[QUOTE=Libby2563;8743710]
One piece of advice: do NOT use these plans from WikiHow. The base is too narrow so the things are top-heavy and blow over in the wind. I used them with tape to temporarily close off part of my arena for baby backing, and would find them lying down on their sides all the time. They just aren’t stable. I would have loved to use them for jumping one day but it seems like if the horse brushed the rail the whole thing might come crashing down.[/QUOTE]
The stability issues you have experienced isn’t because of the plans more so from the “engineering flaw” in the length of the “feet/legs”. The base is too narrow. Especially when set on uneven ground, sand etc.
The design itself is the standard (no pun intended) way of going about it.
12" is too short. 16" ( 1’-4") is better and efficient use of materials. An 8-10-12 foot board cut in 16" increments will not have any “scrape” left over. But you have to take into account the “kerf” thickness of the saw blade when making the cuts. Otherwise the last “foot/leg” will be shorter than the rest.
18" seems to provide a nice stable base. You will get 5, 18"cuts out of an 8’ board with 5 1/2+ inches of scrape. But it will give 5 equal size feet.
Only use pressure treated 2X it will last a long time without rotting. These plans use 2X8 material. I use 2X6. Plenty strong enough and I like the look of the lower “profile”.
The “miter” cut, the angle cut is more for looks than it is necessary. You can take this step out to save time. Personally I like the look. I measure 9" from the post “butt” end and mark, measure 2 1/2 or 3" on the opposite butt end and mark, take a straight edge and draw the angle cut.
Make all the cuts for you “starter” foot and use as a template for the rest.
These plans use wood screw to attach the legs to the post. Personally I find using carriage bolts gives superior holding strength. I use 3/8, 8" with washers and nuts. But this does take a bit more effort and expertise. But once bolted on they rarely come loose. 2 bolts on one “set” of feet for a total of 4 needed per standard.
A “C” clamp comes in handy to hold the 2 opposing feet in place to drill the 2 holes needed so the holes line up correctly when drilling through both feet and the post. Buy an 8"+ 3/8 drill bit so you can go all the way through.
When drilling the holes for the other set of feet remember not to line up the holes that same as the first set. Otherwise when you go to install the bolts they will hit the first set of bolts. Move up or down 1" or so. This is very important to remember.
Best to make 2 feet/legs and mark and drill the holes in the right places and use these as your template for all of the other feet/legs. Make sure to stack in 2 different piles.
Jump standards get dragged around, knocked over etc. which puts a fair amount of stress on the attaching points. Wood screws don’t tend to stand the test of time and abuse.
If using wood screw I would use these;
http://www.homedepot.com/p/SPAX-10-x-3-in-T-Star-Drive-Flat-Head-Partial-Thread-Yellow-Zinc-Coated-Multi-Material-Screw-72-per-Box-4191020500756/202040973
They have a “star head” (driver bit included) so unlike Philps heads they don’t “cam out” when screwing in. Especially when using a drill driver or by hand. The best and VERY handy power tool to own is an Impact Driver. They make short work of a lot of projects. Especially when having to drive lots of screws and even more so for using with hard wood like oak.
Avoid using “Deckmate screws”. These are meant to be used to screw deck boards “down”, flat onto the framing. They have very poor shear strength and break easily when used on something that will get “torqued”.
If using wood screws I strongly suggest using construction adhesive between the leg and the post. Make sure it is rated for exterior use.
If not using carriage bolts I would use 3/8, 3 1/2" lag bolts with washers instead of the smaller wood screws. Use 3 in a “V” pattern.
Using the rail cup is a good way to go about lining up the holes. But it is very important to try and keep the drill perpendicular otherwise the drill bit won’t line up with the hole on the other side. Obviously if one has access to a drill press it will make the task go much quicker with perpendicular holes. Use a drill bit that is slightly bigger than the diameter of the pin. Assuming it will fit in the cup hole if using one line up the holes. When I have used the exact size the wood can tend to swell and make it difficult to slide the pin in at times.
Another way to make fast work of marking and drilling the holes is to make a template out of a 2X4. Mark and drill holes as explained. Take this and clamp it to the post and drill away. Remove and go on to the next post. Saves time on repeated measuring. Drill all of the posts before attaching the legs.
Another way to make simple feet is to just cut, 2 18" or 24" 1X6 pressure treated board, deck board are even better because they are a full 1" thick. I have used broken oak fence boards.
Stack and form a “+” drill a hole in the center and use a long ½ lag bolt and bolt to the bottom of the post. Use construction adhesive. Because they are “stacked” the bottom of one leg of the + is going to be higher than the other one. Measure and cut a “filler” to screw to the bottom of either side to fill in the gap. Using 2 3/8 lag bolts is better, keeps the “platform” from coming loose and “spinning” when being moved repeatedly
This is quicker than the other way but if you want to set 2 Standards next to each other they do not “fit” very well, the legs get in the way.
To give a finished look to the the top of the Standard go the deck/fencing material section of a Home Depot, Lowes etc. They have various “caps” made to fit on top of a 4X4, screw in balls etc.