rcworld2000

ok now that im done with training i wanna convert my hobbico 60 to wing bolts

any help would be greatly appriciated..

kiwibob72

Why, what exactly are you looking to gain from bolts that the rubber bands won't allow for?? (I've seen guys totally abusing "trainers" with heavy handed aerobatics etc without issue before, so am a little lost as to what more you need from it - if in doubt, put another band or two on)

balsatermite

No matter how long you fly, your never done learning.

52larry52

My Feedback: (1)

Both kiwibob72 and balsatermite are right on all points! The Hobbistar 60 is not an easy one to convert to bolt on wings due to a lack of room to install dowels in the front, or a structurally strong bolt plate area in the front area (for 4 bolt style) of the wing. It will require surgery on the wing, engineering, and fabrication skills to accomplish. There is a talented guy from Canada who did one a few months ago and did a thread on RCU about his project. He also installed a gas engine in the makeover. Search for his thread and see what he went through. Not worth it, in MHO. Do as kiwibob says and throw an extra two rubber bands on if your going to fly a little "sporty". A better project for your Hobbistar 60 would be a taildragger conversion and learn to fly that landing gear configuration.

Avistarpilot

I was reading on here somewhere of a guy that was using 2 bands of HD velcro. Sewed the rear in a loop to slide over the rear dowel and go under the front dowel then wrap it around front and hook it back onto itself. Sounded like it worked pretty well. With that said I've done some pretty heavy positive and negative G maneuvers with my Avistar and I've just got rubber bands with epoxied wing halves. I think I usually strap about 10-12 bands over the wing and haven't had an issue yet. Rubber bands are a bit of a pain since most scrap them after a day at the field but that's up to you. They are cheap enough to replace.

rcworld2000

With all that being said. I never thought about just adding a few more bands. I think I will consider the tail dragged idea. And threads that can help with that?

jester_s1

Waste of time on both. Let the trainer be the gentle flyer that it is, and use your Ultra Stick for bashing around the sky. Taildragger conversions are fairly involved because they require moving the landing gear block and building the necessary reinforcements to keep them in place. You'll have a day when you decide you want to get your trainer out again and just float around in a calm sky. Leave it alone and eventually pass it on to another student who wants to learn on it.

TomCrump

Years ago, I converted my trainer to a tail dragger. It proved to be an easy project, that took less than an hour.

The tail dragger version put new life into a model that would have been ignored otherwise. I flew that old Goldberg Eagle II until I wore it out, and then built another, as a tail dragger, because I liked it so well.

Calvinman

I like using wing bolts just for the fact that you get the wing in the same spot every time and it is a lot less hassle than handling rubber bands.

I would not go through the hassle of converting an aircraft over to it though, as stated it is not worth all the effort.

A tail dragger conversion sounds like fun though, the challenge with the trainers is to make the tailwheel steerable. I used a pull pull on my Tiger two with heavy duty thread and it seems to work ok, at least a lot better than when it was rudder only ground steering.

Calvi

AMA 74894

My Feedback: (1)

steerable tailwheel = no problem!

grosbeak

Talented guy from Canada - now that's a description I can live with!

My Hobbistar has certainly come a long way. From the very first day of flight school...




... to now.



You can check out the RCU wing bolt conversion thread or the full write up with pictures on my website: http://www.grosbeakrc.ca/aircraft/ho...oltonwing.html

52larry52 is dead on in one respect - the Hobbistar is not super easy to convert to wing bolts. Having done it, I do think it was worth the trouble. Note, though, that I'm one of those guys who gets as much out of shop time as I do out of flight time. And while I didn't keep track, I estimate this took between five and ten hours of work.

The end result is that it's quicker and easier to attach the wing, it's always centred, you don't need a constant supply of rubber bands... and it just looks better.


Other mods to this airplane include the following:

• Wing rebuild (post tree strike)
• Tail dragger conversion
• Dual aileron conversion
• Gas engine installation (DLE 20)
• Ski / wheel combination
• Heat formed custom cowl

Calvinman

Looks sweet Grosbeak, love the tundra tires!

Jim the challenge with making a steerable tailwheel on most of the trainers is that the rudder ends on top of the fuse.

Calvi

rcworld2000

that thing looks awesome

Calvinman

I am going to check out your thread Grosbeak, maybe I can adapt it for my Tiger 2, I love shop time too

Calvi

AMA 74894

My Feedback: (1)

+1... think I was having an early 'senior moment' nonetheless, still not a terribly difficult engineering feat
good luck however you decide to go!

Calvinman

I have been having a few of those myself lately Jim

Calvinman

Here is a pic of the tailwheel steering on my Tiger 2, note the upholstery thread to make it pull pull.

rbenn

The answer to you question is in the AMA's Sport Aviator article "Not your stock Hobbistar" by Frank Granelli. https://www.modelaircraft.org/mag/FT...22/22main.html

grosbeak

That was a challenge with the Hobbistar. I notched the elevator - here's my first approach:




That was a lot to ask of a little wire and it ended poorly this year in the snow...




... so I've extended the rudder instead.






You can see all of my tail dragger conversion photos on Flickr: Hobbistar 60 - Tail dragger conversion
You can see all of my Hobbistar pictures on Flickr too: RC - Hobbistar 60

- - - - -

Thanks for the kind words, folks. It's been a lot of fun!

ho2zoo

My Feedback: (5)

Many years ago I converted a 60 size Ugly Stik to have wing bolts. It seemed easy in my head but it was a little bit of work. Was it worth it? Well, I think so. I did learn a lot. Du-bro used to make a wing-bolt kit, with plastic mounts to accept the bolts, but I don't know if they still do. The hardest thing I think is getting everything lined up so that the wing will sit right. I had to strengthen the center of the wing with plywood and epoxy to make sure the dowels did not rip out. Here is a simple drawing:

Calvinman

Hi ho2zoo, I had to take out one of those old Du-Bro bolt kits from an old Sig Kommander wing I have kicking around for my second Ultra sport, I did not double check every thing and when I drilled the holes for the wing bolts, the bolt would bind on the torque rod for the aileron(flap in this case). The bolts in the Du-Bro kit were waisted down above the threaded portion for easyer break away. Alas the plastic was too old and brittle and broke under the first tightening. Now I have had to remove some of the material from a standard /4 inch nylon bolt.

I seem to remember back in the days of RCM one of the writers recommended cutting these bolts part way through to make them break away easyer? I also found nylon bolts with a bevel under the head(flat?) and a nylon washer to accept the bevel which helps spread the load.




Calvi

a70eliminator

I converted my trainer plane to wing bolts simply to eliminate contact with oil soaked rubber bands, had absolutely nothing to do with aerobatics. Do it and you won't ever regret it, rubber bands are a hassle.

52larry52

My Feedback: (1)

Yes grosbeak, you're the "talented guy from Canada" that I referred to. Glad you found this thread and posted a link to your Hobbistar redo thread. Each flyer can read your report and decide for themselves what Hobbistar mods they want to tackle.

jester_s1

On the topic of weakening wing bolts so they'll break in a cartwheel topic, just don't do it. Nylon is remarkably flexible and takes shock loads very well. If you weaken it enough to allow the wing to snap off of the airplane in a crash, you'll also be weakening it enough to let the wing snap off of the airplane in a tight loop. I hear it from time to time that nylon bolts can save your wing or landing gear, but I've yet to see it happen. The only real advantage of nylon bolts over a smaller steel bolt is that the nylon won't vibrate loose. That's reason enough to go that route, but don't expect it to prevent aircraft damage in a crash. If you want that, stick with rubber bands on the wing since that's the whole reason trainers use them to begin with.

And on the conversion process, ho2zoo gave you a good start. But I've done it too to a BUSA Phaeton and will add that you need to make a hardpoint inside the front of the wing for the dowels and will need to make double sure that the plywood plate at the back is going to handle the loads well enough. It's not technically right to use the plane on the back like that, since you'll still be tightening the wing bolts onto a hollow surface. That said, many pilots get away with it since the loads at the back of the wing aren't really that high. But if you glue dowels into the front and just have them stuck through the spar and attached to the sheeting, that won't likely be strong enough to take the flight loads.

grosbeak

It happened to me with a different aircraft - a Pulse 125. I had a fairly slow cartwheel on landing and the stock wing bolts broke just like they should, saving the wing. That was my aerobatic plane and the time so it had been subject to plenty of load.

As for rubber bands, they'll break in a cartwheel - unless you use too many.