New Member- Question on mounting platform to steel beam

[SafeHome]

My first post - this is a great site with lots of talented athletes, carpenters and welders!

I am building a basic 36" square wood platform to mount in my basement and will need to mount it to a steel beam overhead.

The platform is two layers of 1" wood glued and screwed together. (Three boards on hand.....) I'm guessing total weight is 50-60 lbs.

Should I come up from the platform with recessed bolts to the steel beam? I am concerned the weight of the platform will strip itself off the bolts, although I see commercial platforms using this method to attach the platform to the tubes.

Or should I mount metal ""U" type frames with 1.25" lag bolts to the top of the platform and bolt the metal frame to the steel beam? With this method I am concerned the lag bolts will come loose from the top of the platform.

I hope this make sense.

Either way - how many points of contact to the steel beam should I use and how far apart should the bolts be from each other?

Thank you for any advice you can share as I dig deeper into this site.


Thanks again!

[rdshackleford]

Can you post a pic of the steel beam?

-Rusty

[SafeHome]

Thanks Rusty,
The Beam is 5.25" wide with 2" available on either side of the the beam to the center of the "I".

The steel is .25" thick drilling from the bottom to the top of the lip. I have mounted a small bag for the kids as seen in the attached image years ago.

I'm going to cut the square 36" to a round 34" drum today based on some of the ideas I've seen on the site.

Thank you for any advice you can share. It is greatly appreciated!

[StevieMac]

As for recessed bolts from the bottom of the board Vs lag bolts from the top; I think either would work but I'd opt for bolts from the bottom personally.

Here’s an old thread where two of our members made REALLY think/heavy platform drums and I believe one used 4 recessed bolts for mounting and it looks like the other used lag bolts. http://www.speedbagforum.com/forums/...ead.php?t=4606

Is the drum going to be bolted directly to the beam or do you need to extend downward from there to get the drum at the correct height? You want the belly of the bag level with your mouth. If you will be using different sized bags I’d set the height for the largest bag and then if/when you move to smaller bags you can stand on a mat or a couple mats as needed to raise you up a bit.

I would probably mount a piece of steel perpendicular to the direction of the beam so I could have four solid mounting points closer to the outside edge of the board rather than close to the middle.

Hope that helps. Keep the questions coming and keep us posted on your progress.

[rdshackleford]

...You want the belly of the bag level with your mouth...

He does? Maybe you do. I don't. Well, maybe sometimes. But not always.

-Rusty

[StevieMac]

^ Fair enough Rusty. It's common advice around here but YMMV of course...

[rdshackleford]

I figure my mileage on an I-beam is at least 100 million punches on a heavy bag when using a simple metal cable loop...



-Rusty

[SafeHome]

Thank you!

Thanks StevieMac and Rusty for your reply and comments. I am planning to use 3/8" x 4" bolts recessed to secure the drum to the flange of the IBeam. I will separate the bolts a good distance towards the outside of the drum.

I was concerned the drilling may jeopardize the strength of the IBeam but have been told this is not a concern with the size of the holes I plan x 4. I am hopeful that noise and vibration won't be too much - to be determined.

I've attached an image of the revised drum, she's not pretty... but she's mine http://speedbagforum.com/forums/imag...lies/smile.gif.

Looking forward to sanding, staining and mounting and beginning my practice.

Thanks again for our input and advice!

[rdshackleford]

Mechanical engineers correct me if I am wrong, but a few 3/8" holes drilled into the bottom flange of a structural I-beam won't effect the integrity. iirc, that part is for compressive loads.

-Rusty

[Dutchman]

Pretty much, yeah. A couple of holes won't compromise the beam. Now if you drilled a whole line of those holes, that's a different story.......

[StevieMac]

I've attached an image of the revised drum, she's not pretty... but she's mine http://speedbagforum.com/forums/imag...lies/smile.gif.

Looks pretty good to me. Keep the pictures coming.

[rdshackleford]

What tools did you use to cut the drum round? How do you do that?

-Rusty

[SafeHome]

Thank you!

Hi Rusty and Dutchman,

Thank you again for your feedback! Greatly appreciated! I used a circular saw and a hand saw. Had to take a rough sander to the edges to make it semi- round. I would have been much easier cutting the two 1" layers separately before gluing and screwing them together. Lesson learned. Good enough to get me going, looking forward to finishing it and mounting.

Thanks again!

[SafeHome]

Holes Drilled

Getting close to mounting, used a mahogany stain on hand and polyurethane for cosmetics and durability.

The holes were a bear to drill in the quarter inch steel beam. Slow and steady - took about an hour for 4 holes working from the bottom up but they are ready to go. Next to drill and bolt the swivel then drill and recess the four bolts to mount to the beam. Looking forward to the final install.

I have a new heavy bag arriving on Friday - now to start researching the best way to mount it! http://speedbagforum.com/forums/imag...lies/smile.gif

[StevieMac]

Looking good