Jump to content

Jon H

Members
  • Posts

    8,685
  • Joined

  • Last visited

  • Days Won

    36

Everything posted by Jon H

  1. RPM will not change significantly with time or running in. When recently testing the rebuilt inlines they all ran the same +- about 100 revs. Some were new, others loads of hours.
  2. A 150 of that era should do 8300-8500 on a 16x8 depending on the brand. Newer apc 16x8' run slow for some reason, around 8000. If its always run slow and always been in that model i recommend making sure the carb is actually opening all the way. Also, how hot is it? Check the throttle linkage, if that is opening fully take a video of the engine running and slap it up on here. fire it up, show the problem, retune it etc. Do it all on video but make sure the camera is out of the prop wash or we wont be able to hear anything useful.
  3. if you make very long and/or heavy extensions the unbalanced mass will cause resonance and overload the clip and/or the weld holding the exhaust together. If you need an extension longer than 50mm it needs to be supported and tied back to the rotational centre of the engine. In the case of a twin, the engine mount bolts are ideal for exhaust supports.
  4. Retune effectively from scratch on all needles. In many cases little adjustment will be needed, but in some cases it will be quite meaningful. Going from purple laser 5 to red laser 5 needed a fair tweak on both needles. Its also a safe bet to just assume everything needs doing and doing it, rather than hope you can get away with not doing it only to find you cant as you turn final and the engine quits. Anything after 2000 will be fine, after 92 should be fine, before 92...ehhh it might be fine.
  5. Oh really? i know they never seemed to have stock but didnt realise they abandoned them entirely. I have a 6th scale busa pup to build and was under the impression that it would fit in the car in one piece. My Flair nieuport is he same size and it fits without any trouble. Still, you wont be getting a 1/4 in unless you own a transit van. When it comes to the undercarriage that is just the nature of the beast unless you have a split wing setup. It should not be a big problem though as the model should sit inverted on its struts giving access to the hardware. While i dont have to remove the gear i do flip my 1/4 stampe over in this way to get the bottom wing off. Its not a ig deal, despite my stampe needing 14 screws tending to each time i rig or de rig it. Takes about 5-10 minutes...not a huge problem but when i build another i will make some changes to reduce the count.
  6. I believe the busa models do not require rigging. Just bolt the wings on and go, any rigging is decorative only. The DB and Reeves certainly need their rigging if you want the wings to stay on. When i comes to space in the car i can fit 3 80 inch wings, a 1/4 stampe fuselage and 5th scale warbird fuselage, one girlfriend (when i had one!), all my flying gear, tent, BBQ and all connected junk for a weekend camping at wings and wheels, and a 70 odd inch sport model in the previously mentioned golf/astra/focus size car so it should not be a big issue getting it to the patch.
  7. Just a quick one as i popped in to laser today to sort out one or two bits. First, some have got the wrong idea about the fix needed for the inline engines and a pair of flat twins have appeared for 'fixing'. There is no fix for the FT's as they do not need one. The return/fix is only for the inline engines. Secondly, spares...again, and in particular, valve springs. Stop getting in a flap about valve springs. There is no problem with them, and there will be no problem with availability. MSL just need to phone Stirling Springs (the manufacturer) and say 'oi, we need another bag'. £2000 and a few weeks later 500 springs will arrive. I have been informed that someone on the laser facebook page is saying 'i can get you some springs' and offering to fit them to engines.... Unless he raids the factory, no, he cant get you springs. You cannot just use any random spring. If you do it will either fail, or the engine will not run correctly due to the spring not being strong enough, too strong etc. Do not use anything other than the correct springs or your engine will very likely be damaged and if it is, not all spares are going to be readily available to fix it. So if you use bobs random spring and it fails, the valve will drop into the cylinder destroying itself, the piston, and the head. If that happens the engine is finished as heads are not something there will be many spares of and are not something it is easy to just knock up. Equally if bobs spring is too firm it will overload the timing gear and cause premature wear on rockers, pushrods and adjustors, tappets, cams, backplates and crankcase bushings. Things like rockers, crankcases, backplates and cams are very unlikely to be available in quantity as spares. In fact if the spring is really firm it could even cause fatigue failure of the valve at either end, cause fatigue failure of the collet retainer....the list is endless, just use the right parts and dont trust people on the internet who promise the world. Finally, stop being so impatient. Closing down a business that has run since the 60's takes time. The machines are not yet all sold, some are still working, some have moved out, and this has been the focus. With my departure there is no day in day out attention on laser so its taking a while to tie up the loose ends. It might be another year before the final laser engine is actually assembled and efforts are currently being made to actually make the stuff as an engine can be assembled later on the coffee table assuming all the parts are there. It might be annoying that your favourite model is out of action while waiting on a part, but accept that, park the model for a season and fly the wings off it next year. Whinging and bodging will not make things happen any faster and, ultimately, may destroy both the engine and the model its bolted to. Attached are a few photos showing some of the slowly growing spares stock. This will last a good long while as long as people dont totally loose their minds and buy up stuff they dont need.
  8. I would argue that two sets of rigged half wings are far more challenging to store and transport than two long but thin single piece wings. As for the rest i agree. I always aim for looks good in the air as much scale detail is invisible more than 10 feet away.
  9. I have a reeves 1/4 pup too build as well as a DB 1/4 Pup. The DB is essentially a larger flair type model and i have no concerns. The reeves is another story. I bought it off a chap who was selling as he knew he would never build it. During the chat he revealed that this would be his 3rd and this would be the one het actually got right having practiced on the other 2 3 year builds. Having taken a look at the kit it is a daunting prospect given the non existent instructions and excessively complicated construction. In any event i am yet to decide which route to go when it comes to scratching my 1/4 pup itch so both kits remain in stock for future adventure. If you are looking for a functional club model and not a championship winning example i would go for the busa camel and just get on with it. I would ditch the non scale undercarriage, but that is a minor mod in real terms. I have been able to check out a few busa camels as i had some customers pop in with their fuselages and bits for engine fitting advice and it certainly looks like a decent enough kit. I would not worry about making it split wing either. I have loads of wings of that size and they are no bother for storage or transport in a golf/focus/astra size car.
  10. oo interesting. the ARTF of its day Still, if a nib kit is located i would knock apart the fuselage and draw round all the bits before putting it all back together. With your own set of plans in hand it would be easy enough to clone. I am sure the cowl can be copied as well. If anyone has one unused a mould could easily be made.
  11. With a straight wing and simple lines it should be easy enough to clone the thing. All you need is one rib template for the foam wing, and the tail/fuselage side outlines off the original plans.
  12. Probably as i referenced it as a benchmark. The 16x6 will be better for the cub, but i use 15x8 @ 8500 as my benchmark for more or less all 120's. There is variation between brands, props, fuel etc, but 8500 +- 200 will be about right.
  13. sounds like the engine has been apart and the pushrods have been swapped on reassembly causing the imbalance of clearance. I would set both to 4 thou and forget it. Incidentally, what makes you think its down on power? What is the prop, fuel, plug, and top end rpm? I would be expecting around 8500 on a 15x8 apc
  14. 4 thou or .1mm is more or less standard for all model 4 strokes. You can go a thou or 2 either side for top and bottom limit but 4 is fine. I quick and dirty way to set it is to run the adjustor in until it just touches the pushrod, then back it off 1/8 - 1/4 turn and nip it up. Check there is some movement and just run it as is. Set clearance when cold and with the engine at tdc of the compression stroke.
  15. Jon H

    Laser 180

    a 2 stroke 30cc petrol will out perform the laser 180 with relative ease, but as most 30cc models are over powered anyway it will probably be fine
  16. Jon H

    Smoky O.S.

    frankly i think 10% oil would be sufficient for all modern engines. I have been running an asp 160 twin on 10% oil for some time now and it still makes enough of a mess to know its well lubricated
  17. I dont remember when i actually started but as far as i can remember i always flew with the pinch. I find it the most comfortable and accurate. I have never used a strap as i find it just gets in the way of everything and is a safety nightmare. Many moons ago working at a model shop i did discover that not all tx's allow for a pinch if the bezels are high around the gimbals. Also i have fairly large hands and long ish fingers. If you dont, then it may not work for you depending on your radio.
  18. Ah i missed that, thanks GG. Before i left i drew up a list of engines that could be assembled once the missing parts were manufactured. This list included 180s, which were by far the most numerous in terms of parts left over. Depending on what the boss chooses to do as many as 40 more 180's could still be manufactured so have a chat with MSL and see what they say. I also know for a fact that there are some finished CDI spark ignition but glow fuel 180's at the factory as they were sat on the shelf when i popped in the other week. Those are available for sure as i test ran them before i left. I think there is even one petrol engine left that i completed as well. Its unclear if these will go to MSL or if the boss will sell them off directly. Beyond that, the 180 on ebay could be a bargain for someone if they bid low and its not got much wrong other than the cosmetic side. Equally, it could be a money pit if its as bad as it could be. Also the financial impact of a bearing change is about 20 quid if you have the tools and expertise, but over 100 if you have to send it to someone to do the work. This also has a big impact on the value proposition. Personally, i love engines with dead bearings as it kills their value and i can grab a cheeky deal!
  19. eh, its a non event with the tiger as theres loads of room to drop the tank.
  20. Jon H

    Smoky O.S.

    That all sounds reasonable. Its likely the recycled oil is causing the issue and a simple test is to disconnect it from the intake. Just make sure you plug the nipple on the intake manifold to prevent the air leak. You will then need to retune the whole thing and see how its going. I actually tested a laser 180 with this breather-intake setup and it smoked like an old train. This was before the switch to low oil mind you but it was enough for me to abandon the idea pretty quickly. With oil in mind dropping to 15% fully synthetic would be a good idea across the board.
  21. Jon H

    Smoky O.S.

    looks like a MkII surpass with later alpha exhaust. The breather pipe should connect to the carb intake and these ones do smoke more as waste oil is dumped into the cylinder again. That said, my 91 isnt a problem at high power when using this setup. When you lean off the needle how far do you go? Until you see an rpm drop?
  22. Its tricky as i recommended a 100 for a customers 96 inch cub and it flew fine at half throttle. The bird dog will be draggier though i suspect and a good bit heavier. you could go for the 180 side mounted with a 20x6 prop it will be over powered flat out but will also waft along effortlessly at half throttle. If you had a spare 155 it would likely do, but you havent so use the 180. As Chris says, if you find it is too much swap it for something smaller. Its only an engine mount change provided you didnt mutilate the cowl.
  23. I would expect a 90 to walk it. 30cc is mental as the 1/4 stampes out there go like a rocket with 30cc in them despite being nearly a foot larger and nearly twice the weight. Frankly, it would probably fly on a 70 if you wanted really scale performance.
  24. Jon H

    Smoky O.S.

    If its the 5/15/2 smc fuel mix it should not smoke that badly, but binning the castor will help. Does it smoke all the time or only at high/low throttle? Also is the engine a 2nd hand unit you just got? if so it might be flooded with castor oil and its taking time to burn off.
×
×
  • Create New...