Here is a list of all the postings Trevor Crook has made in our forums. Click on a thread name to jump to the thread.
|Thread: Anyone for a Tiffie?|
Trevor, the motor in the 6s Spitfire I mentioned is 380kV, and turns a 15x10 3-blader. I think 500kV is a bit high for 5+ cells. The motor is available as a spare from HK, as are the props. The latter come as a blade set and a very strong hub/spnner set, each costing about £6.50.
It's ages since I looked at the plan, but I thought it showed the battery in a vertical box that's on the front of the firewall, with the motor on the front of the box. That's how mine is, with a hatch underneath via the cowl. This gets the battery as far forward as possible. I'll try to post some pics in the next day or so, meanwhile if you look at the shot below, and imagine the lipo in front of the line that seperates the cowl.
You certainly have to watch the weight at the rear. My 90% version flies on a 4s 3000 mounted vertically behind the motor, and a 4-cell NiMh to power the retracts also sits under the cowl. Nonetheless it still needed lead to get the cg forward enough.
Now mine is fitted with a lower kV motor (about 500kV) and turns a prop from a Dynam Hurricane. The old 2-blade setup pulled 600W, this one is just over 700 so it flies with more authority. Obviously the proper sized one will need a 6s setup. I reckon the motor/prop combo from the Avios Mk V Spitfire would work well, I've got one and it's rather overpowered for scale. Haven't measured the power, but I reckon it's at least a kW.
|Thread: Galaxy models mystic - help on electric conversion|
The cockpit move was quite straightforward, but I can't remember all the details and no longer have the model, so I can't give a definitive guide. Obviously the angled top side pieces have to be remade. I used the supplied canopy, so I think I made sure that this would fit the new former at the rear of the cockpit first. If you make that former to fit the back of the canopy moulding, allowing for the thickness of the top side sheet, then make the new side sheets, you should be fine.
The Magician is a really nice-mannered aircraft, and given that bigger normally flies better, your Mystic should be superb. I've attached another picture showing the battery compartment.
Oh and I think the leccy version looks much neater without lumps of metal sticking out of the nose! I moved the Magician's cockpit forward too as I preferred the look
David, your summary is basically correct. I've never electrified a model of that size but estimates of just over 1kW seem about right. I electrified the smaller Magician and that flew nicely on a 3s setup producing about 450W.
The only 6s model I have is an Avios 1450mm Spitfire. This weighs 6lb and uses a 380kV motor to turn a scale 15x10 3-blade prop. Unfortunately I haven't measured the power, but there's lots of it, it takes off on half throttle and I only use full throttle for big loops. I'm estimating it's at least 1kW. Plenty left in the 3000 pack after an 8-minute scale flight.
I think you will be in the right ball park for the prop size you are aiming for with a motor around 500kV. The great thing with leccy power is that, armed with a wattmeter you can try a very wide range of props to get the results that you want. Just make sure the model is securely anchored/held by a helper when measuring!
|Thread: Durafly MK24 V2 Spitfire|
I've got the V1, which has the same u/c. The wire leg is one piece, with a sharp bend to make the axle. I suspect the oem legs use sub-standard wire. I have made new legs using proper 3mm piano wire, obtained from Mantua Models in Windsor.
Take out the u/c units, and remove the wheels and doors. The plastic dummy oleos can be carefully prised off with a knife.
Use the old legs as a template, you can get a sharp bend using a vice and hammer. Remember to file flats near the top of the leg, at the correct angle to the axle axis, for the grub screws. The oleos can be re-fitted with a smear of UHU Por or similar. Hold the wheels on with soldered washers.
Mine have lasted quite well. They supplied coiled units with the 109E, which are much better. I don't know if a pair of those could be fitted, with some mods.
The Mk24 u/c has been changed from exact scale to improve the ground handling, and I've found it quite forgiving. The MkI/V has also been changed, but not so much, and is a lot trickier. It is also a few ounces heavier, which doesn't help for a gentle touchdown.
|Thread: Now that Solartex has gone...|
Indeed, Pete. As I am now leccy only I can get away with using any paint, but I'd like to find a Prymol substitute as I've had good results painting film after using that.
Oratex may be expensive, but it would probably be used on larger more expensive models, so perhaps not such an issue? Probably more important is the colour range available, as many of us use it without painting.
|Thread: Electric Cars.|
Not quite true Peter - Nissan's first and second generation Leafs have always been electric only, as has the Renault Zoe, BMW i3 and Jaguar i-Pace.
I agree about the bloating - Ford Cortinas used to seem huge but on the rare occasion I see one now they look quite small. My wife has a modern Fiat 500, which is probably the most faithful of the retro cars in terms of styling, but we parked next to one of the originals and they are absolutely tiny!
The development of very fast chargers is interesting Percy, although I would worry about battery longevity if I was using one regularly. I would me more interested in reliability and ease of use of public chargers, without specific apps and cards etc. Tesla seem to have the most elegant solution - plug into their supercharger and it reads the VIN number, cross-references to the owner's registered details and debits a payment.
The e-Golf wouldn't interest me as the range is too short but a Kia e-Niro would be very tempting - plenty of room for the models and a 250 mile real-world range. Something to look out for in 2023 when I've paid for my petrol Hyundai!
|Thread: Beth's off.....|
Congrats Beth. Get that sleep in now while you can!
|Thread: Battle of Britain film.|
As was Bob Stanford Tuck, Percy. One of the reasons the film still looks good is that it was shot in 70mm.
I've nothing against CGI if it's the only practical or affordable way of doing things, but the way the aircraft moved in "Hurricane" was unrealistic. The same is true of the sequences in "Red Tails", although the rendering of the aircraft was better in that, and the story kept me watching until the end.
I also saw "Dunkirk" recently, and thought it was quite good, despite the unfeasably long Spitfire glide. No CGI used in that, and the R/C He111 was well flown. Superb dead stick landing sequence on the beach by Paul Bonhomme and an American pilot whose name I've forgotten.
I watched about half of "Hurricane" on Netflix a couple of weeks ago, before giving up. It made me appreciate how good The BoB is.
|Thread: Hurricane/ do they need rudder/aileron mix?|
I've had a couple of Hurries, the Balsacraft one years ago and the Dynam one more recently. Both exhibited significant pitch down on application of a moderate amount of rudder. They would have benefitted from a rudder/elevator mix to reduce this, but I never got around to trying it.
|Thread: C No Ohmen|
Chris, I've just remembered a minor mod I made to Peter's design. I wanted to retain the battery hatch with magnets at the back and a dowel at the front, so I angled the rear face of the hatch backwards slightly so it would drop down once the front dowel was engaged. This of course means re-profiling the rear former on the hatch and the corresponding top part of the fuselage. It works well, but was just my personal preference.
Exactly what I did Chris, except I didn't use the "sandwich" method for the ribs, just used the ply template and a scalpel for each one. Personal preference, I tell myself it's less wasteful on sheet balsa!
|Thread: Electric Cars.|
Yes, that's where a major impact on grid generation could be made. If all suitable new builds were forced to fit solar pv panels and storage batteries, a lot of extra power would be produced locally. Instead, it's been mandated that all new builds from 2025 will have no mains gas supply, so where is all the extra power for heating going to come from?
Peter, the other comment is right - fossil fuel advocates always omit the amount of emissions and environmental damage that extracting, refining and transporting oil products causes.
Interestingly, the world's largest battery is being constructed in Texas. It will be charged by a solar array and will be used to power their oil production facilities! Ironically, it's much cheaper than powering it with oil or gas.
|Thread: C No Ohmen|
Chris, I have one of these and the u/c is fuselage mounted with a torsion bar arrangement. It is held in place with 4 screws.
Are you sure you need to make the wing 2-piece? It's not a very large model.
I am a very average builder but had no trouble building mine from scratch, no pre-cut parts used. It's a great flier.
Yes, I always found Clearcote and Solarlac to be completely fuelproof, although the latter wasn't at its best if brushed on - it dried quickly so brushstrokes didn't smooth themselves out.
Fortunately all of my builds are for e.p. now, but I would like to find a replacement for Prymol.
|Thread: Electric Cars.|
Martin, I've watched a few videos of electrified classic cars, and they all have transmission whine, which you wouldn't normally notice with i.c. propulsion. Purpose designed evs don't have a conventional gearbox, although they probably have a couple of reduction gears between motor and axle. They are very quiet, road and tyre noise becoming dominant.
An exception is the Formula E racing car, which presumably has gearing designed purely for maximum effeciency - square cut teeth? They sound horrible, like supercharged milk floats!
Seen the ads for the wonderful new Toyota self-charging hybrids? Several people have asked me how this fantastic new technology works, as it suggests they have invented a perpetual motion machine.
Of course, it's the same technology they've been using in the Prius for more than a decade, and uses regenerative braking and the petrol engine to replenish the battery, which by itself can only drive the car slowly for a mile or two.
Although they give commendable fuel economy, these are effectively i.c. cars, and Toyota have done their image no good with this confusing marketing ploy - perhaps a sign of desperation that they have no pure ev offerings yet.
I played safe for now and bought a petrol Hyundai a couple of months ago. I plan to keep it for 4 years, will seriously look at an ev then. The technology of the cars is pretty well there now in terms of range, and battery prices still seem to be falling. I could, and would, mostly home charge. Regarding using a public charger on a long run, having to take a break while it charged after 150 miles or so wouldn't bother me, but fiddling about with the right phone app etc. would. Hopefully in the next couple of years they'll sort out just needing your credit/debit card to pay, just like with fuel.
I've watched a few of the vlogs from the young lady with the Zoe mentioned above, and despite some negative experiences, she seems pleased with her choice. I like the way she can set up her car to charge overnight for 5p/kWh - that's cheap fuel!
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