[BenR]

Really? Hot glue has enough strength? I was worried that something like that would come apart at the first good puff of wind. I have seen the cheapie shops showing glue guns and thought "yes I should get one of those for repairs" but by itself that is strong enough?

[Raptorfly]

Really? Hot glue has enough strength? I was worried that something like that would come apart at the first good puff of wind. I have seen the cheapie shops showing glue guns and thought "yes I should get one of those for repairs" but by itself that is strong enough?

Yep, Hot glue melts into the joint and it will not come apart.
Just becarefull not to put too much/too hot and melt the foam.
Wipe excess with finger or have something to scrape off before it cools and dries. Instant fix. the quickest and cheapest way.

[kizza42]

+1 for getting a hot glue gun, be careful of it getting too hot however, 2nd degree burns from scalding glue on your fingers gets old real quick!

[samste]

Really? Hot glue has enough strength? I was worried that something like that would come apart at the first good puff of wind. I have seen the cheapie shops showing glue guns and thought "yes I should get one of those for repairs" but by itself that is strong enough?

Trust Me Hot Glue Works,

Steve

[secant0give]

Yes it's great stuff the old hot melt glue. I've used tons of it
Wet you finger before you wipe off the excess and you wont get burned so bad

[BenR]

Well.... I have to admit I was doubtful, but you all seem confident enough about it - gluing tomorrow morning hopefully in time to fly Sunday.

[gbanger]

Thats the other great thing about Hot glue, Ben.
You can fly your plane 5 minutes after you have finished repairing it!

[BenR]

I stand corrected. After trying it, the plane is in one piece. Control horn is back on the rudder. Side panel for the battery area is re-secured. The tail may be slightly out of alignment to the rest of the plane but hopefully not much at all - I cannot see it with the naked eye. As much as it may be possible to fly it again soon, I will hope to get it back in the air Sunday.

[Flying fisho]

New plane, time to hit the Q&A thread . Finally got the HK Silent ( Extra 300s lookalike. Major difference underside missing the flat section).
Q.1 As per parts list there are 4 control horns but only 3 teardrop shape bases to glue onto control surfaces. Elevator has 3 narrow carbon fibre plates strengthening the narrow section of the one piece elevator. Thought perhaps control horn intended to be glued to carbon fibre but all horns have tab to penetrate horn bases . No slot in carbon fibre & feasablity to cut seems poor . Considered removing one tab.
Q.2 there are 2 "EPP filling pieces" but no instructions where to fit. Similar size & shape to plywood motor mount base. No instructions for how to or how much offset motor or if necessary. Suggestions please.

[samste]

I added the infills to motor mount area to bring motor forward some but you not need too on your model depending on motor and shaft length.

I rehinged all my control surfaces with plastic hinges and taped along as well.

Control horns i used are the same, glued them on with hot glue / super glue both pieces.

Used z pliers to adjust my servo rods as i glued my horns on in the wrong position. ( Build Note )

Do you have landing gear with it ?

If so use cable ties supplied with the two pieces of ply on top and underside and weave cables through and tighten landing gear rod to it.

Steve

[Flying fisho]

Thanks steve, but still not sure about elevator control horn, can you elaborate please. Landing gear in place, intend soldering extra cross wire as you did.

[samste]

Hope this helps, Elevator strenghtening with carbon strip and balsa strip underside.
   

[Too Drunk to Fly]

Spent some time on my HET Flying Wing last night.                    
I've tacked the new firewall on with epoxy, just not sure how to line it up correctly for most efficient thrust angle. Any suggestions?

It will be cemented with epoxy all round as soon as I'm confident it is at the right angle.

[kizza42]

I think as straight as possible, you don't have any CF plate or old circuit boards to do the firewall with?

[Too Drunk to Fly]

I think as straight as possible, you don't have any CF plate or old circuit boards to do the firewall with?

No, I should be fine with what I got. Old piece of plywood I had lying around. I fibreglassed it.

All I've got to line it up with is steel ruler and square. Not that easy, but if all goes well, I should finish it tonight and have a nice glider ready to fly in what remains of these August winds

[BenR]

Question about chargers......

The batteries I have have a connector that goes to the ESC for flying (XT-60, Deans, etc). There is also a white plug that is used for balancing when charging (as many wires as cells, plus an extra one). When I connect up a battery for charging, am I meant to hook up just the white plug or both the white plug and the plug for the ESC? Or even just the ESC one and use the white one for balancing only?

[paulj]

Hi Ben
Connect both plugs when charging.
What charger do you have? Is it a Hobby King one?
If so you need to adjust the total amps for your particular battery.
eg. If you have a 2200Mah 3s battery set the charger for 3 cell 2,2 Amps.
If it is say a 4000Mah 4s battery set the charger for 4 cell 4.0 Amps.

[BenR]

I do have a HobbyKing one. And when I use that I set it for charging at 1C.

The reason I asked is the BNF T28 I got today has a charger with it that only has a plug for the balance port which made me stop and wonder why and if I was doing something wrong.

[smuzz]

You can safely put the cheapie charger which came with the plane in the bin, Ben.

[Raptorfly]

I do have a HobbyKing one. And when I use that I set it for charging at 1C.

The reason I asked is the BNF T28 I got today has a charger with it that only has a plug for the balance port which made me stop and wonder why and if I was doing something wrong.

Yep the simple 2S 3S chargers use the Balancing lead to charge. While the HK charger will use the power leads to charge and the Balancing leads to keep each cell balanced. Much better.
Just keep the cheap charger Just incase the good one breaks down.. which is not uncommon.

[gbanger]

Ben
There are 2 major ways to charge your batteries...

If you select Fast charge or Charge then the only plug you need to plug in is your Deans /ET60, etc. Select the Lipo cell number and the amp input as Paul suggested and the charger will charge the battery to a set voltage for that particular battery and switch off. ( It doesn't monitor the cells it just pumps it up to a set voltage)

If you select Balance charge you need to plug in both leads. Be careful when plugging in the balance lead. The black wire on the balance lead is your negative all the others are cell posatives. The black wire plugs in to the corresponding pin at that end of the charger balance pins. If you stuff that up you will short out your battery or blow up your charger.... not good!!
If your charger came with a cell balance pin adapter then you just plug it into the right hole and you can't stuff that up.
Then you select your cell count and Input amperage as before. It will then charge the battery till all the cells are stable at 4.2 Volts each. This is the method 95% of people use as it looks after your battery by ensuring all the cells are evenly charged, and that will ensure you get maximum life out of your Lipo's.
Hope this helps.
Gazz

[BenR]

If you select Balance charge......

If I select balance charge, am I doing that at 1C as well (eg 2.2A for a 2200 mAh battery)? Or is it something that is done at very low amps to let some cells charge and others that are high stay the same/discharge?

[gbanger]

If you charge at 1C you are charging at the rated amperage of the battery
eg: 2200 mAh battery charged at 2.2 amps
If you charge at 2C then a 2200 mAh battery would be charged at 4.4 amps.
Some batteries can be charged at higher C rating and this obviously will charge a lot faster, but experience shows that batteries charged at really high C rates do not normally last as long. So I charge at a high C rate at the field when I'm in a hurry to reduce charging time, but whenever I have the option I always charge at 1C, they just last a lot longer that way.
Gazz

[secant0give]

I usually Balance charge at 1C
My batteries last a long time I haven't thrown many away yet

[Claudius]

If you stuff that up you will short out your battery or blow up your charger.... not good!!
If your charger came with a cell balance pin adapter then you just plug it into the right hole and you can't stuff that up.

Ahem, I (or at least HobbyKing) found a way. Just in case anyone else gets caught by this...

Even though you can only fully insert the plug in one way, the pins on at least one of the charging boards HK sells are slightly too proud - if you attempt to connect the balance plug in the wrong way, contact can be made with the balancer plug pins before you're prevented from inserting the plug in all the way. And, if you've already plugged in the main power plug, things get sparky.

Blew out the trace on the underside of one of my boards that way, one time I was absent-mindedly plugging-in by feel instead of looking. Easy fix, but now I always check visually before plugging the balancer in.

If I select balance charge, am I doing that at 1C as well (eg 2.2A for a 2200 mAh battery)? Or is it something that is done at very low amps to let some cells charge and others that are high stay the same/discharge?

The bulk of the balance charge would still be done at 1C (2.2A in your example).

What happens towards the end of charge varies from charger to charger, but more or less what you'd expect to see is that as the first cell hits 4.20V, the charger will begin to ramp the current down to whatever is needed to maintain that cell at 4.20V. (i.e. initially 2.1A, 2.0A, and so on, falling away to zero).

At some point, zero amps are required to keep that cell at 4.20V (i.e. that cell is fully charged), but the other cells are slightly lower (e.g. 4.17V). At this point, the charger will switch from supplying current via the main power plug, and will instead supply the final balancing current to each of the not-quite full cells at a reduced rate through the balance plug, until each is registering 4.20V at zero amps (i.e. until all cells are fully charged).

There are variations on this (for example, I believe the most common chargers only ever supply charging power through the main power plug, and instead use the balancing plugs to resistively bleed power off the higher-voltage cells), but that's the basic idea.

[smuzz]

... one time I was absent-mindedly plugging-in by feel instead of looking.

Yeh, well, .... I guess we've all made that mistake in the past - perhaps longer ago for some of us!

[gbanger]

Was that ...... Long ago, In a Galaxy far far away.

[Claudius]

Question for all...

I've got a few props made for a 1/4" (~6mm) shaft, which I now need to fit on a 8mm OD prop adaptor (swapping out the Park 480 in my little SBach with something beefier in a last ditch attempt to make this plane more fun).

Was wondering how others generally approach this. Does everyone else just use a drill press or prop reamer? (neither of which I have) Any luck with manually drilling (perhaps in 0.5mm increments) or any other tricks?

[gbanger]

I just drill the suckers in a drill press and they are always pretty spot on, a little bit of work in the balancer and they are good to go.

[smuzz]

I've got a small drill-press Claudio - if you'd like to come over and use it some time, then just let me know!