Any scale 250 machines floating around out there?

[skunkworx]

I have been getting interested in maybe setting up one of my older 250s as a scale ship. I missed a deal on an MD500 fuse on Ebay the other day but I'm still thinking of setting one up just for grins and giggles. It will be a flybar machine and set up for pretty basic flying/relaxing. So how neat would it be to have a little micro MD500 or Cobra/Apache???

[Pilotrob]

Funny you bring this up SW, that is the main reason I built my FB 250.I even bought the fuselage before I bought the 250 kit . I about had it fine tuned and was going to start on the fuselage, then last weekend I lost orientation of it when I got low near the tree line and crashed it , man it was so smooth too. Just got the parts in today to rebuild it ( feathering shaft, main shaft and flybar rod). I really like the way my 450 flies so I was trying to do the same with a 250. I have no problem what so ever with orientation with my 450 and it flies very smooth. All the plank guys really like the sound of it

[skunkworx]

That was almost the exact fuse I was bidding on (the yellow one). It was actually a camo brown color but same shape in general. Can't be many manufacturers out there for them I don't think.

On a side note, I bet is awesome flying down there in Pensacola! I went to school there and loved every second of that place. I actually sold my first ever heli at one of the local shops after unsuccessfully trying to learn to fly. If only I could've stuck with it he while time!

[Pilotrob]

I hope you are able to find one. When I was looking to get one I only saw the yellow one and a police one but the police one was sold out. That is why I went ahead and got one because it looked like they would be hard to get. I wish there were more choices. I want to make sure my 250 is flying right before I install it because I would really hate to crash it. Got all my parts in last night and now the tail will not hold , I hope I didn't hurt my mems gyro. I am going to put the E flite gyro back on tonight and see if it will hold. Something is not right.
If you keep checking on ebay you will probably be able to find one, that is where I got mine. Amain also sells them but they were sold out when I was looking.
That's neat that you lived here , if you are ever down this way again look me up there are a couple of nice fields around to go fly. Good luck with your search for a fuselage
Edit: I just checked on ebay and they have one like mine for sale

[skunkworx]

What tail servo are you using? Would you be able to pick up a Spartan Quark gyro instead of the Eflite? Also, did youdo thedouble bearingtail mod?

The tail is a chore to fix on the 250 but it works great when you put quality electronics in it and add the second bearing to the tail grips. I can fly mine every bit as hard as my 450 so it's certainly possible to get it set up well. I'm just not sure what steps most people go through to get theirs airworthy.

[Pilotrob]

I am running the E flite eflrds76t tail servo and the Assan ga 250 gyro. Everything was working great till I crashed it. Now I am trying to figure out why the tail is not holding. I haven't done the tail mod yet. Do you have a link on how to do it? If I find out that the Assan gyro has gone bad I think I will switch to the Quark gyro that you mentioned. The Assan gyro worked up until the crash, I also have it on my 450. I am going to do some more testing after work.

[skunkworx]

I can't really speak to how well the 76t works, but I have one in the 180CFX and it seems ok at getting the job done. I currently usean OMG H1 and MKS 95i on a couple of my 250s with perfect results. I have a few Align tail servos that I haven't had a chance to mess with yet, but I imagine I'll get them when I get a few more Talon 25s. I swapped out my tail blades to the larger type and that helped a lot on tail hold (even with a good gyro and tail servo).

For the tail mod all you need is a set of the 681XX bearings and a slightly longer screw to hold the grips in the hub. Take the grips off, pop the extra bearing into the grip, refasten the grips with slightly longer screws, done! It takes up all the extra play in the grips and makes the gyro hold a lot better. I ended up taking a really long screw and sanded it down to fit because I couldn't find an exact match. Unfortunately I didn't get the measurement otherwise I'd be happy to share the info.

http://www.amain.com/rc-cars/align-2...Pq0hoCginw_wcB

[Pilotrob]

I finally got my 250 flying really good for some sport flying. I adjusted the gain till I got the tail to hold with out wagging (65%), thanks Skunkworx for your help. I got the fuselage mounted yesterday and tried to do a test flight but there is a lot of vibration coming for the tail when I spin it up and the rpm gets to the take off point. So I am in the process of trying to find out where they are coming from. I don't know if the tail blades are out of balance or something else, they were not this bad before. Or at least I don't think they were this bad because it was flying fine, maybe this fuselage is magnifying them

[skunkworx]

Dude, that's awesome!

Tail shakes are pretty common. I think with my first one it ended up being a slightly bent tail shaft. That or a bent head block. Hard to say....

did you try the double bearing mod? It's possible the added parts are magnifying it, but the problem isn't likely due to the fuse itself. Keep at it though. That's a heck ofa nice looking ship!

[Pilotrob]

Hey thanks, I haven't done the bearing mod yet, going to order the bearings this week. After checking it over I found that the right tail case bearing has a lot of slop in it so I went ahead and ordered the Align tail unit. This thing is slowly getting more and more Align parts on it LOL, skids, main shaft, feathering shaft, main gear and now the tail unit. I did replace one of the tail blades and glued a carbon rod to the back of the vertical tail fin because when it would start vibrating the tailfin would start wobbleing making things worse and that cut the vibration down so I could fly it. I flew it four times in the backyard yesterday but going to wait till the new tail case comes in before I take it to the park, hopefully that will make it smooher.

[skunkworx]

The tail shake is an indicator of the vibration but not the cause. If you stiffened it up its just masking the problem so you'll want to investigate further still.

[Pilotrob]

Yea, I`m pretty sure the vibration is coming from the right tail shaft bearing. I will know more when I swap out the tail unit. I have noticed one thing since I installed this fuselage and that is my motor is getting hot as a firecracker! , it was only getting warm before. I might get a different motor like a E flite 320 motor but I`m not sure yet what to do. For anyone who is thinking of getting one of these fuselages, there is a couple of things I had to do.
1- I had to make a tool to reach the back two mounting bolts. I took a small screw driver and welded a 1.5mm to the end of it ( see pic, its not the prettiest thing). I already had it made for my 450 so I just had to find some screws that fit..
2-Whichever side your back servo is on, mine happens to be on the left side. Don't glue the window in. I used velco to secure it so it can be taken out to get the tool down through to reach the back screw on that side.
3- The mounts that came with the fuselage were too high because the back servo on the left was hitting the fuselage, so I used two popcycle sticks (one for front, one for the back) that I cut to size. Then I had to drill four holes in the wood helicopter base so the bolts would clear the mounting base that attaches to the frame.. That lowered the frame so the back servo wouldn't rub on the fuselage.
4-I ended up CA ing a CF rod to the back of the vertical fin (see pic) to help stiffen it up. It is kinda flimsy. My vibrations made it wobble from side to side which made the vibrations worse. If mine didn't have vibrations I probably wouldn't have to do this step.

[skunkworx]

Oh, I understand what you mean now. I was thinking a regular fin, not a to fin for scale. But I suppose it's all the same really.

It's good to know some of the tips you came up with. I'll have to refer back here if I end up with a fuse for one of mine someday.

[Pilotrob]

Here is a better picture of the tail fin. The wood they use is too flimsy. The CF rod helped to stiffen it up a lot. I am using the CopterX motor but I think it is under powered for this fuselage. What would be a good motor to get that will carry this extra weight? Any recommendations?

[skunkworx]

I have a Hobbymate 3900 in my primary machine right now. It seems to work great, but maybe a bit too hot for a scale ship? Most seem to agree that a 3600 is the perfect combo for this size machine but in haven't really played much with any of mine (I've got about 4-5 different brands/sizes).

[MGPTWEGB]

I don't think you can beat the price of the Hobbymate............... It's a good little motor.

TIm if ya look around a good HS.... You can find a helicopter model kit that will fit the 250. I have a friend that has done this. I don't remember what scale his model was that he picked up....BUT it is very cool looking.

[skunkworx]

I'll experiment around once I get one. I have a 3200, 3400, 3600, and a few 3900Kv motors at my disposal so I'll figure out which ones are the best of the bunch and use that. Whichever it may be I'm not really planning on doing any major 3D with it, but I know they probably still could. I just want to have one for relaxing with because the stunt stuff takes a toll on you after a few short crashes!