Spotter arms on commercial power racks with slotted racking systems?

[dumb.bell]

Attached is a picture of one of the spotter arms from my rack which has the stainless slotted racking system. It is made of what I'm assuming is a 2 x 3 38 inch piece of 7 gauge steel with a 1 inch steel rod running through the rectangular piece and the quarter inch plate end pieces. I was able to confirm that the steel rod runs through it by using a flash light to look into one of the screw holes where the hard plastic is attached to the top. There is a small gap of approximately 1/8 of an inch between the inside wall of the tube and the rod. The spotter arm weighs 27.5lbs.

For any of you who have Hammer Strength or similar racks, does the steel rod run through your spotter arms, or is there just a small piece of steel welded into the end of them? What are the length and weight of your spotter arms?

If I were to build a set of comparable spotter arms using 7 gauge or possible 1/4 inch steel 2 x 3 tube, would it be necessary to run the rod completely through the steel or is that overkill? Could I get away just using short pieces of steel rod welded through the end plates? Would your answer change if the span was 48 inches rather than 38 inches?

[Skyaura]

Dumbbell,

I have a 11 gauge steel rack with a slotted rack system with 3 inch spacing. In contrast to your rack, there are actually two rods that run completely through the spotter arms. In other words the two pipes are racked in two slot positions instead of one. The inside spacing from post to post where the spotter arms are placed is 33 inches. The two steel rods are 35 inches. Total length of the spotter arm is 41 inches as it wraps around the post. The spotter arms weighs 25 lbs.

To answer the second part of the question, I would run the rod all the way through instead of welding two short pieces.

Hope that helps.

[dumb.bell]

Thanks, I appreciate the help.

Dumbbell,

I have a 11 gauge steel rack with a slotted rack system with 3 inch spacing. In contrast to your rack, there are actually two rods that run completely through the spotter arms. In other words the two pipes are racked in two slot positions instead of one. The inside spacing from post to post where the spotter arms are placed is 33 inches. The two steel rods are 35 inches. Total length of the spotter arm is 41 inches as it wraps around the post. The spotter arms weighs 25 lbs.

To answer the second part of the question, I would run the rod all the way through instead of welding two short pieces.

Hope that helps.

[hulked]

dumb.bell, I dont have safeties of this type, but I am guessing that if you just short pieces welded to the end plates, then the max load is limited to the strength of the weld. It won't be the case if you run the rod entire length. Just my 2 cents

[dumb.bell]

dumb.bell, I dont have safeties of this type, but I am guessing that if you just short pieces welded to the end plates, then the max load is limited to the strength of the weld. It won't be the case if you run the rod entire length. Just my 2 cents

I had thought about that too, and that was why I was going to drill holes in the 1/4 inch plate end pieces and pass the rod through them so that I could weld them on both sides of the plate before I welded the end pieces on. However, I agree that it would be stronger if I just run it the full length.

[dumb.bell]

Dumbbell,

I have a 11 gauge steel rack with a slotted rack system with 3 inch spacing. In contrast to your rack, there are actually two rods that run completely through the spotter arms. In other words the two pipes are racked in two slot positions instead of one.

I'm actually wanting to use two steel rods like your describing. I'm wanting to offset them so that I can flip the spotter and end up with 2 inch increments for the spotters. But with 4 inch hole spacing I'd have to have a spotter arm that has a 5 inch space in it (so probably a 5.5 inch safety). With that in mind, I'm leaning towards running one rod through the safety and then just using some small pieces for the second slot position.

When you get a chance, could you take a picture of one of your spotter arms?

[Skyaura]

I'm actually wanting to use two steel rods like your describing. I'm wanting to offset them so that I can flip the spotter and end up with 2 inch increments for the spotters. But with 4 inch hole spacing I'd have to have a spotter arm that has a 5 inch space in it (so probably a 5.5 inch safety). With that in mind, I'm leaning towards running one rod through the safety and then just using some small pieces for the second slot position.

When you get a chance, could you take a picture of one of your spotter arms?

Dumbbell,

No problem. I will do it tommorow.

[daniel327]

dumb.bell, I dont have safeties of this type, but I am guessing that if you just short pieces welded to the end plates, then the max load is limited to the strength of the weld.

Considering the old rule of thumb for welds (i.e 1" x 1/4" of good fillet weld will support 2200 lb), and the fact that more than 3" of weld would be applied around a 1" pin, I wouldn't be too concerned.

[ninjaneer]

i've got a nebula phase rack, the rod goes all the way through. if you're going to make a custom safety, another thing you may want to consider is making them reversible. my rack is slotted every 4", but the safeties can be installed upside down, allowing for 2" increments. if you put them in normally, the rod is biased towards one side, but if you flip it over and keep it in place with a latch, you'd get a smaller adjustment because of the height of the safety.

not sure how less safe it is to use the safeties with the rod on the lower side, but it has served me well.

Attachment 5342413

[dumb.bell]

if you're going to make a custom safety, another thing you may want to consider is making them reversible. my rack is slotted every 4", but the safeties can be installed upside down, allowing for 2" increments.

This is what I was attempting to describe a few posts up.

if you put them in normally, the rod is biased towards one side, but if you flip it over and keep it in place with a latch, you'd get a smaller adjustment because of the height of the safety.

not sure how less safe it is to use the safeties with the rod on the lower side, but it has served me well.

Attachment 5342413

The latch is another way to arrive at what I was trying to achieve with double posts. Did your spotter arm come this way from Nebula or did you customize it?

[dumb.bell]

Considering the old rule of thumb for welds (i.e 1" x 1/4" of good fillet weld will support 2200 lb), and the fact that more than 3" of weld would be applied around a 1" pin, I wouldn't be too concerned.

Good information - Thanks

[Stasher1]

I'm actually wanting to use two steel rods like your describing. I'm wanting to offset them so that I can flip the spotter and end up with 2 inch increments for the spotters. But with 4 inch hole spacing I'd have to have a spotter arm that has a 5 inch space in it (so probably a 5.5 inch safety). With that in mind, I'm leaning towards running one rod through the safety and then just using some small pieces for the second slot position.

When you get a chance, could you take a picture of one of your spotter arms?

Have you considered just using some 2"x2" steel to construct a "saddle" of sorts that could just sit on top of your original spotter arms? It could easily be done with 6' of 2"x2" and a dozen 3"x3"-5" pieces of 1/4" plate.

[ironwill2008]

If I were to build a set of comparable spotter arms using 7 gauge or possible 1/4 inch steel 2 x 3 tube, would it be necessary to run the rod completely through the steel or is that overkill?

Overkill, even if you parked a '56 Buick on it.

[dumb.bell]

Have you considered just using some 2"x2" steel to construct a "saddle" of sorts that could just sit on top of your original spotter arms? It could easily be done with 6' of 2"x2" and a dozen 3"x3"-5" pieces of 1/4" plate.

Yes, I have considered something like that, and it is still a possibility that I might do that for my gold rack. Although I think I like your plan better than the one I was considering.


Nevertheless, I'm planning on constructing another rack out of two half racks. Basically, just putting two of them up facing each other and running a spotter arms between them. This lifting area in this rack would be 48 inches. I'm thinking that I could set up one side for squats and the other for benching. Here is a picture of one of the half racks I set up the other day. The pullup bar is upside down right now because of where it is located. Once I move it out into the middle, I have an additional foot and a half of clearance.

[dumb.bell]

Overkill, even if you parked a '56 Buick on it.

Good to know!

This reminds me of when I hung a 100lb framed mirror on the wall for my wife. It just turns out that the backside of the wall where I was hanging the mirror was in a closet. I went into the closet and cut away some sheetrock so that I could put in some cross braces in between the studs where I wanted to drive the anchors into the wall. I basically stacked 4, 2 x 4s in between the studs for both of the 8 inch oversized screws that I used as anchors. I drove the screws down at an angle so that they pierced at least two if not three of the cross braces.

When my friend who is an engineer showed up, he laughed and said that I could probably winch a car up from those two anchors. In that case I just remember that my wife had spent several thousand dollars on the piece of furniture that was beneath the mirror and she told me that I needed to make sure that mirror didn't fall on her furniture.

[ironwill2008]

Good to know!

This reminds me of when I hung a 100lb framed mirror on the wall for my wife. It just turns out that the backside of the wall where I was hanging the mirror was in a closet. I went into the closet and cut away some sheetrock so that I could put in some cross braces in between the studs where I wanted to drive the anchors into the wall. I basically stacked 4, 2 x 4s in between the studs for both of the 8 inch oversized screws that I used as anchors. I drove the screws down at an angle so that they pierced at least two if not three of the cross braces.

When my friend who is an engineer showed up, he laughed and said that I could probably winch a car up from those two anchors. In that case I just remember that my wife had spent several thousand dollars on the piece of furniture that was beneath the mirror and she told me that I needed to make sure that mirror didn't fall on her furniture.

Lulz. Better safe than sorry, especially where accomodating your other half is concerned.

[irongrandpa]

Good to know!

This reminds me of when I hung a 100lb framed mirror on the wall for my wife. It just turns out that the backside of the wall where I was hanging the mirror was in a closet. I went into the closet and cut away some sheetrock so that I could put in some cross braces in between the studs where I wanted to drive the anchors into the wall. I basically stacked 4, 2 x 4s in between the studs for both of the 8 inch oversized screws that I used as anchors. I drove the screws down at an angle so that they pierced at least two if not three of the cross braces.

When my friend who is an engineer showed up, he laughed and said that I could probably winch a car up from those two anchors. In that case I just remember that my wife had spent several thousand dollars on the piece of furniture that was beneath the mirror and she told me that I needed to make sure that mirror didn't fall on her furniture.

You've got a great wife, do whatever it takes to keep her happy.

[ninjaneer]

This is what I was attempting to describe a few posts up.

The latch is another way to arrive at what I was trying to achieve with double posts. Did your spotter arm come this way from Nebula or did you customize it?

and so you did~ that's what i get for posting past prime time. wasn't a custom order, that's how it came from nebula. if you search around for old descriptions of the phase, you'll see it in their nomenclature. i actually didn't even realize i could flip them till about a year after i got my rack! for me, it only comes in handy for benching, but it allows me to squat and bench with the safeties in the same slot. i just flip the latch and i'm good to go.

[dumb.bell]

You've got a great wife, do whatever it takes to keep her happy.

I try my best!

[Skyaura]

spotter arm.jpg

Dumbbell,

Hope this helps.

[ProtienandIron]

Dumbbell, IMHO running the rod all the way through is complete overkill. Daniels info on weld strength is on the money- a collegue of mine who used to work in the ship building industry as a welder told me the same. Nonetheless if I was building it I would still drill the plates to a tight tollerance and weld both sides before welding to the beams. Many j hooks (including my own) are constructed this way and the bar load is only shared over two points, whereas this will be over 4.

[a7stringkilla]

Here are a couple pics of my Atlantis safeties. Dont know whether the rod goes all the way through though. I would assume it does since there is no sign of a weld on the outsides of them. If you have a good fabricator build your safeties, you really wouldnt even need to have the rod go through that flatstock on the ends. It could just be welded there and there would be nothing you could ever do to break them off. Im not saying thats how you should build yours (Im all for overkill!), but truthfully, you could. During the day, I work at a commercial launch facility (Yup, Rockets!), and the things that the welders do there blow me away. BUT, if I were to have safeties built, I would build them as gnarly and over the top as I could. Not because I need them to be, simply just so I can say that they are. Hey, if youre gonna go through the trouble to build something, MAKE IT AWESOME!

[dumb.bell]

I'm assuming that there is a certain kind of steel rods that are used for safeties, does anyone have any suggestions as to what kind of steel?