P68C Advice

[Mike S]

As long as you have ventilation holes in the nacelle you shouldn't have a problem with overheating, you shouldn't be over taxing the esc with what you are running off it. One difficulty I found with the DC3 was threading the wire from the esc to the receiver threw the wing. You will probably find that the wing was built around the power lead, and any other wire you have in it. I know that this is not a particularly good solution but if you are having difficulty threading the esc lead consider running it on the underside of the wing. This would be preferable to smashing wing ribs when attempting to pull the wire threw.
Phil

I did think about the how the rec wires would get threaded, but will go down the road you suggested and run them along the wing.  I will also cut vent holes in the nacelle to and see how it goes.

[Mike S]

Just a quick Q.

Whats the best way to connect the esc and motor wires together. Should I solder them if so whats the best method:

Twist wires together and run the solder over the wires?

Wires side by side and solder?

Solder wires end to end?

Or?...



Thanks

[phild]

Use gold bullet connectors, is the best way, select a size that suits the equipment. I say that because you will probably need to change them over to get the motor running in the correct direction.
Talking of directions do you intrend to have the motors running in opposite directions, (counter rotating) if so don't forget to get 1 pusher prop and 1 normal prop.
Phil

[Mike S]

Use gold bullet connectors, is the best way, select a size that suits the equipment. I say that because you will probably need to change them over to get the motor running in the correct direction.
Talking of directions do you intrend to have the motors running in opposite directions, (counter rotating) if so don't forget to get 1 pusher prop and 1 normal prop.
Phil

Ok gold connectors it is then, 3.0 or 3.5 would be a good size I think to handle the amps for the esc to motor. For one motor to run in the opposite direction I assume you connect the motor wires red to black and black to red when connecting the esc to motor.

[Russ]

Ok gold connectors it is then, 3.0 or 3.5 would be a good size I think to handle the amps for the esc to motor. For one motor to run in the opposite direction I assume you connect the motor wires red to black and black to red when connecting the esc to motor.

Just swap over any two of three motor connecting wires to reverse direction. Some ESCs also allow you to reverse the motor in their programming. 

[Mike S]

OK this is probably the slowest model conversion known to man but I have got round to installing the the motor mount and adding support to the firewall.



I have also installed the motors and soldered on the 3.5mm gold connectors to the esc & motor but still need to add the heat shrink.



I need to order the props and a rx and sort out the nacelles.

One question with the lipo I know its a 3s needed for theses escs but should use one lipo or two?

[phild]

If possible use only one lipo, which will keep both motors running the same. If you use two batteries you stand a chance of one of them becoming flat before the other, effectively leaving you with one motor, which could be a little embarrassing. It all depends on the amount of room you have in the fuselage, as I should think you will need at least 3300ma battery for both motors.

If you use one battery you will bring up the old argument of should you extend the battery wires to the centre or should you extend the motor wires and bring the esc's to the centre. I have used both methods with success, but I am sure others will say that you shouldn't extend the battery wires.

[Mike S]

Cheers Phil, food for thought.

At the moment with the current setup I would have to lean towards having the lipo in the fuse as the batt wires are already set in the wing? par the photos.

So the idea is to set each esc in each engine bay and run the rx lead on the outside of each wing.

I would like at some point to add flaps so when this happerns I can put all wires in the wing.

So as long as the lipo is a 3s what would the max mah I could use? I would imagine the higher the mah the heavier the batt but say could I use a 3s 5000mah batt?

[phild]

If you have room for a 5000ma battery you should have enough power to fly the aircraft with the extra weight , but you will increase the wing loading from the original design, and therefore have to fly faster to give the lift required to keep it in the air. If you only have 5000ma batteries try one, but I would probably be looking at using a 3300ma battery if I had one.

Phil

[Mike S]

Cheers Phil..

I don't have a 5000MA lip so i will get a couple of something like the overlander 40c 3200 3s lip.

The lipo wires coming out of the wing have their connectors soldered on and heatshrink added. The motors and escs have been heatshrinked and fitted in to their postions in the wing nacelles.

I run up each motor yesterday with its esc to test them and all looks ok.

To add cooling of the escs I have modded each bottom engine bay shroud by adding four air scoops to each and one larger exit in each shroud to run cold air over the enclosed esc's.

Next stage is to remove all the control surface's as the hinge tape has dried out and is peeling off so it needs replacing.

I need to source some good props at 7x5 size one normal and one a pusher.

[Gareth]

Mike,

I would have expected APC to do the props as they are a standard size.

If you have a couple of 3s 2100's that you use on your 450 heli you could wire these up in parallel to give you 3s2p 11.1v and 4200mah. these should ideally be the same make and about the same age.

If you are only going to be pulling 40 amps i would have thought you could get away with a single 2100 as the 450 pulls 35 amps. This would reduce your flight time a bit but would make the model lighter and give you packs you can use in other models.

Gareth

[phild]

Allways use the batteries you have if they will do the job, Why go for a 40C battery when you only need tops 40a a 20c 2000ma battery would give you that. Try Hobbycity for batteries they are very much cheaper even with the postage
If you cant get APCe props from Slough, Micron Radio control usually have a good selection of both pushers and pullers.
Phil

[Mike S]

Sorry guys my lipo knowledge is limted, I thought the the higher the c rating the better the batt could give power for a given time.

Some good prices on that website Phil.

How about this one:?

http://www.brchobbies.co.uk/?page=shop&action=additem&item=708

[phild]

What batteries do you have at the moment?
Phil

[Mike S]

I have three 3s lipos:

2 are eflight 1800 20c & one is a align 1900 18c

One of the Eflights has almost had it now.