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concrete lathe pad

Gary Chapman

Gary Chapman

Joined
Mar 3, 2009
Messages
244
Likes
1
Location
Madison, Indiana
I have had my shop for 5 years working on crawl space flooring and my woodfast would just shake when i would put a large chunk of wood on it. I finally got smart and had a foundation,block, and concrete pad poured so I can attach my lathe to it.
How nice it is to now stop the vibration and have a stedy lathe. I can spin a 50,60 pound block with ease. I don't know what took me so long.
 
So you're saying you bolted it down? Any idea how much improvement just the bolts by themselves were, if so?

Thanks.

Rich
 
I had it bolted down to the plywood flooring in the shop but with big pieces spinning on the lathe the floor joices shook and all my other tools shook.
Now with the lathe bolted to the concrete pad, it is solid as a rock. Gary
 
In the coming year, the Light of My Life will be moving me and my dust out to the upstairs of our garage. (On a plus side, I can finagle a new lathe in the deal 😀) Anyone have any suggestions on how best to secure a 16-20" lathe to a plywood floor with 2X8 joists below? (I've got access to the joists and underside of the floor) Or stabilize/reinforce the floor to minimize movement?

Thanks.

Dean Center
 
Gary
Makes a big differences when the lathes solid huh.🙄
Dean
You really need to look at load limits for those joist, I believe you'll need to put some double or maybe triple 2 x 10s or 12s under that big lathe also they have to have the same support going down to the footer I believe.
Just my$.02
 
Gary Chapman said:
I have had my shop for 5 years working on crawl space flooring and my Woodfast would just shake when i would put a large chunk of wood on it. I finally got smart and had a foundation,block, and concrete pad poured so I can attach my lathe to it.
How nice it is to now stop the vibration and have a steady lathe. I can spin a 50,60 pound block with ease. I don't know what took me so long.
Click to expand...

Good going, Gary.....!

There are those who have lathes on a concrete garage slab and still don't bother to bolt it down! Now that you've taken this step, there will be no turning back. All that's required is a few cement anchors and a hammer-drill.....so, easy to do.

In your case, it did require quite a bit of effort to find out how much of a help this step really is. It's like adding hundreds, or depending on how big the slab is.....thousands of pounds of weight to your lathe. This is what tames that vibration.........😀

ooc
 
Dean Center said:
In the coming year, the Light of My Life will be moving me and my dust out to the upstairs of our garage. (On a plus side, I can finagle a new lathe in the deal 😀) Anyone have any suggestions on how best to secure a 16-20" lathe to a plywood floor with 2X8 joists below? (I've got access to the joists and underside of the floor) Or stabilize/reinforce the floor to minimize movement?

Thanks.

Dean Center
Click to expand...

I'm with Odie for adding ballast to reduce vibration at the source.

For reinforcing the joists, the most effective, and almost simplest, is to add flat steel bars to the bottoms - similar to reinforced concrete. They probably don't need to be full length, but you'll need a lot of lag screws for attachment, preferably with the floor temporarily propped. According to Google, there are several structural engineers in Bozeman, and a chat would be money well spent.

If your shop is anything like mine, you'd be wise to consider other equipment to be added to the load.

Most important, how do you propose to lift the lathe upstairs?
 
Dean...I agree with Harry. You really need to reinforce those 2x8 joists with something a LOT more substantial. Depending on the spans involved, you might be dealing with the same vibration issue that Gary resolved with his concrete footing and slab. Or worse, you might overload the joists and cause them to sag or even fail. I suggest finding a local structural engineer to look at it and design something for you...money well spent.
 
2 X 8 floor joists should handle the weight fine, but they will flex, and vibrate with the lathe. The possibilities of finding a resonating frequency where things really start to move are probably like Murphy's law. You could do some pier pads and extra bracing (like 4 X 4s cross wise under where the legs will be) up to the joists right under the lathe, and that would probably do the trick. I have my lathe on a concrete floor, and do not have it anchored down. It does move, so the leg on the headstock end is up against a cabinet, and the leg on the tailstock end is up against a block of wood that again is up against the wall. Seems like the lathe wants to rotate counter clock wise. I am in the school of 'don't bolt it to the floor'.

robo hippy
 
robo hippy said:
2 X 8 floor joists should handle the weight fine, but they will flex, and vibrate with the lathe.
Click to expand...

Hey robo - hope you're doing well down south.

Be careful with such a blanket statement. My garage second floor has 2x8 with 24" centers... no where near stout enough to handle a 500 pound lathe without concern. Granted, it was built c.1920 and doesn't adhere to modern codes, but Dean didn't offer much by way of specifics for his situation.

In keeping with my wariness in recommending anything specific to Dean, he really does need to examine the structure more thoroughly. I've asked my city building department about structural loads and have gotten great advice.
 
[Harry,
I didn't just pour a concrete pad, I cut a hole in the flor, reinforced the joices, went down to the ground, poured a footer, laid block up to the floor or 5 inches shy, and then poured a slab. I tried beefing up the joices first and still had vibration.
I did it 1st class this time, cost me some bucks but it was worth it. ThanksQUOTE=Dean Center;78320]In the coming year, the Light of My Life will be moving me and my dust out to the upstairs of our garage. (On a plus side, I can finagle a new lathe in the deal 😀) Anyone have any suggestions on how best to secure a 16-20" lathe to a plywood floor with 2X8 joists below? (I've got access to the joists and underside of the floor) Or stabilize/reinforce the floor to minimize movement?

Thanks.

Dean Center[/QUOTE]
 
2x8 #2 SYP will span about 9' with a 100# load, which is 2.5 times what a house is. That is 100# PSF.

Having said that, a concentrated load, such as a piano, giant bookcase, or a lathe, should be treated differently than normal traffic.

Rich
 
Reinforcing floor

I was a custom home builder for 40 years and I don't have enough information to suggest a way to make the floor more rigid. I need to know - what is the span of the 2x8's ? How are they spaced ? (16" oc, 24"oc) How are they supported now. Is it a double car garage or single? Do the 2x8 joists run front to back or side to side. Can you put post supports down with out blocking the garage bays? If I had this info I could tell you how to support the floor.
 
Gary, I apologize for highjacking your thread. But I really appreciate the advice.

The joists are 16" oc 2X8's hung on joist hangers between the side walls and a center beam and 10' 7" long. The beam runs the length of the garage between the bays, it's a true measurement 5" X12" glulam with 19' of free span between the 6X6 posts at the ends. The post at the door end sits on the slab and footing wall, and I'm not sure if there is reinforcement under the other post, because it's not in the wall, but a a stairway's distance from the end wall. I can ask the contractor. The joists are Hemlock/Fir, and almost certainly Rocky Mountain Doug Fir.

Joe, good question and one I haven't wrestled into submission yet. Maybe I could hire 300 Egyptians who got laid off when a pyramid was finished. I'm old enough I know not to shoot an elk 5 miles from the road, so I should have solved this part right off.

Dean
 
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Tie the joists together at short intervals to make them act as one rather than allow spread and distortion. Make sure your flooring is screwed at short intervals to prevent it from becoming a sounding board, adding another layer if you see fit to help spread the load.

Intuition says the lathe should span rather than follow the joists, and should be as close to the supporting beam as is practical.
 
Slightly better than simply tying the joists together, attach plywood to the bottom of the joists to create a box beam of the entire floor, or most of it. There should be a large enough increase in stiffness, to not need propping for camber. Substantial increase in strength too. Your structural engineer and contractor can work out the details, including extra screws on the top. The screws are the cheapest component, so no need to skimp.

Regarding moving the equipment, temporary dis-assembly could help. OTOH, King Arthur's Tools here (Lancelot) established a WT instruction venue on their second floor; Four or 5 Jet's IIRC, plus band saw and drill press. They put a sliding door at one edge, to allow forklift access from the loading dock.

ps. I'm both a structural engineer and a former guest at Holiday Inn Express.
 
Foor strenth

Cut 2x8 blocks 14 1/2" long and glue and nail them between the floor joists, 3' oc. Clad the under side of the joists with 7/16" sheathing. This will spread the live load across the entire floor and should be suffient.
 
Thank you all very much. The joists have ties about half way in the span between side wall and beam, so this shouldn't be too much work. I'll probably double the joists under the section where the lathe will go. Now, anybody got a used 3520B they want to sell?

Dean
 
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