Blaster 2 DLG Build

[Peewhit]

That nice Santa lady (alias the other half) delivered the Blaster 2 exactly on time on Christmas Day and it's a nice shade of girlie pink.

 

It seems very well built with carbon in all the right places and is featherweight at around 6oz for the whole thing.

 

And it comes with the usual hardware

 

 

Interestingly it is designed so that the flaperon servos can either go in the wing (as per the instruction) or in the pod as per Vladimir's Models  latest recommendation and has four pushrod sleeves coming into the pod

 

And two of them exit right by where the flaperon horns will be

 

It will need to be built as light as possible and that calls for some lightweight kit

 

Spektrum AR500 receiver at just 7G.

I am debating over the battery between a 360mAh NiMh 4 x 2/3AAA which should give about two hours flight time and an 800mAh 4 x AAA which will last much longer.

The 800mAh is 3/4oz heavier.

 

The servos are Logic LSX 110 which are identical to Ripmax SD100 and Dymond 4.7 except that they are £5 cheaper each.

They are 8 x 22 x 17mm, weigh in at just 4.7G each and have a torque of 1.1kg.

Average power consumption is 80ma which brings me back to that battery choice.

Think I will try and fit the 800mAh in as two hours flight time is not a lot on the slope.

 

The deck is flat balsa which is glassed on both sides and I don't want to cut very much of it away.

I therefore have the top and the bottom of it to fit in four servos, receiver, battery, and possibly a Futaba micro switch.

And, it needs to balance without any added weight.

The recommended C of G is 78-82mm behind the leading edge.

I have heard that 85-90mm is far better for the Blaster so I am going to aim for 85mm with (hopefully) the flexibility to move it back a bit.

 

I played around with all sorts of deck layouts and came up with something like this - apologies for the artificial light photos

 

Top of the deck with the two flaperon servos and battery, and some flexibility to slide the cells backwards or forwards.

 

And the bottom of the deck with the rudder and AMT servos, receiver, and possibly switch.

 

And it balances just where it should.

 

Well that's the planning bit done and it's on to the building of it next

 

 

[Peewhit]

The first cut is the hardest, and hopefully not the deepest as it is going into the flaperons to mount the control horns.

 

Masking tape on to stop the knife slipping and mark out where the slots need to go.

They are 1/2" from the center of the wing.

The holes in the horn are lined up along the hinge line.

There is a 1/4" carbon spar along the front of the flaperon and the horns are designed so that you don't have to cut into the spar.

 

Cut the top skin with a sharp knife and open up the slot using a small screwdriver to make it wider and deeper (to the opposite skin) so that the horn will fit in it nicely.

 

The Blaster has a wing dihedral of 165 degrees.

 Ideally the horns should be vertical, yet I wanted them to point inwards slightly in order to line up better with the pushrods.

 

An angle of 100 degrees to the flaperon seemed about right so I made a highly technical template from a beer can box

 

More masking tape to stop any epoxy going onto the wing surface, epoxy in the slot using that small screwdriver again, epoxy on the horns, push into the slots, remove the masking tape and clean up with isopropyl alcohol.

Check the angles and leave for ten minutes to set.

 

And two control horns with the holes directly on the hinge line.

[Former Member]

[This posting has been removed]

[Andy Green]

I've got the Blaster 2e (Electric version) and its my most flown model. Have fun.

 

Andy

[Peewhit]

Electric version - bet that's fun - how much power is in it?

 

Well, have managed to do a little bit more, but first a daylight pic just for Eric

 

Now to look at the back bit.

 

The rear of the AMT should be 5mm in front of the fin.

When sliding the carbon mount onto the boom for a nice fit - mine was 22mm in front of the fin so the hole in the mount is too large.

 

I could mount the AMT in this location with no adverse effects yet to counterbalance the

4 x AAA cell going into the nose, I need it as far back as possible.

 

So a thin smear of epoxy on the inside of the mount, sanded down lightly, and a nice tight fit in just the right location

 

Next to install the pushrod guides which is easier to do before gluing on the AMT mount.

 

I marked the location of the AMT mount using masking tape, and the pushrod should exit  55mm in front of the AMT mount, and at the top of the boom

 

I used masking tape to lessen the possibility of the drill bit slipping and started with a 1.5mm hole which I gradually widened to the required 2.5mm.

 

Then I elongated the hole to a 6mm slot (those dremmel things are wonderful!) so that the pushron will be nicely in line with the hole in the mount

 

 The rudder pushrod is supposed to exit 3mm behind the fin slot, yet this would weaken a crucial area and did not seem to line up well with the rudder horn which is 13mm long.

 

I therefore went for a more forward location

Also, my Blaster 2 is a left handed version so the rudder horn needs to be on the left ie the opposite side to the launching winglet on the tip of the (in my case) right wing.

 

Having made sure that the pushrods will exit the boom in the correct place, which for me is the lower side of the deck, I removed the masking tape then lightly sanded the pushrod guides and cleaned with isopropyl alcohol

Then the pushrod guides were fixed in place with 10 minute epoxy, slighly thickened with micro balloon, and I nearly forgot to slide on the AMT mount first

 

I have also lined up the AMT with the wing and epoxied the mount it in place, but it was dark by then so I will wait for daylight before taking a pic - just for Eric

 

The Blaster 2 comes with 0.7mm carbon pushrods which are not very substantial.

 

I am going to replace these with 22swg piano wire (0.71mm), yet now have to wait for this to arrive before I can finalize the locations of servos etc on top of and underneath  the deck.

[Tony Smith 7]

Looks good!   Will it be tough enough for the rough-and-tumble of slope flying, or do you have nice soft landing zones?   Is that 6oz the all up weight?  I love light wind light lift scratching, much prefer it to gale dangling.

[Peewhit]

Hi Tony,

 

6oz is without the gear and the 800mAh 4xAAA weighs 2.75oz.

 

I am hoping for an all up weight of around 10.5 to 11oz - will let you know

 

It should fly well in 5 to 10mph on the slope and with those wind speeds, I should be able to catch it as opposed to land it.

 

That fin sticks down a long, long way below the boom

[Chris In The Vale]

Hi Peewhit,

Haven't posted for ages - but seeing a Blaster 2 the same as mine (and the same "easy to spot" Pink" colour) made me want to just say "Well done Santa".

 

 I actualy went with the wing mounted servos and will be interested as to how easy the  alernative turned out to be. I also cringed at the tail boom exit point and pulled back an inch or so for the dremmeling.

 

Mine has had about 50 to 60 hours in the air - and the only incident was the tail connect to the boom failing in the first few hours - (1st attempt at a catch - panic - drop on tail)  - the fin connection is a well known weak spot on the model - most seem to glass the area somewhat to add strength (or  just do so when the inevitable happens). The fin does indeed get a little "landing rash" ; having said that, my braking is set up to ensure the landing aspect is such that the nose is down just momentarily before the tail, reducing the risk of grinding to a halt using the fin as a brake. (actually, the rudder itself never touches the gound).

 I may buy a replacement fin at some point (£21.00) - but it has lasted many, many hundreds of landings thus far so I wouldn't be too concerned unless landing on concrete.

I went with the mini lipo (rhino 360) and small 5 gramm regulator/alarm which affords about 2 to 2 1/2 hours easily. Your options look good also. My all up weight these days is 11.6 oz, including the major apoxy / glass fix to the tail and about 10 grams of lead in the nose.

I use additional 5 / 10 gram velcro weights to add/remove to/from the nose depending on headwind conditions when DLG launching. My usual balance point on a fairly windless day is several mm behind the recommended one (about 8mm in front of the rear screws). I'm sure you'll find your own preference.

 

It can fly suprisingly fast - down to below walking pace if prefered - and the huge ailerons make slowing down and landing with flapperons a breeze.

 

DLG launching or light sloping - you are in for a great time Peewhit.

 

[Peewhit]

Chris,

 

Many thanks for the encouragement and I will let you know when mine has clocked 50 hours.

 

Have managed to do a tiny bit more in wrecking that nice flat battery configuration and adding the Futaba micro switch.

 

What I did not want was the spaghetti of wiring which came with the switch, so I just hot wired it straight to the battery.

 

With the switch on top of the battery, the nose cone will just clear.

For charging, I will either unplug the battery / switch assembly from the receiver, or use a very small servo extension lead to connect the two.

 

Still waiting for the 22swg pushrod wire which was ordered on 28th December with 24 hour delivery. Just wondering if anyone is working this week - particularly at Elite Models?

 

In the meantime, the servos will be mounted flat on the glassed deck.

Any suggestions as to what lightweight adhesive to use?

Edited By Peewhit on 31/12/2010 17:58:34

[Peewhit]

Well the wire arrived  - 24 hour delivery but not 24 hour despatch.

 

Also managed to get on the slope last weekend - the first time for six weeks, and I have done a bit more to the Blaster.

 

The receiver will be mounted on the bottom of the deck with the plugs sticking up through the deck .

This will be the only hole in the deck, and I reinforced it top and bottom with 1/64" ply

 

Then to connect up the AMT and rudder linkages, and to mark which is which.

 

The first problem - piano wire comes in 36" lengths which is long enough for the AMT but not for the rudder.

So wire for the AMT and the supplied carbon rod (39" long) for the rudder.

 

CA the little metal dubrey to the end of the carbon rod and mark the position for the rudder horn.

Cut a slot through the masking tape, remove the tape, widen the slot with a small screwdriver and epoxy the horn in place

 Then to fix the pusrod guides to the inside of the boom

 

With the piano wire inside the guides, a couple of magnets on the outside of the boom hold the guides nicely in position along the bottom of the boom.

Hold the boom nearly vertical and dribble in some thin CA  from the back end - beware as just a few drops of CA go a long way - too much and it is likely to run out of the front.

And both pushrod guides glued in at the same time.

 

 

 Epoxy in the fin

 

 

Also connect up the AMT mount

 

Measure the pushrod lengths, and mount the servos using aquarium grade silicon

 

Z bends always seem to have that little bit of slop therefore I used L bends with two small pieces of pushrod guide tube CAed to the wire to hold it in place.

 

These are the aileron servos and aileron movement is 20mm up and 45 degrees down (about 40mm) for landing - ie more down movement than up, therefore the horns are raked back slightly.

 

Using the DSX9 transmitter in glider mode, strangely one aileron servo goes to the aileron port and the other to the throttle.

 

The aileron horn connections need to be detachable.

 

I used an extra piece of pushrod wire held on by plastic heat shrink and then CAed in place. This makes them nicely spring loaded for connecting onto the horns

 

 

[Peewhit]

This slope soaring really does get in the way of building

 

35 mph  on the edge yesterday and the Wizard Compact with 24oz of ballast on board just lapped it up - fast, furious and lovely.

 

Back to the Blaster, and I have found problem number 2.

 

Having carefully calculated the required servo arm lengths, one of the aileron servo arms is stopping against the other aileron servo.

This limits aileron up movement to 15mm as opposed the the recommended 20mm.

 

Options include turning the servo round and making a new pushrod (and needing to extend the wires), or trying to fit in longer arms.

 

Clearance from the top of the arms to the nosecone is just over 3mm so I opted for trying the longer arms.

 

A little bit of surgery to flatten out the very top of the arms and they JUST clear the nosecone - and I now have that 20mm aileron movement.

 

Epoxy the aileron  guides in place where they exit the pod at the front - those old fashioned clothes pegs are wonderful things.

 

And mount the micro switch onto the battery with silicone sealant.

 

The two battery units (3 + 1 cells) are  mounted onto thin foam and held in place with Sellotape Diamond ultra clear wrapped right around the deck.

And the receiver is mounted again using  that silicone.

 

Top of the deck complete.

I decided to include a charge plug and soldered it straight onto the battery terminals.

 

As is the bottom

 

And the C of G is spot on at the 85mm I wanted without adding any nose weight.

 

Drill a hole in the bottom of the pod for the long bit of the AR500 aerial, feed it through using a spare piece of pushrod guide and secure the end with Sellotape Diamond

 

The discuss launch winglet is quite large and  really puts the wing out of ballance

 

I did consider inserting a counter weight  into the other wing tip, but the wing is very thin and I took the easy option  of epoxying a small piece of lead to the underside.

 

The Blaster is designed for five flight modes - launch, cruise, land, speed and thermal.

You can download templates for the necessary aileron angles in each flight mode from the Hyperflight web site, and print then onto card.

This made the set up very easy and I mixed a bit of rudder into the ailerons for thermal and land modes only.

 

The flaperons come down 45 degrees for landing and the recommended elevator down compensation is unusual in that it is 6mm at 20 degrees then reduces to 4mm at 45 degrees.

Thank you Macgregor for multi point programmable mixes on the JR DSX9.

 

All finished and ready to fly.

 

All up weight is 11.25 oz - not bad considering that 800 mAh 4 x AAA cell battery.

Using the smaller 320 mAh battery would have brought the weight down to 10.5 oz.

 

A bit too windy for it today though.

Edited By Peewhit on 15/01/2011 14:12:02

[Chris In The Vale]

 

Nice Job Peewhit.

It's a beautiful looking wing isn't it.

I just took delivery of my new replacement pod and boom this last week (I went for red this time to 'compliment' the pink). I am looking to see how I might lay out the servos a little differently to the last time. As it happens my aileron servos are placed in the wing, so I at least have the luxury of having one servo beneath the board and the other above it.
I do however want to do what you have managed to achieve and push the servos far enough forward to reduce the need for the lead weights I currently have in the front of my current blaster 2. I have never thought about counterbalancing the peg. Maybe I will give it a try – I guess I somehow imagined that the rudder fixing far back on the right would somehow offset the peg on the left further forward.
I may well find that I still need to use a little bit of lead as the Rhino 360 Lipo battery and the mini regulator only amount to about 28 g in total.

Thanks for the great build thread Peewhit, definitely one to bookmark and use for future DLG builds, or to forward onto others doing a blaster 2 build.

Best wishes for the maiden ! Post some details when you get a chance as to how you think she flies. I'm definitely up to experimenting with different setups and would love to compare notes.

Regards,

Chris

 

Edited By Chris In The Vale on 15/01/2011 19:18:56

[Peewhit]

Hi Chris and thank you for your kind words which make the whole thing worthwhile.

 

I have built several gliders - wood, foam and moulded.

This is my first DLG and I am definitely no photographer.

 

I have stuff that will slope in up to 50 mph and nothing that will fly happily in less that 8mph.

That's where the Blaster comes in to complete the flight envelope, and I might even occasionally discuss launch it on the flat.

 

You may be right about the rudder fixing offsetting the peg.

I have always  balanced the wings on my models and old habits die hard.

The proof will be in the flying and I will let you know.

 

With your light lipo and regulator you will have the opposite problem to me in that the tail will need to be as light as possible.

 

Moving the AMT forward by about 1" would help and will not upset flight performance. Wrap some fine grade wet and dry around the boom and turn the AMT mount round on it until the hole is the right size - check the fit very often during this process.

 

You could even shorten the boom by the same amount and move the fin forward if you are good with a dremmel.

Make a template of the fin slot first.

 

The key to it all is that C of G.

 

I connected up all the rear pushrods  and then moved things around on the deck - blue tack is great for temporarily positioning servos, battery and receiver - until that C of G was just right.

Then start to fix things in and leave the most flexible item which in my case was the single cell of the battery until last.

In your case it will probably be  the servo on its own on the lower deck.

Don't forget to include the nosecone which I held in place on the side of the nose with masking tape.

 

Good luck and please post your settings on - I also love a good tweak.

 

Kind Regards,

 

Peter

 

 

[Peewhit]

Well finally a day with little wind - have never wanted little wind before - and time to maiden the Blaster, and no finer place than at the Hole of Horcum.

 

The wind was just 6mph on the edge and I certainly would not have thrown a mouldie sloper off in that.

 

The Blaster just flew up and out with a touch of down trim needed.

 

I started off by keeping near the edge of the hill just in case, and soon discovered that this is an open air machine as opposed to a hill hugging foamie type.

 

It can fly surprisingly fast and cover a lot of ground in a short time.

 

The wind picked up a bit to 8mph and it was time for some real fun.

 

It does not have the momentum for large loops but small ones are really quick, as is the roll rate, and it is great fun to fly.

 

Balancing the wing to compensate for the weight of the discuss winglet seems the right thing to do as it flies straight and level.

 

Tried it in thermal mode and it just floated up and up.

 

The speed mode also works well and is great for aerobatics.

 

Had five flights in all totaling two hours and still had 40% of that 800 mAh battery left.

 

The recommended C of G is 78-82mm behind the leading edge, and mine is set to 85mm.

 

It did lose some height in the turns and pulled out of the dive test which indicates that the C of G is still too far forward, so I will take it back to 87mm and see.

 

Spoileron braking was a bit hairy the first time.

The recommendation is 6mm down elevator (AMT) compensation for the ailerons at 20 degrees down, and reducing to 4mm at 45 degrees down.

 

After the first landing, I set it to 6mm down at 45 degrees as well, and even then, it had too much initial elevator compensation and not enough at the end.

Will set it to 4mm at 20 degrees down and then progressively to 8mm at 45 degrees down.

 

Can't wait to tweak it as above and then take it out again.

[Tom Satinet]

cool. I've heard that you can go to 90mm on the cg.

 

I had one but sold it before i built it which I kind of regret. Maybe if it's a windless summer.....

[Peewhit]

Have now sorted elevator comp and C of G set to 88mm

 

The Blaster will probably fly in 15 mph off the slope.

 

Forget this discuss business and F3K - it's a slope machine!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Ed Anderson]

I have a Blaster 2 in green and yellow. For me it is an F3K/DLG contest plane. I alternate this one with a Polecat XP5, which is a bagged win DLG.

 

The XP-5 is lighter but the Blaster seems to do better in the wind if I keep the speed up.

 

 

So, how is the flying going? Slope only? Pity.

[Peewhit]

Just got back from taking the Blaster out for the second time.

 

Went to a local slope 10 minutes down the road where the hill slopes for about 100 yards with nothing more than about 30 degrees - in other words, hardly ideal for sloping.

 

The wind was 7mph and the Blaster flew superbly and stayed aloft in what was very little lift. I even had to put in some down trim.

 

The C of G at 88mm is much better with very little height now lost in the turns, particularly if a little bit of rudder is added.

It does still pull up very slightly in the dive test, and would take a 90mm C of G.

Everything is now at it's most rearward position and to move the C of G back to 90mm would involve adding some weight at the tail which sort of defeats the object.

 

Anyway, in very little lift in cruise mode, the Blaster was doing loops, rolls and stall turns beautifully, so I think that I will leave the C of G at 88mm.

 

It would also fly far out from the slope and really is an open air machine.

 

Managed to get the flight modes sorted out nicely, and on thermal she just headed for the sky.

Thermal mode has both ailerons (acting as flaperons) lowered slightly and to go with this I have reduced the aileron differential to lower the risk of tip stalling and have 20% of rudder mixed in to the ailerons.

Landing mode also has 20% of rudder mixed in with ailerons to keep turn authority when the flaperons are lowered, and works very well.

 

And on speed mode it just soars across the sky.

 

Confession time in that I have about 70 degrees of down spoilerons for landing as opposed to the recommended 45 degrees - told you it was a sloper.

This makes landings very easy and the Blaster just hovers with no forward motion and settles down onto the grass very very gently.

 

In summary, I am extremely pleased with the Blaster in that it really does complete my flight envelope nicely.

Anything from 5mph to 50 mph and I can be there on the slope with one of just three models.

 

The only flight mode I have not sorted out is the launch one for that discus stuff on the flat - perhaps one day but I am having too much fun with it on the slope.

[Tim Mackey]

Sounds great PW - no flying here today apart from roof tiles, wheelie bins and rain.

[Peewhit]

Well the Blaster has been out on the slope again, and a proper slope this time.

 

The wind was forecast for 5mph and when I arrived it was 18mph on the edge - you just never can tell until you get out there.

 

The Blaster lapped it up and penetrated really well with no problems at all.

 

I did not realize that it would be so versatile.

 

It does bunts just as well as loops and today's game was vertical eights.

 

Fun, fun and fun

 

Very sorry you F3K guys, this lovely slope machine is wasted on the flat, and to watch it hover and just settle down on top of the heather is beautiful.

[Chris In The Vale]

Hi Peewhit,

After DLG launching the Blaster 2 for well over a year - I finally took it up a hill yesterday (The Meio in South Wales) for the first time after being caught with "no light stuff" on my last few visits.

I too am staggered by how well it slopes and will slope it as often as possible from here on in. Deploying (almost) full Flapperon 100 feet above the edge and hanging absolutely stationery like a buzzard turned a few heads on the slope.

Glad you made the post - if you hadn't mentioned your sloping activities with it I probably would have just taken the lightweight foamy stuff and still been unaware of it's true potential.

Chris

[Peewhit]

Well done Chris.

 

Done any vertical eights with it yet?

 

I told you it was a slope machine.

 

Seriously, sloping is exactly what I (sorry, that should read Santa) bought it for, and I too am astounded by how well it does perform on the slope.

 

Thanks to Mr. E. for the recommendation.