Andy W
May 07, 2004, 08:00 AM
!Hacker-Model Joker
| spec2
| @907458
|> <b>Length:</b> |< 36”
|> <b>Wing Span:</b> |< 56”
|> <b>Wing Area:</b> |< 2.8 sq’ (409 sq. “)
|> <b>Weight (tested):</b> |< 21.7oz
|> <b>Wing loading (tested): |< 7.75 oz/sq’
|> <b>Servos:</b> |< Hitec – HS-55 Rudder/Elevator
|> <b>Receiver:</b> |< Hitec Electron
|> <b>Motor:</b> |< Provided – Hacker-Model Sprint 400 7.2V
|> <b>Motor:</b> |< Upgraded - Rocket 400 with Model Motors 6:1 GB
|> <b>Battery:</b> |< 7xKAN950 NiMH
|> <b>ESC:</b> |< Jeti 35 with BEC
|> <b>Prop:</b> |< Stock – Graupner CAM folding 6x3,
|> <b>Prop:</b> |< Upgraded - Aeronaut CAM 14x8” folding
|> <b>Supplier:</b> |< <a href="http://www.hacker-model.com/">Hacker Model Production</a>
The Hacker-Model Joker is targeted at beginners, being a simple model to construct, and just as easy to fly! It requires only two servos to control rudder and elevator, and a speed-400 power system. The color scheme is simple and effective for orientation – an important factor for beginners. Most importantly, the model flies almost hands-off, making it easy for a beginner to fly.
!What’s In The Box
@907459:Not many components!
I received my sample in a box that looked too small to contain a sailplane! Even for an ARF, it still contained surprisingly few components – a lightweight fuselage, molded from fiberglass, a lightweight vacuum-formed canopy, three wing panels, the horizontal and vertical stabilizers with the elevator halves and rudder pre-attached, a Hacker-Model Sprint 400 7.2V can motor motor, and a small bag of hardware. The wings and tail surfaces are each built-up wooden construction, pre-covered with red (wings and horizontal stab/elevator) and white (vertical/rudder) Oracover covering. A comprehensive instruction manual, and a large decal sheet, are provided too.
!Assembly
I won't retrace every step of the manufacturer's instructions here -- that's what the manual is for! However, I did want to point out some high points, and how incredibly quick this bird goes together.
!!Wing
@907460:The wings joined in just a few moments.
I was very pleased to find a section in the manual to cover the importance of checking the wing (and tail surfaces) for warps, and ensuring the wing panels are correctly aligned when joining. Following the simple steps provided should assure that even the most novice pilot will have a model that flies as intended. A warped wing, or incorrectly installed panel, would make any model difficult to fly.
Step 1 in the assembly sequence was to join the wing panels. This literally took just a few minutes –align and glue the panels,, ensuring they were held in position until the adhesive cured. The panels had a small gap between them when correctly aligned, so I choose to use Elmers Polyuretahne Adhesive – ProBond – to join these components. A quick application of ProBond and some masking tape over the joints was all that was needed, and I used a couple of wooden blocks to ensure the panels held their alignment until the adhesive cured. Other than adding decals – which I did when assembly was complete - the wing was done! Wow...
!!Fuselage
*The fuselage assembly was clearly documented with numbered steps...
*Drilled 2mm holes to allow the control rods for the elevator and rudder to pass through
*Taped the wing to the fuselage, ensured it was aligned (easy to measure from the tips to the tail, with no tail surfaces attached)
*Marked then drilled the wing-mount bolts
*Use provided (yes, provided!) tapping screw to thread the pre-mounted wing-bolt blocks.
*Drop in some thin CA, rethread, you’re done!
Things were moving along nicely.
The instructions included attachment of the rudder and elevator surfaces to the appropriate stabilizer. They were already taped in place, however, which made the insertion of the elevator joiner even simpler!
The horizontal and vertical stabilizers were mounted to the fuselage by simply removing the covering material where the parts met, roughing up the fuselage, checking alignment, and applying adhesive. I grabbed a soda and checked the <a href="http://www.rcgroups.com">RCGroups Discussion Forums</a> while those parts set in place – if there’s one step where you should take your time and let the glue cure before proceeding, it’s here. A misaligned tail will make for a poor flying model!
The control surface pushrods were installed next. Looking through the instructions, I found that they want you to use the mini connectors at the servos. I choose to reverse these connections – I used z-bends at the servo, and the connectors out on the control horns. This made adjustment of the surfaces with the model assembled a little simpler, as the fuselage is quite narrow.
@907461:Tail surfaces with control horns installed. With the pushrods already installed, it was easy to ensure the control horns would be correctly located.
@907462:I preferred this method of canopy attachment.
Step 12 showed the canopy being held in place with tape. Another Hacker-Model sailplane, however, used a simple system of a pin at the front, and Velcro holding the canopy against the fuselage, with a small balsa filler piece, at the rear. I liked this arrangement, so I made up similar pieces for this model. Five minutes work for a lot of convenience when installing the battery later!
The servos for the rudder and elevator were mounted on wooden rails, glued into the fuselage on top of a spruce support. There was also a spacer that held the control rods against the sides of the fuselage behind the wing saddle. The instructions suggested epoxy here, but I chose to use ProBond again, so I had to wait overnight for these parts to be securely bonded before completing installation. The entire assembly process to this point, however, had taken just a couple of hours.
@907463:Servos and Receiver installed
The next morning, I slipped the z-bends into the servo arms, and screwed the HS-55 servos in place. The control surfaces were centered using the provided adjustable connectors out at the surfaces themselves. I chose a Hitec Electron 6 receiver– a perfect fit for this models narrow fuselage!
@907464:Air scoop is cleverly located above the spinner.
@907465:Vent hole behind wing saddle.
The only step that was not numbered was the opening of the vents for cooling air over the motor and other power system components. I actually did this at the same time as opening the holes for the rudder/elevator control rods. I used an Exacto knife, as well as a small Dremel cutting tool, and as the fuselage is so light and thin, it took no time at all to shape the vent holes as required.
!!Power System
The only remaining task was to install a power system. The kit included a Hacker-Model labeled Speed 400 motor. They also show a 6x3” folding propeller, but I was not provided this part. I had a suitable Graupner 6x3” CAM propeller, however, and installed this. As the provided motor was rated at 7.2V, I chose a 7-cell pack of KAN950 NiMH cells. For an ESC, I chose a spare Jeti 35 unit I had in the drawer. A quick test of the power system showed it should perform adequately, and I proceeded to mount the motor. As the wooden mount was pre-installed, this is accomplished by simply drilling a couple of mounting screw holes in the front of the fuselage. I also opened up the hole in the center of the nose to allow the motor to seat against the bulkhead. Mount the motor, install the propeller, plug the ESC into the receiver, and the model was ready to fly!
@907466: The Graupner spinner fit well, and the small 6x3 blades folded flush against the fuselage.
I was amazed at how quickly this model had gone together. I had yet to apply decals – but they were no problem to cut from the sheet, and it took just a little longer than the time taken to charge my 7-cell battery!
!Flying
@907467:Ready to fly!
@907468:A friend launches for me. This model is a breeze to self-launch, however.
The test flights were uneventful. Although the stock power system provided a less aggressive climb rate than I was used to, it was perfectly normal, and certainly suitable for the beginner-class of pilot that this model was intended for. The model reached a nice thermal altitude in about a minute of full-power motor run, and required just a few clicks of ‘up’ trim and a little ‘left’ rudder to get it flying straight and level hands-off. It flew a touch faster than I’d expect for this wing loading, but was still stable and controllable at much lower speeds. My model stalled almost straight ahead, and recovered quickly – it will also recover very quickly from a hands-off dive condition, useful at a distance or at altitude when attitude may be difficult to determine.
@907469:Looking for lift.
@907470:Found some – going up!
Landing was effortless and predictable – trimmed for straight-and-level flight, I held a little up-elevator to bring the nose up a touch, and she'd bleed off airspeed and start to sink nicely. Without additional surfaces to control sink rate, you’ll have a job making spot landings, as she’ll float along quite a bit, especially in ground effect. Again, however, there is no tendency to stall, and the controls are still very effective. The only time I would use caution is in gusty conditions, where a sudden change in wind can raise a wing, and you have to be quick to correct it. In these conditions, I just bring her in a little faster, and flatter, and fly her all the way down to the ground in a nose-down attitude. For short and spot landings, the wing would benefit from the addition of flaps and spoilers, but I believe that would add a level of complexity that would make this model less suitable for a beginner.
@907471:Ready to enter the pattern.
I’ve cart-wheeled the model a few times trying to see how slow I can get her, or just making dumb choices in the last seconds of my landing approach! I am happy to report that only the fuselage has suffered any damage that required attention- a few cracks have developed around the wing saddle and canopy area. Fuselage repairs required just a few drops of thin CA over re-aligned cracks, however, and were accomplished in just a couple of minutes. The wing and tail have held up incredibly well to my abuse!
!!Upgraded power system
The stock power system provided adequate performance for a beginner, but climbs were slow and the motor needed to be run for extended periods, less than ideal for an intermediate and above pilot. This is certainly not an issue for a beginning modeler, as they are not looking for competitive levels of performance. I just happened, however, to have a more powerful system available in a Rocket 400, a Model Motors 6:1 planetary gearbox, and an Aeronaut CAM 14x8” folding prop. This system was installed after a few test flights with the stock power system, and I have to say, it made quite an improvement! A friend flies competitive 1/2A LMR sailplane events, and the low weight of this model was surprising to him. With this power system, this model could probably compete in 1/2A LMR events. Most of the photographs used in this review are with the upgraded power system – the big prop and carbon spinner just look cool! It’s a lot of fun to power to altitude in just a few seconds, then glide around for a while before juicing it up again. I’ve received a lot of positive comments from other modelers, and even casual spectators, on the performance of this model.
@907472:Unable to leave things alone,
@907473:I installed an upgraded power system!
!Conclusion
I’ve flown this model quite a bit, and it’s a nice, relaxing model to fly. Lightweight, it performs very well for a beginner sailplane, but it can still withstand a lot of abuse with only minor dings or cracks to show for it. When correctly trimmed, it flies hands-off, can thermal well, and lands predictably and at a gentle speed. It can also handle moderate wind without difficulty. The provided power system is perfectly acceptable for its intended use, but can also easily be upgraded to provide very good and even potentially competitive performance.
@907474:A close fly-by.
I have no reservation about recommending this model to a first-time electric sailplane pilot, or even an absolute R/C beginner!
| spec2
| @907458
|> <b>Length:</b> |< 36”
|> <b>Wing Span:</b> |< 56”
|> <b>Wing Area:</b> |< 2.8 sq’ (409 sq. “)
|> <b>Weight (tested):</b> |< 21.7oz
|> <b>Wing loading (tested): |< 7.75 oz/sq’
|> <b>Servos:</b> |< Hitec – HS-55 Rudder/Elevator
|> <b>Receiver:</b> |< Hitec Electron
|> <b>Motor:</b> |< Provided – Hacker-Model Sprint 400 7.2V
|> <b>Motor:</b> |< Upgraded - Rocket 400 with Model Motors 6:1 GB
|> <b>Battery:</b> |< 7xKAN950 NiMH
|> <b>ESC:</b> |< Jeti 35 with BEC
|> <b>Prop:</b> |< Stock – Graupner CAM folding 6x3,
|> <b>Prop:</b> |< Upgraded - Aeronaut CAM 14x8” folding
|> <b>Supplier:</b> |< <a href="http://www.hacker-model.com/">Hacker Model Production</a>
The Hacker-Model Joker is targeted at beginners, being a simple model to construct, and just as easy to fly! It requires only two servos to control rudder and elevator, and a speed-400 power system. The color scheme is simple and effective for orientation – an important factor for beginners. Most importantly, the model flies almost hands-off, making it easy for a beginner to fly.
!What’s In The Box
@907459:Not many components!
I received my sample in a box that looked too small to contain a sailplane! Even for an ARF, it still contained surprisingly few components – a lightweight fuselage, molded from fiberglass, a lightweight vacuum-formed canopy, three wing panels, the horizontal and vertical stabilizers with the elevator halves and rudder pre-attached, a Hacker-Model Sprint 400 7.2V can motor motor, and a small bag of hardware. The wings and tail surfaces are each built-up wooden construction, pre-covered with red (wings and horizontal stab/elevator) and white (vertical/rudder) Oracover covering. A comprehensive instruction manual, and a large decal sheet, are provided too.
!Assembly
I won't retrace every step of the manufacturer's instructions here -- that's what the manual is for! However, I did want to point out some high points, and how incredibly quick this bird goes together.
!!Wing
@907460:The wings joined in just a few moments.
I was very pleased to find a section in the manual to cover the importance of checking the wing (and tail surfaces) for warps, and ensuring the wing panels are correctly aligned when joining. Following the simple steps provided should assure that even the most novice pilot will have a model that flies as intended. A warped wing, or incorrectly installed panel, would make any model difficult to fly.
Step 1 in the assembly sequence was to join the wing panels. This literally took just a few minutes –align and glue the panels,, ensuring they were held in position until the adhesive cured. The panels had a small gap between them when correctly aligned, so I choose to use Elmers Polyuretahne Adhesive – ProBond – to join these components. A quick application of ProBond and some masking tape over the joints was all that was needed, and I used a couple of wooden blocks to ensure the panels held their alignment until the adhesive cured. Other than adding decals – which I did when assembly was complete - the wing was done! Wow...
!!Fuselage
*The fuselage assembly was clearly documented with numbered steps...
*Drilled 2mm holes to allow the control rods for the elevator and rudder to pass through
*Taped the wing to the fuselage, ensured it was aligned (easy to measure from the tips to the tail, with no tail surfaces attached)
*Marked then drilled the wing-mount bolts
*Use provided (yes, provided!) tapping screw to thread the pre-mounted wing-bolt blocks.
*Drop in some thin CA, rethread, you’re done!
Things were moving along nicely.
The instructions included attachment of the rudder and elevator surfaces to the appropriate stabilizer. They were already taped in place, however, which made the insertion of the elevator joiner even simpler!
The horizontal and vertical stabilizers were mounted to the fuselage by simply removing the covering material where the parts met, roughing up the fuselage, checking alignment, and applying adhesive. I grabbed a soda and checked the <a href="http://www.rcgroups.com">RCGroups Discussion Forums</a> while those parts set in place – if there’s one step where you should take your time and let the glue cure before proceeding, it’s here. A misaligned tail will make for a poor flying model!
The control surface pushrods were installed next. Looking through the instructions, I found that they want you to use the mini connectors at the servos. I choose to reverse these connections – I used z-bends at the servo, and the connectors out on the control horns. This made adjustment of the surfaces with the model assembled a little simpler, as the fuselage is quite narrow.
@907461:Tail surfaces with control horns installed. With the pushrods already installed, it was easy to ensure the control horns would be correctly located.
@907462:I preferred this method of canopy attachment.
Step 12 showed the canopy being held in place with tape. Another Hacker-Model sailplane, however, used a simple system of a pin at the front, and Velcro holding the canopy against the fuselage, with a small balsa filler piece, at the rear. I liked this arrangement, so I made up similar pieces for this model. Five minutes work for a lot of convenience when installing the battery later!
The servos for the rudder and elevator were mounted on wooden rails, glued into the fuselage on top of a spruce support. There was also a spacer that held the control rods against the sides of the fuselage behind the wing saddle. The instructions suggested epoxy here, but I chose to use ProBond again, so I had to wait overnight for these parts to be securely bonded before completing installation. The entire assembly process to this point, however, had taken just a couple of hours.
@907463:Servos and Receiver installed
The next morning, I slipped the z-bends into the servo arms, and screwed the HS-55 servos in place. The control surfaces were centered using the provided adjustable connectors out at the surfaces themselves. I chose a Hitec Electron 6 receiver– a perfect fit for this models narrow fuselage!
@907464:Air scoop is cleverly located above the spinner.
@907465:Vent hole behind wing saddle.
The only step that was not numbered was the opening of the vents for cooling air over the motor and other power system components. I actually did this at the same time as opening the holes for the rudder/elevator control rods. I used an Exacto knife, as well as a small Dremel cutting tool, and as the fuselage is so light and thin, it took no time at all to shape the vent holes as required.
!!Power System
The only remaining task was to install a power system. The kit included a Hacker-Model labeled Speed 400 motor. They also show a 6x3” folding propeller, but I was not provided this part. I had a suitable Graupner 6x3” CAM propeller, however, and installed this. As the provided motor was rated at 7.2V, I chose a 7-cell pack of KAN950 NiMH cells. For an ESC, I chose a spare Jeti 35 unit I had in the drawer. A quick test of the power system showed it should perform adequately, and I proceeded to mount the motor. As the wooden mount was pre-installed, this is accomplished by simply drilling a couple of mounting screw holes in the front of the fuselage. I also opened up the hole in the center of the nose to allow the motor to seat against the bulkhead. Mount the motor, install the propeller, plug the ESC into the receiver, and the model was ready to fly!
@907466: The Graupner spinner fit well, and the small 6x3 blades folded flush against the fuselage.
I was amazed at how quickly this model had gone together. I had yet to apply decals – but they were no problem to cut from the sheet, and it took just a little longer than the time taken to charge my 7-cell battery!
!Flying
@907467:Ready to fly!
@907468:A friend launches for me. This model is a breeze to self-launch, however.
The test flights were uneventful. Although the stock power system provided a less aggressive climb rate than I was used to, it was perfectly normal, and certainly suitable for the beginner-class of pilot that this model was intended for. The model reached a nice thermal altitude in about a minute of full-power motor run, and required just a few clicks of ‘up’ trim and a little ‘left’ rudder to get it flying straight and level hands-off. It flew a touch faster than I’d expect for this wing loading, but was still stable and controllable at much lower speeds. My model stalled almost straight ahead, and recovered quickly – it will also recover very quickly from a hands-off dive condition, useful at a distance or at altitude when attitude may be difficult to determine.
@907469:Looking for lift.
@907470:Found some – going up!
Landing was effortless and predictable – trimmed for straight-and-level flight, I held a little up-elevator to bring the nose up a touch, and she'd bleed off airspeed and start to sink nicely. Without additional surfaces to control sink rate, you’ll have a job making spot landings, as she’ll float along quite a bit, especially in ground effect. Again, however, there is no tendency to stall, and the controls are still very effective. The only time I would use caution is in gusty conditions, where a sudden change in wind can raise a wing, and you have to be quick to correct it. In these conditions, I just bring her in a little faster, and flatter, and fly her all the way down to the ground in a nose-down attitude. For short and spot landings, the wing would benefit from the addition of flaps and spoilers, but I believe that would add a level of complexity that would make this model less suitable for a beginner.
@907471:Ready to enter the pattern.
I’ve cart-wheeled the model a few times trying to see how slow I can get her, or just making dumb choices in the last seconds of my landing approach! I am happy to report that only the fuselage has suffered any damage that required attention- a few cracks have developed around the wing saddle and canopy area. Fuselage repairs required just a few drops of thin CA over re-aligned cracks, however, and were accomplished in just a couple of minutes. The wing and tail have held up incredibly well to my abuse!
!!Upgraded power system
The stock power system provided adequate performance for a beginner, but climbs were slow and the motor needed to be run for extended periods, less than ideal for an intermediate and above pilot. This is certainly not an issue for a beginning modeler, as they are not looking for competitive levels of performance. I just happened, however, to have a more powerful system available in a Rocket 400, a Model Motors 6:1 planetary gearbox, and an Aeronaut CAM 14x8” folding prop. This system was installed after a few test flights with the stock power system, and I have to say, it made quite an improvement! A friend flies competitive 1/2A LMR sailplane events, and the low weight of this model was surprising to him. With this power system, this model could probably compete in 1/2A LMR events. Most of the photographs used in this review are with the upgraded power system – the big prop and carbon spinner just look cool! It’s a lot of fun to power to altitude in just a few seconds, then glide around for a while before juicing it up again. I’ve received a lot of positive comments from other modelers, and even casual spectators, on the performance of this model.
@907472:Unable to leave things alone,
@907473:I installed an upgraded power system!
!Conclusion
I’ve flown this model quite a bit, and it’s a nice, relaxing model to fly. Lightweight, it performs very well for a beginner sailplane, but it can still withstand a lot of abuse with only minor dings or cracks to show for it. When correctly trimmed, it flies hands-off, can thermal well, and lands predictably and at a gentle speed. It can also handle moderate wind without difficulty. The provided power system is perfectly acceptable for its intended use, but can also easily be upgraded to provide very good and even potentially competitive performance.
@907474:A close fly-by.
I have no reservation about recommending this model to a first-time electric sailplane pilot, or even an absolute R/C beginner!