110" TIMBER Assembly Thread

[john Derstine]

Did you replace the blind nuts? This seemed to be the weak point for me, the ones included are pretty weak/thin and will eventually give up by stripping or shearing unless they've addressed this already.

That's a good point, I did not, but I was just looking at it this morning and thinking 3mm bolts and blind nuts here look pretty wimpy. With the aluminum strap the forces no longer transfer to the Tnuts but each strut to the other, the hole is tight no slop, but it sure wouldn't hurt to pop out those T nuts for something a little stronger.
I'm wondering if anyone has opened the little holes in the wing to see what the wing situation is with regards to the strut attachments.
My home field is rough, so I'm erring on the side of caution with everything, plus the flying loads alone on struts. In addition Looking at the Ohio superstar 1/3 scale tailwheel as an option. already ordered Airtop wheels from Top model will be here in a day or two. (three days from France to Cebu City) Looking at gear and tying to decide if I want to bend the original before replacing I'd like to make my own, but sourcing 6061 T6 here is problematic, TNT want's 100 bucks. could just brace or reinforce the original set.

 

[john Derstine]

In my Timber I have Castle Hv 120A. No Sbec. Run one 4000mAh for the radio as far forward as possible to balance, it is only that big because I had it on hand and the plane balance perfectly with it.
The Castle has worked great never any problems and worked right out of box, great unit. The only thing is after doing some research on ESC and also speaking to Exstream-Flite they recommend that I take look at their new scorpion Tribunus ll 12-130A ESC SBEC. the research I have done up to now I am really interested in the unit the programming looks doable. The one thing that really interests me that you set the battery size and after flying up that amount the esc will cut back telling you you reached the set amount you like to use. Great feature no timer and always get maximum use from your battery and never over discharge the batteries.

Interesting to note you need the extra weight of a flight pack for balancing, negates the reasoning for using a separate BEC. still may go gas, have not pulled the trigger either way.

 

[john Derstine]

Went ahead and added the larger T-nuts. I wanted 4mm but could only find 5mm. OK if you use the metal strap between the struts, I would not use 5mm un reinforced as it actually weakens the wood as it is so close to the margin of the ply. easy job. ripped off the barbs epoxied them in with hysol. useful to have a magnetic wand.

 

[john Derstine]

My take on landing gear reinforcement. Cheap easy and effective using scrap ordinary aluminum to make two tension straps. Added almost no weight and made the gear as stiff as if I had made a new gear from 1/4" 6061 T6. Happy with the result. wheels are in customs for three days arghh.

 

[AKNick]

Good work on the gear, that should work.
I know there is about 914 posts and 92 pages to find it, but I did open up the strut mounts in the wing. The little square hole on top will give you the access. I put some epoxy and tri stock in there along with a new T-Nut.

 

[Snoopy1]

My take on landing gear reinforcement. Cheap easy and effective using scrap ordinary aluminum to make two tension straps. Added almost no weight and made the gear as stiff as if I had made a new gear from 1/4" 6061 T6. Happy with the result. wheels are in customs for three days arghh.
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Please not that particular set that is shown in the picture. If I am seeing it correctly the brace and gear form a triangle. If so the suspension will not flex unless there is change in length in one of the members. The stress in the bolt holding the inner strap at the fuselage will many hundreds of pounds load.

 

[john Derstine]

I was a little concerned about that, but the force applied is not exactly a shear force or a tensile force, so hard to calculate, Shear is about 60% of Tensile, but should be good for 800-1500 pounds (maybe). I'm counting on the up coming inflatable tires to take some load, it's an experiment, if I shear or pull a bolt then I know it was too weak. ultimately it's what I had to work with from materials around the house

 

[john Derstine]

Wheels today, at the risk of being redundant, I'll add a little update to the Airtop situation. As of today I think Airtops will be the only alternative bush wheel solution, PMT's are not available for 3-4 months as of this date. PR's are non existent.
Anyway my Airtop 180mm wheels arrived. Plenty big enough for me without looking cartoonish. two issues to note. the description on the Top model site said they are supplied with 6mm bearings, mine came with 8mm, which ultimately doesn't matter because the 6mm stock axels are too short anyway, second issue there was a missing wheel bolt, guess they have a problem counting to 8, forcing me to source a replacement. I'll use an 8mm (5/16) SAE grade 8 (8,8 metric) bolt, head facing out with a jam nut and a nyloc on the outside of the gear. I'll also need to bush down the gear hole from 10mm to 8mm. this will give some scrounging to do. fun fun. I used this set up (sans bushings) on a tow plane I designed and kitted in the 1990's, and it proved bullet proof with unforgiving 7" Sullivan Skylite wheels.

 

[john Derstine]

What I ended up doing to mount the airtop wheels:
first I found the missing hub bolt laying on the floor apparently slipped out of the little zip lock bag and was floating around in the main bag, then fell on the floor.
I decided to use stainless steel axels instead of grade 8.8 as the 8.8s were only black oxide coated and would rust easily. In the US grade 8 comes with a cadmium plating that resists rusting. so the 8mm was a perfect fit to the supplied bearings, and I coiled up shim stock cut from an aluminum beer can (AL 3004), left it a little proud of the 2 pcs of gear leg material (drilled to 10mm as supplied) so it would compress nicely and form a good tight fit. Worked well. the wheels spin toooo well may have to use the Velcro pad brake idea.

 

[john Derstine]