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Old Feb 03, 2012, 08:32 PM
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Quote:
Originally Posted by I want to C OSD View Post
Hi guys... nice work you've done scatsob... listening to the sound of your full power run and the way the spinner came together, it's a fantastic looking and most likely performing bird to be proud of.

However all this is way out of my league. What has caught my eye is you're using the CR50L Brushless Outrunner from HK.

My nOOb question is this...

Having taken the motor all the way down and retrofitted, can you think of anything that would stop using this combo as a 'pusher'. By that I mean the shaft points aft, pushing the model ahead of it. Obviously the props need to be turned around ie. using your props the writing on the Master Airscrews must still face forward, but other than that I can't see anything that would prevent it.

Much appreciate your view and expertise...

cheers
I don't see any reason why this motor could not be used in a pusher configuration. As long as you do the things I have done to the motor to ensure reliable operation. You probably do not have to replace the bearings if you do not want to but the thrust bearing between the inner shaft and the front bell is a must. Hopefully they have fixed the wobbly rear bell thing. I know some people getting this motor directly from AEO here in the states have not had the rear bell issue.
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Old Feb 09, 2012, 10:26 PM
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Gen2's are out. Now they just need to be in stock.

http://www.troybuiltmodels.com/items...ITF-73ER2.html
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Old Mar 06, 2012, 01:48 PM
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Any progress Scott?
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Old Mar 07, 2012, 08:49 PM
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Hey Walter. No not really. I have been doing a lot of research on the tail wheel and developed a plan of action but I have not done anything yet. Also with the berth of our fourth and my motherinlaw leaving I will have no time for hobby stuff. I have also been working on a project in my other special interest, EDF. I am also waiting on gen2's to come back in stock at TBM. The gear for the spitfire sold out the first day they were in stock, just my luck .
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Old Mar 07, 2012, 10:04 PM
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Hey! Congratulations on the little one!
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Old Mar 08, 2012, 05:28 AM
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Thanks.
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Old Mar 09, 2012, 08:44 PM
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I guess 4 isn't so bad, as long as they are all asleep....including my wife.

I managed to make a little headway on the retractable tail wheel. In keeping with the theme of making everything that could possibly break removable, I am making the tail wheel removable. It will be held to the rear most bulkhead by four screws. It would not be easy to remove, but at least possible. I had to remove the pull-pull lines for the elevators and cut out part of the bulkhead for the control rod that will actuate the retract. The servo will sit directly underneath the pilot. Perhaps tomorrow night I can get the control rod fabricated and the doors mounted.
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Old Mar 10, 2012, 05:34 PM
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That bird is gonna be sweet!
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Old Mar 10, 2012, 09:04 PM
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Thanks Walter . It is a labor of love, and itís going to take forever to finish. Again I lied and found time to do a little work. I was on a mission really, to get the dang retractable tail wheel working along with the doors. I got the doors mounted up with some little nylon hatch hinges. (Thanks HK!) I know these hinges are not scale but they are very easy to work with. I even screwed one side up and all I had to do was pop them off the epoxy and glue in a new set.

The doors themselves are just the hatch cut in half. It is not a precision part and does not fit terribly well. I didn't really care, it still looks good and is fun to do. Plus I am gaining experience on setting up retract doors.

To actuate the doors I decided to go simple and used some springs tied to a threaded rod in the retract itself to pull the doors shut. It works pretty well and again, is simple. All that is left is final installation of the retract unit and setting up the servo and control rod. Maybe next weekend.
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Old Mar 11, 2012, 09:40 PM
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I got everything working with the retractable tail wheel today. Now I just need to get the rudder mounted and the rudder servo and lines in and I am done with the tail of this plane. I did manage to get a video of the tail wheel to show you all how it works. Sorry for the bad camera work, I am too lazy to edit it. And it is focused on the background in the first bit for some reason but you get the idea. For clarification, the cutouts in the doors are not for wheel clearance when retracted, but rather to allow the doors to not hit the wheel as they retract as the doors are attached to the tail wheel with springs. I did this for simplicity since I would have to actuate the doors with another servo otherwise, further complicating an already complicated setup. You will also notice the servo buzzing then the wheel is retracted. This is because the servo is still working to keep the doors closed as one is stubborn and needs a little help to close all the way. I put the setup on a amp meter and the servo pulls 0.4A when closed. I dont know if I should be worried about this. I use 1800mAh LiPo's for RX batteries so I know I wonít run it out in a 6 minute flight, but I also don't want to burn the servo up and have to land on the rudder. The servo is a 60g, 275 oz.-in. Turnigy.

ESM 72" Spitfire Robart retractable tail wheel test (0 min 55 sec)
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Old Mar 12, 2012, 07:18 AM
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I fitted a retractable tailwheel to my ESM Mk XIV using the Robart unit and actuated in a similar way that you have. It works well. However, The geometry of the actuating arm means that as the mechanism goes down it needs less torque and locks easily Conversally as it goes up it needs progressivily more torque. In the fully up position it requires max torque. Disconnect the servo and using the pushrod try retracting the tailwheel and restraining it with your finger. The more it moves up the more effort it needs. At the top you can stop it with a very light touch. This is the problem the servo has. To get good retracting with no stalling I arranged for the spring effort required to close the doors to be a minimum and made sure all the mechanism was as free as possible. I fitted a very high torque standard size servo, which also retracted slowly which looked more scale like and did not stall at the end.

Bob
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Old Mar 12, 2012, 06:29 PM
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Thanks for the advice Bob. I do need to work on it a little more. Part of the problem is one of the doors is a little crooked so to get it to close all the way the servo needs to be pulling pretty hard. I just have not taken the time to look at all the places it could be binding and eliminate them. I might just have to re-hinge that door for a third time. I think the servo is fine at over 15 kg-cm.

I started setting up the rudder today. Looks like I will actuate the tail wheel off the same attachment point as the main rudder lines. Ill post pictures later in the week.
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Old Mar 12, 2012, 07:02 PM
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Did you get your retracts yet?
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Old Mar 12, 2012, 09:00 PM
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No not yet . I was going to order them and then the same day they went out of stock. I guess a lot of other guys were chomping at the bit for gear for this plane. As soon as they are back in stock I will order a set, and some servo hatch covers that I desperately need for my huge foamy jet project.
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Old Mar 13, 2012, 07:49 AM
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They will be getting them at VQ warbirds also.
http://www.vqwarbirds.com/product_in...1321f8348b71a1
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