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jmcowart 08-23-2011 07:39 PM

Apprentice 15e Modifications
 
Having read all the forum posts Icould find on the E-Flite Apprentice 15e it became apparent there were two problems that came up several times. These are problems that can be solved, or at least addressed. Even by a novice of unskilled hand and uncertain talent.

The two problems are the tendency of the landing gear and small wheels to cause problems when landing in grass. Particularly long grass. A lot of us are in that state and are faced with long grass on a routine basis. Secondly, it seems that when the aircraft is snagged by the nose gear and pitches forward onto the propeller it frequently causes bad things to happen to the engine case. Ihave seen a lot of discussions regarding cracked portions of the plastic case.

As I say, these seem to be related problems that can at least be addressed.

I just purchased the Apprentice 15e. Looks like a great trainer and a good investment - once the apparent problems are dealt with. I found some excellent posts by leonstevens on the landing gear. To make his work description very brief, he installed 3 1/2" light foam wheels on all three gear - mains and nose wheel. The factory nose gear he replaced with a 5/32" music wire nose gear (as available from Du-bro) bent outwardcarefully so as to center the wheel on the nose strut and nose wheel steering mechanism.

I followed his lead and did the same thing. Three and a half inch soft foam light weight wheels on the mains - using the original wire frame and a three and a half light foam nose wheel as well. This required removal of the original nose gear, drilling out the nose gear strutchanneland some cutting and bending of the 5/32" rod to properly fit and center the wheel. Sits up higher, clears the prop more, looks either a little funny or like an Alaskan bush plane if you prefer.

Next thing Idid was replace the plastic case 15e motor that came with the Apprentice from the factory with a new E Flite Power 15e. Puts out a bit more power and is stonger by virtue of its metal construction. It is also necessary to replace the ESC with a 45 amp ESC to match the motor.

Removal of the cowling is simple, as is removal of the motor and motor mount in order to take out the ESC from the front. Lot of gentle trimming white sticky materal from the ESC to take it out. Don't loose the red thrust washer added to the motor mount for correct thrust line and do be sure to put it back where it came from.

I used the original motormount for the new Power 15e and the original screws to mount the engine. With the washer and the mount thickness itselfthe screws are not too long for the case. The screws furnished with the motor are far too short to use with the factory motor mountso the original screws work very well. Take care removing the mount screws and they are of soft metal and can be "buggered up" fairly easily. A hard metal Phillips head screwdriver is a dangerous tool in a soft metal screw - as I demonstrated, just before ordering a new mount with screws from product support at E Flite. (The courteous and helpful representative there,that helped me noted clearly that they had not proven the power 15 motor in the Apprentice and is wasn't an authorized modification and that they are now using metal cased motors in the newer kits of the Apprentice......

I soldered connections of the motor, the ESC and am ready to put it all together when the new mount and screws arrive. Iam also ready to finish the bending of the new 5/32" nose gear when the Higley benders get here.

Seems like these two relatively simple and easy modifications can make things a little more reliable and easy when flying the Apprentice on grass fields. All thanks to the forum members who originally came up with the ideas.

Has anyone else tried these or other modifications for improvement of utilization or performance of the E Flite Apprentice 15e? Thanks. Mike.

jmcowart 08-24-2011 06:33 PM

RE: Apprentice 15e Modifications
 
As a follow-up, the higley 5/32" bender came today, and so did a K&S Heavy duty bender I had also ordered. It was a good thing Idid.

I had some trouble fitting the new 5/32" nose gear into the benders, so I used the Higley bender to angle the nose wheel shaft outward a bit, and then used the K&S to bend the axle portion of the gear back in a little over 90 degrees so that it would be level (considering the added outward bend Ihad also added). Well it worked great wittheverything lined up, everything fits. Iwas able to drill out the mounting shaft for the new 5/32" nose gear shaft without tearing up anything.

Turns out I didn't have any 5/32" wheel collars, but as luck would have it, one came with the Du-bro nose gear and Ihad two of those, so it worked out. Blue Lock-Tite on the set screw on each collar and done. (I put a collar on eah side of the nose wheel.) Added the three and a half inch wheels to the main gear using the existing wheel collars - done and done.

Now just waiting for the new motor mount and screws to come in from E-Flite. Ihave finished soldering the ESC leads to the male EC3 connectors, ready to connect to the battery. Ireally have to learn how to solder better. I think Iput more heat into the support stand holding the EC3 male connector than I got into the connector. Finally just dropped solder into the cup at the end of the connector and stuck the wire in. It held. Iam sincerely hoping it made a satisfactory connection too.

If anybody has experience with any ofthese things, or ideas how to do it better, or any advice at all, please jump in - Ican use al the help I can get. Have a good evening. Mike.

jmcowart 08-27-2011 06:09 PM

RE: Apprentice 15e Modifications
 
Got the "Sujper" Apprentice all together. As expected, it is nose heavy. The steel cased Power 15 motor, the 5/32" nose gear, the solid metalspinner nut that goes on the collet prop adapter, and of course the light weight foam 3.5 inch nose wheel - all add up.

I have to add weight aft of the CG to make up for it. I guess I'll stick some lead in the ventilation holes in the fuselage underside behind the wing, with some GE Silicone Sealant to hold them in. I guess I'll just keep adding weights until the aircraft comes into balance at the CG 3 1/4" behind the wing leading edge......

All this extra weight will increase the wing loading a little bit. Idon't think it will be enough to matter since there is plenty to spare on this trainer. Just have to be careful initially to avoid departure stalls and snap rolls to a dramatic finish.

Hope I can fly it next Sunday.

Can anyone give me any tips or things to check or lookout for....? Thanks. Mike.

acdii 08-28-2011 08:04 AM

RE: Apprentice 15e Modifications
 
Yep a big one, REDUCEYOURRATES! Ihave mine set to 50 and an expo on the elevator at +30. I kept the rudder at full rate. This plane has a rather large elevator which can quickly put this plane into a vertical on take off. At full rate it will do a 10' loop. Mine has the metal case motor, but the prop shaft came loose, something to check. Ihave the same issue with grass takeoffs, landings arent too bad, as long as the prop has stopped by the time it touches down. Iset the brake on the ESC. Take offs though, if the prop catches grass, it will pull the plane into the ground due to the down pitch of the motor.

I dont know what Ican use though to clean the grass stains off the plane without harming the foam. Ididnt want to modify anything on the plane, so Im putting on a 3" nose wheel and 2 1/2" mains, and will see how she does, that 1/2' difference in nose wheel that Ihave on now may make up the difference. Iam also considering a smaller prop once I determine the pitch.

Reason I set expo on the elevator is that Ifound that it can pitch up quickly with just the slightest touch on the up, usually when I am bringing it around for a flyby or landing it would pitch up when leveling off, it was very sensitive to pitch, adding the expo smoothed out the stick center and now she flies great. My last landing was picture perfect, came in over the soybeans, my friend was sure I would nail them, but I didn't, it flared out nicely, where I had problems before, Iusually stalled it here, and it touched down gently and rolled about 2 feet.

The previous landing before this was a disaster. Ijust couldnt get it down to the ground where I wanted it to be, and it just floated past the barn where the cross wind caught it, hit that big tail on it and pointed the nose right at us, so between trying to straighten it out and land at the same time Icaught a clump of grass and spun it around on its wing and tail tips. Munched the trailing edge of the left wing and wrinkled the tail feathers. I had to make some large trim adjustments on the next flight due to the elevator now being warped, but after that she flew great. So two minor haphazard landings out of 7 flights, and the plane is holding up great.

jmcowart 08-28-2011 01:15 PM

RE: Apprentice 15e Modifications
 
Got it! Thanks acdii - I will take heed and set rates and expo as you suggest. I'm looking forward to it..... Mike.

rcjunky67 08-28-2011 02:20 PM

RE: Apprentice 15e Modifications
 
check it out MAKE SURE TO PUT SOME THIN CA ON WING POST CAPS!!!!!! You dont want one of the caps coming offr during flight. She's a good trainer, my first in fact. And our field is grass too. Though I didnt modify my LG , I did replace all wheels with 3" dubro's and after bending the motor shaft on a nose in , I also used a power 15 motor, but I continued to use factory ESC and 11x8 prop.It did just fine,no problems. iIf your using stock battery, get your self an E-flite battery [3s 11.1v 3200 mah 30c] better thrust and flight times ,and it cost less than direct replacement with the same as the original.

acdii 08-28-2011 04:53 PM

RE: Apprentice 15e Modifications
 
I'll check those. you're referring to the posts the rubber band connect to I assume. GenAce batts are better than the Eflite. They fit perfect and have higher C and mah ratings. I have 3 3300 MAH 25c Gen ace that I use, and get 12-15 minute flights. Best part they are 1/3rd the cost. I paid $24 each. Plane balances out nicely too with these batts. Imade an EC3 to Deans adapter for the plane so I didnt need to mess with the plug on the plane. All my batts are Deans fitted, makes them safe and easy to connect.

jmcowart 09-02-2011 06:41 PM

RE: Apprentice 15e Modifications
 
This isa Chapter ending in the modified Apprentice story - Got the birdall set up. Perfect CG balance Had to add one cent coin to bottom tip of right wing to balace on roll axis. All control surfaces aligned. Using DX5 transmitter there is only low and high. With low you still get 70% control movement. High is 100% of course. I stayed on low. Measuring the actualcontrol throw it was stillat 100% (still on selected Low setting by switch) movement and couldn't get it to less than that without taking loose all the servo arms and moving pushrods closer to axis - that is to say in to the 2nd or 3rd or even 4th hole on the servo arm. The control horm was already as far out as it wouod go. I was too lazy and left it as is. Ican't decide if that was the second or third stupid thing Idid in a chain of classic stupidity......

Took it to the flying field for taxi tests. I actually wanted to see how the nose gear and 3.5 inch wheels did in the grass. The plane was a pleasure to taxi, either on grass on on asphalt - did really well.

After a couple or so increasingly swift runs on the asphalt runway things were going so good I just added a bit more power and off we went! Yes - Iknow this was a major step in the stupid chain. Well, the elevator was, as warned, very responsive, even touchy. Got that tamed and turned downwind. It was balanced and trimmed well with wind out of the SW about ninety degrees to the runway, but only about 5 kts or so.....

The Apprentice handled well but very touchy. Ifound myself seriously wishing Ihad taken the trouble to reduce the control throws by adjusting linkages even more. Made a sharp left turn to come around on left hand pattern and approach for landing, low pass, touch and go, or whatever it turned out to be... The sharp turn required some back pressure - up elevator- as it began a descent in the steep turn - that started a porpose so I just let go the sticks to let it smooth itself out as opposed to my overcontrolling.

At that point I realized I was heading for the trees on the north side of the field. Fumble, panic, clutch, twitch, crash. The sound of that Apprentice crashing through the tree tops was an awful, terrible, sound that I still hear.

So on the unplanned maiden flight of my "Super Apprentice" I flew the durn thing into the trees.

As Iam old, fat and not at all athletic I did not elect to try and climb the 30 foot sweet gum. Elect shoot! I coulnd't climb it if I had to.. Well I was there all alone and the poor Apprentice was hanging there upside down on a limb dutifully beeping the ESC every twenty seconds to tell me it was still ready and willing. I really hate the think about it all alone out there in the woods, beeping its heart out. I hope the LiPO doesn't ignite when it discharges way past where it should. I most sincerely hope I don't add forest fire to my list of sins.

I am going to attempt to hire a tree company in the morning and get them or one of them to go out with me and either climb the tree, use a long lasso, or basket and get the high dollar Apprentice back. I must do that as the Gulf hurricane effect is due here Sunday night or Monday and have at least two to four inches of rain and wind. That will pretty well finish the tree bound Apprentice. Hope I can get it down with the tree company help, of course. By the way - we have had many weeks and months of douught. Dry as a bone. Soon as I put my Apprentice in the tree top comes the monsoon and tropical rain with wind.

If I do get it back in any kind of usable condition- first up will be to bind the thing (after repairs and replacement components) to my DX8 so Ican program EXPO and mix. Then Iwill adjust the control linkages to book values. Imay also seek out a friend and ask him to kick me hard in the butt.

I never said Iwas a really smart guy. I continue to have that demonstrated to me through stupid misadventures and screw ups such as this CF. MIke.

acdii 09-03-2011 06:12 AM

RE: Apprentice 15e Modifications
 
Been there, done that, years ago when I first tried to get into this.

 I maidened my T-34, or I should I let my friend take it up to trim it out, and good thing I did, turned out I had the CG off and it was tail heavy. I would have wrecked it for sure. < See. lesson learned :)

When you get it back, grab some gorilla glue and glue it back together, and set it up like I mentioned, tame the beast and you will find it flies a lot easier. It really is a good plane, even in gusty winds.

Only mod I have done so far is larger wheels. The nose is 3" mains 2 1/2" and that combination worked perfectly. plane took right off without digging into the grass as it had with the smaller wheels. First landing though, came in a little too nose heavy and bopped its nose into the ground, but no harm done, it just looked bad. Second landing, remembered the larger wheel and flared it a little more nose up this time and perfect 3 point.

Practice make perfect, now I need to go practice my orientation, I still have problems lining it up to the runway. I keep landing it too close to the soy beans.

jmcowart 09-03-2011 10:41 AM

RE: Apprentice 15e Modifications
 
Thanks, acdii - that is a most encouraging post. I just minutes ago walked back in the door after the recovery mission on the Apprentice. Found a tree man (Xxtreme Tree Work is the name), whose climber zipped up the tree, tied a nylon rope around the Apprentice and gently lowered it down to me. Looking around on the ground I found the main landing gear and the propeller with collet still attached. Prop was broken. Collet was not.

Some dents on the leading edge where I flew the poor thing into the tree tops, broken prop, and the clevis attaching the nose gear steering pushrod was broken at the servo arm. The beefy 5/32" nose gear didn't even notice anything wrong. The ESC was still beeping when I got back to the tree this morning, and the LiPO was hot and soft. I can't see any damage or problem with the E-Flite Power 15 motor. I expect that was due to the collet coming off soon as the prop hit something.

I am going to bind it to my DX8 and use the Expo and every other feature available. The DX5 is currently employed as a door stop. The controls are sensitive, just as you warned, particularly the elevator. Iam going to tame the controls as first order of business and I wish Ihad followed your caution the first time around.

Thanks again. After this learning experience I will proced with a bit more common sense and less over-confidence. Mike.

acdii 09-03-2011 05:28 PM

RE: Apprentice 15e Modifications
 
Good luck and relax your next time up, the nerves are a real killer the first time up and doesn't help at all when the plane is twitchy like a squirrel on caffiene.

When setting the expo, first set your rates, mine are set to 50 on low. Watch the tail when you move it and see how its moving around center stick, then start setting the expo and see how it changes, you want it to where you can just notice a change, go beyond that and it can be detrimental. You should see a difference in rates just by going full up or down on the pitch and hold it there while flipping the rate switch, the elevator should reflect the change.

One more thing, keep the rudder on high rate, just dual the aileron and elevator, you will want as much rudder it can give you. In fact onmy DX6i Iuse the rudder rate switch to control the rate on both channels, so one switch for the rates instead of individuals makes it quick to change rates and can be flipped without taking my fingers off the stick.

acdii 09-06-2011 07:55 PM

RE: Apprentice 15e Modifications
 
jmcowart Dont feel bad anymore, I flew mine into the side of a barn tonight.DOH!

Earlier tonight the wind was gusting and pretty strong, and flying the E was exciting, I didnt think I would get the plane lined up for landing, yet somehow I did and landed it OK. Then flew my T-34 for my first solo flight with it. The wind was obnoxious, and I nearly lost it, I mean, lost sight of it lost it. It flew pas a tree in my line of sight, so I had to run to the other side of the house and found it and eventually got it to come back towards me, then got it around and had a decent landing.

Well I jinxed myself on the way to dinner saying, "cross my fingers i dont do something dumb and wreck it".

When we got back, the sun was below the horizon and the wind died to a whisper, so up I went with the E. I flew it about and had some fun with it, did some rolls, loops, and other goofy things, then brought it around to line up for a touch and go and from a direction towards the sun, so I could see it better, and thought I had it lined up perfectly, then it started drifting to my right, which is towards the barn, the barn on my right, the field on my left, and I got my right and left mixed up and BANG into the barn it went.  Well a busted spinner, snapped the fin in half and knocked the main gear off.

The fin, took a couple pieces of packing tape, good as new, landing gear snapped right back on, and the spinner, just pulled it off and bolted the prop back on.  The only thing that I still need to fix though is the wing, it twisted when it hit the wall and the rubber bands sheared into it about an inch. I need to find some foam and cut a small section out and glue in a block and shape it to match.  All in all though it held together great considering the noise it made when it hit. Good thing the throttle was off when it did.

 I need to figure out the left drift thing though, it seems to always drift to the left when coming in slow.  I can have it lined up perfect like I did tonight but it always tends to drift off to the left.  Maybe I have to trim the rudder more right.  I'll try that next time I put it up.

jmcowart 09-07-2011 04:36 AM

RE: Apprentice 15e Modifications
 
It's a good thing these are tough birds, huh? By the way - thanks, Idon't feel so bad now.

The remains of the tropical depression have now passed here so Iam going to try again with mine. First I must reprogram/rebind to the DX8, check control throws, check balance on the new prop, reinstall the wing. I'm using the same rubber bands, from the tree crash. I ordered more, but they haven't yet arrived.

One thing I guarantee though, I WILL stay away from trees and barns. Have a good day. Mike.

acdii 09-07-2011 04:44 AM

RE: Apprentice 15e Modifications
 
Yep, watch out for those barns, they just jump right up in front of the plane!

levram1 09-07-2011 05:30 AM

RE: Apprentice 15e Modifications
 
I got my #64 rubber bands at Big Lots. $1.00 for a 4 oz. bag.

acdii 09-07-2011 06:02 AM

RE: Apprentice 15e Modifications
 
I'll have to check that out, the LHS didn't have any long enough, the ones I got will work but are very tight. Ithink had Iused those the wing would be in 2 pieces after last night instead of just having a short tear.

levram1 09-07-2011 06:19 AM

RE: Apprentice 15e Modifications
 
Also, most place that handle postal supplies will have the # 64's.  # 64 is what you should be using.

acdii 09-21-2011 05:28 AM

RE: Apprentice 15e Modifications
 
The Saga continues.

Two weeks ago after smacking the side of the barn, I thought I had repaired the fin OK, so took it up last night for a test flight, but should have waited until the wind died down a a bit under 14 MPH with gusts. The plane handled like crap, pitchy, roll rates were sloppy, not at all the plane it was before. Ibrought it down to adjust the elevator link as it was pitching down with full up trim. The landing was bad because of the sloppy handling and it wound up in the soybeans. Adjusted the elevator trim and took off again. This time though, when it hit the cross wind at the end of the barn, it slid 90* left right into the wind and headed right for the tree by the drive, and it would not roll, so basically I had two choices, hit the ground, or hit the tree, chose the tree, and the ground. The ground hit was much softer after the tree caught it. Other than some scratches and dents, the fowm is holding up well.

Basically the fix on the tail fin didnt work, it was too loose and looks like it flopped around which caused the poor handling. Ialso noticed the motor mount is pitched down, which probably contributed to the pitchiness. The wing repair worked fine, but the smack into the ground cracked the foam I used to repair it, and found the CA I have is not foam friendly, so will have to patch it again. Iguess Ishould spend the $20 for the tail and motor mount, and get a new cone while I'm at it. Ineed to remember this plane loves to skew into the wind when going slow, had it not been for the strong cross wind, it probably would have flown a bit better, but the turns were too sloppy.

OTOH, the T-34 flew great.

Snowstorm11 04-26-2012 09:27 AM

RE: Apprentice 15e Modifications
 
Hi All,
Beware of the ESC in the Apprentice. It can only supply 700ma to the receiver.
If you have a sticky or cold servo this current rating will be exceded and you plane may end up doing some very scarry acrobatics.
Hobby King have a seperate UBEC for the receiver that is rateed at 3 Amps. Easy to install it may save your plane.
Mine is just recovering from a major repair job caused by the above fault.

flexduct 05-18-2013 03:32 AM

RE: Apprentice 15e Modifications
 
I have just finished my basic training on a Mini Super Cub and now interested in moving up to either the Apprectice or the Hobby Zone Glasair. Both planes seem quite similar.
Your suggestions, please. Thanks.

Old_RC_Guy 12-03-2014 02:45 PM

After losing several spinner cones for my 15e and S 15e, I went searching for a more robust solution. I found the DuBro Black 2" Nylon Spinner (DUB273) for $3.89 works great. With the stock Apprentice prop you have to take a little bit off of the openings on either side for clearance, but with the Master Airscrew propeller it works without modification. The 2" spinner is a bit bigger than the stock spinner, but looks just great in my opinion.

No more looking for that lost spinner cone every time I nose over!!

-Jeff

acdii 12-04-2014 06:09 AM

I found an easier way, just smash it against the side of a barn. no more cone to worry about! LOL I have not flown mine at all this year, but I will keep that in mind if the cone starts doing its dance.

Jon1 05-31-2015 08:03 AM

Don't understand "reduce rates to 50." Does this reduction apply to aelirons, rudder, elevator? I have the Spektrum DX6 with an Apprentice.
Jon


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