PatMc
-
Posts
6,014 -
Joined
-
Last visited
-
Days Won
4
Content Type
Profiles
Forums
Blogs
Gallery
Calendar
Downloads
Posts posted by PatMc
-
-
1 hour ago, Rich Griff said:
You know of ken enya In Japan ?
Very good service which is quite quick.
I purchased 2 carbs and exhausts to fit to Cox td09, some mods needed but not much.
I think you'll find that K enya is in E Africa. 😉
-
1
-
-
5 hours ago, Paul De Tourtoulon said:
Move, who would want to live in Wales other than singers,,😅,
You mean Wailers. 😁
-
1
-
-
Brian, I wanted to buy my current PC from Currys about 3 or 4 years ago after some research & checking out a demo one in their N. Tyneside branch. Problem was they didn't have one in stock nor were there any stocked within reasonable distance for me to collect. I located one at their Hull branch & asked my local shop if they could have it transferred to their stock or have have Hull branch arrange delivery to my home address via an internet order. They flatly refused to do either. I never got a reason for the transfer refusal other than that it wasn't company policy. I later realised that they wouldn't deliver it via an internet order because it would make them liable to the conditions of the remote purchase legislation. As it happens one of my brothers lives near Hull & was planning on visiting us within a couple of weeks so he agreed to pick it up & bring it with him on his visit but he had to pay for it himself at the shop. (Must try to remember to reimburse him on day 😁)
IMO, if you are able to make a direct purchase from Acer it might be a better option.
-
1
-
-
10 hours ago, Peter Jenkins said:
In what way PatMc?
The post that my comment quoted as reference, also the general discussion that prompted the quoted post.
-
1 hour ago, Peter Jenkins said:
Yes, there is the rotating slipstream but the effect of motor torque applied at too low an airspeed is also a major factor. The yaw is corrected by rudder but the roll has to be countered by aileron. The combination of the two can be disastrous.
All high performance piston engine fighters, apart from those fitted with contra rotating props, had to be handled carefully when at low airspeed. Application of power smoothly was very necessary. I heard that the Fleet Air Arm used to teach this problem graphically by getting the pilot converting to the Sea Fury to set up the landing configuration and speed at 10,000 ft and then slam the throttle open. The aircraft performed a roll in the opposite direction to the prop rotation! I have also seen a grisly sequence of photos that showed what happened to a P51 that did a long straight approach and so never saw the other P 51 taxy onto the runway and start his take off. It was only when the P51 on the runway grew bigger than the nose of his P51 that he panicked and slammed open the throttle. His P51 took a few chunks out of the P51 taking off narrowly missing that pilot and then ploughed into the grass on the runway side inverted and disappeared in a fire ball!
Like I say, the combination of rotating slip stream and engine/motor torque at low airspeed is a problem.
You're quoting my post out of context.
-
22 minutes ago, Martin Harris - Moderator said:
I’m yet to be convinced that a stumbling run holding a model at arm’s length above the head followed by an unbalanced lunge is better than a carefully controlled hard push from a balanced stance.
The typical javelin thrower holds his projectile well behind him before launch and uses back muscles, shoulder rotation, pectoral and arm muscles to release his javelin while maintaining speed and balance - not qualities often observed at the model flying field!
Most people who hand launch for someone else run hard up to the point of launch then stop before chucking. 😉
-
2
-
1
-
-
20 minutes ago, Martin Harris - Moderator said:
One factor that comes to mind (although the effect may be debatable) is that in a typical outrunner there is a significant rotating mass at a larger diameter than an IC engine’s rotating components. Maybe where the idea of EP producing more torque effects came from?
At model sizes I would agree that helix effects probably outweigh torque effects but ask a Sopwith Camel or high powered WW2 piston engined aircraft’s pilot whether they are significant!
I would have thought that the difference in mass between an IC & EP prop acting at a far greater mean diameter would pretty much negate any difference in gyroscopic effect.
-
6 minutes ago, Chris Walby said:
Difference between IC and EP...well IC will be ticking over a 2000 rpm and WOT at 10,000 so difference of 8,000 and most like launched at WOT. EP typically 4S and 1100KV so off load motor speed of 16,280 rpm and probably around 15,000 rpm with the prop on. Hence the prop will be accelerated by nearly 50% more rpm.
EP most likely launched before the motor has got to full speed so the accelerating prop has a greater torque effect with EP than IC hence the greater tendency to roll. With very over powered funfighters etc I have found launch at less than wot and waiting until the motor has stopped accelerating helps with the launch.
Open to any other theories though 🙂
For the same power, torque is greater aat lower rpm.
-
There's IC, EP & BS. When folk who primarily fly IC give advice on EP they often include BS in large dollops. 😁
-
1
-
5
-
-
3 hours ago, paul devereux said:
Why would that be a thing with EP but not with IC? Edit: just saw Nigel posted the same question. The only setup difference I can imagine is that the EP prop is different, but I still can't see how the airflow would have a different effect on the plane.
Sorry Paul, I didn't make myself clear. I wasn't refering to any difference between EP & IC but, as Leccy has pointed out, to the misuse of the term "torque roll".
-
1
-
-
51 minutes ago, Simon Chaddock said:
It does seem odd to use rudder to correct torque roll in an hand launched plane if it has ailerons as well.
In terms of roll control the rudder only has a secondary effect whereas the ailerons are primarily for roll.
On the other hand a ground take off with undercarriage the torque and "P" yaw effects can only be controlled with the rudder until the plane is actually flying.
Just an observation from someone who due to field conditions has to hand launch practically everything whether or not it has a rudder.😉
The main problem isn't actually "torque roll", in fact its a yaw caused by it the rotating slipstream striking one side of the fin.
-
3
-
-
1 hour ago, leccyflyer said:
An exception that I've noted in this type of model- don't know why - is the Ripmax Bf109E. Our Ripmax Spitfire and Ripmax Mustangs all go away dead straight from a handlaunch. The Ripmax Bf109E on the other hand definitely rolls to the left on launching and both myself and my pal Derek launch the 109 with a bootful of right rudder to counteract that, having been caught out early on.
Some marks of the full size Bf109 fin & rudder had an asymmetric airfoil with the camber on the right side to counteract torque roll. The characteristic may have had something to do with the higher tailplane position when compared with other fairly similar layout fighters of the time.
A number of full size aircraft to have the fin mounted at a slight angle or the rudder permanently offset for the same reason.
-
2
-
-
2 hours ago, Brian Cooper said:
Isn't Philip 61 ?
And Holly looks different too.
-
If there's anyone at the field running an ic engine you probably can't hear an EDF anyway, particularly when they're carrying out the mandatory pre-flight "tuning" ritual that they fondly imagine will make their engine run better than it did last flight. 🙄
-
1
-
4
-
-
On 19/06/2023 at 16:50, Phil Green said:
I remember the RCMF fly-in where the Popsie was the theme model. There must have been a dozen or more but IIRC none flew well if at all, most crashed on launch or shortly after 😁
Me & Paul J were watching a Popsie that wouldnt fly at Old Warden, he said his own Popsie simply wouldnt fly either. I've huge respect for Vic but the Popsie wasnt his best 😁
The Poppet on the other hand is a superb flyer, FF or radio!
To be fair to Vic Smeed the model in question isn't a Popsie, it's a Lightwork Pops. There appears to be a number of design changes including some "beefing up", wing repositioning etc that would make a difference to how the model would need to be trimmed.
-
If you have or can borrow a tachometer & a DVM or wattmeter you can calculate the Kv. Just divide the rpm by applied volts at full throttle.
-
Somehow I don't think Mike has the 29" span 1948 f/f original model in mind. 😉
Or maybe he has ? 😊
-
The original Popsie only used the Mills .75 for free flight, it used an ED Bee for rc.
Model weights according to the plan (Outerzone) F/F - 15.75oz; RC model 23oz.
Engines - Mills .75 1.75oz; ED Bee 2.75oz.
Note that the kit you've built from has quite a number of alterations from the original so the plan may show the cg in a different place from Vic Smeed's version.
-
1
-
1
-
-
It could be the Taranis Neck Strap & Bracket listed here.
-
Chris Gold designed & built quite a number of scale, mainly multi engined & edf, models using foam & brown paper. They weren't small models.
A club mate, sadly no longer with us, also specialised in the method of construction on both small & average size scale models. His models included a Sunderland, Junkers 52 among many others. The Junkers had a central Laser engine with 2 freewheeling outers, span was around 6 ft. The corrugations of the full size were replicated using recycled corrugated cardboard boxes courtesy of the staff at a local Morrisons.
-
1
-
-
I don't know when the 1 engine out training stopped, it could be that sims were well established by then. Also if you consider the rarity of deadstick occurrences with single engine RAF jets I believe the statistics endorse the decision.
-
After a spate of crashes the RAF curtailed asymmetric training practice with Canberras because there were more accidents in these practices than there were genuine 1 engine out occurrences.
-
1
-
-
David, if you are only going to change 1 or 2 batteries over to XT60s then you might as well buy both male & female then use the "gender" that's not already fitted to the ESC. You really need a spare unconnected mating connector anyway as it's best to plug the one you are going to use to it into in order to minimise the risk of it's pins moving if the plastic body softens due to the heat. I usually clamp the spare connector by it's plastic body in a workmate in this situation.
-
40 minutes ago, Simon Chaddock said:
It is quite possible that the motors are indeed the same and actually run at the same voltage. The input voltage being reduced to 6V max electronically inside the servo.
If that was the case wouldn't there only be one set of torque & speed figures for the HV version ?
Who has First Hand experienced a LiPo fire ?
in Gadgets and Electronics
Posted
When I got my first 4 or 5 lipos I stored them in a redundant oblong Pyrex casserole dish. This was placed in centre of the concrete floor of the garage with a couple of plastic bags of sand covering it. Idea being that if there was a fire the heat would melt the plastic dumping the sand over the dish, hopefully containing any flames & heat - it was never tested in earnest.