Bolts on mounting arm stripped?

[bleeker]

the four bolts on the bottom of the mounting arm (the ones that adjust the arm level and plumb) wont tighten.

The bolts dont look stripped, could it be the holes?

I was thinking about buying either larger diameter bolts, or nuts for the ones that are in there.

Any suggestions?

[SSW_Exposure]

There are several different ways the four tightening points work for different versions of masts.

Now you say "the four bolts on the bottom of the mounting arm (the ones that adjust the arm level and plumb) wont tighten."(makes a difference if your talking nuts or bolts). If you are talking bolts, then you probably have one of the types of mast that have a 'bracket' inside (I know of two types made by D*), and have seen these strip out, brand-new.
Basically you can replace any of the components that are used to tighten the mast to the foot, with about any other way to tighten it down. (Avoid using one long bolt that goes all the way through.)

Around here most of us installers have more of these than we know what to do with and give them to anyone who needs a new one. Heck, you can even stop the cable guy, he probably has one in the back of his truck.

[bleeker]

There are several different ways the four tightening points work for different versions of masts.

Now you say "the four bolts on the bottom of the mounting arm (the ones that adjust the arm level and plumb) wont tighten."(makes a difference if your talking nuts or bolts). If you are talking bolts, then you probably have one of the types of mast that have a 'bracket' inside (I know of two types made by D*), and have seen these strip out, brand-new.
Basically you can replace any of the components that are used to tighten the mast to the foot, with about any other way to tighten it down. (Avoid using one long bolt that goes all the way through.)

Around here most of us installers have more of these than we know what to do with and give them to anyone who needs a new one. Heck, you can even stop the cable guy, he probably has one in the back of his truck.

Well, there wasnt anything inside the arm...

I went to lowes and bought four new 1/4 bolts and nuts (the old ones didnt have any nuts, just bolts with nothing on the inside)

I got a small wrench and slipped it inside the bottom of the arm to hold the nut while i tightened the bolts, seems nice and sturdy now.

[Mike500]

Well, there wasnt anything inside the arm...

I went to lowes and bought four new 1/4 bolts and nuts (the old ones didnt have any nuts, just bolts with nothing on the inside)

I got a small wrench and slipped it inside the bottom of the arm to hold the nut while i tightened the bolts, seems nice and sturdy now.

You had the 1/4"x20 self tapping screws that were first used by KTI (ITI), now CalAmp, and now Terk and many more foreign manufacturers. Most others use a 1/4"x20x2-1/2" lomg piviot bolt and nut and two 1/4"x20x1/2" long carriage bolts and nuts, with the nuts sticking outward.

The easiest way to fix your problem is to use two 2-1/2" long 1/4"x20 machine bolts with lock washers and nuts.

Carefully remove the piviot screws first. These are the ones higher up on the mounting foot. Ream out the holes with a 1/4" drill bit on both sides. Run a 2-1/2" bolt through the whole foot, through the mast and out the other side. Put a lock washer and a nut on it and tighten it to about 10-12 foot pounds. Do the same for the lower mast bolts, and you are finished.

On the alternative, you could have used the 1/4" carriage bolts, but you'd have to file the holes at the bottom of the mast square to the size of the shoulders of the carriage bolts. Fit them in from the inside and place the lock washer and the nou on the outside.

This is a lot easier than trying to get a bolt and a wrench inside the end of the bottom of the mast.

[SSW_Exposure]

bleeker,
Your method is sure to keep a secure attachment between the mast and foot. You should never have to worry about it again.

ButThe easiest way to fix your problem is to use two 2-1/2" long 1/4"x20 machine bolts with lock washers and nuts.I would never suggest this, with an 1 1/4" air gap between the bolt head and the nut, you will never, never ever, get enough contact pressure to insure long lasting holding pressure. I have come across old mounts of this type that seemed to have been tightened every year, until he bolt runs out of threads and the mast is egg shaped and lost its structure.

Any professional installer would know this.

[Mike500]

The original dish mounting foot has a through bolt on the pivot, SSW Exposure. The pressure on tightening the bolt has never been the reason that the bolt holds. From my Mechanical Engineering class days, I know that it has always been the friction of the lock washers, the star washers being better than regular split washers. Like a leaking faucet, the answer to the problem is not always applying more torque. It only strips threads and deforms components.

The quality of dbs mechanical components have degraded since the early days of 1995, 1996, and 1997. The mounting mast tubes used to be 16 guage and thicker, with through bolts and carraige bolts and star lock washers. Since KTI, Terk, and others came up with self tapping thread cutting screws to mount the masts, and thinner masts of lower quality steel have come into use, these screws often strip.

As a professional installer, I have a large supply of mounting poles, masts and feet. I'd just switch them out. I just hate those with selt tapping screws. Too many people over tighten the screws thinking tighter is better. It isn't.

Frankly, if I had a stripped out screw situation, I'd just take out the cordless drill, a 5/16" hex socket and drive in a self-drilling hex-tex 1/4"x20 screw on each side of the foot between each of the original screws on each side.

In a situation, where just tightening does not fix the problem, more tightening just ruins everything.

[bleeker]

Yea, it is a KTI, and it DID have self tapping screws,
very bad design in my view.

Anyway, it wasnt had at all to slip an open end wrench into the bottom of the arm to hold the nut while tightening the new bolts. took about 10 minutes to replace all 4.

Cost about $1.10 for the 4 bolts and nuts, and I know it is very secure now.

The idea of replacing with 2 long bolts doesnt seem "easier" or "better"
It would have taken longer than 10 minutes to drill out the holes and put these in, plus I dont think 1 long pivot bolt and one long level bolt would be as good as the four bolt system.