Portable mast tilt-up device

On our first camping trip of the year I took my EARCHI antenna and the Spidebeam 12m pole. I used a couple of ratchet straps to attach it to the awning arm assembly.

Spiderbeam pole attached to camper

Spiderbeam pole attached to camper

Once it was up it was fine. The problem is that standing the pole up can be a two-person job in most cases. While the pole isn’t heavy and it only has a wire antenna attached it still is 12m long and a bit unwieldy on the way up. You really need to keep the base anchored in order to stand it up easily. If nothing is around to serve this purpose you need a person to hold it while you walk the pole up. There may be instances where nothing will serve and no one is around to help so some sort of device is needed in order to enable standing up one of these poles solo.

I’ve seen various forms of mast holders comprised of a round tube of some sort attached to a board which is placed under your vehicle tire for support. These are useful devices but the problem is that they typically don’t allow for tilting the mast up. You need to stand it up and then place it in the tube. I’ve also seen versions that use a tube attached to a piece of square tube that it placed into the 2″ receiver on your vehicle for support. Some versions allow for tilting but only perpendicular to the anchor point.

I wanted something that would allow me to tilt up the pole solo and allow either the aforementioned vehicle support or free-standing. Searching the Internet did not result in any device that quite fit my needs. One really good homebrew version that I found was the One Person Antenna Raiser by KL7JR. This is a very good example of what I was thinking of building. As with all homebrew projects he’s built several versions with improvements that all adhere to the base design.

I considered buying square tube and building it out of steel or aluminum but cost and weight were a factor. So I decided to build it from Ash. I’ve got a reasonable stock in my woodshop and more is readily available at my favorite hardwood store, Kettle Moraine Hardwoods.

Two Ash boards

Hardware

Hardware

I planned to use a 3 foot length of 4 inch PVC to hold the base of the Spiderbeam pole. This was the closest fit to the OD of the Spiderbeam pole with the end cap left in place. The plan was to insert the bottom of the Spiderbeam pole into the PVC which was held in place by a tilting mechanism with some form of support once in the upright position. With an initial design drawn up and some inevitable changes along the way the build proceeded as illustrated below.

test

Parts cut

I added some extensions to the base to provide some additional stability when used stand-alone.

Tilt mechanism

Tilt mechanism

To lock the tilt mechanism down I used an eye bolt held by a threaded rod with a plastic knob with a large washer epoxied to the bottom of the knob.

Tilt Mechanism

The completed device

With finish applied and PVC pipe in place

With finish applied and PVC pipe in place

The PVC pipe is 36 inches. I wanted a reasonably good part of the Spiderbeam pole supported. When I stood it up it immediately reminded me of the Mobile Launch Platform (MLP) for the Saturn V.

Saturn V launch pad for comparison

Saturn V launch pad for comparison

My device is just a little shorter and much lighter than the MLP.

Free-standing, ready for the Spiderbeam with site inspector cat

Free-standing, ready for the Spiderbeam pole with site inspector cat

Free-standing with Spiderbeam pole

Free-standing with Spiderbeam pole

Rebar stakes hold the device in place. I plan to form the tops into handles and add some stops to the rebar so that they firmly contact the device and hold it in position. Once the pole is standing bungee cords are used to hold it in position against the rests on the upright portion.

The complete package

The complete package

The device, less the Spiderbeam pole weighs around 5 pounds and folds to make it easy to put in your vehicle.

 

This device makes standing the Spiderbeam pole up very easy. It goes up and comes down in complete control.

 

Advertisements

2 responses to “Portable mast tilt-up device

  1. Excellent post Tim. Great design well done.

    • Thanks Andrew. There was a wee bit of scope creep during the build process with the expansion to stand-alone in addition to holding it down with my truck tire placed on it. It worked out well. It’s still easy to pack up and throw in the truck and takes all of the potential drama out of raising and lowering the Spiderbeam pole. That thing wallows about a bit when you are raising it. Especially with the EARCHI on it as the matchbox is about 10 feet in the air when it’s up and that little bit of weight can add a wee bit of excitement swinging in the breeze on the way up. 73, Tim KA9EAK

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s