Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Scale Helicopters > Scale Projects <790


Scale Projects <790 Scale Projects <790 Discussion


Like Tree3Likes
Reply
 
LinkBack Thread Tools Display Modes
Old 01-07-2017, 04:53 PM   #1 (permalink)
Registered Users
 
Posts: 1,175
 

Join Date: Jan 2014
Location: Little Neck, NY
Default FunKey AS350 based on TREX 600CF

I just started this build, using my belt-driven TREX 600CF for the mechanics. The main reason to start this thread is to have a way to upload pictures and ask for help, so I hope some of you experienced scale builders watch this thread from time to time.

First order of business was to correct the wrong skid position of that FunKey fuselage. Moving the front brackets further back is easy, but the rear mounting brackets require a set of small holes to be drilled into the fuselage underneath to get access to the screws. In my case one of that screws was pretty much covered in epoxy, which made it impossible to remove. I therefore had to cut off that corner of the mounting bracket in order to get it out.
Attached Thumbnails
Click image for larger version

Name:	rear-mounting-blocks.jpg
Views:	231
Size:	44.5 KB
ID:	687631   Click image for larger version

Name:	rear-position.jpg
Views:	218
Size:	39.7 KB
ID:	687632  

Last edited by getsuyoubi; 01-07-2017 at 08:58 PM..
getsuyoubi is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 01-07-2017, 05:03 PM   #2 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

Moving the rear mounting blocks to their scale position required new struts for the skids because the blocks ended up closer to the center, so the horizontal part of the stock struts would not have been long enough to reach into those blocks. Well, the stock skids are too thick anyway, so i made my own. Since I live in an apartment there was no way of brazing any steel brakeline skids, so I used aluminum instead and joined them using JB Weld. To strengthen the joint I inserted wood dowels into the skids and drilled holes into them, as suggested by Don "Keyrigger" here:
https://www.helifreak.com/showthread.php?t=767398
The struts are 5/16", the skids 7/16", which is as close to scale as it gets. I bent them in pairs by taping them together, using a 3" cast iron sewer pipe that happens to run down about 1/2" off my garage wall. Using some old magazines to adjust that gap this allowed me to bend the tubes without messing up the part that's supposed to stay straight, because that was supported by the wall.
I built a jig out of pink foam to support the whole assembly while it cured.
Attached Thumbnails
Click image for larger version

Name:	bent-tubes.jpg
Views:	176
Size:	52.6 KB
ID:	687633   Click image for larger version

Name:	new-skids-during-testfit.jpg
Views:	201
Size:	42.1 KB
ID:	687634  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 05:18 PM   #3 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

I inserted a little aluminum piece into the rear wood dowel of each skid to attach those skid blades, similar to what npomeroy did on his: https://www.helifreak.com/showthread...light=npomeroy
Before I detail the skids it's time to install the mechanics. Here's how the fuselage sits on the new skids. I had initially messed up the front strut position, but fortunately npomeroy came to the rescue and pointed me in the right direction. Correcting that took a mere 10 minutes, but of course it left me with another set of holes in the fuselage that need to be closed. Well, at least I got the rear struts positioned right the first time...
Attached Thumbnails
Click image for larger version

Name:	skidblades.jpg
Views:	135
Size:	66.4 KB
ID:	687635   Click image for larger version

Name:	fuselage-on-skids.jpg
Views:	251
Size:	36.8 KB
ID:	687636  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 05:30 PM   #4 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

I ran into some - well - challenges with the mechanics installation. My tail unit uses a single screw on its right side (the tail rotor side) to clamp it onto the boom. If I push the mechanics back far enough that this screw clears the fuselage tail and ends up in the opening for the tail unit the main shaft ends up quite far behind the center of the opening in the doghouse. Furthermore, the long elevator swash ball fouls the former that's between the main shaft opening and the air cooler opening, while the aileron and pitch linkages end up about 1.5cm behind the joint line of the fuselage.
However, I don't think I can hide that clamp screw on my tail unit in the tail cover anyway, so I will have to cut a small opening somewhere regardsless - either in the end of the fuselage boom, or in the tail gearbox cover.
The pictures illustrate this whole situation - the off-center main shaft, the tail unit (rotated 90 degrees because I haven't yet cut off the lugs for the tail fin), the bare tail boom, and the tail unit mount by itself.
Attached Thumbnails
Click image for larger version

Name:	main-mast-top-view.jpg
Views:	176
Size:	35.3 KB
ID:	687638   Click image for larger version

Name:	tail-unit-position.jpg
Views:	206
Size:	39.2 KB
ID:	687639   Click image for larger version

Name:	tail-unit.jpg
Views:	185
Size:	42.6 KB
ID:	687640   Click image for larger version

Name:	tail-end-in-fuselage.jpg
Views:	193
Size:	38.3 KB
ID:	687641  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 06:13 PM   #5 (permalink)
Registered Users
 
Posts: 2,861
 
My HF Map location
Join Date: Aug 2009
Location: New Zealand
Default

Looking good. Is the aluminium skid tubing the mild grade sold in hardware stores or a harder alloy such as kit tubes? Just wondering about the strength. It may be worth considering strengthening by filling with epoxy or even pulling through some rope-like fibre soaked in epoxy. I'm thinking about the struts, not the horizontal tubes.
__________________
Nelson JR DSX9 II; Stretched Atom 500 in Bell 222 body , Stretched TRex550 in 600 size AS350 - . Trex 450 S and 550E for sport . practice.SK720 all round..
npomeroy is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 07:21 PM   #6 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

It's aluminum 6061 T6, with a wall thickness of 0.065" (1.6mm):
http://www.onlinemetals.com/merchant...=71&top_cat=60
That should be strong enough, I hope. It certainly took some serious effort bending them with my brute force sewer pipe method...
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 07:27 PM   #7 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

I've been looking a bit more for the correct main shaft position, and it turns out that I would have to go even a bit further back than required by the tail unit.
The pictures show one of those drawings you can find on the web, and a photo of the doghouse of my AS350. I have enhanced the panel lines around the main shaft with a pencil, and indicated the correct position for the main shaft according to the drawing as well.
I had planned to install the mechanics this weekend, but today's snowstorm prevents that. I would need to run back-and-forth between the apartment for measuring and checking and the garage for actual cutting and drilling and grinding and filing. With this snow that's just not practical, because every time I come back inside I would make a mess that certainly wouldn't sit well with my wife. Well, at least that allows me to re-think this whole positioning issue over and over...
Attached Thumbnails
Click image for larger version

Name:	doghouse-panels-and-main-shaft.jpg
Views:	123
Size:	29.0 KB
ID:	687650   Click image for larger version

Name:	eurocopter-350.jpg
Views:	181
Size:	66.3 KB
ID:	687651  

Last edited by getsuyoubi; 01-07-2017 at 08:56 PM..
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 08:49 PM   #8 (permalink)
Registered Users
 
Posts: 2,861
 
My HF Map location
Join Date: Aug 2009
Location: New Zealand
Default

Assuming the c/g is in line with the main shaft, it is quite close top the rear of the skids (on the full sized version). I'd work with what the tail mechanism needed and let the main shaft position fall where needed. When I enlarged the top opening rearwards, I did wonder whether to fill in the forward part of the "hole" but decide against it.
__________________
Nelson JR DSX9 II; Stretched Atom 500 in Bell 222 body , Stretched TRex550 in 600 size AS350 - . Trex 450 S and 550E for sport . practice.SK720 all round..
npomeroy is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 09:23 PM   #9 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

It looks like the main shaft position you achieved on you build is very close to being correct. Incidentally, if I push my mechanics back into what I now determined as the correct position the servo hubs end up right on the flange - as is the case with your helicopter, though its a totally different mechanics.
I was also already thinking about closing the front of that opening somewhat. That would require attaching something to the front half of the fuselage, because otherwise it would prevent the swash and head from slipping into position during installation. I'll see what I can do once I get there.
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 09:50 PM   #10 (permalink)
HF Scale Support
 
Posts: 2,601
 

Join Date: Jan 2010
Default

What might help a bit is to see the tail rotor housing together to get a sense of where the hole is going to end up in relation to the fin and housing cover. When I used the 600EFL Pro, the main shaft ended up right where it is on the drawing and the tail rotor exited the cover right on the spot where it is on the full size, or as nearly perfect as was possible. Mark the tail area with the middle of the square section cover and assemble the boom and housing putting the main shaft dead center in the doghouse hole. That will give us a better view of the setup so that a more informed answer can be made. It's hard without a complete picture expose. Take care.

Don
Keyrigger is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 09:58 PM   #11 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

These are pictures of the main shaft in position (I removed it for test installation and just stuck it into the top bearing through the fuselage opening, that's why the swash is sitting so high) and the completely installed tail unit.
The tail unit ends up so far back now that I don't even have to remove the lugs for the stock tail fin until I install the scale cover.
Attached Thumbnails
Click image for larger version

Name:	main-shaft-position.jpg
Views:	198
Size:	25.1 KB
ID:	687667   Click image for larger version

Name:	tail-unit-installed.jpg
Views:	178
Size:	27.8 KB
ID:	687668  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 10:03 PM   #12 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

This photo shows how that tail unit clamp screw would stick out of the fuselage.
Attached Thumbnails
Click image for larger version

Name:	tail-unit-clamp.jpg
Views:	128
Size:	44.5 KB
ID:	687671  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 10:32 PM   #13 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

This one shows the position of the tail rotor relative to the tail gearbox cover and vertical fin. Seems too far back, I think. Certainly further back than yours, Don.
Nelson, do you have the corresponding photo of yours?
Attached Thumbnails
Click image for larger version

Name:	with-tail-cover.jpg
Views:	151
Size:	38.7 KB
ID:	687673  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 11:20 PM   #14 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

The tail rotor on the full size is certainly not as far back as in my photo. The main shaft also appears to be not as far back in photos as shown in the drawings.
This is really confusing...
Attached Thumbnails
Click image for larger version

Name:	full-size-tail.jpg
Views:	151
Size:	53.2 KB
ID:	687674   Click image for larger version

Name:	full-size-doghouse.jpg
Views:	152
Size:	56.8 KB
ID:	687675  
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 11:45 PM   #15 (permalink)
HF Scale Support
 
Posts: 2,601
 

Join Date: Jan 2010
Default

It looks like you could move the main chassis forward so the main shaft is center of the hole. That will bring the tail rotor closer to where it should be as well. Both Nelson and I had to clear the canopy lip so that it would leave room for the arms. For some reason, that seems to be the norm with this body. Not much to do but remove the offending material. As to the lug on the left side of the boom, get rid of it. the one on the right side may allow the closing of the opening with the fin but if not, remove as much as you can and then make new screw holes with self tapping screws to hold the tail housing in place. The lugs on the torque tube tail are vertical rather than the setup on that housing, so it was possible to have the original lugs clamp the tail in place. As I said, I just used the screw to hold it but I might have tightened up the lug on the bottom. You can always use a hose clamp with the screw on the bottom to put pressure on the housing and then the screw to hold it from turning. The gear looks fine.

Don
Keyrigger is offline        Reply With Quote Quick reply to this message
Old 01-07-2017, 11:55 PM   #16 (permalink)
Registered Users
 
Posts: 2,861
 
My HF Map location
Join Date: Aug 2009
Location: New Zealand
Default

Here is mine. The right side is not taken perpendicular and may be difficult to ger measurement from. the left side shows the cut out in line with the tail rotor shaft.



Attached Thumbnails
Click image for larger version

Name:	AA tail 2.jpg
Views:	840
Size:	236.9 KB
ID:	687676   Click image for larger version

Name:	AA tail side.jpg
Views:	833
Size:	106.6 KB
ID:	687677  
__________________
Nelson JR DSX9 II; Stretched Atom 500 in Bell 222 body , Stretched TRex550 in 600 size AS350 - . Trex 450 S and 550E for sport . practice.SK720 all round..
npomeroy is offline        Reply With Quote Quick reply to this message
Old 01-08-2017, 12:23 AM   #17 (permalink)
HF Scale Support
 
Posts: 2,601
 

Join Date: Jan 2010
Default

Here is the best side shot I have that shows how centered the tail housing ended up and the main shaft is dead center in the factory opening. I didn't even sand it, lol. I kind of regret selling the body as it was a good looking helicopter and was well liked where ever I flew it.

Don
Attached Thumbnails
Click image for larger version

Name:	HSM 2014 1.jpg
Views:	140
Size:	78.5 KB
ID:	687680  
Keyrigger is offline        Reply With Quote Quick reply to this message
Old 01-08-2017, 08:16 AM   #18 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

It looks like my tail rotor would be in the same position as Nelson's, but I can see Don's point that it should be further forward, more or less at the center of that tail box cover. Since Nelson's has five rivets, it would have to be by the 3rd rivet, while his is at the 4th when counted from the front. That can be accomplished if I either get rid of the lug (the other two for the stock tail fin will be cut off for sure), or cut a tiny opening.
I'm still baffled by the apparent discrepancy between the drawings and photos when it comes to the main rotor position. Maybe that's some sort of optical illusion, but in photos the main rotor seems to be more to the front than in the drawings. Based on the two panel lines across the doghouse, which are 127mm apart, the main shaft should be positioned 90mm aft of the front panel line (=37mm ahead of the aft line) according to all those drawings I found. But the fuselage has it the main shaft pretty much centered between those panel lines.
It almost seems to me that FunKey made a compromise to get the tail rotor in the correct position at the expense of the main shaft too far forward, as the distance between the two is fixed by the mechanics. It certainly is on mine because of the belt; I doubt that one could find a slightly shorter belt somewhere.

Last edited by getsuyoubi; 01-08-2017 at 10:28 AM..
getsuyoubi is offline        Reply With Quote Quick reply to this message
Old 01-08-2017, 11:28 AM   #19 (permalink)
HF Scale Support
 
Posts: 2,601
 

Join Date: Jan 2010
Default

Unless the body is being scratch built by an individual that is very intent on keeping the placement correct (presuming that the mechanics will fit in the main body), most aftermarket bodies like those from Fun-Key are built to fit a range of mechanics, not just one specific system. Although your 600E and my 600EFL Pro are very different, they share the same boom so where the difference comes from, is the distance from the ends of the tube to the shafts, main and tail. If you were to convert to torque tube, you might have a slightly shortened shaft to shaft length but I am not enough of an expert on Align configurations to guarantee that, sigh. Hope this helps.

Don
Keyrigger is offline        Reply With Quote Quick reply to this message
Old 01-08-2017, 12:30 PM   #20 (permalink)
Registered Users
 
Posts: 1,175
Thread Starter Thread Starter
 

Join Date: Jan 2014
Location: Little Neck, NY
Default

I have pretty much decided to adjust it such that the clamp lug on the tail unit just appears in the rectangular opening. That seems to be the best compromise for both main an tail rotor placement.
I just cut off the mounting lugs for the stock tail fin. Fortunately the snow has been plowed overnight, so I can go back-and-forth between the apartment and the garage without making too much of a mess. My garage is not heated, so I keep everything indoors and spend as little time as possible in the garage, only for cutting, grinding, drilling,...
getsuyoubi is offline        Reply With Quote Quick reply to this message
Reply




Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Location
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.

Log-in


Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1