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Louis Wu

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I want to build this for our club. I’m not a fabricator, but think I can figure the bottom brace/pivot if I use a punched steel bar or brace. I know the picture is not sharp enough, but can someone tell me what’s being used for the second axis, where the rod Is mounted? It seems to be two pieces, one with the rod, at right angles to the pivot piece, going thru the blast shield.
3A50F9B6-F956-4345-9EB0-A25FC635A8C2.jpeg
 

BEC

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I want to build this for our club. I’m not a fabricator, but think I can figure the bottom brace/pivot if I use a punched steel bar or brace. I know the picture is not sharp enough, but can someone tell me what’s being used for the second axis, where the rod Is mounted? It seems to be two pieces, one with the rod, at right angles to the pivot piece, going thru the blast shield.View attachment 427387
That looks like that was taken at a Blue Mountain Rocketeers launch some time ago. I don't think they use these same LPR pads any more....

That said, the piece that holds the rod is most likely just a length of 1 inch (or so) square wood. We had a set of similar pads on our club rack (likely made by the same fellow). On ours it was a four inch square and 1 inch thick block of wood between the arms of that inverted C pivot. We used a ceramic tile with a hole in the middle as the blast deflector instead of the sheet metal parts shown here.

I recently replaced all those steel yoke/wood block pads with the two-eyebolt style pivots (based on this design, but using all stainless steel parts except for the homemade versions of the Odd'l Rockets Adeptor from the post just above: https://www.rocketreviews.com/scratch-el-cheapo-launch-pad-by-mike-goss.html) and blast plates from NARTS on our two club racks.
 

Louis Wu

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That would work for me. I can't find them searching for two eye bolt style pivot. Any help in naming that contraption so I can look for it would be appreciated.
 

BEC

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Look at the rocketreviews.com link in my post.
 

Louis Wu

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I see now. Great bom. I thought they were ones with the teeth. Thanks for this.
 

BEC

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You're welcome. Also, after having built over a dozen of these (I use them on my personal pads as well as the club racks) I'd suggest using a regular 10-24 hex bolt and nylon insert lock nut to hold the two eyebolt assembly together. You can set the tension to suit your needs and it won't want to loosen like the thumbscrew/wingnut assembly in the link.
 

Louis Wu

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Yeah, I see pretty long ones. I don't have a drill press, nor do I have a tap or even a vise. There are some ready-made couplers for motor shafts but they're not threaded. It sucks being me when it comes to building anything.
 

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RocketNut9

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I use a drill chuck to hold the launch rod. The chuck I use can hold any size rod size from 1/8" to 1" rods. If you do use a drill chuck may sure you use WD 40 penetrating oil after a day of launching, or the chuck will seize up on you.
 

MOF410

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I imagine its just a metal block with a hole for the launch rod, with another hole on the side for a set screw.
 

Louis Wu

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Is there something like that that I can buy and use? I can't weld, or drill and tap a solid piece of metal. I might be able to make it out wood, though
 

RocketNut9

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Rocketnut9, how do I ensure that the drill chuck will fit the eyebolt?
eyebolt?

The chuck has a threaded hole in the bottom of it. So you just drill a hole in the pad assembly, then just bolt the chuck to the pad.
 

rklapp

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How long are these nuts? Don't seem to have a lot of depth for the rod. A little steep at $13.99 a piece.
This looks the same as the ones at Home Depot that can fit a 3/16" rod. Has anyone else used these? If too wobbly, I could solder or epoxy the 3/16" and use the Estes launcher for the 1/8".
 

kuririn

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This looks the same as the ones at Home Depot that can fit a 3/16" rod. Has anyone else used these? If too wobbly, I could solder or epoxy the 3/16" and use the Estes launcher for the 1/8".
The hole and set screw can accomodate either a 1/8" or 3/16" rod, but not a 1/4".
Yeah, I see pretty long ones. I don't have a drill press, nor do I have a tap or even a vise.
The Adeptor at $13.99 is cheaper than buying a drill press, tap and die and a vise.
And no learning curve.
 

Louis Wu

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eyebolt?

The chuck has a threaded hole in the bottom of it. So you just drill a hole in the pad assembly, then just bolt the chuck to the pad.
Yes, I see doing that but it would not allow the rod to pan and tilt as with the eye bolts. Am I right?
 

caveduck

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We use 1/2" cheap drill chucks too, still OK after 4 seasons of heavy club use (with periodic cleaning). I adapted them to tripods by getting some 1/2-13 x 3/4" bolts and drilled/tapped the bottom for 1/4-20 tripod studs.
 

rklapp

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The coupling nut screws straight onto the tripod. The 1/8” is a little wobbly so wrapped a bit of aluminum foil around the end of the rod.

642A68C6-FA5C-47FC-BA9B-BCC9ED970AF8.jpeg
 

OverTheTop

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Yeah, I see pretty long ones. I don't have a drill press, nor do I have a tap or even a vise. There are some ready-made couplers for motor shafts but they're not threaded. It sucks being me when it comes to building anything.
85018DDE-4BFA-4AD5-841E-614F142D0ABF.jpeg
Watch out for using coupers like these. They are not internally threaded and rely on the grub screw for attachment. Their biggest disadvantage in this sitiuation is that they are flexible. That's what the spiral in the middle is about. Great for coupling motors to shafts though.
 

OverTheTop

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If you don't want to fabricate blast deflectors you can use ant caps that go on the top of house stumps. They are available in stainless steel and work a treat.
 

Handeman

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If you don't want to fabricate blast deflectors you can use ant caps that go on the top of house stumps. They are available in stainless steel and work a treat.
Ant Caps seem to be a down under thing. I did a lot of googling and could only find them mentioned on .au sites.
Maybe you can start shipping them our way? I could use a half dozen for our club
 

Louis Wu

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i decided to build the swivel out of some cedar I had from an unused wine rack.
74E2CC42-3606-4FAC-A208-E9B90F4EDC97.jpeg

I'll glue and screw the base but what do I use for the top part. I guess I don't need to drill thru the entire piece to be able to adjust it. How do I make sure I can have it loose enough to position it and then tighten it enough so it doesn't move?

The base gets screwed to a 2x4 and the sawhorse or straight to the plastic sawhorse.
 

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Louis Wu

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I went with M8 hanger bolts and wing nuts For the top piece (which I could’ve used a dowel if I hadn’t had the material already)
6D58DD38-1A60-417D-A6C9-730A48653697.jpegF94364DE-56E5-4075-9D9A-0777FDDCA71D.jpeg
 

o1d_dude

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My rocket clubs seem to prefer large grinder cut-off blades for their launch pads.

Not flammable, large enough hole in the center to fit, and relatively inexpensive.

I’ve also seen red clay flower pots used for the same three reasons.
 

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