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The Crane Reel: A new method of controlling my line
edited June 2014
Cool. Reminds me a bit of the old military backpack wire spool marynowskhy was using:
I am experimenting with a wider stratospool-type reel myself and had to create a multi-position "line-guide" controlling spooling to make it work well.
Are you guiding the line with your free hand while spooling (so as to evenly distribute it and keep it from piling against the flange) ?
Pictures and everyone is happy :-)
I'm happy! Picture picture picture.
I need to go over them and think about it before replying. I'm kind of a halfway between the halo guys and the Stratospool guys. I have mixed feelings about both.
I will try to pick up on the open items in the above posts:
This afternoonI decided to test he time requirements of my system, using the Adult Reel.
Arrived at park at 2:55
Kite assembled at 2:59.
Started actual flight at 3:03.
Achieved all line out (half mile) at 3:07.
Kite back in my hand at 3:14
Kite and reel loaded in trunk of car at 3:20
Wind velocity at basic, using the Beaufort Chart, 4-6, frequent increases of 7-10, and some gusts at 11-16.
Kite is 9 foot Gomberg Delta.
Power from Battery powered,18 volt, 3/8 drill from Home Depot (El Cheapo)
I level wind the line across the spool so it does not pile up. Piling up can cause it to embed or go slack on the spool. Use gloves on both hands because of wind velocity. Line pull was between 5 and 8 Lb., and in gust up to about 12 Lb. while rewinding.
I have tried mechanical brakes but because of the great variation in line pull, the only effective way is to use a gloved hand.
To Mr. Grumpy --- I have a very short attention span. No hard feelings. Appreciate all comments.
The power drill can easily handle 25 Lb. of pull. Any more than that it slows and uses two batteries to finish the job. Is 20 Lb. pull "slack line"?
The frame strapped to chest can get in the way, but it is easy to release the waist strap if you need to climb up on something. Also it is easy to release the shoulder strap and carry the whole thing to another location using the rope brake. The whole thing can be strapped to a ground anchor.
edited June 2014
I like your idea with the drill. However that 3/8 drill and reel will implode under load unexpectedly. The reason i say this is because I have been using a similar system for over six years. Dozens of variations. I have included a pic of my current winder which holds 2000 ft of
dacron and has not failed in its current configuration under extreme load at times. Most likely failure will come much sooner with the spectra twisting forming a small knot due to slack conditions. Line twist will be a major problem unless the line is maintained when needed. At first signs of line twist I send the kite up with no camera and attach a ball bearing
ball bearing swivel . When I reach a splice in the line I let it spin out while spraying lubricant to the swivel as it can get very hot. All this must be done on the fly. I do not want to sound like an expert but I probably have thousands of flights with this method. You need a drill like the one pictured. This drill has 650Ft inches of torque with 3 speeds with a speed sensitive trigger. You will also need a drill with a clutch,extra batteries,charger in your car along with a 700 watt inverter to power the charger. The handle on the drill is key as it acts as a stand on the ground and allows you to let line out. To conclude a 3/8 drill and a plastic reel will fail under load with a 20kt wind a 9ft delta. Have any questions please feel free to post a message.
Darren A Wood
Real is made from:
Bow roller for boat trailer; Boat Us: $30.00
1/2 Threaded Rod
1 inch x 1/8 Diameter Hollow aluminum pipe
3/4 x 1/8 aluminum hollow pipe slleved inside 1 inch pipe
spacers ford threaded rod to align properly in pipe
4 stainless 1/16 x 1 1/4 inch washers for 1/2 threaded rod
2 Stainless 1/16 x 3/4 inch washers
2 1/2 inch jam nuts
Washers should be of high quality marine stainless from boat store. Hardware store washes will cup very easily the crack.
Pipe in between reel no loneger than 5 inches
Threaded rod must extend into chuck 100% or chuck will loosen under load
Google+ links did not work for me.
Jim should be workingh now.
edited June 2014
I like your approach to this. The modular PVC construction is a great idea. I had not considered using PVC as a building block, but I can see from your design that it has a lot of possibilities. How did you form the curved components? I also like the idea of the reel axle being open on one end because it eliminates the need to have a "live" axel when connecting a power drill to it. I also like how you've constructed the core of your spool. Looks like it can handle a lot of compression without collapsing. It would be interesting to see how this would work with a narrower spool. This would require larger diameter and more robust sheaves on the ends because the line would pile up against them. Some type of friction break would be nice as well, although I agree that a gloved hand works well for this. Do you have any way of locking the spool in place once you've let it out as far as you want?
I can see that you've done a lot of development work on this. For me, the evolution process of this sort of stuff can be as fun as using the final product. Keep up the great work and I'm looking forward to see how this design progresses.
edited June 2014
It is interesting that Mike mentioned the compression - enormous pressure caused by the windings of fiber. The hub and its connection to the sidewalls has to be very strong and durable. That is why the durable little winding hoops amaze me!
This thread reminded me of some good discussions which may be germane to Frank's reel, if it evolves in terms of hub strength. To be really honest about it, I applaud The Crane Reel but feel it may be a little weak after daily use. It IS a great start and a good idea!
It may be worth mentioning that this subject becons back to 2012, when Wind Watcher initiated a group study of sorts, intended to address strength and lightness for high-pulling kite lines.
is that very educational thread. As a result of those discussions and interest in the crushing and side-exploding strength of winding kiteline, I contacted a researcher, Timothy Walker, who actually specializes in reel strength and dynamics. Using his own computer modeling, he offered the following information for typical braided 200 pound braided Dacron.
Given a 2-inch wide, 4-inch diameter hub, and just a 1-inch build up of line having only 10 pounds of tension, Timothy found the nominal inward radial pressure to be 500 psi (or about 3450 kPa) - WOW! The outward pressure on the sides of the sheaves (a major part of our discussion in that thread) can be anywhere from 50 psi to 300 psi. The result is very variable and relates to the "sliperyness" of the line and several other factors.
Bottom line, just know that the hub must be very strong, and the sidewall intersection must be very resilient. Here are some geometries that I played with later. I am sure others have ideas as well.
Please ignore these diagrams' laminated plywood material - we were talking about Sratospools at the time. Stiff wire "saddles," gentle filets, and even periferal beads on inner faces would help prevent broken walls over time. (To clarify the beads, these would prevent line from hitting directly on the stress-riser intersection of the reel face).
These recent postings are very impressive. I'll try to answer without going into too many technicalities.
I cannot understand why anyone would tolerate a system that causes twisting of the line. Tangles and kinks do more to damage line than most any hazard except maybe stepping on the line over gravel. In the example of my recent time trial, when I disconnected the kite and let the loop dangle below the spool there was not a single turn of the loop. I do not want a swivel because of added weight and the added exposure to line weakness at the connection.
In my experiments I found the diameter of the barrel to be important in terms of leverage, speed of recovery, cost , and weight. In addition, forming the multiple layers within the spool is very precise. The outer layer is heated to expand before it is assembled so it fits tightly. Inside are three layers. One is a layer of Sched. 80 PVC which adds enormous strength. It is probably a case of being "over-built", but in my research and reading several comprehensive engineering studies on compressive forces, I concluded that there was not enough scientific evidence of the actual force encountered in the loading of a spool barrel under the conditions we see in flying a kite. I would not like my spool to be used for anything over three miles and not more than 50 Lb. of pull, but I cannot always be in control of that.
In addition to the barrel diameter, the length is important at 7 &1/8 inches so the line can be wound without loading it against the flange. The studies show that barrel failure is most vulnerable at the end of the cylinder. Furthermore, loading the line against the flange could expose the line to nicks and damage.
Each turn of the spool creates a specific amount of force. The PSI is not especially important, any more than when I weigh myself should the scales tell me how much I weigh per square inch. The spool diameter is 18 inches. A half mile of line would be 1760 turns. A pull of 20 Lb. creates a compressive force of 10 Lb. on each revolution. The accumulated force would total 17,600 Lb. of compression. That's why so many of the reels on the market have failed, including some of my earlier models. I have tested the barrels in my current design and have never found any distortion.
Earlier I wrote about making a lighter weight spool, but I am not sure that would be a good idea. A shorter barrel may result in someone winding the line against the flange and that is something that should be avoided. I do not want to put anything on the market that could result in problems.
Rewinding the line, as I said in reporting on my timed trial, goes very fast. It took 7 minutes to bring in a half mile on one battery. I do not always use the power drill. I can bring in a half mile by hand in about 20 minutes. Arm gets tired, but I like the feel of a kite. It almost as if it is alive. The location and length of the handle is designed to give the best leverage and arm motion to make this fast and easy. The handle is also used to lock the spool in place when you need to stop the outgo.
The way I have built the spindle allows me to remove a spool and replace it with another one with a different kind of line. When I give instructions on the use of a power drill, I require the tool be dual and variable speed, with adjustable clutch. The clutch is critical because if the line snagged on something, the power of the drill will rip it right out of your hand before you break a 80 Lb. line. I also include references to standard kite rules and FAA stipulations.
I have been offering my reels for sale locally here in the San Jose area for the following prices:
Reel frame adult size, including belts, scissor, and spindle removal tool ------- $75.00
Adult Spool without kite line ---------------------------------------------$25.00
Junior Frame including belts, scissor and spindle removal tool ---------------$40.00
Junior Spool without kite line --------------------------------------------$15.00
Drill rewinding attachment -----------------------------------------------$10.00
I have no idea what shipping costs would be. I have an inventory of 10 completed reels for each Adult and Junior sizes and would like to sell to recoup my materials costs. That means my loving labor is for free.
edited July 2014
Hey Frank - That all looks reasonable in terms of what you have put into this rig and the strength it offers (you may have typo/meant "18 inch circumference" in the post above by the way), and the wall intersection with the hub appears not to be a big issue.
Two things I am concerned about relate to the reel's operation when in hand-only mode. Even though the adult version will crank a minimum of 18 inches per turn, how do you let the line OUT quickly when the wind is doing the work -- would the handle be swinging around really fast? If so, is your gloved hand on the hub or the left side face? I seems it would be hard to grab the right side of the hub. Sorry if I missed something in the photos.
The second thing is, with a fairly short handle (not using the drill in this case), wouldn't the pull required on each turn bringing the kite in under strong tension be a little high? Is there some kind of extention handle?
These are not criticisms - just questions. Everything we see - even in nature - started as a concept, yes?
Explanation Of The Re-Wind Attachment and more,
Wow --- How to make that error? Yes it is circumference of 18 inches. Thanks for picking up on that.
On letting line out, if the wind is low, one gloved left hand on the spool flange is enough braking power. In strong wind I reach through with right hand glove putting pressure on the spool barrel, avoiding the handle because it is spinning rapidly and will give my knuckles a good rapping. Many experiments with handle length came down to a fairly short draw. True, if you are getting up to 25 Lb. pull or more, it is a good workout if you have a lot of line to rewind. With only a thousand out it is nothing.
Some people said they didn't understand how the drill attachment would work They want to see it in action so I will set up a photo display soon as I can. In the meantime, please go back to my photo spread. In the last photo you can see the white PVC cup is on the drill. See the copper cup in the center, and that the white cup has two grooves. I operate it while I have the reel apparatus strapped on my chest. I hold the rewind cup up to the handle on the spool so the two grooves latch on to the handle and the center cup is supported on the spindle. In Pic. 3 & 4 you can see the handle and central spindle. Turn on the power drill, slowly at first and gradually increase the speed. At top speed it is turning too fast and pulls the kite too quickly. At that speed the kite is likely to pass directly overhead into the wind and if I kept going like that it would crash behind me. When the line reaches vertical you have to keep your eye on it and slow down. You also have to keep a hand on the line at all times to level wind the line. At he end of flight especially because it will go slack and get wrapped around your neck.
There is absolutely no twisting of line; no tangles to waist time on; no nicking and weakening of my line. As soon as I have my kite down I am ready to attach another kite and start another flight. One time I took some small stakes with me to hold the reels in the ground and flew three kites at the same time, each one on a different kind of line. When you do that you can really see the difference in line/wind drag with the fatter Dacron line compared to the Spectra.
I kept studying the post from Connecticut Kaper, Mr. Wood, to try to understand why he has to use the swivel all the time. It looks to me like he plays the line off the end of the spool rather than having the spool turn. That would account for the constant need for the swivel. However, If the line goes out flat and returns flat there is no twisting.
I have not done thousands of flights, only a few hundred. The power from my cheepo,18 volt drill, is more than enough to bring in a half mile of line in seven minutes. The spool is made from plastic, but not just ordinary plastic materials. The outer casing is the type of PVC used in deep water wells. The gray Schedule 80 on the inside is used in high pressure commercial applications. The spool is over seven inches between the flanges so I do not load any line up against the flange. In my earlier trials I always rewound my line under less tension when I got home so it wouldn't stay so tight on the spool barrel. I was afraid there would be some distortion. I don't bother to do that anymore and I do not see any evidence of the spool imploding in the near future.
It is more fun to not be in any hurry and just bring my kite in by hand. You get the feel of the wind, the kite is alive and the birds are curious because you can stop and start over and over again!
This is Frank Crane signing off ----
Thanks Frank for the extra detail on the materials used in your kite reel. I agree the strength of the materials used is critical. I agree the kite reels permit rapid deployment and retrieval times. The stratospool that I currently use can also play out and retrieve line in about the same time that you mention above.
To help us get a better feel for the operation of your reel I recommend a simple YouTube video showing the following basic functions of your reel (the adult size). You can do this with any simple cell phone or point and shoot camera and past the link or direct feed here in this thread (see example below).
- Playing line out
- Winding line in with the manual crank
- Winding line in with the power drill
- basic overview of the parts and how they are assembled.
See this video that I did for the stratospool as a reference.
Looking forward to seeing the spool in action,
There are some really nice graphics above suggesting ways to stiffen Strato-type spools to better resist line-stretch/compression sidewall blowouts, and as I have been redesigning my reels a bit, I have been planning to switch from the eye-screws I have always used as line guides, to a u-shaped metal piece attached to the top crossbar.
As I thought about it, though, the eye-screw is an automatic system for loading the higher-stretch line in the center of the spool, because when the wind is light, it is easy to use the top hand's thumb to shift the line in or out on the spool, but when line pull increases, that hand is busy holding the reel, and less likely to artfully arrange the line as it comes in. A system that allows tight line to load right against the spool sides will increase chances of blowout.
I have already started using a different type of assembly screw, with a much larger head, which will make the spool even stronger. I would like to mention, though, that I have built almost 1000 reels, and have only heard of a couple that have failed, both used by folks flying hard-pulling kites in big winds at or exceeding my design specifications, and those folks stored their reels with highly tensioned line still on them, something my instruction sheets caution against. One repeat customer, who could certainly have asked for a replacement, merely let me know he had had a problem, and when I remember to mail it, I will be sending him a new one.
One good thing about your Crane reel is that the wide spool should be pretty immune to crush issues.
I have posted two new videos on YouTube. You can find them on YouTube @ The Crane Reel --- and here are the links for both scenes.
I went to my daughter's place south of San Jose where it would be away from traffic noises. The only problem was that there are lots of trees that blocked most of the wind velocity at ground level. Up at 50 feet or so I had about 6 to 10 mph. When you bring a kite in as rapidly as my power system works, the kite can play tricks. This might be different when the kite is loaded with camera equipment. I have not tried that. So I let my kite float to the ground and reeled in the last of the line.
There is one technique I did not show: How to slow the spool using both gloved hands, with a strong wind and strong pull. It really works just fine. Place the left hand on one flange and the right hand on the barrel of the spool. Keep hand away from the handle when it is spinning fast because it will give you a good rap on the knuckle.
I think the chief disadvantage of the Crane Reel is its weight and bulk. At a total of about 8 Lb. The frame at about 13X13 and 9 inches tall it takes up more space than other reels. The spool alone is about 8 X 8 inches. Even so, It is easy to carry the whole thing with one hand when the spool is locked in place. It is easy to hike with it strapped to your chest, just don't climb fences or jump across ditches. Also the spool can be taken off and carried separately.
The length of the spool barrel is important so that the line can be wound entirely on the flat part of the spool and not piled up against the end flanges. The left-hand glove is necessary to control this aspect. The location and length of the handle is critical for effective leverage and speed. The handle also transmits the feel of the kite line so you know at all times how the kite is responding to changes in the wind velocity without actually holding the line. The spool bearing is an aluminum bushing, not plastic because plastic would overheat and wear out.
The Junior Reel is a great way for youngsters to get started flying and I have recommended using 35 Lb. line and a max of 1200 feet of line. It is pretty sturdy for that kind of flight, but it is not built to handle a pull of any more than 20 Lb. I have not seen any distortion of the spool with the testing of line with a 10 Lb. pull and the frame has had no failure. But that reel is not the subject of interest to KAPers. That's why I showed it only briefly in my demonstration.
Last year I went to the Kite Festival in Berkeley and had a blast showing my reels as I walked around meeting people. I was not really ready to sell anything at that time so didn't push the idea. I'll probably go to Berkeley at the end of July and maybe see some of you there, July 26 and 27.
But in the meantime if you have questions or comments, shoot me a reply.
This is Frank Crane
The Crane Reel:
Excellent summary and video. Job well done. This helps a lot to understand how the reel works. Thanks for posting.
There are several aspects of the earlier postings in this forum that I continue to puzzle over. I studied Connecticut Kaper's notes on his reel system and like to inquire as to how the line is twisted so much that the swivel gets hot. There must be a problem somewhere. Furthermore, a hot attachment on the kite line can weaken the line.
On the question of the power drill having the capacity to rewind the line, my test a few days ago proved that there are limits. My first flight with 9-foot Delta out almost half mile and retrieval time took about 8 minutes. So next I shot my 11-ft. Delta up about 1200 ft. and brought her in rapidly but the battery ran out of power when I still had a couple hundred ft. to go. I had a spare battery in the car but I just cranked the last of the line in by hand. There was a couple of families watching so I pretended that this was on purpose.
Reeling in 2600 feet of line in 7 minutes requires the reel to turn at aprox. 4 turns per second. This can only be done with a strong power drill, not by hand.
A year ago I used to rewind the line under lower tension after I got home. I thought there could be distortion of the spool barrel because of the tight line. I don't do that anymore. Never have had any distortion at all. Now, I have to qualify this statement: I have not had a kite flight session where the pull was sustainable at more than 18 Lb. Some brief gusts have given me over 20 Lb. pull and you can really feel it. This part of California does not get that kind of wind very often. I think most of us avoid kiting with winds of 20 or 30 MPH. Am I right on this?
edited September 2014
20lb on a 9 or 11 foot delta would be pushing things I think. Higher tension is usually related to other kites. Sleds, rokkakus, flowforms, pilots, etc. Maybe a 16 foot delta. Kites with which the phrase "pulls like a horse" is associated.
It's why a lot of us like working with deltas. They are amenable to slack line conditions, will almost never try to cut our hands in half if we accidentally or intentionally wrap a gloved hand, do well with thermals, keep a steep line when that's desired, can be handled easily by hand during the entire launch/flight/retrieval. . .
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