Ricks Rush 750 build thread

[backburner1955]

Originally Posted by rdlohr

Yep, we deserved to lose, or maybe better said, the Ravens deserved to win.
Rick

They did play a solid game.

[dunkonu23]

Rick,

Should you decide to use CA on a replacement torque tube, you might be able to eliminate the bearings sliding by lightly scoring the torque tube with an Xacto blade--that's the way I did mine and there was no issue. In fact, I doubt I'll ever be able to get the bearings off--and they were straight.

Scott

[rdlohr]

Originally Posted by dunkonu23

Rick,

Should you decide to use CA on a replacement torque tube, you might be able to eliminate the bearings sliding by lightly scoring the torque tube with an Xacto blade--that's the way I did mine and there was no issue. In fact, I doubt I'll ever be able to get the bearings off--and they were straight.

Scott

Thanks Scott.
Rick

[rdlohr]

Originally Posted by DominicD

You know kinda build thread has no photos only long text ????? MIke's.

Originally Posted by backburner1955

That is Scott's build thread and his pics, yours could and would be different.

Now get busy posting pics, your Pates are losers...

Having given it a bit more thought, you guys are right. There are some things that I have talked about that pictures should help clarify. I went back and added a few.
Rick

[dunkonu23]

Good job, Rick! The pictures are excellent and show exactly what you're talking about. You ought to do this more often, sir!

Scott

[rdlohr]

On the tail boom supports (Assembly 12), I just realized it calls out for Red Loctite. I hadn't noticed that and I used blue. Once again, I'm questioning why use red for connections that may well need to be removed in a crash? Do I need to remove these screws and put red on them?

Rick

[th0rg0d]

Originally Posted by rdlohr

On the tail boom supports (Assembly 12), I just realized it calls out for Red Loctite. I hadn't noticed that and I used blue. Once again, I'm questioning why use red for connections that may well need to be removed in a crash? Do I need to remove these screws and put red on them?

Rick

I think they call for red here because of the large threads and high vibration potential. I chose to use blue and will be checking them very frequently. If they back out, then I will be using red.

[dunkonu23]

I used Xcell Green thread locker on those threads. Since I started using green on boom supports I've not had one issue with boom support screws on any helicopter coming loose. Food for though, perhaps. Your mileage may vary. Objects in mirror... But hey, it works for me.

Scott

[rdlohr]

Originally Posted by th0rg0d

I think they call for red here because of the large threads and high vibration potential. I chose to use blue and will be checking them very frequently. If they back out, then I will be using red.

Originally Posted by dunkonu23

I used Xcell Green thread locker on those threads. Since I started using green on boom supports I've not had one issue with boom support screws on any helicopter coming loose. Food for though, perhaps. Your mileage may vary. Objects in mirror... But hey, it works for me.

Scott

I have always used blue and never had a problem with screws coming loose. But, I have never used screws this large, and never had a heli this large. A Logo 600 is my largest.

We have exceeded my knowledge level on loctite. Here is what I remember:

Blue: Medium strength. Removable
Red: Permanent strength. Not to be removed. (need heat to remove?)
Green: Adhesive. Not sure if this is stronger than red or not.

I don't remember anyone saying the size of the screws played into how well the loctite held, but everywhere red was called out in this manual there are large screws. Can someone add to my knowledge here because I would rather do this right once than have to worry about screws coming loose.

Thanks,
Rick

[dunkonu23]

Rick,

Blue: Medium strength. Removable (Correct)
Red: Permanent strength. Not to be removed. (need heat to remove?) (Correct, but difficulty of removal is directly related to the amount used.)
Green: Adhesive. Not sure if this is stronger than red or not.

Green is capilary, it fills voids such as thread-to-thread. It can be used as a bearing retainer. It is not as strong as Red, but if you use a lot, you may end up having to use a wrench on a hex driver to get the screw to turn (I found out the hard way). Other than that, it's what I'd use.

Scott

[dodgeboy]

Rich, i used blue and mine came loose and the blades chopped it in half. cost me blades and some supports.. put red on it please

[dunkonu23]

Originally Posted by dodgeboy

Rich, i used blue and mine came loose and the blades chopped it in half. cost me blades and some supports.. put red on it please

I still recommend green, it is removable yet not allow the screws to back out. I think we agree... Blue is not the way to go.

Scott

[SYMAWD]

Originally Posted by rdlohr

I have always used blue and never had a problem with screws coming loose. But, I have never used screws this large, and never had a heli this large. A Logo 600 is my largest.

We have exceeded my knowledge level on loctite. Here is what I remember:

Blue: Medium strength. Removable
Red: Permanent strength. Not to be removed. (need heat to remove?)
Green: Adhesive. Not sure if this is stronger than red or not.

I don't remember anyone saying the size of the screws played into how well the loctite held, but everywhere red was called out in this manual there are large screws. Can someone add to my knowledge here because I would rather do this right once than have to worry about screws coming loose.

Thanks,
Rick

Loctite recommends purple (222) for bolts up to 1/4" in diameter, blue (242/243) for bolts 1/4" to 3/4" in diameter, and red (271) for bolts up to 1" in diameter.

Green (290) was designed to be used after assembly (the loctite will wick into the threads).
Green (609) is used a retainer for things such as bearings.

[backburner1955]

All depends on which green you are talking about. Green 609 is a Bearing retainer (adhesive) and Green 290 is a General Purpose Med / High strength thread locker meant to be applied to assembled parts. It is removable, but stronger than 242 Blue.

[rdlohr]

Thanks all. So it sounds like Green 290 may be a good choice here?

As far as how much red I put on. I generally put a few drops on a plastic bag, spin the end 1/8" of threads in the drop, then spin the threads between my fingers to remove the assess. Would that be considered a lot or a little?

Rick

[backburner1955]

Originally Posted by rdlohr

Thanks all. So it sounds like Green 290 may be a good choice here?

As far as how much red I put on. I generally put a few drops on a plastic bag, spin the end 1/8" of threads in the drop, then spin the threads between my fingers to remove the assess. Would that be considered a lot or a little?

Rick

That is how I do it too, not too much that way. Even if you choose to use red like that, to remove it, just set your soldering iron to a high temp and put the tip on the bolt head for a minute or two and it will break down the loctite.

[dunkonu23]

Green 290.



For the win.

Scott

[rdlohr]

Originally Posted by backburner1955

That is how I do it too, not too much that way. Even if you choose to use red like that, to remove it, just set your soldering iron to a high temp and put the tip on the bolt head for a minute or two and it will break down the loctite.

OK, thanks.

Originally Posted by dunkonu23

Green 290.



For the win.

Scott

Thanks Scott. I'll have to pick some up.
Rick

[rdlohr]

Loctite has 50+ threadlocker & retaining compound formulations-- not just blue and red. When it comes to threadlockers 242 (blue), 271 (red), and 290 (green) are the most easy to find versions because they are are double marketed both as industrial and "consumer" grades, the latter of which you can find on the shelf at almost any hardware or automotive store. Many more formulas of loctite are available from industrial suppliers.

Besides the specific version of thread locker used, the diameter, pitch, and length of the thread (i.e. total bonding surface area) has a lot to do with the final cured strength and torque resistance of the threadlocker. Using 271 high strength loctite on small 1.5-2mm bolts with only a few threads engaged will retain the screw better than 242 medium strength but the fact is there isn't much surface area for the loctite to bond to on the small screws so they're typically still removable without adding heat. Put 271 on a larger fastener (i.e. feathering spindle bolts) and the break away strength greatly increases and heat or a specialty solvent may be required for removal.

Loctite 271 (the commonly available high strength thread locker everyone calls "red loctite" ) is the high strength easy to find consumer version. 271 is recommended up to 1" diameter fasteners with no suggested limit on the small end so it is appropriate to use even on the small 1.5-2mm hardware found on our helis.

http://www.henkelna.com/cps/rde/xch...tUID=0000000HWJ

If you read the datasheets the standard medium strength "blue" 242 loctite that nearly everyone uses is recommended for 1/4-1/2" diameter fasteners-- a bit out of range for the hardware size on our helis and it's not the ideal product for the application.

http://www.henkelna.com/cps/rde/xch...tUID=0000000HWW

Of the common "consumer" grades of loctite available 290 (green) is the most appropriate our helis as it is recommended for 2mm - 6.5mm hardware. It's a medium/high strength threadlocker and heat is recommended (but not required) for removal. My experience is that 290 develops a much more consistent bond on small hardware (4mm or less) than 242. It is a low viscosity "wicking" threadlocker that can be applied either pre or post assembly.

http://www.henkelna.com/cps/rde/xch...tUID=0000000HW3

For a medium strength small-screw threadlocker the best product for the job is Loctite 220 which is a specific formula for small screws, it's recommended up to 1/4" / 6.5mm diameter fasteners with no limit on the small end. It is also a "wicking" grade and can be applied pre or post assembly.

http://www.henkelna.com/cps/rde/xch...tUID=0000000I07

Unfortunately 220 isn't a formula with "consumer level" marketing and you can't find it at your local hardware stores. However, you can pick up 220 from industrial suppliers (McMaster-Carr is always the easy source.)
Loctite 222 is the low-strength threadlocker for small-hardware applications but I can't think of an application on a heli where I would recommend a low-strength threadlocker.

Personally I use 271 on critical fasteners I can easily apply directed heat to (i.e. swash balls that can be easily heated with a soldering iron), 290 on critical hardware that I can't apply directed heat to and/or has plastic components nearby that limit the use of heat, and 220 on frame-related hardware, less critical hardware, and anything that may be removed more frequently for adjustment such as motor mount screws.
Slip fit non-threaded items (i.e. bearings) require a retaining compound that will vary based on the strength required and slip fit clearance. Ben covered all the appropriate grades to use for this application.

[dunkonu23]

I just know I use blue, blue 243 on nitro, green on everything that I don't want to come off due to vibrations, and red very sparingly on things like the spindle bolts (but I've used green there too, with no ill effect).

I know there are industrial grades of nearly everything and I've read the data sheets on thread locker compounds, but really, we're consumers, and frankly I hope all of us as team members passed the test.

Scott