Bridgeport leveling screws

I don’t know if I’m wording this correctly but I’m trying to find out what size bolt/thread pitch the 4 holes located at each corner of the base of a M head I’m going to pick up... I need to run a long piece of all thread through each one so I can raise the machine up enough to get a pallet jack underneath it to move it around... also would these be typical with all Bridgeport models...?
Any help would be greatly appreciated..

Neither of my Bridgeports came tapped in the corner mounting holes. I would suspect 3/4 NC would be what to expect as the holes in my base were 5/8" and the 3/4 tap worked well. Just bring a 3/4 NC tap and some threaded rod along. Cut into 9" lengths and with a nut welded on one end. Should do the job or cover the most likely scenario.

Hate to be the bearer of bad news, but the holes in the base aren't threaded, they are simply clearance holes for bolts to hold the machine to the floor, and for most purposes gravity works well enough.

To raise the machine get yourself a 4 or 5 foot long pry bar, and bring a whole bunch of 1/2" or 2/4" plywood squares, about 6" x 6", for blocking. You'll find the machine has a small slot in the bottom center of the front of the base that is just big enough for the tip if the bar. lift here, block the front corners, then lift the back corners and block. Keep going round and round until the machine is high enough.

Unless the machine has to travel a long way, I don't like to use a pallet jack. The tricycle wheel arrangement of a pallet jack can be tippy under a Bridgeport, and if the jack starts to tip, the machine will slide off. I prefer to use three or four lengths of 3/4 or 1" water pipe long enough to span both edges of the hollow base. 1" pipe is better, but lots of people have Pony clamps made with 3/4, and that will work almost as well. The pipe rollers keep the machine low enough to the ground that it can't topple over if it slides off.

Either way, lower the knee as low as it will go before moving to lower the center of gravity.

Good luck with the move.

Dennis

The person who is there says that the holes are threaded,,, they just don’t have any way to Check the size or thread pitch But they did it stick a 5/8 size bolt in the hall and it was bigger than that but that’s as much information as I can get

I have gone the pry bar and blocking route before. Raising the machine is a lot easier if you invest in a toe lift jack.

Thank you guys..

Bellaru433 said:

Thank you guys..

Click to expand...

My 1966 Bridgeport base is threaded
3/4-10

Bellaru,

I did this last weekend. The holes are PERFECTLY sized for 3/4-10. I ran the corresponding bit into the hole and almost no material was removed. I then tapped the hole. The casting is fairly soft but actually a bit thicker then i expected (about 5/8 - 3/4 - i was worried that there might not be enough material to hold the weight of the machine but i was surprised and it works perfectly). I chucked the tap in a drill, used plenty of oil and it cut through it like butter.

Once tapped i used 6 inch Stainless Steel bolts, 1/4 inch thick stainless washers (1 1/2 OD as you cant go too big with the angle of the casting in the rear) and these Toggle Pads in the link below. You have to use skinny toggle pads as there is not enough space between the casting and the hole for the thicker food pads. 2.5 inches is about max. These work perfectly, swivel about 10 degrees and are much less expensive then most other options.

Toggle Pad - 3/4-10 Thread Size - Northwestern - US Made - 45406 - Lot/4 Pads | eBay

Good luck!

ETRem1 said:

Once tapped i used 6 inch Stainless Steel bolts, 1/4 inch thick stainless washers (1 1/2 OD as you cant go too big with the angle of the casting in the rear) and these Toggle Pads in the link below. You have to use skinny toggle pads as there is not enough space between the casting and the hole for the thicker food pads. 2.5 inches is about max. These work perfectly, swivel about 10 degrees and are much less expensive then most other options.

Toggle Pad - 3/4-10 Thread Size - Northwestern - US Made - 45406 - Lot/4 Pads | eBay

Good luck!

Click to expand...

Thanks for posting that link. I think that's a much better leveling mechanism than shims I've been using. I'm having trouble visualizing how you did this with bolts and the toggle pads on the bottom. Were the SS bolts tap bolts? If so, I would imagine you threaded the bolts down through the top of the base and down into the toggle pads? If so, where did you use the SS washers?

Randal,

Ill take and post a picture for you tomorrow but here it is in words! I bought 6 inch stainless steel fully threaded bolts. I screwed a nut on (also stainless just for looks), placed the 1/4 stainless washer under the nut and screwed the assembly into the tapped hole. I threaded it all the way down and screwed the toggle pad on the underside (attached it with red lock tite) and adjusted the bolts up and down to level the machine. Once leveled i just tightened down the nut against the washer to act as a jam nut and make sure nothing moves.

6 inche bolts are about perfect on my machine. It probably gives 3/8-1/2 of total adjustment. Ill send pictures tomorrow.

Here you go! My little system worked great.

Thanks for the pics. Very nice!

By the way, were did you buy the ss tap bolts and the 1/4" thick washers?

I bought them on EBAY.

Washers (these are super nice)
(1 pc) extsw 3/4"ID x 1 1/2"OD x 1/4" Thick 316 Stainless Washers | eBay

Screws
1 or 4! 3/4-10 x 6" Stainless Steel SS Hex Cap Screw Bolt w/ Nut FULL THREAD PO | eBay

Foot Pads

Toggle Pad - 3/4-10 Thread Size - Northwestern - US Made - 45406 - Lot/4 Pads | eBay

Tap
3/4"-10 HSS Plug Tap and matching 21/32" HSS 1/2" Shank Drill Bit in plastic ... 696534782248 | eBay

Randal,

One other quick thing. One of the rear holes on my machine had a lot of filler AND paint buildup and was drilled a little closer to the stem then the other. Because of that, the washer on one side wouldn't sit fit. A die grinder took quick work of that. The other side had about 1/8 to 1/4 of clearance. I suspect this was just my machine and will not be a problem on yours. Anyway, if you are doing a full restoration, check before you paint. I had my machine all painted and then had to go in to preform surgery which wasn't ideal.

As to the Washers, don't go larger than 1 1/2. That is max OD.

Bellaru433 said:

I don’t know if I’m wording this correctly but I’m trying to find out what size bolt/thread pitch the 4 holes located at each corner of the base of a M head I’m going to pick up... I need to run a long piece of all thread through each one so I can raise the machine up enough to get a pallet jack underneath it to move it around... also would these be typical with all Bridgeport models...?
Any help would be greatly appreciated..

Click to expand...

Sorry if this is useless to you: I'm doing something similar. I want to slip my pallet jack under my mill, but I want to do it from the front OR from the side.

So here's my question(s): How do you intend to do that? Has anyone else done it?



I have a std pallet jack and measured it yesterday at 27" + change. There are other pallet jacks:

There are at least three sizes of basic pallet jack

What I was planning to do was to bolt 3' long outriggers, made from simple 3" x 1-1/2" tube stock, to the front holes (one piece) and rear holes (one piece), such that the outriggers are parallel to the x-axis. At 3' long, my pallet jack would fit nicely between the leveling feet from the front. From the side however, the space between the outriggers would be 28-1/2"-3" which is too narrow for my pallet jack to fit between. I would be able to squeeze between the leveling feet, but the jack would sit on about 1" of each outrigger. Maybe that's ok.

Anyway, threading through the base made me think you could end up with bolt bending, depending on how exactly the machine sat on the pallet jack. I guess without the outriggers, a pallet jack could fit snugly from the side. I guess you'd need a narrow fork jack from the front.

Thoughts? Am I over analyzing this?

Place the machine on a pallet first.

Then pallet jack is simple.

Lift is only fraction of inch and no tipping

If machine is on jack it is too high and slippery to boot...

Hitting a nut on the floor causes jack to stop but machine continues.

Build a suitable pallet to place machine then bolt to pallet if wanted but gravity works

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