HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

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chris williams
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HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by chris williams » 22 Aug 2018, 09:58

This seems an opportune moment to describe my method of E-Assist for scale gliders. I would emphasise the word 'my' as there are many and various solutions out there: this one works well for my form of glider construction. The method has evolved through four previous models to my current project, and the mission statement is simple enough. To enable slope flying in light conditions when there is a danger of the model landing out, and to hide the evidence when sustained flight is not necessary. Luckily, this ties in nicely with the current WSRFC rules for electric flight, and many enjoyable flights have been made in situations when coffee consumption would have been the only choice.

Rather than fit the motor to the front of the bulkhead, it is fitted behind to avoid having to ruin a nose profile that is seldom circular. This involves reversing the motor and fitting an extended shaft out of the rear. Needless to say, I would be useless in this situation, and I usually outsource the job to my pal Smallpiece, so it's over to him to explain what needs to done...
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Barry_Cole
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by Barry_Cole » 22 Aug 2018, 10:20

Yes, he did warn me, but I am not quite ready yet, so watch this space.....

:roll: :roll: :roll: :roll:

BC

OK, hope this helps, it makes sense to me. If not just ask.
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chris williams
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by chris williams » 23 Aug 2018, 17:09

Looks like the lines of communication to Arlesford-Stan have been re-established :D

So, first job, make sure F1 is securely tied to the rest of the fuselage, whilst at the same time providing a base upon which to mount the motor.
Polyster resin is simply poured into the front of the fuselage, and the fuselage stood upright as it cures. (You can angle it slightly to accommodate some downthrust, but I tend to let my Taranis take care of that)

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chris williams
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by chris williams » 23 Aug 2018, 19:55

Here's a schematic showing the set up in the Super Javelot... (In the event, as E-Assist models tend to be nose heavy, the Lipos had to migrate more to the rear!)
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chris williams
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by chris williams » 24 Aug 2018, 09:11

First, the solid nose is made up around 3mm liteply templates. Where normally lead would be screwed to the bulkhead, block balsa is placed instead to cut down the amount (and weight) of filler used...

The filler is applied in instalments and roughly shaped with 40 grit in between applications
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mick a
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by mick a » 25 Aug 2018, 11:05

chris do you use normal car filer - i haveisopo is that ok ?
i’m fitting motor , and want to say thanks to you and barry for your advice
all clear now
do you always put down and side thrust in if so how much ? have been told about 3degrees which seems about right , but not sure if need down thrust ?
mick

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Barry_Cole
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by Barry_Cole » 25 Aug 2018, 11:29

Mick,
As far as I know, no down or side thrust. Not intentionally anyway. They all climb like the proverbial angel, but some down elevator and/or throttle control will hold it. After all, all we want it to do is climb.

Don't over complicate it.

BC

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chris williams
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by chris williams » 25 Aug 2018, 11:43

That's right, I don't worry about either side or downthrust...Any variations can be controlled by your thumbs or by the transmitter

Any decent car body filler will do the job

mick a
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by mick a » 25 Aug 2018, 12:53

that’s good news
lot easier to set up 👍👍

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chris williams
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Re: HOW TO E-ASSIST WITHOUT GETTING CAUGHT:THE WHOLE ROTTEN SAGA

Post by chris williams » 25 Aug 2018, 15:21

Once the nose is more or less complete, it's time to drill the central hole for the shaft. It's best to start with a pilot hole so that any navigational errors can be rectified as you open the hole out. The engine mounting plate is held in place with screws, as the thrust forces push the motor into the bulkhead, and the the rotational forces are easily contained. With the motor screwed in place, the bearing, if one is being used, should be able to slide into place without exerting any bending forces on the shaft. The hole can be enlarged quite easily with a small drum sander in necessary. Once epoxied into place, the front end can be tidied up with a drop more filler. Most of the prop gubbins is now neatly concealed inside the nose...
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