Bridgeport on wood floor joists and plywood???

[vascon2196]

As you can see by the title of this thread I have an issue...or maybe not...I don't know which is why I am asking.

I built a shed about 8 years ago using concrete blocks, 2x6 floor joists, and 3/4" PT plywood. I have attached CAD images for reference on how it was constructed. The shed is 12ft x 12ft x 8ft.





Do you think a Bridgeport would sink or swim in this situation?

If a concrete floor is needed, how could I add a concrete floor if the shed is there already? Could I tear out the plywood, box the floor in from the outside, and fill it with cement???

I have a raised ranch and putting the mill in the garage right beneath my bedroom is out of the question (at least in my wife's eyes). I also do not want to build a brand new structure just to house a milling machine.

Any suggestions would be greatly appreciated.

Thank you!!!

 

[n4zou]

You can cut a hole in the floor, frame in a form, and pour a pad. You can get away with pouring the concrete directly on top of the ground. Someone might hate that you did that 30 years from now IF they keep the building and the Mill. If it shifts while you still own it you will just need to level the Mill when required to compensate. More than likely you'll have done yourself a favour by making that concrete pad easy to remove along with the building sometime in the (distant) future.

 

[Cogsy]

You could also cut out that section of floor, sink some solid posts into the ground and build a solid platform tied into the existing structure. Personally, I'd just go for the concrete pad directly under the mill though.

 

[kvom]

I would use an air conditioner pad under the shed and another one on the floor of the shed, connected with 4 pieces of iron pipe threaded onto flanges, You only need 4 small holes in the flooring for the pipe supports to pass, and the flanges can be used for leveling. The pads are typically thick plastic and very rigid. Your material cost would be less than $200.

 

[steamin]

Chris,

Thank you for asking about placing such a heavy item on your shed floor. The first thing I see that causes great concern to me is the placement of the blocks. The holes in the block should be vertical. Structurally they are much stronger and designed to be used that way. I know flat surfaces are better to work with, that is why there are cap blocks. I know of first hand about someone who used blocks as you did to help elevate their car to work under it. The blocks broke and caused the individual great harm.
Second, you have no supporting blocks towards the middle of the shed. The static load bearing will be way to much for the 2x6's and single layer of
plywood that you have.

Third, do you have any concrete footers that the cement blocks are resting on ? If not, then all the weight that you plan to put in your building will cause the building to just sink into the ground every time it rains.

The building you have is a great "shed", but to turn it into a machine shop would be a disaster in the making. Sorry to rain on your parade and I know you are all excited about having machine tools and such, but please rethink what you have and what you are trying to do with it.

I can see the corners being jacked up to correct the block and foundation situations. I can see the existing plywood floor being taken up and heavier timbers and more support points being installed. I would consider a double layer of 3/4" plywood cris-crossing for the floor.

Probably the easiest and safest thing to do would be to pour a proper concrete pad and deconstruct your current shed and build it back on the new concrete pad.

Again, I am sorry to raise so many concerns, but I am thinking of you..
All the best to you and your endeavors,
Larry

 

[vascon2196]

Thank you Larry...I am considering everyone's input. I will definitely be taking my time with this decision.

 

[va4ngo]

I agree with all that steamin said, especially orientation of blocks. If you elect to do that, regardless of what size slab, use some form of waterproofing such as plastic sheet to prevent water rising through the slab and causing rot and rust.

Phil in Melbourne Australia

 

[stevehuckss396]

I wouldn't do it personally. Pour yourself a pad with footings and build the building on the pad anchoring the walls to the concrete. A good quality machine deserves a good quality building.

 

[vascon2196]

I have decided to pour a small 7ft x 12ft foundation just to the left of the shed. The shed was built 7 years ago and is still level and I just could not bring myself to start cutting holes in it.

At least with the foundation poured I have a future home for a Bridgeport once I find one that I can afford.

Thanks for the input fellas.

 

[vascon2196]

I just received a call from my old employer...he is willing to sell me a full-size original Bridgeport including shipping for $5,000. The machine has been well taken care of.

I still have to pour the concrete slab!!!

What do you guys think?????

 

[Sshire]

My list when I got mine
1. Everyone wants to know how old. "What's the serial number?" I'd rather have an old, lightly used BP, than one that's much newer but has been used to death.
2. What head? J head (pulleys) has many fewer parts than a Vari-speed(2-J) head. Since virtually all are 240v 3 phase (unless that's your power supply in the shop), a VFD with a J head gives you variable speed, soft start, dynamic braking, etc. Some folks will tell you to get a rotary phase converter. The continuous whine, for me, was not acceptable. Plus I wanted variable speed, etc.
3. Chrome ways? Much less potential for wear.
4. What is the spindle runout?
5. Are power feeds installed? What type? BP or Servo brand are most common. Once you have them, can't live without them. Especially on the knee. The cranking (10 cranks to the inch) get old, real fast
6. DRO?

 

[kvom]

$5K for a BP seems high, but depends on what comes with it and how far to ship.

I'd recommend calling John at http://www.j-lscraping.com/. He reconditions Bridgeports and is located in MA. In the past his refurbs have been well less than $3K.

 

[Lakc]

Its hard to comment on the worthiness of that offer without knowing a bunch of specifics, like year, model, condition, accessories, and shipping/rigging.
Base price for a used/good BP in our area is only 2-3k.

 

[Sshire]

2-3k sounds right for the mill. How far is is traveling and does it include putting it in place? I.e. rigging.

 

[Wizard69]

I just received a call from my old employer...he is willing to sell me a full-size original Bridgeport including shipping for $5,000. The machine has been well taken care of.

I still have to pour the concrete slab!!!

What do you guys think?????

I have to agree with others that price is high for a used Bridgeport of any reasonable age. A relatively new machine with lots of support parts might be worth it.

Beyond that if you don't have the slab poured and have no place to store the mill, the Question is already answered isn't it.

Speaking of that new foundation what is right for your area might not be right for others. For example do you have a frost problem, lots of moisture, strange clays subject to shifting & etc. It is a good idea to get input from local builders, engineers or inspectors that is applicable to your area. The last thing you want is your slab shifting after the machinery is installed.

Also slabs for machinery should be a bit thicker than the structural requirements might imply. Thicker will provide more mass for one thing but it also provides for the ability to install solid anchor bolts which are always desirable.

 

[vascon2196]

Here is what I know so far.

Serial # 2J-107413-2,

DRO installed,

Pneumatic Draw Bar System,

Vise Attached,

Purchased new,

No power feeds,

42” table,

Price includes delivery and installation (5 to 6 miles)

 

[Sshire]

1968 manufacture date based on the serial number. Given the power drawbar, vise and DRO, not bad but seems a bit high. Check spindle runout. Move table to center x and y. Lightly tighten x axis locking handle. (just enought to crank on x). How tight it gets toward the ends is generally an indication of wear. Repeat with y axis.

 

[vascon2196]

Thank you Stan...I want to offer $4,000 but would hate to be insulting. I worked for this man for 6 years and left on good terms. The machine shop has been family owned for over 100 years...

I want to believe I am getting a good deal, if you know what I mean?

I will check the wear and runout best I can.

Thanks to everyone for the input...it means a lot!

 

[kvom]

Check the vise. The Bridgeport original vises didn't have removable jaws and are not up to more modern vises like Kurts.

The air draw bar is a good thing!

Do you have 220V power at your shed? You'll need that plus a VFD to power it.

 

[vascon2196]

I do have 220V but no VFD.

I'm going to pay a visit to the shop soon...I'll check out everything and take pictures if I can.

Thanks again,