Which clevis to use - RC Groups
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Apr 04, 2014, 07:43 PM
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Which clevis to use


This may seem like a trivial question but I would like to know what brand clevis's pilots are using. Flying models for 40 years I have always been partial to dubro metal clevis's because the pin is welded on. The clevis's that come with Pike's, Explorers, etc have removable clevis pins that I didn't feel at ease using. My concern was that the pin might come out.

It is probably easier to attach the removable pin clevis rather than the dubro. My thoughts now are the removable pin clevis's are probably fine or they wouldn't be included with high performance sailplanes. I've also read about Hays brand clevis's that many people seem to recommend. I would like to hear some feedback.
Thanks,
Last edited by Hoot; Apr 10, 2014 at 10:40 PM.
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Apr 04, 2014, 08:04 PM
F3J-F3K-F3F- What to Fly??
Dale Thompson's Avatar
MP JET's work well.
https://www.rcgroups.com/forums/show....php?t=1645444
Apr 04, 2014, 08:16 PM
ak79's Avatar
Never once had a MP jet pin come out. I've put them on to many sailplanes to even count.

To help keep them tight and for added insurance use a needle and put a drop on thin CA on the pin.

I would much prefer to use all metal clevis's but I hate trying to pry them open near molded skins, and you have to make the slots bigger in the skins to accommodate them opening.

I stock a lot of MP jet stuff-

http://flightcomp.com/hardware/
Last edited by ak79; Apr 04, 2014 at 08:31 PM.
Apr 04, 2014, 08:22 PM
Hot Dawg Glider Pilot
schrederman's Avatar
I used the MP Jets on my newest Xploder, and bent a pushrod at the J contest in Houston, but the clevis and pin held.
Apr 04, 2014, 09:58 PM
Registered User
I have recently been using a steel clevis at the servo arm and a MPJet plastic clevis with brass pin at the control horn. Like ak79 I don't like to be trying to pop open a steel clevis around the surface wiper and the wing skins. Plus I like to make the pushrod slot in the wing skin and surface wiper narrow, which rules against a steel clevis at the control surface.

lc
Apr 05, 2014, 04:28 PM
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vespa's Avatar
The pins don't come out, but they sure are easy to lose when they do. I use 4 types of 2-56/M2 clevises depending on the application:
  • Hayes black plastic w/ steel pin -- Straight, solid, and light -- fat, not suitable for grinding and difficult to pop loose. Best in the fuselage or tail.
  • MPJet removable pin -- Straight and light, reasonably thin, great for wing exit slots that don't provide opening clearance -- very difficult to remove, not so solid, and not suitable for grinding. Best on wing surfaces.
  • European silver metal -- Straight and very slim, very easy to remove, grind-able -- do not stay solidly closed. Best on removable tails.
  • Sullivan gold -- Can be glued shut, lots of meat for grinding -- must be glued shut, must be straightened. Best on wing servos.

Overall, the Hayes is the best quality and Sullivan is unbelievably poor. But I use Sullivans far more than anything else because they are rock freakin' solid once you bend them straight and glue them shut.
Apr 05, 2014, 05:55 PM
Registered User
Tuomo's Avatar
Quote:
Originally Posted by Dale Thompson
They are the best available. Only problem is if you have to open clevis in field and loose the pin.
Apr 05, 2014, 08:24 PM
RIP MC
fnnwizard's Avatar
I use:
Flaps:
Hayes at servo end, steel at flap horn, steel rod.

Ail: Hayes at servo, MPjet at Ail with carbon rod.

The mp jet actually requires a longer exit slot in the tip panel. This is due to the thicker threaded hub. Look closely and see where the mark would be for a steel clevis.

For the steel clevis, I put it on the horn and then screw it into the flap. Makes for the smallest cutout grinding. I didn't grind the wiper at all, what you see is from the factory which has the grind on the wrong side for this install anyway.

If I use a steel clevis for ail, I grind them down like in the pic.

There are various reasons to use which depending on:
length of servo arm, if flat or bumped covers are used, servo position under the cover and which way arm is situated, ie towards spar or ail and weight.

One thing to keep an eye on is if using steel rods with the plastic clevis. Some rods are smaller then 2mm at the threads and thus can be pushed right through the plastics' threads. A little rubber ca helps out here.

Lastly, I need to source some bubble covers for the clevis exits.. helps keep plane quiet !
Apr 05, 2014, 08:31 PM
Registered User
Avaldes's Avatar
Do you have to glue in the horns on the Xplorer? Or is there a threaded insert for them? Just curious.
Apr 06, 2014, 12:49 AM
Fly R/C writer
Threaded insert, brass.

Mike L.
Apr 06, 2014, 04:24 AM
Registered User
Avaldes's Avatar
Cool, thanks!
Apr 06, 2014, 05:31 AM
Registered User
Tuomo's Avatar
Quote:
Originally Posted by fnnwizard
The mp jet actually requires a longer exit slot in the tip panel. This is due to the thicker threaded hub. Look closely and see where the mark would be for a steel clevis.
Wow, you are really fuzzy with small exit slots I cut them much larger, about 8x20mm.

I find that with MP-Jet clevis is much more easy to get a good fit to brass horn. Maybe because of tolerances? You can also press MP-Jet pin directly unlike with steel clevis.
Apr 06, 2014, 12:22 PM
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webbsolution's Avatar
I have been using the hays 131 clevis for 4 years now. Its lighter than steel and easier to bind to carbon with confidence. IF you are a linkage tinker'er then this style is probably not for you since you dont get any adjustment. I have never had a pin come out or a clevis fail. I have taken them to 2 f3J World Championships and countless contests in North america.

They do require a larger slot in the skin and wiper for field changes if you set the surfaces up for that but everything I build is field serviceable (or at least thats my goal)

I went to this clevis because I wanted to reduce the mass impacting my servos on repeated F3J style landings and overall find ways to reduce weight. The shock absorption capabilities of carbon and hays are also totally superior to metal. You will bend most metal linkages on impacts that only flex the carbon. Take a look at all the posts about broken brass horns and alternative materials and ways to dig pieces out of wings. The only time I was able to break a horn with Carbon and Hays clevises was when the model piled in from the top of a launch.
Apr 10, 2014, 08:40 AM
Registered User
Web solution,
What glue do you use for the carbon rod / Hays clevis bond? I will need to order carbon rod so Would you happen to know the diameter of the rod?
Thanks !
Apr 10, 2014, 10:46 AM
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webbsolution's Avatar
Quote:
Originally Posted by Hoot
Web solution,
What glue do you use for the carbon rod / Hays clevis bond? I will need to order carbon rod so Would you happen to know the diameter of the rod?
Thanks !
I use thick CA and I take the clevis to my local hobby store and just match it up - there is always stock in the prepackaged carbon rods section there and its a perfect fit which slides easily with no slop. Thats an important factor because you have to work fast with CA. I need new batteries for my caliper to get you that measurement - if anyone else can get that and post please do - otherwise ill head to the hardware store and get some batteries !

The process is simple -

Figure out your linkage requirement perfectly with metal threaded links and then set that linkage in a digital caliper.

You have about 3 seconds to get the bond right I set one end first making sure a little carbon rod sticks out into the clevis business end, hit it with kicker, then set it in a digital caliper of the exact size requirement and put a drop on the end of the rod and slide it into place making sure you have your desired orientation (flat and opening to whatever your desired direction is). I also make sure a fine bead of CA seals the clevis to the rod at the end of the clevis and rod. Kick it and wait 60 seconds - I leave them under a spot light if the room temps are low -


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