Retriever

[jbrandon]

After returning to the hobby last year and deciding I again wanted my own winch and retriever I went looking for them on the Net and found them but just too much money for my budget. I decided to build my own again. Off and built the winch in the style of what we used in the 80’s in Southern California, drum set up to feed off the bottom of the drum. Well when trying to make the brake work I found it almost impossible to get to work reliably with the line feeding off the bottom of the drum. Also we use to have the battery and winch as one unit with wheels and when setup the wheels would be removed. Well, I was a lot younger and evidently somewhat stronger in those days than I am now. I now have found the combined weight of the winch and Optima D31 battery a little too much for my back.

Started looking around and decided to split them up, making a small compact winch configured so the line would operate from the top of the drum making the break easier to configure and use. Got that all sorted out a couple months ago and then realized I really did need that retriever, so I built one like the ones we used in the 80’s.

I most often fly by myself (can’t seem to find many sailplane pilots in North Kansas City) and have been having a little bit of a problem with the retriever line knotting after I release from the tow line. When I have a retriever operator I don’t have the knotting problem, only when I am flying alone and allow the line to just float down. I was using #9 twisted line and today changed to #9 braided but still experienced similar problems, maybe not as many. And if there is much of a breeze like today then the line will drift back behind the launch point. After about 20 launches today I had no problems other than the line knotting, they can be easily worked out without cutting the line but it’s annoying. The #9 braided seems bigger than the #9 twisted but I have not been able to find a cost effective line to replace it with. I found a fishing line, 65# but it’s $15 for 150 yards and would need two, maybe even three spools and don’t really know how well it will hold up with use. I can load the retriever twice from one spool of line and usually the line will last two seasons and cost about $10 for the spool.

Those of you using a retriever what line do you use?

Attached is a picture of the pair set up and working together like the team they are. (And yes the winch is modeled after the Tim McCann winch and the retriever does resemble the Rahm retriever but is not direct drive.)

[sleep4]

Make sure you have two #5 ball bearing swivels connected with a stout split ring back to back where your retriever line is connected to the tow line. This should eliminate any twisting problems. I use # 9 braided line from Memphis Net & Twine.

[jbrandon]

Yeah, I did forget to mention I am using the double swivel setup and the line is from Memphis Net and it is #9 braided. The retriever line is attached to the bottom end of the chute with a split ring and the double swivel like you suggested.

[rogerflies]

It sounds like the line isn't being retrieved immediately after the launch. True?

The swivels won't do much if the slack like falls on the ground before being retrieved. But it's difficult to fly the plane and operate the retriever at the same time. One thing you might try is an automatic pick-up for the retriever line to guide the line down to the turning pulley when the retriever is started. That greatly simplifies operating the retriever, and you can run it just long enough to keep it from being slack when it hits the ground. Complete the retrieve after you finish the flight.

To do this, the turning pulley (TP) is mounted on a pivot rod, and a curved wand is attached to the top of the TP shaft. The whole thing is spring-loaded to move the wand in front of the retriever pulley (RP). A bar from the TP pivot rod runs over to rest on the belt driving the RP. When the retriever starts, the bar is flipped off the belt, and the wand moves over to pick up the line and guide it down to the TP. You have to reset the bar after you complete the retrieve so the line can come off the RP. I may be able to come up with a photo if you want.

It's not to hard to make. Judging from the looks of your winch and retriever, you could do a nice job of it.

I usually fly by myself, and I gave up on using a retriever. I just walk out in the field, use the chute as a landing target, and pull it back for the next launch.

Roger

[jbrandon]

Thanks for the complement! But let’s face it, the beautiful winch drum makes this combo shine! I get many complements on the winch drum, always give you credit, thanks again.

Yes, you are right about not being retrieved right after launch, I just run the chute down almost to the turn around and the retriever line will float back a long ways depending on the wind. But that was not root cause of the problem, the line was tangling even before release from the tow, video proved this.

I have looked at the idea of an automatic line pick-up and would like to add one but I am of the same opinion as you, when flying alone just leave the retriever at home. I took some video of the process and slowed it down and I found a couple of problems I could not see at the field. I would like to see pictures of your automatic pick-up setup.

First I had too much line on the retriever which was causing the line to almost stall then shoot off at great speed causing it to tangle when starting to pulse the winch. I guess I had almost 1000 feet of line, far more than needed. This has helped some, I now only get a tangle every forth or fifth launch or so instead of almost every launch.

Second is the retriever drum is flat bottomed so the line piles up and does not want to pull off evenly causing the line to want to tangle and ravel off when the launch line slackens a bit while pulsing the winch. I have not solved this one yet but will probably change the retriever drum to have a V bottom. And yes, when retrieving I never pulse the retriever, just start it and run it all the way back in one shot to help keep the line tensioned evenly. Leaned this one many years ago.

Maybe I’ll work on the retriever drum today but heck, I just received my Honey Bee King and it is just crying to be built and crashed - and I am sure I can do it all in one day!

[rogerflies]

We always used a hoop (similar to the one in the photo) in front of the retriever to keep the line under control as it came off the spool. Maybe that would help some.

The other pics show a somewhat larger retriever (16" bike rim) with the automatic pickup. Hope they help.

The first shows the wand in the retrieve position in front of the spool.

The second shows the wand in the launch position.

The third shows the bar resting on the drive belt holding the wand in the launch position.

Roger

[mdennis]

JBrandon,
I fly on the other side of KC. Here is a drawing by Mark Drela of a hands free retreiver design and picture of another hands free design courtesy of Brian in Tullahoma. I have more pictures of Brians setup if you want them email me at m-dennis@swbell.net

Mark

[ThermalBuster]

Over the years we have found that if tension is not maintained on the retriever line during the retrieve it will jump off the spool in a snarl on the next launch. I expect that when you let the line drop to the ground and then retrieve the first part of the retrieve is loose on the drum. That is what I believe causes your snarls. If the retrieve is started while the line is still in the air the line is taut enough to provide the necessary tension. A hands free setup will probably solver this problem.

We also load our retrievers with line by pulling the end of the retrieve line off of the shipping spool from the retriever clear out to the turn around and back to the winch. The first retrieve pulls the winch line out and through the turn around and back to the retriever. This puts an initial tension on the retrieve line and seems to make it less inclined to twist up. The pull is made without a harness so that both lines pass easily throug the turnaround.

We use the MN&T braided line.

Hope this helps.

[Tonasty]

I got this Retreiver

[mlee8249]

Hi Tonasty,

And that's one fine looking retreiver, sir! Note the wet look, indicating an all-weather, all terrain model retreiver...very rare indeed. Does this one have the voice command option?

Mike Lee

[jfrickie]

Just FYI Jim. My retriever uses 40lb waxed kite string and I am able to fly and retrieve by myself. Are you going to ST. Louis this weekend? If so I will provide the adult beverages.

[jbrandon]

ThermalBuster (http://www.rcgroups.com/forums/member.php?u=41868): I agree with your reasoning and use of the retriever, we learned that many years ago in California. The line tension is very critical, especially when putting the line on initially but I also learned as long as the retrieve was uniform then it worked okay also. I still think part of my problem is the diameter of the line and the shallowness of my drum allowing the line to whip off and tangle with surges during the launch. But alas, I had to play helicopter pilot today and did not get the drum modified, went through 4 battery charges and still have a chopper in one piece, although my nerves aren’t! Did manage to hover for about 90 seconds at one time, not totally!

jfricke: Unfortunately I will not be able to go to St Louis, sure wish I could for a number of reasons. I did send you an email…

What and where do you get the line you use? The 40# test should be more than adequate for this purpose. I really think the #9 is part of my problem (shallow drum) but have not found a cost effective solution. I have seen your retriever and it is an automatic one which I really like but do not know if I can duplicate the bail yours has. I also looked at the drawing presented by mdennis but have not studied it enough to decide if I can do it or not. Chopper got in the way today.

Tonasty: Looks like you are abusing that retriever! Poor dog, wet and cold, probably hungry! I sure hope you let him sleep in your bed with you at night! Golden’s are such great dogs, can’t even really call them dogs, more like good friends.

You know, the voice command option sounds great! Far better than any piece of automatic hardware!

[Tonasty]

I've actually been working on the whistle activation system. Also the smooth retrieval needs a little work. Yes she is more like a friend and she is definitly a better fish spotter than a retriever though.

[jbrandon]

Okay, thanks to everyone for their suggestions. I think I have solved my problems using a combination of just about everyone’s ideas. But I think the biggest was remaking the drum with a valley to accommodate the line so as the line is laid into the groove causing the line to have a more flat top surface thus not causing it to bind and lay up over its self which results in smoother feed out during launch. See picture. I tried a 1” V groove but did not work a lot better. This one is 1 1/2" wide and more rounded. In the picture the back side appears to be lower but in fact both front and back are the same diameter and the bottom of the valley is almost centered. Still using #9 braided line (would like to go lighter and smaller diameter) and loading the drum with the spool at the winch and running it out to the turnaround and back to the retriever, line is cut, swivels added and winch line attached and pulled back with the retriever thus tensioning the line before the first launch. This gives more than adequate line resource without overloading the retriever drum.

Here is the setup, winch and retriever set about 5 feet apart. The winch is set up as you normally would, retriever is staked down and a “hoop” is placed 25 feet in front of the drum with the line running thought it. Retriever line end has a snap swivel with second swivel (no snap) in the opposite direction (butt to butt) to the bottom ring on the chute. Launch operation is normal, when plane is off the line it is placed around the hub and retriever is started and NOT stopped until the line is back to the hoop. I did try a couple of launches and just ran the winch line down with out retrieving and after landing retrieve the line (one man flying session) and it seemed to work okay but did notice some line twisting but not enough to bother anything. But here again, it was only three or four not an all day affair. So for flying alone I think I will leave the retriever at home and hoof it out to land and grab the line and walk back, hey I need the exercise anyway!

Made about 35 (trying for 50) launches yesterday and NO, repeat, NO snags, tangles, retriever induced popoffs, breaks or any other retriever malfunction other than the motor, it died! I have a lawn tractor starter motor to replace it with.

I’ve also included a drawing of the retriever if anyone is interested.

Thanks for everyone’s help sorting this out. And yes, that is a glass of water!

[dr.E]

Retreiver and turn around ;)

[sleep4]

Some pictures of my newly completed launch/retrieve trailer. The retriever is the Hands Free competition model from Rick Bothell.

[rogerflies]

That's a nice looking outfit. Is that the production version of the retriever pictured here? Looks similar in function.

What is the black plate with the hoop on it at the front left of the trailer?

Roger

[sleep4]

This is indeed the production version of the one in your picture. The black hoop is a line guide for the retriever. It is placed about 10 feet in front to guide the line to the spool as it is being retrieved. Sorta like the line guide on a spinning rod.