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Getting Started

General building discussions, not model specific.
Dale
Posts: 188
Joined: Tue Mar 13, 2012 5:18 am
Location: Beautiful British Columbia, Canada

Re: Getting Started

Post by Dale » Sat Jan 25, 2014 5:52 pm

Just to set a few things straight......

Jerry.... You wrote, "You are correct. The Rebel, Super Rebel and Moose primarily use pulled rivets, although the spars have regular bucked rivets."

That statement is incorrect, the Rebel has NO solid rivets in the wing spars.

Garry.... You wrote, "There is absolutely nothing in the rebel that requires solid rivets."

That statement is incorrect, the Rebel H-Stab struts are put together with solid rivets.

As far as Darryl's aircraft designs, all were designed to primarily use the avex rivet. The Super Rebel, Moose & Yukon use solid rivets in the wing spars by design. The use of solid (AD rivets) in place of avex rivets does not make it a stronger plane. The rivet pitch has already been placed with the use of the avex rivet, therefore putting in a solid vs avex has no benefit. The skin will fail before the rivets do.

Benifit to using avex, the drilled hole does not have to be perfectly round; avex rivet by design will fill/form to the not so perfect round rivet hole. The use of solid (AD) rivets requires a perfectly round hole, it will not fill/form to a not so perfect hole.

Just my little tid bit from a person that has put a lot of these kits together.
Dale
British Columbia, BC
Mountain Flying at Its Best

tedwaltman

Re: Getting Started

Post by tedwaltman » Sat Jan 25, 2014 7:45 pm

I'm appalled at the lack of research and outright WRONG information some of you posted here. To say that there is no difference in strength between solid (AD) rivets and pull rivets is ludicrous.

Murphy supplied pull rivets are of the multi-grip category. They have a shear strength of 150 pounds and a tensile strength of 220 pounds. Not thousand of pounds--plain pounds! Check the engineering specs at hansonrivet.com.

Now compare the below specs on solid rivets:
"AD" rivets are fabricated from 2117 aluminum and heat treated to the T4 condition. They have a shear strength of 26,000 PSI and a tensile strength of 38,000 PSI. Prices below are for 1lb. quantities. All rivets can be purchased in 1/4 lb. (use qty .25) and 1/8 lb. (use qty .13) packages. AN470 (MS20470) AN426 (MS20426).

Yes, the skin will tear first. You are right there. But only due to rivet layout and spacing per Darryl's design. After reviewing the above specs, a pulled rivet isn't even eight percent of the strength of a solid, let alone 80% (you weren't really serious, were you?)!

Avex multi grip rivets are not used in commercial, certified nor in military aircraft.

Geesh. Talk about sending builders seeking learned input down the wrong road!

irishfield
Posts: 1707
Joined: Fri Mar 16, 2012 11:17 pm

Re: Getting Started

Post by irishfield » Sun Jan 26, 2014 7:18 am

I see the intent Ted... but don't forget to calculate the amount of square inch represented in an 1/8" rivet and then multiply that by your 26,000psi. So for a 1/8" solid it's shear strength is only 318.9 lbs.

It's a generally accepted fact / statement / what ever you want to call it that 5 avex rivets = the strength of 3 solids.

There are a few certified birds out there using the avex rivet, but not very many.

Elite583
Posts: 184
Joined: Wed Feb 29, 2012 9:11 pm

Re: Getting Started

Post by Elite583 » Sun Jan 26, 2014 7:31 am

First, I'd like to add one more tool to the recommendation. Expanding on what Mike E. mentioned, I would add a selection of 3M EXL deburring/polishing wheels and a small air die grinder for deburring all the edges of all the punched & sheared sheet metal parts that come with the kit, much more civilized than doing it all by hand. They can be had from McMaster & MSC Supply and no doubt your local industrial supplier although you may have to go with a P/N in hand.

Second, to add to the discussion about rivit strength, if you agree that the 1/8" Avex rivit has a shear strength of 150 pounds (I didn't look it up) then that translates into a shear stress of around 12,200 PSI which compares to the driven rivit shear stress value of 26,000 quoted by Ted. By my quick calculation that puts it at about 50% of the driven rivit strength.

Like Ted says though, the strength of the kit was Engineered to the strength of the Avex rivits and quantity and spacing reflects that. I believe Murphy/Hiscocks used only the cross section of the aluminum of the rivit in their calcs, not the added strength of the (captured) mandrel/head so that's a "bonus" factor of safety.

Dave
Elite 583, a work in progress......

tedwaltman

Re: Getting Started

Post by tedwaltman » Sun Jan 26, 2014 3:05 pm

Good point Wayne. Thank you


tedwaltman

Re: Getting Started

Post by tedwaltman » Sun Jan 26, 2014 3:08 pm

I'd bet there are zero out there using MULTI-GRIP Avex. Maybe some using regular, so to speak, Avex.

User avatar
Walter Klatt
Posts: 708
Joined: Tue Feb 21, 2012 5:56 pm
Location: Vancouver, BC

Re: Getting Started

Post by Walter Klatt » Sun Jan 26, 2014 3:57 pm

Besides tools, this is good page (go to the bottom) to read about standard practices for building a Rebel.
http://www.pattersonaerosales.com/Aircr ... chSpt.html
Walter Klatt

Mechanicalman12
Posts: 29
Joined: Thu Mar 08, 2012 9:05 am

Re: Getting Started

Post by Mechanicalman12 » Sun Jan 26, 2014 5:44 pm

Not an expert by any means but these tools helped alot. A counter sink bit with a rubber tube for grip, a die grinder round burr for deburring at an angle. I hand bombed all the holes, a 1/8" foam pad under the skin, a little pressure and a little twist is all it took. Lots of holes but it went pretty fast. Great for hard to do spots.Two punches, one sharp to punch the mandrel then a flattened one to punch the rivet out in case of redos, worked good. A deburring tool with a hooked end, you can deburr from either side of the hole, works great and are available at Acklands Grainger. Also for installing flush ( tapered rivets ) I shaved the end of a used mig tip to the size of the rivet head and drilled out the center to mandrel size ( about 3/8" long ). Slide it onto the rivet. Pushes on the rivet head nicely not the skin. Flap wheels work really nice on inspection holes or skin edges after they have a groove in them and come in all grits and sizes. Another useful tool was a flexible extension on the drill with adaptor where your drill is on an angle and a long bit wont do. I bought alot of clecos, way more than in the kit. Found them on line for cheap. Maybe I overkilled the holding parts together thing but everything went into place nicely so maybe not. I wish I had the air cleco tool, it was a job. My rebel is fuselage inspected ( passed ) and soon getting started on firewall forward and instruments. Another thing, listen to the very wise people on this site!
Attachments
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Tools to build with

Dale
Posts: 188
Joined: Tue Mar 13, 2012 5:18 am
Location: Beautiful British Columbia, Canada

Re: Getting Started

Post by Dale » Mon Jan 27, 2014 2:43 pm

Ted.... Hope it wasn't something I wrote, if so please tell me and I'll stand corrected.

Cheers,
Dale
British Columbia, BC
Mountain Flying at Its Best

tedwaltman

Re: Getting Started

Post by tedwaltman » Mon Jan 27, 2014 5:05 pm

Dale, your posts were all good, correct information. I sent you a private msg via the list--maybe that function is not working? Thank you for your reply/comment here Dale.

Dale
Posts: 188
Joined: Tue Mar 13, 2012 5:18 am
Location: Beautiful British Columbia, Canada

Re: Getting Started

Post by Dale » Mon Jan 27, 2014 5:21 pm

Ted,

Did not get your PM, this function work for me in the past. Maybe another glitch in the site system, nothing has changed on my settings.
Dale
British Columbia, BC
Mountain Flying at Its Best

akarassowitsch
Posts: 5
Joined: Wed Jan 08, 2014 5:34 am

Re: Getting Started

Post by akarassowitsch » Fri Jan 31, 2014 5:39 am

I thought I'd send out one more thank you to all that responded. Holy smokes you guys are on it! Apparently the rivet question turned over a rock with lots of squiggly things under it. I look forward to getting some metal in my shop!

User avatar
Walter Klatt
Posts: 708
Joined: Tue Feb 21, 2012 5:56 pm
Location: Vancouver, BC

Re: Getting Started

Post by Walter Klatt » Fri Jan 31, 2014 6:10 am

Andy, lots of people here with great experience and advice. Some mods are important and good, but some are just extra weight, and some can be downright dangerous. Good news, most of these have been discussed at length, and lots of info available in the archives. You do want to build your plane as light as possible, too. Weight is the biggest enemy of performance, as you probably know. An ounce saved here and there adds up to a lot of pounds when complete.

But without any doubt, the Rebel is for sure, the best kit you can buy, for this size and type of plane. I am often amazed when I look at some of the competing kits, and what they cost, for what you get. The Rebel is indeed still the best choice for performance, utility, safety and value.
Walter Klatt


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