New mill, anchor to floor or just sit it down ??

hman said:
Geez, youse guys! Wuz I copying you or wuz you copying me? Here's the feet (McMaster_Carr, ⅝" stems) and steel bars I just installed on my new mill today! (With help from a neighbor with a backhoe.) One of the bars is 1x3½", the other 1x4" - both straight out of the rem bins at Industrial Metal Supply. As wide as they are, I was able to "cheat" a bit, and place the feet up to 2" further forward and back from the mounting holes. The long stems allow me to raise the mill enough to get a pallet jack underneath.
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What mill is that?
 
It's a PM 835S - slightly smaller version of the classic knee mill. I got it about a week or so ago, been busy cleaning it, doing some minor mods, and planning how to add a 3 phase motor and VFD. Durn thing is too durn tall for me, so among other things, I'll be adding a platform to the front.
 
I've always used Haas level-pads & jack screws but I also used to have unlimited access to them.

The newer ones are available in both aluminum & cast iron for $35 a pop if their website is accurate. They supposedly have some kind of "cold-flow anchoring" material on the bottom that is supposed to approximate, well, anchoring. Looking at the patent just now it says a "material such as nylon."

The way it was explained to me is that anchoring isn't about macro level movement, it's about making the machine "appear" larger than it is to dampen vibrations. But there was an incident involving a tool room lathe, some unsupported bar stock, and a constant surface speed setting that defaulted to "ON" with every power cycle that showed macro movement can absolutely be an issue. Hopped itself ~3 feet out of position & gave the operator a freaking heart attack.

Shouldn't ever run into that problem with a mill though. LOL. I had some reservations when folks said to use rubber for vibration dampening but looking at the photos it's pretty thin & I guess it's been done for quite a long time w/o issue. I would consider adding a tiny amount of texture to the bottom if those leveling feet are smooth. Logic there is the same as the "cold flow anchoring;" which is textured slab + textured feet = better deformation of the pad into the concrete to provide a stronger interface between the two in effort to provide an approximation of anchoring w/o any of the work or potentially massive headaches, especially in your case.

Just some stuff to think about!

Regards,

Steve

Sent from my SM-N975U using Tapatalk
 
Iceberg86300 said:
I've always used Haas level-pads & jack screws but I also used to have unlimited access to them.

The newer ones are available in both aluminum & cast iron for $35 a pop if their website is accurate. They supposedly have some kind of "cold-flow anchoring" material on the bottom that is supposed to approximate, well, anchoring. Looking at the patent just now it says a "material such as nylon."

The way it was explained to me is that anchoring isn't about macro level movement, it's about making the machine "appear" larger than it is to dampen vibrations. But there was an incident involving a tool room lathe, some unsupported bar stock, and a constant surface speed setting that defaulted to "ON" with every power cycle that showed macro movement can absolutely be an issue. Hopped itself ~3 feet out of position & gave the operator a freaking heart attack.

Shouldn't ever run into that problem with a mill though. LOL. I had some reservations when folks said to use rubber for vibration dampening but looking at the photos it's pretty thin & I guess it's been done for quite a long time w/o issue. I would consider adding a tiny amount of texture to the bottom if those leveling feet are smooth. Logic there is the same as the "cold flow anchoring;" which is textured slab + textured feet = better deformation of the pad into the concrete to provide a stronger interface between the two in effort to provide an approximation of anchoring w/o any of the work or potentially massive headaches, especially in your case.

Just some stuff to think about!

Regards,

Steve

Sent from my SM-N975U using Tapatalk
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Good food for thought, thanks for that info! These feet are cupped on the underside, and I suspect they will upset to a certain degree, to conform to surface irregularities. Plus, I figured that Barry, and the gang at H&W likely have hundreds, if not thousands of these out in circulation and if there were any big issues, they'd know it by now.
 
I have 3 full sized mills (--for the moment, don't ask...) Been milling for 30 years, never bolted down any of them I don't use rubber vibration dampeners, as I settle my mill to as close to level that I can measure on my precision level... I've always been leery that they'd compress and I'd need to re-level. I'm also lazy... :tranquility:
 
It must be the thing to do when everyone is doing it... My contribution, cost $65 for materials and PolyMounts (McMaster).
These are for my Lagun FTV-3. If I could do it again I would have used bigger CRS because I think the 1"x2" is flexing under my unusually heavy mill (4400 lbs). These are 3/4" studs on the pleasantly affordable PolyMounts.
455436a8f21495519af80be5ab1b9e0f.jpg
 
My Jet JTM-2 has sat still now for a year with out any issues.
It's sitting on the pads it had been sitting on for 25 years at the PO's place.
 
pontiac428 said:
It must be the thing to do when everyone is doing it... My contribution, cost $65 for materials and PolyMounts (McMaster).
These are for my Lagun FTV-3. If I could do it again I would have used bigger CRS because I think the 1"x2" is flexing under my unusually heavy mill (4400 lbs). These are 3/4" studs on the pleasantly affordable PolyMounts.
455436a8f21495519af80be5ab1b9e0f.jpg
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Those FTV 3's and 4's are some serious iron!
 
Install the mounts directly under the holes in the base of the mill where the bolts would go if you bolted directly to the floor.
No need for the extra cross piece, just asking for issues there I would think.
 
I'd have done that with my mill, if it weren't for the need to get a pallet jack under it (1) to move it from the driveway into the shop, and (2) to allow future movement with a pallet jack. There wouldn't have been room for thepallet jack between the feet if they were in the factory holes (not to mention that I'd have had to do some serious adaptation to get the ⅝-11 stems into the ~15/16" diameter holes in the mill base). With the feet set well outboard, I can easily get the pallet jack between them after raising the mill by adjusting the feet on their 4" stems.

In addition, I get added side-to-side stability for the mill. And with the 3 ½" and 4" wide bars, there's absolutely no problem with flexing.
 
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