RCTimer Argonaut 370mm Hex

[pheasant_plucker]

I';ve been fancying a small multi for a while to use as an FPV platform and this caught my eye on Tuesday night. After filling the basket with a full set of parts to complete it I clicked on "Checkout" by accident 

As is my experience with RCTimer they sent high value orders by DHL and the whole lot arrived today (Saturday) 3 days from china seems to be the norm by DHL and yet again it only cost £3.80 for the DHL waybill.

Total order cost £240 for

• frame with integrated PDB, 5v BEC';s and 20a ESC';s loaded with BHheli
• 6 off 1806-1450KV Multi-Rotor Motor
• Mini ArduFlyer V1.0 Flight Controller
• NEO-6M GPS module & MAG v1.2
• (4pairs) Rctimer 6x3" Carbon Fiber Propellers
• Elgae 5.8Ghz 200mw FPV Wireless AV Tx & Rx Set
• Elgae 5.8GHz Cloud Spirit Circular Polarized Antenna Set RP-SMA
• Radio for telemetry Air Module 433Mhz
• 4m each of 18,20,22awg silicone cable
• Arduflyer/APM Power Module

Photos and a build log to follow shortly

Gerry

[DebianDave]

BUILLLD EEEET!

[richardg6paj]

Looks gorgeous that does!
But why have they spoilt the arms by putting slots across them, they are really weak like that.

Richard

[pheasant_plucker]

Yes they are weak spots but these are a really strong 5mm carbon/glass/carbon sandwich and if those weak points weren';t there in the event of a hard arrival there would be a good chance you would break the main plates. Personally I would rather just replace an arm if required.
It';s good engineering!

I';ll try and get time to unpack this later today and post some pictures.
I';m intending to make this a Christmas holiday build so it will probably be a couple of weeks before i start it.

Gerry

[pheasant_plucker]

As promised I have unboxed this and taken a few pictures. I';m really impressed with the quality of the frame which is really beefy, especially the arms!
I have posted an image of one of the arms held next to a standard Deans plug to give an idea of the thickness

Basic frame components


The whole package


Really dinky little motors






Nice and neat with the built in ESC';c which are only 25mm square
There are 11 off 5v outputs available on the centre header block


The arms are really strong and neat

[robshaw]

That looks awesome. I want one. Will be keenly following this thread.

[robshaw]

What lipos are you planning to use with this?

[pheasant_plucker]

I have several Turnigy 2200 20c packs so I will be trying those first. If they don';t provide sufficient flight time or power is marginal I';ll look at replacing them and will probably try a 3s or 4s 3500.
i suspect the 2200';s will be fine though. I like to get ten minutes per pack even if there is 30% left I never fly over that, preferring to change the pack rather than run them down.

Gerry

[guest325]

I don';t think your 2200 20c will be up to it, 44A total potential;  6 x 20A esc';s potentially 120A a massive deficit.  Even if you only use 1/2 power to hover that';s still 60A!

[pheasant_plucker]

I can';t see this even touching those figures. I would expect to see a possible 50amp burst when wringing it';s neck but the packs are rated at 35c burst so even that shouldn';t be an issue. I will of course run this up on my watt meter to make sure everything is in order before flying it.

Gerry

[pheasant_plucker]

I was up with the larks this morning and with a fortnight off work I thought it would be a good time to start assembly. So a five o';clock session in the shed has resulted in this...


First the spacers are screwed on to the main plate from underneath



Then the bottom plate and arms are fitted



Nutserts are pre-fitted in the bottom plate but a couple were a little slack so a drop of thin Cyano was used to hold them in place.



Motors fitted and landing legs snapped into place.
The motors are retained using M2 cap head set screws. The slots in the arms are a little too generous for my liking so I have used a washer on each one.
The landing legs simply snap in place and there are small reliefs in the legs for location. they are incredibly strong and rigid with no signs of movement.



All the Motors fitted



Wires platted and soldered to the pads on the ESC';s

[kilby]

I';m fancying the look of that hex

[pheasant_plucker]

I had planned to use my Mobius for this but there is that much gear to fit i think I';ll have to buy a board camera to fit on the front camera mounting plate instead.
The top deck will need to house the receiver, GPS, VTX, OSD, telemetry. After that there isn';t a lot of room left.

Gerry

[kilby]

You have feet on the machine, so if they show themselves as holding up to high speed landings you could put the movius on the underside of the machine

[criticalmass]

Really digging this build. Been looking at those frames for a while pondering between this and a HK Thorax to stick my abundance of 2204-2300kV baby beasts on...

Any experience of the BlHeli Fw in the esc';s?

[pheasant_plucker]

You have feet on the machine, so if they show themselves as holding up to high speed landings you could put the movius on the underside of the machine

Once the battery is slung underneath i don';t think there will be sufficient room for the Mobius. I think I';ll keep the Mobius for my Spyder and pick up a board camera for FPV.

Gerry

[pheasant_plucker]

Really digging this build. Been looking at those frames for a while pondering between this and a HK Thorax to stick my abundance of 2204-2300kV baby beasts on...

Any experience of the BlHeli Fw in the esc';s?

No, I';ve always used SimonK but from everything I';ve read BHheli is just as good if not better. The proof of the pudding will be in the eating.

Gerry

[criticalmass]

No, I';ve always used SimonK but from everything I';ve read BHheli is just as good if not better. The proof of the pudding will be in the eating.

Gerry

Pray for good weather mate.... Can';t wait to see the footage of this in the air!

[pheasant_plucker]

Another 5am start and more progress with the build.

The Mini APM holes are at 35mm spacing. The holes in the frame are 30 - 40mm. Why they couldn';t have made them diagonal slots buggers me.
I decided to use double sided adhesive pad to mount it in place. i would have preferred mechanical fixing using nylon standoffs but the pads are more than strong enough for the job.
the APM motor loom is shortened to stop it looking like Spiderman took a poo on it.



The Power module.
I haven';t decided how or where to mount this yet but I am considering strapping it under of the rear arms.
I believe these are essential to APM operation so I don';t just want to run the APM off one of the available 5 off 5v BEC';s
The power connections to the Mini APM are reversed to a normal APM so a special cable is provided with the mini APM.



The receiver is mounted inverted under the top plate with the antennae protruding through two convenient slots.
Note the shortened looms for the receiver and the one at the bottom for the Compass/GPS module



Compass/GPS mounted using nylon standoffs. The holes for this had to be drilled because the ones in the top plate are 40mm spacing.
This shot also shows where I intend to mount the VTX.


I still have the OSD and Telemetry modules to mount but I am 99% certain I will mount them under the top plate one on each side in between the front arms. this will allow the telemetry aerial to protrude from the radius just behind the GPS and keep all of the wiring short and neat.
This should allow me to connect everything up under the top plate and allow me to assemble it in a modular fashion.

Gerry

[pheasant_plucker]

Oh and why is it that every time I build a multi that every single motor spins the wrong bleedin way 
I had to reverse two wires on every single ESC!

Gerry

[philtrum]

Oh and why is it that every time I build a multi that every single motor spins the wrong bleedin way 
I had to reverse two wires on every single ESC!

Gerry

lol ive only ever got them all right once, mainly theres at least 2 on a quad or 3 on a hex that are wrong

I was reflashing esc firmware yesterday and found an option in the simonk firmware to change the default direction, so its not always a resolder job, depending what esc you have
I think there is something similar in blheli too

Cheers
Phil

[pheasant_plucker]

My Y6 was the same, every single motor reversed.
Doing in the firmware sounds good but i believe the programming pads are underneath these ESC';s and that access to them would mean unsoldering them.
Usually it';s not an issue as i use bullets on the motor wires. thinking on I should have soldered some 2mm female bullets to the ESC pads but I didn';t have any.

Gerry

[pheasant_plucker]

More work done yesterday.


I decided on a way to mount the power module which necessitated dis-assembly of the chassis so i took the opportunity to drill holes to mount the Mini APM on nylon standoffs.



I removed the factory fitted Deans plug and lead the wires through the bottom plate. These were then soldered directly to the power module after removing it';s factory fitted power lead.
The module was then secured on the underside of the bottom plate using a double sided adhesive pad and a cable tie. This is located parallel to the battery with the connections to the front of the Hex.



The connections to the APM were then shortened to remove excess wire and retained with a cable tie for security.

[robshaw]

Looking good mate. Might be an idea mounting apm on foam or some sort vibration isolation.....

[pheasant_plucker]

Once over I used to but I have three others, all mounted on standoffs like this and I have found that as long as I balance the props correctly I don';t have any vibration issues. I think the firmware is getting better at reducing the issues caused by vibration nowadays.

Gerry

[pheasant_plucker]

I don';t think your 2200 20c will be up to it, 44A total potential;  6 x 20A esc';s potentially 120A a massive deficit.  Even if you only use 1/2 power to hover that';s still 60A!

It';s had it';s first test hovers now which has also enabled me to take a few readings and ponder on where to go next with this.

Battery current draw on 3s = 17.5amps so my 3s - 2.2 - 20c are more than adequate

I think i may have made a cockup on the motors!
i ordered 1450kv and it hovers at over half throttle and power feels marginal so I have a choice to make now.
Do I?

• Change the Motors for a higher Kv such as 2300
• Stick with the current set and use the excuse to buy a few new 4s batteries
• Experiment with higher pitch propellers

Or a combination of above.

I also ordered an aluminium case for the MinimOSD off Ebay. They look great but don';t bother trying one as they weigh nearly three times more than the MinimOSD itself putting it';s weight up from 9g to 34g.

Gerry

[guest325]

I don';t think that hover throttle is the best guide, the only real way to prove your setup is good is WOT - you may never go there but it';s always a possibility. I always check mine that way, early on I overstressed some 25C lipos on my F450 that had 4x30A esc';s on driving rctimer 2212 1000kv motors on 9*4.5 props, after a bit of WOT hooning around they came back quite hot and didn';t last very long after - changed to 35C, no problems.

[pheasant_plucker]

The hover throttle is high but there is very little left for climbing and a rapid descent takes a lot of time and throttle to catch it.
I';m thinking of using Zippy Compact 3300 4s I';ve heard only good things about them. they weigh in at almost twice the weight of my 3s 2200 but as an experiment I strapped a 5000 4s to the bottom of the Hex and it was more responsive than the 3s 2200 even though the battery weighs half a kilo. The Zippy is nearly half the weight so it should rocket on it.

Gerry

[teslahed]

If it was me I';d go for 4 cells and then higher pitched props if necessary. It';ll be less work and cost than going with new motors. If it works well enough then you may find you get pretty good flight times out of the lower KV motors and higher cell LiPos than some get with 3 cells and 2300kv motors.

[HexFlyer]

So any updates on this, how has it been flying?  I';ve just received the v.3 version and just started building it, any tips or things you would do different?