Bob Smitham

Posted by LHR Dave on 20/03/2020 16:18:16: Was reading through this post earlier and saw that Jon recommended the Saito 45 fs I have just seen one on Ebay the link is below. https://www.ebay.co.uk/itm/143559493988 Regards Dave I did see your link Dave but I have been reduced to using my phone for all tinterweb activity due to a fialing HDD on my PC.But like all the engines that would be ideal for this build the bidding went over my budget.And seeing has the present lockdown situation has reduced my hobby kitty .I'm keeping the Irivine .PC is now fettled and running so I'll post an update.

Posted by Cuban8 on 20/03/2020 09:13:07: Posted by Manish Chandrayan on 20/03/2020 08:40:13: Love that tank work, but please tell us what's that big bulbous thing under slung at the rear left of the tank ? A drain sump to collect water, I believe. It is and it does need scaling down a few percent .It's not easy to get an idea of the scale until it comes off the print bed and put on the model.I have a small pile of wheel hubs that were a little to small or large.And re scaling in Cura then reduced the the depth of the concave inner surface meaning the hub sat clear of the wheel rim.It was then back to the CAD sketches and pretty much starting again. But isn't that one of the pleasures of a build the wide range of information and skills you learn.I didn't have a clue what a "Venturi" was called or its function until last week.No doubt these will take a few prints and edits to get right ish.

A quick update on the moth build. Still haven't finished the wings .I'm finding the learning curve steep and slow, but what's the rush.The tank and support struts are assembled with some corrugated foam giving a not too far from scale look.A few 3D printed details added.A quick blast of undercoat has revealed a few rough areas that require a bit of work . I then moved on to the under carriage .The one supplied with the kit is huge.So some wire bending with the help of a chefs torch a little balsa whittling were required.The areofoils helping cover some of the ugly soldering and wire that is holding it together.The 3D printer continues to earn it's keep with some hubs printed.These really were a pain on the CAD package to design . I will be applying the same rules to this build as I do my home D.I.Y jobs"it will be reet once it's painted". I will need to be able to strip this plane down for storage( the sheds getting a bit cramped)So a system is needed for the wing struts.Tim's method on his build looked the most straight forward.But after my torrid time with the under carriage I'd had enough of piano wire for one week. The supplied struts were sandwiched between two strips of balsa to give a little bit more shape.I then applied the rigging as per the instructions.This involved a single line threaded from the lower wing crossing the struts and then to the top.This was pulling the wings in all kinds of wonderful contortions.The piano was reluctantly used for the cross between the struts.The rigging now just holding the wings to the fuse rather than actively altering any wing physics.I have some small clevis pins and R clips on order for reasonable faff free removal of the struts A couple of carbon tubes are on order with the internal diameter of the exiting wing supports.I intend cutting and epoxying the existing ones in each wing and the fuel tank.I will then be using the narrower tubes to hold everything in place. Next job will be servos and the long cable runs for the rudder and elevator.For this part of the build I will be following a thread of this kit build on a German forum.All wonderfully explained and precise in a very Germanic way . Once again it's my first build in balsa and using a glow engine.So don't be shy about shouting out any weak points or areas for improvement. Cheers.

Thanks Dennis .I sorted the plumbing out and the Irvine is running fine now(arnt theses little buggers loud). And Andy yes I have two a 12v 10amp and 30v 2amp .After being in a workshop with daily use for twenty plus years and sitting in my damp shed for three years.They still power up when I dig them out once in a blue moon.They will outlive me I'm sure, quality bit of kit.Just wish they weren't so big. PS Thanks Ron Think I have sussed the picture orientation .Oddly enough I have to use MS paint and rotate 90o for them to save to the forum album in the correct orientation.Maybe it's an Iphone/Microsoft thing.

Been busy of late and what time I have had has been spent bogged down on working out a way to replace the flat carbon upper wing to fuse struts.After attempts at hammering a flat edge on each end of some 6mm aluminum tubing.Then bending and drilling cutting slots for the cross members with a dremmel I nearly gave up. Beyond my skills too keep all angles and flattened ends true on the X & Y axis. Several hours CAD and prints tested to breaking point finally paid off, ish.Still not sure if it was worth the time and effort to replaced the supplied probably much stronger supplied struts. (note a small example of failed attempts in the pic) Original and the 6mm ali version on the model. I really must work out how to rotate pictures .They are correctly orientated on my phone and PC. I picked up some fuel the other day so my first dabble in the world of glow engines began.Well lets say it was a success well kinda sorta. A Heath Robinson pocket size (great for the flying field) engine test bench was knocked together.This utilises a kitchen chair my Mrs has been mithering me to take to the tip for months,an old bread board and an ancient huge adjustable bench PSU with a centre tap transformer as a glow plug starter. Lots of half starts and splutters followed.My first mistake having the fuel tank too high.This caused a siphon effect and flooded the engine.My second mistake was tuning the engine over to clear the flood and having the carb spit a stream of fuel in my eye.The cheap glow plug starter soon gave up the fight and my meter shown it was down to 1v hence the old bench supply was brought out of retirement.Several more attempts and she kicked in to life.It was getting on a bit by this time so didn't want to upset the neighbours any more than I had.Another day of tinkering will be needed as the engine cut out with quick throttle changes and needed a lot of fine adjustments to keep running.But all in all I'm happy the ebay engine started up.

Posted by Tim Hooper on 28/02/2020 21:09:14: This looks great, Bob! Thanks for the mention. I really enjoyed building my Tiggie, and I appreciate the way you've refined it even further - especially in the use of 3D printing for the riblets and dash board. I'll be following this thread with interest. Tim It was your build that inspired me Tim .I'm just attempting to learn as I go and hopefully end up with something half as good.