MLG install

[n502pd]

:? Well, I am having a bit of concern about fitting the MLG correctly. Plans page LG-01 shows the dimentions and locations of things like the distance down from the lower fuse, the .7 deg toe in, and the reference point to measure the position of the axel assembly. The first thing I am wondering about is the top end of the MLG. When I have the other measurements all set up nicely, leveled and angled in as required, the top ends of the MLG titanium legs are no longer flush with the engine mount support, and secondly, the ammount of protursion of the MLG are not equal. RH is out more by about 1/8 inch, while the LH is out by about totally by about 1/2 inch. the axels on both sides appear to be properly placed by many different measurements to the airframe and engine mount. Are these protruberences above the engine mount support for the MLG legs important? The plans show a hole 1/2 inch from the top ends of the legs (which I have not drilled yet). Please understand I am scratch building, and everything appears to be properly done...so far. I have recently have comp[leted EAA tech councelor visit with great comments. He is also the DAR I intend to use, so he knows what to look for . I am not seeing something here. any guess or help here? thanks in advance!!

[MichaelFarley56]

Hi Joe,

A couple things come to mind. First, did you get the legs from Sonex? Did you measure them to ensure they are the correct length? Where did you get the engine mount? If it's off on any dimension that can have an effect.

How about the axles? Do the gear legs fit into the axles the proper distance?

If you answer all of that with a yes, then I would ensure the fuselage is straight and level, the axles are parallel to the fuselage (so the plane sits level), then drill the holes. I wouldn't be super concerned with a slight variation in the gear legs as they stick out if the mount as long as everything else lines up.

Of course, a call to tech support is never a bad thing!

Just my two cents of course...

[n502pd]

Mike, thanks much for the nice reply. mount is bonifide sonex from another member here who wanted to go with a corvair. mount is/was virgin, and no dents or bends, and installed without a problem. fuselauge is straignt and leveled on support structure. gear legs are at 34.0 inches per plans, of correct diameter and metalurgy. axels are scratch built, one appears to be 44+ deg and the other is about 44.5 deg...not a real deal breaker for this, IMHO. I dont have any real problem with the top of the legs sticking out above the mount, per se, but that isnt what the plans shows. Do other scratch builders have the same problem? Plans call for a 1/4 in hole, 1/2 in from the top end.I can get both axels and gear legs to meet the allignment specs otherwise.

However, I have not been able to expelicity determine the insertion depth of the leg into the axel. Mine go in 2.75 plus or minus a very small bit, but there isnt any call out for that on the plans, or at least my plans. have you got a spec that was sucessfully used? One other thing you said was if I got the legs from sonex (I didnt) but the plans show them to be exactly 34 in long. I would sure like to have someone measure a leg ( tail dragger config) that was purchashed from sonex to compare. my plans are up to date and nothing mentions cutting them

Sorry for being long winded! Thanks again for the assistance Mike! :)

[MichaelFarley56]

This is just a guess Joe, but i seem to recall from when I did the install on my airplane I drilled the holes in the tops of the legs per the recommendation, installed them, and then adjusted the axle sleeve to give me the proper gear leg length. By doing this my gear legs were flush with the engine mount socket, but I have no doubt there's a difference in length in the axle sockets in order to get the proper length.

Have you drilled the axles on yet? If you haven't, you can probably go this route; if they're already on, I'd leave them and not worry about the slight difference up at the mount. Either way I'm sure you'll be fine!

[n502pd]

OK, I had thought of that, but would submit that would not the axel interface with the gear leg be stronger if fully inserted? Well, I can not think of anything unforeseen at this juncture that would interfeer with leaving the legs proud of the top mount tubes....except for when I install the AeroVee engine. that is what I am worried about because I do not have the engine yet.

thanks much for the suggestions. I think I should ask Kerry and see what he thinks. Maybe there isnt a thing to worry about, or the legs need to be cut off, or I have screwed up somewhere else. Gawd, what a thought now!! I will try to remember to post what I do. Fly safely! :)

[corton]

The factory axle mounts are 4130 steel that has a bolt welded to the end. Welding slag causes uneven pocket depths.

I thought " for sure my axles are equal" sine I bought the full kit. I mounted my legs flush with the top of the mount, slid the axles on to full depth, and drilled. As a result, one wing tip is 1/4" lower than he other. *sigh* Flies just fine, and only one person has noticed the low wing.

[n502pd]

Hello agaion Carl! Yep, I do remember yoiur little 1/4 in problem. Since I scratch built my own axels, I have removed all traces of slag inside. the only thing I found was a slight angular difference between the two sides, maybe 1/2 deg...almost unmeasurable with what I have. so, I have made the very tips of the axels the same distance from the bottom rails per the plans, moved the LH side down about 3/8 inch, left the MLG legs up and above the motor mount be maybe 7/16. I drilled both the upper bolts today, so I am comitted, I guess. I will drill the lower axel bolts early this week. Overall, I expect the actual height of the MLG might be above spec (still) by about5/16..maybe?? but I am taking pains to make sure it is level. I will post pictures later this week on my web page. I hope you are flying again. :)

[n502pd]

Time for a short update. I have installed the MLG. the legs are proud of the engine mount by about 1/2 inch each side. Looks better that way. the RH MLG axel is fully inserted into the axel sleeve and is at the plans height( I forget just now the exact number...CRS dont you know!) the LH sleve is not fully inserted by about 1/2 inch, putting the length the same as the RH side I do not see a problem with doing that. The drilled hole on the LH is still about 2.3 inches from the end. Final drill and fitup of hardware yielded same MLG height and toe in about .9 deg each side. I think I am done with this section. Any comments? I do appreciate any, good or bad. By the way, I have a show and tell for EAA cpt 323 on May 3, so N502PD will be on the ground durring that for the first time (plenty of help on hand). :D

[MichaelFarley56]

Joe, it sounds to me like you did things perfectly and are ready to move on! Great job and I'm sure your gear legs will be perfect!

[n502pd]

Thanks much for the assistance Mike! Over all it went pretty well, even if I had my doubts about half way thru! and thanks to all for the suggestions!