Motor Mount Hooks

[C.Calvin]

Could have sworn I’ve seen a thread about this around here but it escapes me. I’m at the point on two of my custom builds where I am ready to assemble the motor mount. I need ideas on how to make my own motor mount hooks. My local shops do not carry them and I really do not feel like paying extra for shipping just for hooks ordered online. I’m looking for something I may have laying around the house or may cost only a few bucks from the store. I was thinking a simple metal coat hanger but the metal being round instead of flat was a turn off. Ideas?

 

[jflis]

Get an old windshield wiper blade. The backing wire is nearly identical to that used in motor hooks...

Good luck!
jim

 

[foose4string]

To expand on what Jim said....

Go to a auto part store, Jiffy Lube, Midas, or similar auto care immediately after a good rain storm. That's always the time when people decide they should change their wiper blades. Ask the store manager if he's got any old blades in the trash can or dumpster that you may have. He may look at you funny(ok, he WILL look at you funny:blush but explain what you are using them for and I'm sure you'll get all the wiper blades you need. The stainless metal you seek is inside the base of the rubber wiping surface and will strip out of the rubber easily with a pair of pliers.

Many of the stainless steel strips will be a little too wide, thick, and heavy for average LPR and very difficult to bend to shape, but you will also find some real gems that are just the right size and will work very well for our purposes. You'll need some decent cutters to cut through the steel. I used a pair of Klein side cutting linesman pliers. They get the job done. I use the same pliers as a vice and a pair of needle nose to bend to shape.

 

[C.Calvin]

Thanks guys! Well then I should be in luck, according to weatherchannel.com I am “blessed” with thunderstorms the next 6 days. :jaw: Bummer for launching though but gives me the excuses to stay indoors and build rockets.

 

[AKPilot]

Why wait? I'm looking at a whole parking lot full of motor hooks right now! :y:

 

[jimzcatz]

Hooks,we dont need no stinking hooks!!. Friction fit with masking tape,do it old school

 

[powderburner]

If you want to use metal strips from wiper blades, be aware that many of these are manufactured to be stiff (to function as backing for wiper blades). If you simply bend them with pliers, this type of metal (heat treated) will crack. Sometimes they crack when you bend them. Sometimes they crack when the ejection charge goes off and you really need it not to crack.

You can undo the heat treat by heating the portion you are about to bend until it is red hot. (Gas camping stove, or home welding setup, or butane soldering torch.) Let the metal air-cool by itself to (mostly) remove the previous heat-treatment. Make you bends or whatever other shaping you need. Re-heat the bent metal strip until it is red-hot again and plunge into water or oil to quench; this form of heat treating might not be as good as the "factory" but it will partially re-stiffen the metal strip to hold its shape better.

 

[Handeman]

powderburner is right about the heat treating. I would suggest that you actually bend it while it is red hot, then reheat and quench. It's probably 6 of 1 and half dozon of another.

The other question I would have is, what kind of rocket are you making the hook for? I would recommend using screws and clips for anything that uses reloadable motor casings, only because I trust them more then clips.

If you are going to use the hook with RMS cases, I would recommend you bend the hook similar to the purchased ones and use a piece of wire to hold the clip in place while you fly the rocket.

The wire is cheap insurance for a $50+ casing.

 

[Micromeister]

If your going to heat treat them anyway 1/8" wide x 3/32" thick spring steel can be picked up at the hardware store, sometimes in the music wire bins at the hobby shop and of coarse from McMaster-Carr. I bought a 100ft roll several years back that has supplied many a motor hook.

I still like the FREE aspect of using Windsheld wipper blade runners, they work just as well, and are generally a tad thinner and easier to work with.
I also use a butane torch to heat the steel red hot then fold, reheat and temper in a water bath...Good info Powder. Another of the things we do but don't think to pass on.

 

[m85476585]

You can often find windshield wiper inserts laying on the ground in parking lots. I don't know who changes their windshield wipers in the grocery store parking lot, rips out the metal, then throws it on the ground and discards the wiper, but while I was working at a grocery store I found 3 inserts in the same week. One was kind of rusty, but the other ones looked new enough. I don't know if the are stainless (the rusty one probably isn't), but if so they could be quite old.

 

[foose4string]

Tempering the metal is a very good idea, but haven't found it necessary. I never even thought about it to be honest, or else I might have done it. I have made a couple dozen hooks or more without going through that process and none of them have broken or show signs of weakness. The thinner, lighter, gauge metal will bend without much problem...especially if your just making the classic style hooks. I would definitely use heat if I were trying to make the new Estes style hooks, but making that style would be more trouble than it's worth IMO.