JAE21 FE pulling to the right

[John MacLean]

Thanks, Phil. I am feeling more hopeful about this. It was disapointing to see it pulling like that when I was reading all the great success stories of guys who scratch build their own boats. Its hard to cut yourself some slack as a new builder in an environment of experienced builders and racers. Easier to wait for the funds to buy RTR stuff. But if it wasn't for the two guys I run with and the positive input from people on forums like this I propbably would have thrown in the towel.

Blackout, Nope I don't know how fast the thing runs. . . I only know that I was super impressed the first time I saw my SV27 FE run and this thing takes that up several notches.

 

[RodneyPierce]

You have to remember, John, that we all started somewhere. None of us built a perfect first boat. Dont sweat it. If you get the itch like many of us here, this will be only one of MANY wood boats that you build Each one gets better!!

 

[John MacLean]

yep. . . that's the advice i'm giving myself because it is exactly how I'd counsel any of my children or grandchildren who are just beginning any new activity or hobby.

The modifications have been completed. Just have to re-finish the bottom of the one sponson and it is ready for the water. Weather being what it is. . . I'll turn my attention to installing my new flex shaft in the REK outleg of the kneeler. Snapped mine about a month ago and have been wating for replacements until last week.

 

[Neil LaGarry]

One of the 3 .12 JAE hulls I built over the winter was off ,sponson wise. So it happens to us all. It happened to be the. hull I kept for my own. The 2 other hulls have no bad habits. As we all race together. Yes I mess up myself. and crashed my share of hulls. So I gotta build em myself The .21SGX RTR cost is over $400

Now my gas JAE is another story. I've mover and changed the rudder and plan on adding a skeg strut to try to get the hull to go straight at high speeds. It has a skeg on the ski now. I won't race her. the way it is. She has bad habits at high speeds.

 

[John MacLean]

Funny that the boat that looks the simplest to build can turn out to be so complex. One of the two guys I run with laughs at the JAE design saying it reminds him of three popsicles sticks. He isn't laughing quite as often since he has seen its potential for acceleration and handling in the turns. . .

I think part of my frustration was building from a set of plans that had the title FE on them and no details as to dimensions for locating the components. It wasn't until had the thing put together that I realized that the rear sponson is in the wrong place to accomodate a couple of 2s packs and the motor and ESC were both too far forward to establish the 60/40 ratio for the cg. That meant tearing everyting out of the tub except the sponson tubes and starting over. The scratch-build concept appealed to me but if I was to do it again I would purchase the FE kit from Zippkits and go with a proven build.

It was the same with the Redtail Kneeler. The boat was designed for a nitro set-up and the plans didn't really offer much in the way of set up details for FE. It was an interesting build and I enjoyed the challenge but perhaps bit off a little more than I can chew for a guy who had never worked with CA or epoxy. . . .I did a lot of reading but no amount of reading makes up for actual build experience.

Having said all of that I am looking forward to applying some of my hard lessons to building something akin to a whiplash sport 40 or OH-Boy-O'Berto this winter. . And knowing what I do now may even build a second JAE 21 hull.

 

[Neil LaGarry]

I like to hear that John

Don't give up on the JAE as they are fun.

,I used Zpoxy finish resin,Don't use it around nitro .My .21 &45 will need new tubs as the finish is shot and oils have gotten into the wood grain. West or KlassKote epoxy is what you need for a finish. I like KlassKote as it has colors. 30 min epoxy is advised for building ,the longer the setup time the stronger the bond. CA is used on inside framework. Thin CA then thick CA to get a weld like fillet . I always have a spare hull for a race season. And extra boom tubes as I like hitting buoys. My driving has gotten better over the summer. My .45 tagged buoy #6 and needs new right sponson ,which I have. When I build a sponson the brass is all dinged up with a Dremal or file to help hold the brass inside the sponson. Look you can see the screw in the right sponson.A fix between heats. The last shot before she broke apart.

 

[John MacLean]

Cool shot there. Nope I don't plan on giving up on the rigger. I love to watch them run.

Re: epoxy --- I tried the 30 minute stuff when I was building the Kneeler and before I discovered masking tape for holding parts in place on profiles that clamps wouldn't stay put. Sometimes I'd have to pull it apart and re-do because the parts skated around so much with the epoxy. And the first time I used it to seal the wood was a real disaster. . . . put it on with a paint brush and then used so much elbow grease to sand it smooth after it had cured.

I started the rigger about a month after I completed the hull on the Kneeler. This time I used CA to do the inital glueing and followed it up with a coat of epoxy along the seams. That worked a lot better for the tub and sponsons. Then I ran into some difficulty later with the bond between the spacer block on the transom and between the servo mount and the bottom of the tub. I must not have gotten the ratio of hardener to epoxy just right because the first time out the spacer block had pulled away from the transom. On closer inspection the epoxy was still a little gooey. It puzzled me because I was using a electronic kitchen scale to measure the amounts. I went back to the local hobby store and spoke with a guy who has been building wooden boats for a lot of years and he asked a couple of questions: What was I using to mix the epoxy in? I told him dixie cups. He thought they were manufactured witha wax coating which would have contaminated the epoxy. He also mentioned that when epoxy cures it leaves a waxy film on the surface which has to be removed before any toher bonding could take place. I bought some plastic cups, went home, prepped the areas by sanding and wiping with de-natured alcohol and re-glued the components. They haven't moved since. Long sotry short----getting the rigger in the water was the easy part. . . at first. LOL. Those particular issues are behind me now so I will look forward to getting this thing dialed in.

 

[John MacLean]

" When I build a sponson the brass is all dinged up with a Dremal or file to help hold the brass inside the sponson. Look you can see the screw in the right sponson.A fix between heats. The last shot before she broke apart."

Neil, when I was researching this build I came across a thread that discussed the merits of using carbon fiber instead of brass tubes in the sponson and tub because of the ptoential for a better ond between the cf and the wood. I went that route. One of m buddies had a bunch of carbon fiber shafts for the bolts on his cross bow that he wasn't needing anymore. Guess I'll find out how well they stand up and whether I'll use something similar in the future.

 

[Neil LaGarry]

I use paper plates and mixing sticks from Hobby Lobby for small pots of epoxy.{ Mix well} rubber bands and sticks

Use snow driveway markers as boom tubes ,made out of fiberglass. same dia ,Just orange in color. If your prone to hitting buoys Save a few bucks

 

[John MacLean]

Another good news, bad news day.

Good news is that the handlings issues are pretty much resolved. . . Vastly improved handling. Will include video as soon as I get it on my youtube channel.

Bad news. . . snapped a second flex shaft and lost prop and drive dog. This is the second 3/16 shaft in the space of a month. I'm wondering if there is too much of a bend in the stuffing tube. Can't afford to keep replacing flex shafts and props so I'm gonna install a teflon liner and run a .150 flex shaft instead.

 

[RodneyPierce]

careful with the teflon liner. If your breaking shafts, there is a reason. Find the problem and resolve the issue. There should literally zero resistance when you slide the shaft into the stuffing tube and spin it (when not attached to the motor) You also shouldnt be able to feel the s bends when sliding the flexshaft into the tube.

 

[John MacLean]

careful with the teflon liner. If your breaking shafts, there is a reason. Find the problem and resolve the issue. There should literally zero resistance when you slide the shaft into the stuffing tube and spin it (when not attached to the motor) You also shouldnt be able to feel the s bends when sliding the flexshaft into the tube.

Just another piece of information I didn't have in building this. Rodney, according to your description of an "S" bend I'd say that mine is too severe. I can definitely feel the bend when I am installing the shaft. I was careful to use a tube bender so as not to introduce any kinks into the tube and, given the short distance between the motor shaft and the strut, I thought I was careful to bend it as gradually as possible. This shaft last for two 4 minute runs.

Here is the raw video of today's run.

 

[RodneyPierce]

yes, def, too sharp then. Mine is flat at the bulkhead, then starts sweeping down and doesnt come back straight until about an inch in front of the strut. Its a very gradual bend.

 

[gil sonsino]

Hi John I was reading your post and would like to share my experience with you a I'm playing with basically the same boat equipped with a Leo 4082. First I see no reason to use a bend on a Jae Fe just keep the motor angled at aprox 7 degrees so you will have a smooth continuos bend to the strut.Second get rid of teflon liners as they produce lot of drag and up to 35k will make a big mess with your flexshaft.If you 're having issues with a 3/16 shaft I'm pretty sure the .150 won't resist too much too.Take your time and see what it is really necessary to modify ....just to save you some bucks!On my page there is the step by step of my building and feel free to contact me whenever you want.

Gill

 

[John MacLean]

Thanks again, guys. Naturally I was hoping not to have to tear the hull apart again but it seems like I will have to pull out the stuffing tube and re-do it. If I do that will I be any further ahead with the 3/16 shaft or should I abandon it in favour of a .150? I have a spare 3/16 shaft here.

Gil, you're right about not wanting to spend any more money than is neccessary on this build. I,ve already spent about 90.00 just on flex shafts and props and am no further ahead than I was in April. The angled motor is one solution I considered but it would mean fabricating a new cowl and that would make #3. I purchased the first one from Zippkits, then had to abandon it when I relocated the motor and speed control to get the cg right. I spent a lot of time makig the second one and prefer not to do a third this season. So, it looks like it will be a re-do of the "S" bend.

One thing I do know is that I will not put another 3/16 shaft in the current set up. Does this boat need a 3/16 shaft or is it just overkill?

 

[Blackout]

I'm no electric guy, but if you are breaking 3/16" shafts, .150" will not be the fix. Where is the shaft breaking? If you have a bad S-bend you will get a lot of heat at the s-bend. I know because my s-bend will melt any foam in the radio box that touches it, but I have not broken one single shaft even though I am getting too much heat. It's a .21 nitro boat. What grease are you using and what is the make of the shaft?

 

[Jim Caldwell]

Being a "Electric Guy" John I would leave the 3/16, Electric motors have HIGH tq. at start up unlike nitro or gas.

.150's are best suited only for UL 1 motor setups in my opion.

 

[RodneyPierce]

I agree with the above. If your breaking .187 cables, a .150 wont last either.

 

[Jim Caldwell]

Another thought, are you soldering the end of the cable about 1/4" where it goes into the collet?

The collet needs a hard surface to grip onto otherwise the strands move around when you tighten the collet and it loses its grip.

 

[John MacLean]

Jim, the end of the cable is still firmly held in the collet.