere on 11/08/2015 22:41:46 Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 12, 2015 Author Share Posted August 12, 2015 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted August 13, 2015 Share Posted August 13, 2015 Well done with your casting efforts . Re the mills con rod being chewed . I have stripped many of these and the rods have had bad marks on them due to catching the crank case while running. I cant really see the marks in your picture so cant say if its the same cause . It usually occurred when the crank pin wears and throws the rod backwards . the backplate stops it but not before it hits the sharp corners of the casing causing an arc to be cut in the rod. On one of my old runners I dremmeled the offending corner off and it run much sweeter since with no discolouration of exhaust oil. Regards. Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 14, 2015 Author Share Posted August 14, 2015 ED, That's interesting, I have taken some more photos, not great but it's the best my little camera can do. On closer inspection, the marks do look as though there has been some rubbing, however, they are on both sides of the rod but there are no corresponding marks on the crankcase. It is of course possible that they have been already ground down as you described and 'blacked' over again. I think I may have to wait till daylight to inspect it further as my eyesight could be better! I took quite a few photos so I'll sort out the best ones tonight and send them to see what you think. Many thanks for the reply.. Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 14, 2015 Author Share Posted August 14, 2015 Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 14, 2015 Author Share Posted August 14, 2015 I do actually have an aftermarket rod which I purchased from England quite a while ago, ie when I first got this crazy idea of making a Mills and if I need to use it in this one, then I'll have to try making another one! Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 15, 2015 Author Share Posted August 15, 2015 Engine Doctor, Is it ok if I just call you ED? Had another (quick) look at the rod and posted the above photos - It seems to me that those gouges could have been caused by hitting the case, but the fact that they are on both sides of the rod suggests that someone may have had the rod out to check it and turned it round the other way thus the same thing on the other side, - I can't really see any marks on the case where it would have hit, but as you can see by the gouge marks it might be a good idea to replace the rod. When I do eventually sell it on, I wouldn't want it to cause the new owner any problems ( as the last owner has obviously done to me!). ) Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 15, 2015 Author Share Posted August 15, 2015 Then of course it could be a "composite" engine made up from left over bits and pieces someone had lying around in their workshop! - a 'Bitza' - might explain the undamaged crankcase ! - possibilities are endless! Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 22, 2015 Author Share Posted August 22, 2015 Having a bit of trouble posting all this but I'll get there Photos are self explanatory really but I'll talk it through:- Selection of NZ native timbers which I acquired, but I think the one I started with is 'Kauri' (as seen on the lathe) and it turns very nicely - You will see a seam down the middle as I made it up from two pieces glued together with PVA and a piece of paper - this allows it to be split easily in order to make the pattern in two halves. I have decided to use sand mixed with sodium silicate for the mould, this will make a more robust mould as everything is so small and I can't risk using "greensand" as previously as this is more prone to collapsing - this I don't want on such a small pattern. I have included a picture of the Co2 equipment for gassing the sand mixture to harden it. It's a 'Sodastream' charger for mineral water etc, and it is cheap to exchange cylinders at the supermarket, guess you have something similar in the UK. I also need to use a much smaller crucible and therefore will need a correspondingly smaller set of tongs. (crucible I intend to use in the photo), also a much taller 'plinth' in the furnace - both of these I will need to make as well ! The 'Vinamold is a vinyl rubber which can be melted and poured into a cavity, which when solidified can be removed and used as a pattern to make a resin corebox, this can be used to produce cores in the casting (again, I may decide to just machine most of it out, (we'll see). Must say it's all a new challenge to me, it may sometimes be difficult, but it's great fun nonetheless. Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 22, 2015 Author Share Posted August 22, 2015 By the way, how can I remove photos, both from my album and also from my posts? I see the 'edit' button disappears soon after posting. There are a few photos which are more or less duplicates. I would prefer to have them removed in order not to hog too much space on the forum.........Thanks. Quote Link to comment Share on other sites More sharing options...
Paul Jefferies Posted August 22, 2015 Share Posted August 22, 2015 I wholeheartedly applaud what you are doing however have you seen this on ebay.......? http://www.ebay.co.uk/itm/Mills-0-75-type-crankcase-casting-new-copy-/252059317571?hash=item3aafe7f543 Paul Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 22, 2015 Author Share Posted August 22, 2015 Posted by Paul Jefferies on 22/08/2015 08:33:14: [I wholeheartedly applaud what you are doing however have you seen this on ebay.......? Paul ] Thanks Paul, - yes that one looks to be very good indeed and is a reasonable price too! It isn't exactly the same as the original, maybe better, I dunno! - I would actually like to have one........but....... I am not looking for anything ready made, nor do I expect this effort to be a show stopper or a masterpiece of engineering - in fact, I'm not actually looking for a Mills .75 as such - I do already have one! What I am trying to do is learn about casting and foundry technology, using the Mills .75 (I had one when I was a kid) as an objective to aim for, this will include all the machining involved as well - I am already reasonably proficient in machining It's not really the easiest project I could have taken on of course, mainly because of it's small size, but I do believe that I can do it and if someone can learn something from my mistakes (which no doubt I will make ) then I will be happy! Progress will be slow and perhaps a little intermittent, but please bear with me - this is not the only thing I will be casting, but possibly the smallest! I don't really have a sensible reason for actually doing this in the first place, however there is a (slightly crazy) reason for my putting it all on this forum to give me some incentive to see it through - ie by trying hard not to end up with egg on my face! Edited By PC.Vere on 22/08/2015 11:10:42 Edited By PC.Vere on 22/08/2015 11:14:39 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 22, 2015 Share Posted August 22, 2015 PCV, in my book you're a hero. I wish I had the skill to do something like this. Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 23, 2015 Author Share Posted August 23, 2015 [ Posted by Colin Leighfield on 22/08/2015 17:46:38: PCV, in my book you're a hero. I wish I had the skill to do something like this. ] Thanks, but that observation on me is way out! Also,you don't know whether you have the ability or not, and the skill has to be learnt by everyone, but you won't know until you give it a serious try - Of course you do need to have a bit of passion about what you are trying to do though - got to be in, "boots and all"! That's what I'm doing and if it fails, so what? it will have been a lot of fun trying and I will have learnt a quite a few lessons on the way, - maybe I will look silly? - well, nobody here actually knows me anyway! Edited By PC.Vere on 23/08/2015 01:45:12 Edited By PC.Vere on 23/08/2015 01:47:17 Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted August 24, 2015 Author Share Posted August 24, 2015 Colin, I see by your avtar that you may have some interest in motorcycles. They first became a passion for me when I noticed that model aircraft engines very much resembled the motorcycle engines of the day. After owning around twenty (bikes) and now that I'm older and not fit to ride anymore, I have reverted to an interest in model aircraft engines (understanding more of how they work this time). Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 24, 2015 Share Posted August 24, 2015 I'm not fit to ride any more either, but still doing it! There has always been a common thread between bikes and planes for me, probably I have the same instincts as you. Quote Link to comment Share on other sites More sharing options...
PC.Vere Posted October 15, 2015 Author Share Posted October 15, 2015 It's been a while since i last posted, but I have had to attend to some other areas of my life - still not completely sorted - maybe never will be! So, to keep the thread alive, - Starting to pick up on where I left off this week, weather is moving into spring and this year promises to be windy down here (El Nino winds) so I hope it will be suitable for casting. Have been practicing my pattern making and corebox making skills using wood. My efforts are not dedicated to the Mills of course, but I should be trying to do a good crankcase along with all my other stuff using the picture someone (Paul Jeffries I think) sent me from Ebay earlier as a good example of what I hope to achieve! I have found some suitable hi tensile steel for the crank and with a bit of luck, I'll also be able to use that for the cylinder sleeve as well. (quite possibly i'll have to do more than one of each as I can see some challenges looming with fits!). I have also decided to cast as many as 4 crankcases (co-joined) to make the most of a melt, it would be silly to light up the furnace to pour just one tiny crankcase- very uneconomical!, I also intend casting some larger stuff as well with the same melt. That's the plan anyway ............. hopefully sooner than later. Edited By PC.Vere on 15/10/2015 08:45:10 Edited By PC.Vere on 15/10/2015 08:50:11 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted October 19, 2015 Share Posted October 19, 2015 Hi PC.Vere sorry for late reply . Yes those marks/gouges are what I was referring to . I have found them on many mils engines that I have stripped down over the years. There never seems to be any marks on the inside of the Crank case or cylinder liner . I believe its caused by the end float on the big end allowing the rod to catch the case or the bottom of the cylinder liner. it is also accompanied by " dirty exhaust oil" with fine metallic particles. You should be able to check where or what its hitting by removing the back plate and turning it over. Good luck and hopethe casting process goes well. Quote Link to comment Share on other sites More sharing options...
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