E-Diamond

All non-scale topis should go in here for discussion.
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Cliff Evans
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Location: Bristol
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Re: E-Diamond

Post by Cliff Evans » 29 Jul 2019, 19:08

looking good Peter. Have cut the servo covers, will drop them over.

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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: E-Diamond

Post by Peter Balcombe » 31 Jul 2019, 18:17

Looking at the power train at present before I cut the nose off to fit an epoxy motor mount ;)
With overall weight coming in at around 4.5lbs, I am looking at having say 350w available from a 2200mAH 3S Lipo.
So am currently looking at an Overlander Thumper 3548/05 motor driving a 13x5 ish Aeronaut folding prop.

Stan Yeo does epoxy motor mounts for 35 size motors at 37.8mm & 41.8mm diameters & my fuselage moulding thickness is approx. 1.5mm, so am looking at using the 41.8mm ring together with a 45mm cool nose spinner & appropriate yoke/folding blades. A 60A ESC is recommended for this motor.
Cutting the nose back to 45mm diameter will remove approx. 50mm in nose length, which I would imagine is fairly close to the spinner length.

I know that a 3548 motor is probably a bit of overkill, but would rather have some scope for extra power if I need it - at least on this beta build.
A 28 size motor doesn’t appear to be powerful enough, so it may be possible to reduce the 35 series motor length.
With the simple (free) electric flight calculator readily available to me, it looks as if the above power train arrangement should do the job (I cannot input exact components), but wondered if anyone out there had any better info/thoughts?

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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: E-Diamond

Post by Peter Balcombe » 03 Aug 2019, 22:11

Well, I bit the bullet & ordered some parts from Stan Yeo at Phoenix Model Products on Thursday evening & these arrived today.
First up, was to cut 60mm off the front of the fuselage (in 2 bites - just in case) & slide the 41.8mm Glass Fibre 35 size motor mount in from the canopy opening.
I fitted a long M6 bolt into the central hole of the mount, both to help pull it forward & also to check alignment of the motor axis, before fixing in position with polyester resin, leaving a resin fillet on both sides.

The 45mm cool nose spinner fits nicely once the fuselage cut has been cleaned off parallel to the spinner backplate.
The rest of the airframe is now ready for covering, so can also complete that using transparent Oracover.
Photos to follow tomorrow when daylight improves chance of clear images.

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Peter Balcombe
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Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: E-Diamond

Post by Peter Balcombe » 04 Aug 2019, 10:13

Pics of the installed motor mount plus view with cool nose spinner in position.
Also a shot of the cockpit area with 3S Lipo & 60A ESC in position.
Can now get the model covered and make a pair of NACA duct style air outlets under the wing roots.
Also need to check the model balance to see how much lead is needed.
Attachments
Motor mount installed.jpg
Mount for 3548/05 motor
Spinner fitted.jpg
Spinner fitted
ESC installation.jpg
ESC and battery

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Peter Balcombe
Posts: 875
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: E-Diamond

Post by Peter Balcombe » 07 Aug 2019, 12:05

Model now covered & control surfaces hung so its time to do an overall weight & CoG check.
With just a couple of small items to finish off (canopy latch, Fuz. MPX connector cable to fit, Unilocs to fit, flight battery tray & wing servo links) the overall weight comes out at 1.82KG (4lbs) and the model balances 75mm back form the LE (33% of inner wing) complete with 3S Lipo, but no additional nose weight, so I am very pleased :)
Hopefully, everthing can be finished off, ready for a maiden next week, if the weather calms down ;)
Attachments
IMG_1889.jpg
Overall model

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