Here is a list of all the postings John E ( Puffin Models ) has made in our forums. Click on a thread name to jump to the thread.
|Thread: Who is still flying 'Classic' electric airframes?|
I guess my Gordon Whitehead Interceptor (scaled up 4 x Frog Interceptor) counts as a classic electric model. Gordon originally used a 500 can with Olympus drive, and 6 x SubC NiCd. Mine started life with 7 x SubC and a 21 turn buggy motor, became the first AXi demo model, and now sits with a MP Jet outrunner and 3S 3250 that fit within the space of the original battery packs.
My DB Sport and Scale Moth 40 is now well over 25 years old, and originally was rudder elevator (don't do it with this model) with a Saito 40. It now has ailerons with Mega 22/30/4E (In the original engine mount), and runs on 4S 3250.
The fact is that many original electric designs, properly powered, become excellent models.
|Thread: Sig Four Star 120 for sale|
There is interest in this - from me!
After looking at all the power options that might reasonably fit, and my own requirement of using 40:1 petrol mix, I fitted the MVVS 26 (Evolution 1.60) that was sitting in my Graupner Starlet (which now gets a MVVS 30). The 26 is WAY too much power for the Four Star, so the throttle will be limited to make the power level more realistic. For balance, the ignition is in the battery bay, and the 4xSubC NiMh receiver pack has gone in the tank bay - the 500ml tank sits neatly in the front of the radio bay!
Only the final radio fit is to be done and this becomes a valued sports model to join my Four Star 20 electric - also MVVS powered!
|Thread: Puffin Models|
Hi Guys. Thank you for the very kind comments.
On my return home after 4 years of working in London as a Motor Vehicle lecturer (and doing tech support in all of my spare time), Sandra and I looked at the future of the business. We thought that coming out of recession, the business may be better in the hands of someone with fresh ideas, and who may be able to take it to the next level, so we offered the business for nothing more than the then stock value. To cut a very long story short, Bernie Jones of E-soaring Gadgets has taken on our role as UK dealer for Jeti products (with particular emphasis on Jeti Duplex), and he has bought ALL of our Jeti stock with the exception of brushed controllers - which we need as a part of the current business!
Jeti, being moved on into Bernie's very capable, and enthusiastic, hands leaves us looking a lot more like our core business, so we will be continuing with all other ranges and existing suppliers, working in the area that really excites me, that is electric and petrol power systems for model aeroplanes (please see line 1, para 1!) and I have many new models being built and assembled right now - my garage is so packed I am having to work outside! Sandra is also keen to develop what we started a couple of years ago, and that is as South Gloucestershire's ONLY local model shop for model aeroplanes and model boats, and as the buyer for many products, I know we have many items that others simply don't have - and I know how to use them!
Jeti Model, MVVS, and Wemotec all have excellent direct customer support, and we can continue to supply the very smallest item to support MVVS and Wemotec customers. I was just thinking what the current range consists of: RCM-Pelikan (Foxy and Ray motors, controllers, batteries and chargers), Wemotec fans, Aeronaut, APC props, XOAR props, Bambula props, Graupner, MVVS (electric glow and petrol). We have a huge range of specialist and local model shop bits, and I am also looking at what other quality engine ranges we should have.
So, that is the very latest news from John and Sandra at Puffin.
|Thread: Jeti...TX modules, prices, etc.....|
There was a comment that I thought the Jeti DS and DC was comparable to £1500 to £2000 sets from other manufacturers - perhaps I could set the record straight by saying that I believe the Jeti sets are SUPERIOR to all others, including those over £2000. Others copy the features developed by Jeti, but they don't copy the full metal stick units with (as said) hall effect sensors, dual transmitter modules (that can allow full duplication right down to the servo through the Enlink 2 switch units), and other features that customers don't see the need for at the time of introduction. Another point is that all the high end features in the largest receiver are included in the smallest receiver. Price? Hmmmm. The SRP for a DS or DC 16 is around £1300, so UK customers are getting a real discount - I think the DS and DC 16s should have been pitched around £1500, a very fair price for the product, and also to allow for advertising and distribution, but they weren't....... On top of that, my first propo radio was OS Cougar 4 in 1974, and that was a £120 pound set - over £1000 in todays money!
|Thread: flighpack battery death|
John, I thought "consumer cells" was a term in common use. Perhaps only in the US? Perhaps only in my head!
Consumer cell: Cells or battery packs intended for use in "consumer electronics" ie at very low currents, and far less than we use with servos under load. As I said, using cells intended for high current applications, there are all the advantages I mentioned - with none of the disadvanges. Unfortunately, the thickness of plate and insulator needed for high current capability (with the resulting low resistance and reliability) means it is not possible to get a high current capability at 2300mAh into an AA case - or at least I have yet to see one, and I am happy to be proved wrong.....
I do have a battery tester (that checks internal resistance and gives the results in percentage efficiency terms), and I am happy to give the results of any cell or battery pack that anyone would like me to test.
I always replace mine as the capacity goes down - normally after a couple of years use.
What I am wary of is "consumer cells" being used for receiver batteries - in fact I would NEVER use consumer cells in any model of mine, and always advise others to avoid consumer cells like the plague for receiver battery use.
People seem surprised when I say that I ONLY use low resistance electric flight cells for receiver batteries, so if I am using an 650mAh receiver battery, it is capable of a 15A discharge, or even more. What does this mean in reality? It means that the battery is more than capable of carrying the heaviest of servo loads in "normal" models, I suffer absolutely minimal voltage drop, so my servos, even on 4,8V, still operate quickly, and I am unlikely to reach the the 3,2V lower limit of my receivers, even if a cell should go open circuit (normal failure for NiMh cells used at high currents), and because the cells are more than capable of handling the current that I intend to use, the cells are far less likely to fail.
Of course, this is only my own opinion....
Edited By John E ( Puffin Models ) on 20/07/2014 21:41:05
|Thread: Sig Four Star 120 for sale|
I am just finishing a Sig Four Star 120 kit build.
At various stages during the bulid it was going to be electric powered, powered by an MVVS 26cc petrol, and MVVS .90 glow. I have built a torsion box into the wing using 1/16th rear spar webs, and cross bracing between each rib, and this has made the wing extremely stiff for minimal extra weight. The model has engine mounts for both MVVS 26 petrol, and .90 to 1.20 engines. The covering is Graupner "Superfoli" in Cub Yellow, and there is a Graupner tailwheel assembly. I have also tapped the wing fixings at M6 rather than using the American wing fixing bolts. This model was built for my own use, has good glue joints throughout, and it is well fuel proofed before covering. Consider it a quality ARTF!
I am looking to make space for new projects in my workshop, so this is the logical one to go. Any interest?
|Thread: E to IC|
Initial thoughts were "why?", but then I thought why not, and I feel qualified to contribute - others may disagree!
Of course the issues are the reverse ie:
Closing up any cooling holes to the inside of the fuselage,
Battery mounting plates may need to be pulled out, but that will leave masses of space for a good size fuel tank
Resisting vibration by glueing battery access hatches, and adding ply plates or doublers down the front inside of the fuselage (if it's initially a TRUE electric design!).
Of course, fuel proofing.
In general terms:
400 can motor - .049
600 can motor - .10 or 1,5cc
500 or 600 size brushless running around 400W on 3S - .25
4S running around 500W - .40
5S running around 700W - .45
6S running around 1000W - .60
8S - .90
10S - 1.20 to 1.60 20cc to 26cc
12S - 40cc
Hope that is of some help,
|Thread: Seagull Sparrowhawk 62cc wanted|
A quick call to The Model Shop, Leeds (88 Crossgates, Leeds, from memory) has their last Sparrowhawk 62cc leaving today. Thank you for the reminder Paul .
|Thread: Balsa USA 1/3 Scale Kit For Sale|
I hope that David will be happy with me posting this given the nature of the ad.
I bought a Balsa USA 1/3rd scale Cub kit with the intention of flying it at shows to publisize the RAF Benevolent Fund, which I now believe is called "RAF Charities", and yes, I did my bit, paying in for 23 years! Changes in my life mean that this is no longer realistic, and I also need to be sensible about the projects that I take on.
The kit was literally complete and as new (but it appears one of the Dubro wheel covers may be missing - we can get more wheels quite quickly), but with an outer wrap in a very sorry state, and the outer wrap just gave way under the weight as I lifted the kit out of the workshop for photography. The result was that the kit contents all fell out sideways - now I find I can't simply insert an image.... We were going to ask £400 for this £780 kit, but we are open to sensible offers - and clearly you would need to come and see the kit in Yate (near Bristol) before deciding to buy. If you do buy it, please do make sure that you ask for the box with the canopy in it.
We also have a slightly used, and factory checked, MVVS 58 designed to turn the scale 24x10 prop. That engine owes us £250, and that was what I was going to use in this model.
If these don't go, I may be tempted to finish it as Hazel Sig's clipped Cub - and yes, I do see the irony in that!
|Thread: Seagull Sparrowhawk 62cc wanted|
Thank you Paul. I did try Inwoods, TJD etc, and I also found that a search shows it historically on our own site.
I will try Slough (Ripmax?), and of course my old friends at Leeds who have massive stocks of kits upstairs.
Oops, sorry, I have put it in the wrong area.
Perhaps the moderator could remove this thread - thanks
I am really sorry if I have put this in the wrong area.
I am looking for a Seagull Sparrowhawk 62cc kit. This is discontinued, and the dealers I have approached tell me they would get it from Perkins - no, they won't!
Does anyone know where I might find one of these? I am willing to travel, but not desperate to have one!
|Thread: Greasing the taper on a prop adapter|
Also bear in mind that I have done a LOT of motor and prop testing, and having a very light smear of grease on the taper is the only thing that has made this possible!
From the very earliest days of having prop adapters seized, I have used the slightest smear of vaseline or grease on the taper only of prop adapters, and advised customers to do the same. The lubrication on the taper adds to safety by allowing the collet to move into the taper of the prop driver, and tighten down onto the shaft. The lubrication also helps prevent "pick up" of similar aluminium alloys in the taper, and the lubrication also allows the taper of the collet to slide out of the prop driver easier. Also consider the steel collets into aluminum spinner back plates that Graupner use, the lubricant helps to prevent galvanic corrosion (dissimilar metal corrosion). Of course, the use of a puller will also help to remove the prop adapter, but do try to avoid the tap that is normal with a puller as there is a danger of degrading the rear motor bearing.
Beware of MP Jet prop adpters in APC electric props, they look as though they are designed for each other, but the prop hub requires boring slightly deeper to allow the shoulder of the prop adapter to clear the prop hub and tighten fully into the taper of the driver.
Oh, and of course lubricant moves out under centrifugal force, not inwards!
Hope that helps,
|Thread: How Vintage is Vintage?|
For my first 6 years I flew only R/E, and all of the old arguments and misconceptions simply don't hold up. The most common misconception is that without roll control, the model can't turn right, which of course is correct with a flat wing, but introduce dihedral and the yaw of the wing presents the outer panel at a higher AOA - roll control! The biggest problem I had teaching people to fly was that they thought that they were doing something wrong when the model started to veer off course, but of course with the increased dihedral of the R/E model the model simply doesn't veer off, and the student can then concentrate on positioning and speed of the model without it going off track all of it's own accord. And don't get me started on the change of steering control from right stick to left stick at the very time that the model has just left the ground! Yes, I have taught people with both R/E, and with aileron models.
Going further, I was looking at the Graupner Carvelle the other day at near 70" wingspan for a .40, and then thinking of the mass of .40 size aerobatic ARTFs (typically far less than 60") that are simply intended to maximise profits as they make their journey to cross the counter. Many people who do not get on with the trendy hot aerobatic models would have such a great time with older aerobatic designs such as the Astro Hog etc designed to be stable for use with reeds, and originally flown with .35s at approaching 70" wingspan. Put a modern .40 in any of these early designs, and I am sure we would keep far more immediately post A cert model flyers.
I was convinced that the Kadets were in the mode mags when I first started RC (about 1 months pay in 1974)
I have a Super 60! But it was made super tough by a friend before he died. I guess I should clean it up, sort everything out, and get it going again. I started to convert it to electric, and I did look at converting it to my idea of what a low wing 60 should look like, but the changes are too dramatic for a built fus to be a sensible basis for the "development", and the ailerons are "trainer size" with trainer response. Now, a light electric R/E Super 60 (with slight washout - learnt about that improvement by accident!), or a low wing 60 with full size inset ailerons would be enough to get me interested.
It's just a thought, but I have been racing Fast Electric boats for the last couple of seasons (with the trophies to prove it!), and the number of ex-potential model flyers (and ex customers) I have met are enormous. The comment is always the same, and that is that model flying is too hard to learn. I was solo on my 3rd flight with a Kamco Kadet, and the difference is that many of the "trainers" of nowadays require a great deal of instructor time, and yet, I can get anyone flying any R/E model really quite quickly (yes, they have to take off and land directly into wind). It would be great to see more people having a go with some of the older radio designs (both R/E and Full House - that are pre-70s 1/2" balsa block!) that had to be designed to be easy to fly (with bang bang radio) which make it so easy with modern gear.
|Thread: Galahad Build Blog, IanN|
Sorry about the late response.
The two engines you have would be perfect.
From memory the dihedral was taken to what looked normal, and probably about half the designed dihedral. For some reason low wing and biplane rudder/elevator models seem to need more dihedral than high wing models to roll well (no logic to that at all), so I would absolutely stick to the designed dihedral for a R/E model if I do one myself - reduce the dihedral and suffer the resulting slower roll rate.
Perhaps I need to do one!
|Thread: How Vintage is Vintage?|
I received a response from Sig - interesting.....
The Kadet Senior was designed about 1983. The only kits we have that were designed before 1965 are the SIG Astro Hog and the SIG 1/6th scale Cub.
|Thread: glow prop on electric motor|
Gyroscopic effect is frequently forgotten in these discussions.
Take a worn motor and then put an IC prop on it. Fly the model through a few aerobatic manoeuvres, and you will hear the effect on the bearings. The Electric Prop is a LOT lighter because it does not need to absorb the power pulses of an IC engine, and the lighter weight is kinder to the (far smaller and lighter) electric motor bearings. Why are electric motors produced so light? Because customers demand it!
The gyroscopic effect is the reason why some motor manufacturers recommend folding (hinged) propeller blades even with high powered aerobatic models.
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