Well, I ordered the new CMPro T-34 from AK-Models on Monday Jan 26 and it came in today Jan 30. I will document the build of the T-34 from start to finish and hopeful give and get some ideas. My thanks to Alex for a speedy transaction!


Photo 1 The box that it arrived in

Photo 2 The box cover (pretty attractive)

Photo 3 The box as soon as it was open- everything is bagged

I have a T-34 Mentor also but mine is from hangar-9. The entire build took 3-4 weeks becuase we had to order the retracts, retract servos, and pilots. Hangar-9 T-34 has a awsome constructuion with no wrinkles and it has enough room inside for the pushrods. Here are some of the pictures during the build and after. [8D]

Hi ClawWhere did you get the pilots ? I have my T34 about finished except for the pilots. Also did you have any problems with rudder and elevator linkage ?

Jim Whitney

I'm still working on mine- but I will continue to add my pictures with narrative. As you can see, I have been impressed withteh CMPro kits. Everything is bagged and nothing loose inside the box. The balsa wood is of good quality and I have had no issues with it. The retracts are pre-installed, the only thing is the small 55mm (basically 2.25 inch) main wheels. The nose gear is unique in that it self centes itself when retracted. The nose gear is a pull-pull, I see how that works out. As opposed to the H9 T-34, all linkages are outside the fuse. I went to my LHS this afternoon to pick up new rods (2-58 and 4-40s) to use, but to my dismay, the 2-58 is too large for the installed push rod tubes. The 4-40 is being used on the retracts instead of hte supplied wire (which is way to thin IMO to use for retracts. More pics as I download them from the camera.

I live in Maryland so i bought my pilots from Doug's Hobby shop before they closed, but i got them unpainted so i painted them and they came out well. The linkages for the rudder an elevator took awhile to get correct i just put alittle curve in the pushrod and dremeled away some of the wood that the linkages go through.

Continuing with the build - after unpacking and doing an inventory of the parts, I started to dry fit things together. The tail feathers were spot on, and the wings (after some drilling to get the rear line-up pin seated) went together nicely. I also tested the retracts to see if they were workng properly. The only bad part is that the covering did not match up on the printed panel lines on the bottom. The fuse has a couple of minor things wrong. 1. The nosewheel bracing is too long for the cowling to fit (I plan to cut away about 1/2" from the front and reepoxy to thiner lite-ply to restrengthen) 2. The cockpit tub does not fit because of the top of the formers. This will be fitted by cutting the top of the former and down. Using the installed pushrod tubes, I quickly found out that 2-56 rod will NOT fit inside the pushrod tubes! Excpet for the minor things, overall I'm still happy with the ARF. More building pictures tomorrow.

When installing the new 4-40 rod for the main wheels retracts, all I can say that who ever designed the wheelwells actually used their brains. If you notice in the pictures of the wing, there is a screw in the plastic wheelwell cover. I thought, OK, why is it there? The directions do not show it doing anything. Lo and behold, the wheelwell covers are NOT glued in, like most ARFs that I have worked on. For me, this is great. I unscrewed the retract and that little screw and everything just came out as one unit as pretty as you please. Boy does that make it easy to get access to the retract if it ever has problems. No more haveing to cut access holes to get to the clevis if it pops off. The only problem with that little screw is that the balsa sheeting underneath it is thin. When I reinstalled the wheelwells, I just glued a new piece of balsa sheet under the part of the sheeting for the screw to have some virgin balsa to bite into. Worked like a charm. I also installed the the pull-pull set-up for the nose gear steering, it is not a direct pushrod. Not being a big fan of pull-pull systems, I really took my time to get it right. I deviated from the instructions and used clevises on the nosewheel steering arm instead of attaching the wire directly to it (I'll post pictures of what I am talking about). After getting it all set up, I think it really will work out OK. Time will tell. Tonight, it will be time to get ready to hang the engine. I have decided to use my reliable Saito 65 4S. I was going to use an OS .704S, but I would have to pull it from another plane. It would be a pain in the a** and I really like flying that other plane.
More pics tonight

That is so nice...

Well, except for the pictures and a couple of finish touches to the cockpit, I'm ready to fly it. After a late night last night and marathon day today in the shop, it is being recharged as I write this. I decided to put on my trusty Saito .65. Preping the firewall was not a problem. The supplied motor mount beams have a molded index line to show the Centerline (CL) of the beam. The firewall is also indexed for CLs both horizontal and vertical. I decided to use standard mounting bolts and blind nuts instead of the supplied metric. Took about 2 hours of measuring, remeasuring, and the final plunge of drilling holes. Everything came out. The only bad thing about the motor mounts was that they are bent at the ends. Had me worried, but I was able to pull them together to mount the engine. The throttle servo was installed and the pushrod hole redrilled (the plane is set up to install a 2 stroke). Being a Saito. I could not get a straight run on the pushrod (the clevis hit the firewall when trying to get the carb set up), so I did the next best thing, just bent the push rod into a "U" shape and that fixed the problem (I'll post pics, I promise). CUtting a cowl is always a pain, and you'll see I cut this one a little wide for the head, but it's not too large - at least I'll be able to keep the engine cooler.
Now to get to the retract servo set-up for the nosewheel. After installing the retract pushrod and the rudder/nosewheel pull-pull systems, I noticed that I was having to problesm with the pull-pull wires getting caught up in the retract servo arm. I just reversed the servo and hopefully that is solved. Then I decided to see how both retracts sevos were going to play together. Setting up the mains on their servo was a bit*h, but after about 30 minutes, I had it done and no servo chatter. Okay, hooked up the two retracts servos to the y-connecter and hit the switch. Life on both, but wait, something is wrong! The nosewheel goes up and the mains go down. Time reconfigure the servo arm - and now all is well.
Fuel tank installation was a pain - I ended up doing a lot of cutting of interior bulkheads to fit the tank and used a H9 11oz tank instead of the suppied one. The supplied one did not want to go in, but problem was solved. I am using a 3 line system.

Except for finishing the cockpit (pilots and a decent instrument panel), the canopy has just been screwed on. I did end up getting rid of the metal wing mounting bolts and redrilling for standard wing bolts. The last thing I did before stopping for the night was to check the CG. CMPro has been pretty bad at giving the wrong CG location, so I did the standard CG at the main spar (about 4 inches from the LE at the wing root). Amazingly, I was just a tad bit nose heavy, which is where I want it to be.

I'll get pics psoted and hopefully test this weekend, if the winds stay down!

As promised, some more pics. The plane is now at 95% complete- only the cockpit needs to be finished and pilot(s) added.

The plane was started and I did some taxi tests with it. The winds were much too high to test fly a new plane. I noticed a couple of things, 1. The mains are small, but with the current retracts, that is all that will fit (2.25") in the wells. 2. The way that cut out for the engine exhaust is positioned (which is a very nice touch for the plane, and I like it) is that my Saito .65 exhaust is a little long in the pocket. The heat scorched the plastic a little and that was due to my lack of attention. You will notice in the picture that I did add a exhaust deflector after bringing it home. It will be just right for a two stock muffler- if the .65 does not work, I have a couple of 2 strokes that I might try out. Maybe a .61

I know I did not take a lot of pictures for the middle of the build, but most were just the typical items that need to be completed. like installing the servos and the Rx & battery. Plus, once I was on roll, I forgot to get the camera out.!

I'll let everyone know how the test flight goes.

An update on the first test flight. Sunday was a great day, very light winds. I fueled it up and thought I did a good pre-flight, but under the cowl I missed something - the throttle linkage was not hooked up! It happened on Sat when I took the engine out to put on the exhaust deflector. So after cussing myself - I took the cowl off and reattached everything. By that time Stallwart showed up with his H9 T-34. Wow, maybe we'd be able to do some formation flying. Fired up the plane and taxied out to the runway. This is a grass runway, so I knew with the small wheels it would take a pretty good run to get airborne. I advanced the throttle and got about five feet, then the nosewheel collasped. I broght the plane back to the stand and took a look at the nose gear. In the back of my mind, I knew that I would end up replacing the retracts with Hobbicos in the near future, but not on the first flight. After looking for the failure, it was the T-Bar had pulled out the nylon housing. A little bit of muscle and it popped back in. Fired her up again and taxied out. This time I was trying to get a running start, 10 foot, the nosewheel collasped again. Same problem, so she did not fly - maybe in a couple of weeks when I get a new nosewheel retract unit installed. As for Stallwart, his nosegear also acted up and niether of us got to have a formation flight. I was able to fly my 60 size Spitfire!

Conclusion - as a guessed, I should have replaced the retracts from the start. This is not the first set of weak retracts I had from various ARFs by different manufactors and not the last. The mains should be fine, but not the nosewheel. Other than that, until I fly the plane I cannot tell if it has any bad habits or not.

Bassfisher, thank for the photo-build.

I just started the T-34, purchased from Nitro. A couple of questions

Did you use the 1.5mm rudder & elevator pushrods? Mine are so stiff in the housing that I fear they will not ever work. Not wanting to change athe housings but sure don't like stiff linkages.
Will the pull-pull setup on the nose gear work? It appears that just dangling loose when the gear is retracted is an invitation for a snag up.

I am wanting to tuse a Magnum .80 4st. Will the 24 oz. engine weight create a cg problem. My other option is a 2 st which appears a little light for the cg.

I'm just starting so may have other questions later.

Thanks for any help.[8D]

I had ordered my retacts from H9 http://www.hangar-9.com/Products/Def...?ProdID=HAN157 they work perfectly for the mentor, its sturdy and reliable, no wobbly or collapses.. just awsome, i was doing my maiden in november, i was abit nervous at the time. My dad bought me the mentor right after my solo and i have been begging to get the mentor but i didnt know that i was going to get it that early so i was so suprised and happy. The mentor was cool with the retracts in all 3-point landings on the maiden with was easy for some reason iam 14 yro and some guy that has a p-51 .60 with retracts was practicing 3-point landings but had a few flip over's, i asked him to let me try and it was weird but i was able to do a 3-point as easlily as the mentor's ..lol he was mad when i was able to do and he wasnt able too. but i was able to show/teach my technique to do a 3-point.

Way to go Claw1994! Are you going to be in Arkansas anytime soon to teach us down here?

Cajun - The Nitro is the same as being sold by AK-Models. I used the supplied pushrods for the rudder and elevator, since 2-56 would not fit in the pushrod tubes. Usually I get rid of supplied wires, but since the pushrod tubes are already glued in, I'm taking the gamble. I don't see any flexing, so I think they will work out. But I did replace all wire for the retracts with 4-40 rod. Testing the pull-pull on the nosewheel seems to work fine. Yes, once the nosewheel is retracted, they will dangle since there is no tension on the wires. After cycling them many times. I have had no snagging. You can see how loose the pull-pull wires are in one of the last pictures I took - notice that it has no effect on the rudder. Take your time before you clamp the brass collor down on them, make sure everything is tight, but that you still have some room for adjustment on the clevis. The only bad thing was the nosegear collasping. That's the one reason I'm going to change the retracts out to Hobbicos. This will also eleminate the pull-pull system and just leave me a single rod. I seriously thought about putting my Mangum .80 (I still working out some problems on it) on the front, but for a light as the plane is, I decided to use my .65 4S first. I'm going with about 4 3/4" (121MM) for the CG, but might move it forward later. This is what H9 recommended, as CMP is historically a little off on their CGs (I experianced that with my CMP .50 Zero). I will have to rebalance once I install the new retracts. I will also be changing the mains from the 2.25 to 2.50 wheels.

Claw- I agree with Stallwart - come down and teach us!! Was your T-34 the H9 or CMP? Stallwart and I fly together and we both need the help

i talked alittle bit about he plane at the top with some pictures.. its the Hangar-9 (H9) model

sorry guys wont be able to go to Arkansas for awhile i have a trip to the Phillipines in april and ill be getting some air time there so........ ill talk to my parents but it might take awhile to see if not maybe you guys can come to
Maryland heres the sight to our rc club http://www.charlescountyrc.org/ its not much but a regular grass field we also have a forum there but its new so there wont be much to tlak about.

Your field looks a lot like that of bassfisher's and mine. There are some nice looking planes in our club's gallery, too.

Have a good trip to the Phillipines; we'll keep knocking the gear out of our planes lol.

Here's my older H-9 T-34.

The picture of Stallwart's plane does not do it justice. The way that his flies is the reason I decided to get one. Hopefully mine flies just as well as his.

Claw- have a great time in the Phillipines. I never did tell you that your plane looks great.

i never knew H9 distubuted the yellow one, how long ago was that.. in a couple of days/weeks i might be adding some pictures of my other planes and i have a special plane on the way but i wont reveal it until its completed.
Its starting to get warmer here in Maryland but still some high winds here, i was able to fly my mentor the past sat-sun, i forgot how fast it went.. lol almost had an accident thought because i forgot to put down the retracts down on landing, but my flight experience was able to make me put enough elevator to clear the landing retracts. the landed i did that half way down the runway so it was abit scary because my dad was telling me to go back around but i was slow enough to get it to a stop.

that picture was in september or october when i started rc flying.. iam the one in the red.
the other picture is some guys i met while flying and they were impressed on how fast i learned

Just keep practicing - soon you'll be up to the that BIG Extra 300

bassfisher, anything to report on flight testing yet?

I haven't run into any major problems yet. Just little rinky dink China stuff.

I am waiting on a backordered nose gear. I also didn't like the supplied gear. I test mounted the Mag 80, and it appears very nose heavy. I'm trying to decide to go with a ST.45 or OS.60. I don't have a 4s in .60/.72 size range.

Very attractive plane,,,,,,,so far.

cajun- still stuck waiting for my new retracts (backorderd). Also ordered some pilots from Polk Hobbies, hope they arrive next week. Since I can't fly this weekend, no loss. If my .65 4S doesn't fly it well, I've still got a HB .612S sitting on the shelf. Maybe everything will show up next week and I'll be able to fly it!

look forward to a flight report from someone.. not too happy to have to replace the retracts already, maybe should just get the H9 to start with?

Although the H-9 Mentor is a great plane, I"ve had some issues with the H-9 40 size retractable nosegear.