Hole Size and Cherry Max

[Lynnb]

So I had some issues squeezing an AN470AD4-6, and after drilling it out twice I realized I needed to go up a size. Since I had some AN470AD5-6 cherry max rivets I thought this would be the perfect fix. I drilled, pulled it and moved on. Well I went back today and was looking at it and realized I could move it slightly up and down in the hole. So I figure this one needs to come out too. Did I do something wrong when I squeezed it? Was the 5-6 to long to replace a 4-6? If I order an AN470AD6-6 from vans and shoot it, will that be the right correction, or should I find an AN470AD5-6 that I can shoot and save the cherry max rivets for elsewhere?





Thanks,
Lynn

[BobTurner]

Well, it sure looks to me as if it was too long for the application. But why use a Cherry here? General rule is to use a solid rivet whenever possible.

[Lynnb]

The hole had gotten to big for an AN470AD4, so I drilled it to the next size to fit and AN470AD5. The only rivet I had without ordering a solid was the cherry max.

[fixnflyguy]

Ok, in short, the Cherrymax are very "size critical" and come in Nominal, 1st over and 2nd over size. They aren't a hole filling fastener, and need to be in the correct size/length hole. The next problem you have is removing it. If the locking collar has seated, drilling it is a task in itself. Its going to spin, fight and infuriate you until you end up with a 1/4" hole. If you can, hold the "tail" side with small vise grips and grind the head down with a dremel, or small grinder. If after that you still have a decent hole, shoot an AD5 rivet in it, or plan for the correct Cherrymax. If you need assistance with available sizes and hole diameters, send me a PM.

[sahrens]

Aircraft Spruce, and others, sell a cherrymax rivet grip gauge.

http://www.aircraftspruce.com/catalo...lickkey=111976

You should use this to determine the correct length of rivet. At this stage you have a couple of choices; after drilling it out determine the proper cherrymax or the proper sized AN470 and set it.

Drilling out CherryMax rivets is a pain. There is a video on EAA describing one technique. You can find it at

http://www.eaavideo.org/video.aspx?v=14259107001

[BillL]

Originally Posted by fixnflyguy

Ok, in short, the Cherrymax are very "size critical" and come in Nominal, 1st over and 2nd over size. They aren't a hole filling fastener, and need to be in the correct size/length hole. The next problem you have is removing it. If the locking collar has seated, drilling it is a task in itself. Its going to spin, fight and infuriate you until you end up with a 1/4" hole. If you can, hold the "tail" side with small vise grips and grind the head down with a dremel, or small grinder. If after that you still have a decent hole, shoot an AD5 rivet in it, or plan for the correct Cherrymax. If you need assistance with available sizes and hole diameters, send me a PM.

Removing a Cherry Max is a piece of cake. There is a youtube video on it. IIRC, they first step is to center punch, then drill right at the top, then take a pick and remove the steel locking collar at the top, punch out the core, then drill further, pop off the head, and the whole thing will fall out. I will add the link when I find it.

http://www.cherryaerospace.com/produ...20Removal.html

Don't try to remove this cherry max without reviewing the proper process or you WILL regret it.

BTW - get a full assortment of rivets, sizes and lengths. Next time it will be a non issue and you will have all solid rivets.

[Lynnb]

Thanks for all the help. I've ordered some 5 and 6 solid rivets now, and will watch the video tonight.


Lynn