Here is a list of all the postings Jonathan W has made in our forums. Click on a thread name to jump to the thread.
|Thread: OS 91 surpass disassembly|
The plug normally provides access to extract the gudgeon pin, once the liner is out.
Only option for stubborn liner is lots of heat. Maybe try a hot air gun on maximum setting before resorting to the oven or a blow torch.
|Thread: 1.5mm mild steel rod|
You can get welding rod in 1 metre lengths, but you might need to find a local welding shop to only sell you a few pieces instead of a whole bundle as here ebay
Steel welding rod is typically 1.6mm diameter and easy to bend, if that is close enough for you?
Just do a google search or ebay and you will find it.
|Thread: The Big Guff.|
Great job, David!
It's amazing how these bulky vintage designs will go on the merest whiff of power. My Radio Queen climbs forever on little more than idle. Big diameter, low pitch prop is the way to go.
Control-wise, it's like steering a bus where somebody has gone around and loosened all the wheel nuts! My maiden of the Queen was swiftly aborted by a ground loop.
But once aloft, it's lovely to watch these things puttering along on a calm sunny day.
|Thread: Wittman D-12 Bonzo|
Looks like a great subject, very distinctive. Roll on retirement!
Ha ha! I was being a tad facetious, since your original link from 2011 is dead, so I had no idea what the Bonzo was. By luck, I was not that far out from Bonzo the dog . Anyway, I hope you make some progress.
Does this have anything to do with the Bonzo Dog Doh-Dah Band?
|Thread: Warbird Replicas Spitfire LF mk IXc|
What are the exhaust stack options then, Richard? I guess the Mk IX has a longer nose than the Mk V, so if we are being pedantic it should have IX exhausts!
Also, do you have any particular decal sets already prepared?
|Thread: Warbirds Replicas P51 Mustang|
Great job! I'll go for a P51B with original birdcage hood please.
|Thread: Sanwa servos|
I think the old Sanwa black plugs with the ribs and pinouts marked 1, 2, 3 were:
1 Signal / 2 Negative / 3 Positive
i.e. the neg & pos reversed compared to Futaba et al. Later Sanwa had blue plugs with "normal" connections.
|Thread: Enya 45 and 15 bits needed|
Hi Denis, not sure what you're getting at. A 15mm reamer would pass through the 6002 housing, since it's 15mm bore already. Are you suggesting boring out the 6001 housing to 15mm and if so, why?
I don't personally own a 6001 model Enya, though I have plenty of 6002's hanging around. The 6002 front housing is also the same as used on the SS40/45/50 ballrace engines.
Matt does not state whether his 45 6001 is ballrace or plain bearing, but both were made. The 6001 BB housing is still available: eBay
The 6001 is still popular as a control line stunt engine.
It's my understanding that the Enya 40 6002 has a larger diameter crankshaft (15mm) than the earlier model 6001 (1/2" or 12.7mm), so the housings are not compatible between the two models.
|Thread: Poorly OS40 repair|
That's a very neat bearing extractor, Martin. I think all the OS 4 strokes have the same size cam bearing, so I can see why you took the time to make it.
Ref the OS FS40 con rod, it is quite likely to be the same con rod as also used in the OS 2 strokes of the era, i.e. the Max 40 H and 40 FSR. That might open up more possible secondhand sources.
Since I'm stuck in quarantine, I'll have a go at explaining my method of removing a stubborn bearing in a blind housing, like the cam bearing Jon has shown. However, you do need a lathe to make some simple tooling.
Get a piece of round aluminium bar, say around 10mm (3/8 inch) diameter. Turn a spigot on one end to be a tight fit into the bore of the bearing. It needs to be a good tight fit, such that a hammer is required to (gently) drive it in. Then heat up the whole lot with a blow torch. The housing expands, loosening its grip on the outside bearing. The spigot also expands, increasing its grip on the inside of the bearing. If you hold the ally bar in a vice, you can grab the crankcase with thick leather gloves and pull it all apart. If the rust is causing an obstruction, a couple of heating/quenching cycles should dislodge it.
The time and trouble you took to turn the spigot on the ally bar is saved when you don't have to repair the hole that you drilled in the crankcase!
Personally I now avoid buying secondhand 4 strokes off ebay due to so many clueless butchers have made the engines almost impossible to repair! I only buy if I am able to inspect first. Even then you can be in for a nasty surprise after a full strip down.
Edited By Jonathan W on 08/04/2020 12:12:08
Edited By Jonathan W on 08/04/2020 12:12:39
|Thread: Corona Lock-Down Microaces Combat|
Yes, it was meant in an endearing sort of way!!
You've gone stir crazy already! Your neighbours must think you are a complete loon
Very entertaining in any case!!
Try reversing the throttle channel. For safety, remove the propeller while you are doing these checks.
|Thread: Hitec Optic 6 Sport|
I have been trying this with my old Optic 6, which I don't use much these days since switching to an Aurora 9X, so I've been re-learning it.
When I hold down the link button on the back of the Tx while switching on, the LED immediately starts flashing, no waiting involved. To link to an Optima Rx it needs to be flashing red. If it is flashing blue (for Minima Rx), press and hold the link button again for a couple of seconds and the flashing should swap from the blue to the red LED. Then you can turn on the Rx while also pressing its link button, as per the instructions.
If the Tx LED is flashing blue, it won't ever bind to the Optima Rx. If the Tx LED is not flashing at all after powering up with the button pressed, it sounds like something wrong.
My Optic linked first try when following the instructions just now, no problem.
I appreciate that maybe money is tight, but I can recommend the Hitec Flash 7 Tx as a big improvement over the Optic 6, with a much more user friendly menu system and a better quality feel. You should be able to pick one up secondhand for a reasonable price, since Hitec gear is going a little "out of fashion" these days. However, my Hitec gear has always been 100% reliable and never any interference problems.
|Thread: Vintage Futaba servo FD17M - safe voltage?|
Indeed they are the big old 17M's!!
Also note, the old M series radios had servo neutral position at 1.3ms pulse width, whereas modern gear is at 1.5, so the neutral will be shifted. You might be able to correct for this with sub-trim. The servo output shafts are square, not splined, so you won't be able to simply move the arms around. Some of the arms had square sockets, giving only quadrant alternatives. Other arms had 8 point star sockets to give 45 deg position adjustment steps.
The other alternative is to dismantle the servos and move the pots around a bit to reset the neutral.
In any case, you might run out of mechanical travel at extreme end point of 2ms pulse width. It might be necessary to limit end points in your transmitter programming.
I think you'd be pushing your luck going anything over 6 volts. These servos date back to late 70's. In fact, I'm looking at them now in the 1979 Ripmax catalogue!! When using 4 x dry cells, in those days these would quickly sag to below 6v as soon as you put a load on them. But most often it would be a 4 cell NiCad battery pack, nudging 6v fully charged but again sagging to 5.something once under load.
I would stick to 4 cell NiMh, or a UBEC set to 5.0 or 5.5v.
By the way, the FD17M was large "heavy duty" waterproof servo most commonly used in boats and RC cars of the day. They are quite a bit larger than a "standard" servo, so I'm surprised they were used in a glider.
Edit to say: by 6 volts max, I mean 6 actual volts, not a "nominal" 6 volts battery which might be 6.6 or whatever. If you blow these, no spares are available. They'll be slow anyway, at any voltage, compared to anything nowadays. Ripmax catalogue quotes 0.4 sec transit time.
Edited By Jonathan W on 17/01/2020 15:21:22
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