Pole Dancer - Sport Pylon Racer for Cox Sure Start
11-03-2013, 03:37 PM
#1
Pole Dancer - Sport Pylon Racer for Cox Sure Start
For the past year or so my flying buddies and I have been having a blast chasing each other around pylons with planes powered by Cox Sure Start Engines. Just a gentleman's race, nothing too serious, just the fun of watching 3 or 4 Cox powered planes screaming around the pylons in close proximity to each other. Intentional cuts are allowed in order to keep all of the planes together in a pack while sort of trying to avoid a mid-air. No one really wants to be too fast or too slow. The only rule is reed valve engines only, anything else goes!
We started out building GLH type planes but found them a little too big and heavy for sporty performance with a Sure Start. I decided to design something just for Sure Start engines.
My design goals were as follows:
1. High wing for easy hand launches and easy servo installation.
2. Ready to fly weight - 12 oz maximum
3. Fully symmetrical wing
4. Maximum durability as mid-airs do happen!
5. Easy to build and pleasing to look at
6. Elevated horizontal stab to avoid catching on the grass on landing
7. Rounded fuselage bottom for fun slip and slide landings
While looking through some old RCM magazines I came upon the Quickie designed by Fred Reese. I used this design as a basis for the Pole Dancer and set about drawing the new plane in CAD. I drew full size plans and even templates that can be printed on any 8 1/2 x 11 sheet of paper or better still card stock.
Collectively we have built about 6 Pole Dancers between us and we agree that the plane is a BLAST. It flies fast and goes where you point it! The wing loading is light enough to allow whipping around the pylons, BANK and YANK! When the engine quits it glides like a sport plane not a floating glide like some 1/2a planes, this one is on it's way down but in a nice manageable manner. Most of the time if the engine quits anywhere on the course, if you turn toward the runway as soon as the engine quits, you'll make it without problems. If you delay, you walk.
If there is any interest I can post the plans and templates and I'll document my latest build here so everyone can join in the fun! You can cut your own wing or I'll cut one for you for foam, postage and a couple of bucks to buy more Cox parts.
Anyone interested?
We started out building GLH type planes but found them a little too big and heavy for sporty performance with a Sure Start. I decided to design something just for Sure Start engines.
My design goals were as follows:
1. High wing for easy hand launches and easy servo installation.
2. Ready to fly weight - 12 oz maximum
3. Fully symmetrical wing
4. Maximum durability as mid-airs do happen!
5. Easy to build and pleasing to look at
6. Elevated horizontal stab to avoid catching on the grass on landing
7. Rounded fuselage bottom for fun slip and slide landings
While looking through some old RCM magazines I came upon the Quickie designed by Fred Reese. I used this design as a basis for the Pole Dancer and set about drawing the new plane in CAD. I drew full size plans and even templates that can be printed on any 8 1/2 x 11 sheet of paper or better still card stock.
Collectively we have built about 6 Pole Dancers between us and we agree that the plane is a BLAST. It flies fast and goes where you point it! The wing loading is light enough to allow whipping around the pylons, BANK and YANK! When the engine quits it glides like a sport plane not a floating glide like some 1/2a planes, this one is on it's way down but in a nice manageable manner. Most of the time if the engine quits anywhere on the course, if you turn toward the runway as soon as the engine quits, you'll make it without problems. If you delay, you walk.
If there is any interest I can post the plans and templates and I'll document my latest build here so everyone can join in the fun! You can cut your own wing or I'll cut one for you for foam, postage and a couple of bucks to buy more Cox parts.
Anyone interested?
11-03-2013, 05:42 PM
#3
Very nice! That looks like a perfect size and a simple build.
It is always great to hear about guys having fun racing Cox engines.
Before I ever got involved with racing or saw any of it I had no idea how much contact there is when the competition is tight.
It is always great to hear about guys having fun racing Cox engines.
Before I ever got involved with racing or saw any of it I had no idea how much contact there is when the competition is tight.
11-03-2013, 09:04 PM
#6
Tanks and batteries have been a problem for 1/2A flyers for some time.
First tanks: For Pylon racing it is desirable to be able to cause the engine to quit on demand as aerobatics involving negative Gs are not in the flight plan. Therefore any tank with a fixed pickup will work a treat. Some of us are using small control line 2/3 oz to 3/4 oz wedge style tanks epoxied to the firewall so that the wedge is at the bottom. A hole is drilled through the firewall for the wedge tube to go through and feed directly to the engine with a short piece of fuel tubing. The two vent tubes are fed out through the side of the fuselage, use one to fill and fuel will vent out of the other. See pics.
I have also used Sullivan 1 ounce tanks but they are heavy and the tubing is too big, plus the short silicone tube insides is two stiff to allow freedom of movement inside the tank. Generally not a good system without modifications to address the problems.
Cox sells a 1 oz tank that works very well for 1/2A. The tubing is 3/32 stainless steel with small silicone tubing and a clunk inside the tank. The clunk moves freely inside the tank. This tank is a good choice for 1/2A as it is lighter than the Sullivan and generally works much better. The problem is the cost - $10.00! See Pic of tank.
I am now testing a tank that is the ultimate in simplicity for cheapskates like me. It is a #6 cork with a grove cut into it with a dremel and a 1/16 hole drilled through it. Stick a 3/32 inch brass tube through the cork with a bit of epoxy, stretch a balloon over the cork so that the rubber ring on the balloon is seated in the groove you cut and off you go. DO NOT fill to the point where the balloon is stretched! You will have to carefully measure how much the ballon can hold without stretching it and then put in ONLY that much fuel. Be sure to draw all of the air out of the tank before connecting it up to your engine. NOTE: This tank is still being tested, use at your own risk.
Finally I have found a great battery for 1/2A use, it is a LOSB0846, 4.8V 220MA Nimh battery designed for small RC cars. I have tested three of these batteries numerous times with multiple chargers and dischargers. It accepts a 1c fast charge with excellent results as well as slow charge of 1/10c. I have yet to see a discharge capacity of less than 210ma no matter how I charge it (after break in). The weight of this battery is .8 oz and they can be purchased online for between $10 and $15 each. You will have to change the connector and cycle a couple of times to get full capacity out of it when new. Sorry the picture is upside down, too late to fix it.
First tanks: For Pylon racing it is desirable to be able to cause the engine to quit on demand as aerobatics involving negative Gs are not in the flight plan. Therefore any tank with a fixed pickup will work a treat. Some of us are using small control line 2/3 oz to 3/4 oz wedge style tanks epoxied to the firewall so that the wedge is at the bottom. A hole is drilled through the firewall for the wedge tube to go through and feed directly to the engine with a short piece of fuel tubing. The two vent tubes are fed out through the side of the fuselage, use one to fill and fuel will vent out of the other. See pics.
I have also used Sullivan 1 ounce tanks but they are heavy and the tubing is too big, plus the short silicone tube insides is two stiff to allow freedom of movement inside the tank. Generally not a good system without modifications to address the problems.
Cox sells a 1 oz tank that works very well for 1/2A. The tubing is 3/32 stainless steel with small silicone tubing and a clunk inside the tank. The clunk moves freely inside the tank. This tank is a good choice for 1/2A as it is lighter than the Sullivan and generally works much better. The problem is the cost - $10.00! See Pic of tank.
I am now testing a tank that is the ultimate in simplicity for cheapskates like me. It is a #6 cork with a grove cut into it with a dremel and a 1/16 hole drilled through it. Stick a 3/32 inch brass tube through the cork with a bit of epoxy, stretch a balloon over the cork so that the rubber ring on the balloon is seated in the groove you cut and off you go. DO NOT fill to the point where the balloon is stretched! You will have to carefully measure how much the ballon can hold without stretching it and then put in ONLY that much fuel. Be sure to draw all of the air out of the tank before connecting it up to your engine. NOTE: This tank is still being tested, use at your own risk.
Finally I have found a great battery for 1/2A use, it is a LOSB0846, 4.8V 220MA Nimh battery designed for small RC cars. I have tested three of these batteries numerous times with multiple chargers and dischargers. It accepts a 1c fast charge with excellent results as well as slow charge of 1/10c. I have yet to see a discharge capacity of less than 210ma no matter how I charge it (after break in). The weight of this battery is .8 oz and they can be purchased online for between $10 and $15 each. You will have to change the connector and cycle a couple of times to get full capacity out of it when new. Sorry the picture is upside down, too late to fix it.
Last edited by 049flyer; 11-03-2013 at 09:06 PM.
11-03-2013, 09:15 PM
#8
Here are a few specs on the Pole Dancer:
Wingspan - 24 inches
Wing area - 156 sq inches
Length over all - 23 1/2 inches
Weight ready to fly - 9 to 11 oz
Servos used - HS65 or HS 81
Wing is covered with low temp doculam
Fuselage is covered with dime store tissue ironed down with Sig Stix It and then painted with three coats of clear dope.
This version has a modified Sullivan 1 oz tank and a LOSB0846 battery, 4.8V 220MA
Radio is a 1980's vintage ACE MicroPro modified for 2.4 with the FRSKY DIY Module.
Wingspan - 24 inches
Wing area - 156 sq inches
Length over all - 23 1/2 inches
Weight ready to fly - 9 to 11 oz
Servos used - HS65 or HS 81
Wing is covered with low temp doculam
Fuselage is covered with dime store tissue ironed down with Sig Stix It and then painted with three coats of clear dope.
This version has a modified Sullivan 1 oz tank and a LOSB0846 battery, 4.8V 220MA
Radio is a 1980's vintage ACE MicroPro modified for 2.4 with the FRSKY DIY Module.
11-03-2013, 09:19 PM
#9
Looks good but I doubt the short length of tubing inside that small tank will be free enough to follow the fuel. You may have to try replacing it with small silicone tubing or thin wall surgical tubing. I would give it a try, certainly looks better than the Sullivan 1 oz tank.
11-04-2013, 05:57 AM
#13
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These hold about 20cc of fuel, both the clunk and bladder varieties work as advertised. Perhaps not ideal for Sure Start pylon models, the balloon tank I bet is the lightest and most practical.
http://www.rcuniverse.com/forum/1-2-...ml#post9348580
http://www.rcuniverse.com/forum/1-2-...ml#post9348580
11-04-2013, 08:25 AM
#14
Pole Dancer Plans with Templates-
Jpeg image is of the plans sheet PoleDncrV3-11-3.pdf which is 24 inches x 36 inches, provided so you can get an idea what it is all about. Print the pdf file at Kinkos or your favorite plans printer.
The other three files are templates that you can print out on your printer on 8 1/2 x 11 inch paper or card stock. BE SURE YOUR DRIVER IS SET TO 100% SCALE.
The wing is Dow Extruded Blue Foam. I buy it in 2ft by 8 ft by 4 inch sheets for about $25.00. Cost much more in gas driving to the Dow distributor than it does to buy the foam! I can get many wings from one sheet. The wing template is provided on the plan if you want to cut your own.
I will be happy to cut a few wings for the 1/2a flyers in this forum. I'm thinking $10.00 each including First Class postage and enough Doculam to cover the wing.
Jpeg image is of the plans sheet PoleDncrV3-11-3.pdf which is 24 inches x 36 inches, provided so you can get an idea what it is all about. Print the pdf file at Kinkos or your favorite plans printer.
The other three files are templates that you can print out on your printer on 8 1/2 x 11 inch paper or card stock. BE SURE YOUR DRIVER IS SET TO 100% SCALE.
The wing is Dow Extruded Blue Foam. I buy it in 2ft by 8 ft by 4 inch sheets for about $25.00. Cost much more in gas driving to the Dow distributor than it does to buy the foam! I can get many wings from one sheet. The wing template is provided on the plan if you want to cut your own.
I will be happy to cut a few wings for the 1/2a flyers in this forum. I'm thinking $10.00 each including First Class postage and enough Doculam to cover the wing.
Last edited by 049flyer; 11-17-2013 at 08:58 AM.
11-04-2013, 11:29 AM
#16
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Many years ago when 1/2a racing was popular pen bladders were the standard for fuel tanks, see the attached article describing use.
http://www.clcombat.info/bladder.html
http://www.clcombat.info/bladder.html
11-04-2013, 01:03 PM
#17
That's the best article about bladders I've ever seen.
They are necessary for consistent runs in high G force combat planes where running crank case pressure into a hard tank isn't practical.
For pylon racing with reed valve Cox engines, the bladder set up might allow for more aggressive settings but also increase the chances of engine handling errors that keep you from getting in the action.
The hard tank is still pretty hard to beat with all things considered.
They are necessary for consistent runs in high G force combat planes where running crank case pressure into a hard tank isn't practical.
For pylon racing with reed valve Cox engines, the bladder set up might allow for more aggressive settings but also increase the chances of engine handling errors that keep you from getting in the action.
The hard tank is still pretty hard to beat with all things considered.
11-04-2013, 01:43 PM
#18
My Fuji film tanks:
Last edited by Andrew; 11-04-2013 at 01:46 PM.
11-04-2013, 02:07 PM
#19
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Looks a lot like the old Hobby Shack 1/2ASST that was based of the Pride of Santee (POS) model we all flew back in the early 80's. Great flyers...
http://static.rcgroups.net/forums/at...g?d=1238045069
http://static.rcgroups.net/forums/at...g?d=1238045069
11-04-2013, 02:24 PM
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The film cannister tanks work suprisingly well, and I've experimented with other sized tanks (hotel shampoo bottles etc), but most of the time I seem to go back to a slack bladder tank, as they perform flawlessly.
This little racer has been relogated to flying combat against foamies (cos its more fun than racing against yourself,) and with a screaming 061 on a slack bladder, it'll happily do rolling circles around my head, even with only one aileron!
The cork idea is interesting, might give that a go, all I've been using is a peice of aluminium tube, with some saw cuts through it, rounded at one end. push the fuel tube over the aluminium, and the ballon over the fuel tube and attach using dental rubber bands.
This little racer has been relogated to flying combat against foamies (cos its more fun than racing against yourself,) and with a screaming 061 on a slack bladder, it'll happily do rolling circles around my head, even with only one aileron!
The cork idea is interesting, might give that a go, all I've been using is a peice of aluminium tube, with some saw cuts through it, rounded at one end. push the fuel tube over the aluminium, and the ballon over the fuel tube and attach using dental rubber bands.
11-04-2013, 04:33 PM
#22
It is, I believe, an Upstart designed by Owen Kampen. The design was published in '71 . Kampen was a prolific designer of small planes and experimented with many different materials to use in construction. He is probably best known for the Pacer, Super Pacer, Wizzard, Whiz Kid, Rivits and Dicks Dream although these are only a few of his contributions.
11-04-2013, 05:39 PM
#23
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I've been using the insulation off noodle wire (the flexible battery wire many of the car boys use) for fuel tubing. It's fuel proof and works well with clunks, plus it comes in colors (not necessarily a big seller for me). The tubing shown is from 14 AWG silicon wire. But, the balloon tank is likely lighter and it is anti-foaming --- the only downside with rubber balloons is frequent replacement and the chance of rupture (usually, if not frequently replaced).
My Fuji film tanks:
My Fuji film tanks:
11-04-2013, 07:23 PM
#24
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It is, I believe, an Upstart designed by Owen Kampen. The design was published in '71 . Kampen was a prolific designer of small planes and experimented with many different materials to use in construction. He is probably best known for the Pacer, Super Pacer, Wizzard, Whiz Kid, Rivits and Dicks Dream although these are only a few of his contributions.
The whole thing was slightly shrunk to allow for a babe bee to haul it, but in the end I wanted to go fast like ricky bobby
11-04-2013, 08:33 PM
#25
Building the Pole Dancer:
Print out the templates onto card stock and cut them out. Trace the templates onto balsa sheet noting the grain direction on the templates. I like to use a straight edge and xacto knife to cut everything out, even the templates. Pay particular attention to balsa weight and grain and you will have a superior model. I like to break the fuselage up into two pieces, fore and aft, so that I can use a little stronger heavier piece in the nose and some really light stuff for the tail. Use "C" grain for the horizontal stab, it's more warp resistant.
Smaller pieces also mean you can use all of those scrap balsa pieces in the scrap box!
BE SURE to transfer the reference lines and bulkheads location lines onto the inside of your fuselage sides.
Once you have the pieces cut out it's time to start glueing stuff together. Start by glueing the fuselage halves together and the two parts that make up the horizontal and vertical stab/rudder. Use the reference lines with a straight edge to make sure your fuselage halves are properly aligned. I like to use Ambroid here as it is very easy to sand and plenty strong for me.
After the glue dries, give everything a quick sand being careful not to remove your reference and bulkhead lines.
Next glue the nose doublers, fwd fuselage doublers, forward wing dowel doubler, wing saddle, and 1/8 sq bottom sticks to each fuselage side. Glue the triangle stock on the bottom of the slot for the horizontal stab. I like to use finishing epoxy for laminating balsa doublers. Be double sure to make a left and right fuselage side!
Take a little time NOW to plan your servo installation. Use the reference line on the fuselage sides to plan where to glue servo rails. I use 1/8 inch sq rails glued to the fuselage sides then topped with a 1/8 inch ply servo tray. I drew a line on the fuselage side parallel to the reference line where my 1/8 inch square balsa rails will go. Mount your servo as low as you can so you will have plenty of room above for your aileron servo. Especially important if you will be using HS81 or larger servos.
Enough for now. More in a day or two.
Print out the templates onto card stock and cut them out. Trace the templates onto balsa sheet noting the grain direction on the templates. I like to use a straight edge and xacto knife to cut everything out, even the templates. Pay particular attention to balsa weight and grain and you will have a superior model. I like to break the fuselage up into two pieces, fore and aft, so that I can use a little stronger heavier piece in the nose and some really light stuff for the tail. Use "C" grain for the horizontal stab, it's more warp resistant.
Smaller pieces also mean you can use all of those scrap balsa pieces in the scrap box!
BE SURE to transfer the reference lines and bulkheads location lines onto the inside of your fuselage sides.
Once you have the pieces cut out it's time to start glueing stuff together. Start by glueing the fuselage halves together and the two parts that make up the horizontal and vertical stab/rudder. Use the reference lines with a straight edge to make sure your fuselage halves are properly aligned. I like to use Ambroid here as it is very easy to sand and plenty strong for me.
After the glue dries, give everything a quick sand being careful not to remove your reference and bulkhead lines.
Next glue the nose doublers, fwd fuselage doublers, forward wing dowel doubler, wing saddle, and 1/8 sq bottom sticks to each fuselage side. Glue the triangle stock on the bottom of the slot for the horizontal stab. I like to use finishing epoxy for laminating balsa doublers. Be double sure to make a left and right fuselage side!
Take a little time NOW to plan your servo installation. Use the reference line on the fuselage sides to plan where to glue servo rails. I use 1/8 inch sq rails glued to the fuselage sides then topped with a 1/8 inch ply servo tray. I drew a line on the fuselage side parallel to the reference line where my 1/8 inch square balsa rails will go. Mount your servo as low as you can so you will have plenty of room above for your aileron servo. Especially important if you will be using HS81 or larger servos.
Enough for now. More in a day or two.
Last edited by 049flyer; 11-04-2013 at 09:36 PM.