computermonkey

My Feedback: (90)

Hello,

Looking for tutorial on installing mechanical retracts into foam wings.

Thank you,

radfordc

My Feedback: (14)

Here's a thought...google "installing retracts in foam wings"

hook57

My Feedback: (21)

Yep, that's real helpful....
CM, try over on RCG in the classic forum. Lot of helpful build threads and helpful comments over there regarding layout, foam cutting, and retract install/ setup. If you can't find what you need, start your own thread and the guys will chime in with info.
hook

computermonkey

My Feedback: (90)

Would additional work need to be done on the center section to strengthen it where the retract servo goes? Getting ready to build a foam with Dirty Birdy and a Great Escape with 1/16 wing sheeting.
http://www.probuild-uk.co.uk/Resourc...-retracts.html

hook57

My Feedback: (21)

No, you can apply the glass over the center section joint as called out in the instructions. You may want to mark, and even cut out the retract servo area prior to glassing the center section. I typically do that and make the passages for the servo linkages too. Mark the location lightly on each wing half and layout the linkage paths to the wheel well also. You can use blue painters tape to hold the halves together so your layout is symetrical on each half. It's not important to have the dihedral exact at that point. Look it over and you will get the picture of what you want to do. Once you have it cut out, you can place the servo in the cut out, the retract units in each respective location, and the see how your linkage will line up. You can make any adjustments then before gluing the wing halves together. Take a look at the EU-1A thread (JM Desings I think) on RCG, I think he just did the retract install on that plane.
hook

radfordc

My Feedback: (14)

Did you try it. It brings up a long list of links to "how to" pages.

computermonkey

My Feedback: (90)

yes most are not what I'm dealing with.

Pylonracr

I usually make the retract cutout in the core first. Glue the retract mount plate into the core before you sheet it. I cut a groove in the core and laminate a balsa spar with carbon fiber tow. Try to extend the retract plate to the spar. Glue all of this in when you apply the sheeting and bag the whole mess. I like to build the servo mount to join the spars together at the wing seam. When you glass the center section, it will tie the load paths together.

speedracerntrixie

My Feedback: (29)

I use a hole saw to cut the wheel well then I make a verticle grained balsa box in the core. The balsa box butts up against the spar. After the core is skinned the wheel well and retract box is opened up. A ply plate is fabricated to mount the retract and installed into the box. The exterior is finished off with some balsa. When joining the wing, a vertical grained balsa/CF joiner is used and butts up to the rear edge of the spars. Pictures are worth 1000 words.

MTK

CM, in my experience the center section glassing is typically enough strength even when the servo cutout is right there. You don't need 6 oz cloth for that. I used to use a 5" wide strip of 3 oz bias cut, and it was plenty strong

However, the wheel wells present a compromised bottom sheet and believe it or not, I've had sheeting cracks at the wells (3/32" contest balsa to boot, back in the day). It is definitely a good idea to add 1 1/2 oz, 1 1/2" wide (bias cut is better) cloth strips around the cutouts. If you take a few moments and think through the loads the wing will see particularly when landing and/or snapping (not at the same time we hope, lol), and add some internal strips of glass, you'll build a wing for practically any rigor.

computermonkey

My Feedback: (90)

Thank everyone.

Just today I noticed my Dirty Birdy ARF landing gear mounts start to come loose for the second time. Grass fields are hard on landing gear mounts. I wish they did what you say Matt.

JeffH

My Feedback: (43)

I fly off of grass and before I assembled my DB ARF wing, I drilled 1/8" holes through the gear plates, and through the wood walls under the gear plates and inject gorilla glue with a syringe. They have probably 100 landings so far, no issues. I did quirt some water in the holes first kick the GG off. One of my gear mounts was loose right out of the box.

The tuned pipe mount that they put into the wing sucks!!

computermonkey

My Feedback: (90)

Hi Jeff, I just came back from the hobby shop a little bit ago. I'm going to drill 5/16 holes into the wood, take some brass 5/16 rob and drill through the foam and dowel pin the landing gear mounts.