Ridgidity - 833TV vs. 835 vs. 935

[wrmiller]

If your highest priorities are: "can handle larger end mills, can hog largest amounts of steel, can handle hardened steel better", may I suggest you buy a small bed mill and be done with it. Something in the 4000-5000 lb range might work for you.

 

[Batmanacw]

Which machine is more ridgid and can handle larger end mills, can hog largest amounts of steel, can handle hardened steel better?

I've read a few times about the ridgidity issues with J head knee mills when compared to square column bench top mills like the 833.


I've narrowed it down to these 3 mills. I have a PM-25MV mill and I'm looking for a substantial upgrade.

They each have their pros and cons. Travel size isn't that important to me. I've never even come close to being limited to travel on my PM25MV.

You are going to think I'm full of crap but your current mill is far more rigid than my old round column mill drill and I have modified lathe insert holder and cut lots of stainless on it without issues.

You seem quite new to machining and I'm guessing you've read a lot of bad advice on here and elsewhere.

The machine you have now will cut stainless like butter. You just need to avoid rubbing and keep taking a chip. You can buy a very rigid mill and not have any better results.

I humbly suggest you learn to cut stainless on your current mill before you spend huge money and run into the same issues on a $5000 machine you have now. Cutting stainless is easy. So is hardened steel with the right cutter, feeds, and speeds. Your current mill might just need snugged up a bit.

I am not being critical. Just trying to help.

 

[Pcmaker]

You are going to think I'm full of crap but your current mill is far more rigid than my old round column mill drill and I have modified lathe insert holder and cut lots of stainless on it without issues.

You seem quite new to machining and I'm guessing you've read a lot of bad advice on here and elsewhere.

The machine you have now will cut stainless like butter. You just need to avoid rubbing and keep taking a chip. You can buy a very rigid mill and not have any better results.

I humbly suggest you learn to cut stainless on your current mill before you spend huge money and run into the same issues on a $5000 machine you have now. Cutting stainless is easy. So is hardened steel with the right cutter, feeds, and speeds. Your current mill might just need snugged up a bit.

I am not being critical. Just trying to help.

I need to work on my speeds and feeds. I still have no idea how to hand feed at a certain rate. I've just been feeding slow

 

[Batmanacw]

I need to work on my speeds and feeds. I still have no idea how to hand feed at a certain rate. I've just been feeding slow

At 0.1 per revolution your table moves 6" a minute at 1 revolution per second.

 

[7milesup]

I like what Dave Best and Batmanacw had to say. I think they summed it up nicely. I have the 833T and other than the gear train noise, I really like it.

 

[Pcmaker]

Does a heavier table help when machining? You can't lock the axis you're using and would it help when climb milling?

The 835 looks like it has a lot more mass than thr 833

 

[davidpbest]

In my experience, table mass is much less important than adjusting the split-nuts to remove backlash and getting the gibs adjusted properly so the table is restrained from lateral movements during climb-cutting. I routinely climb-cut stainless on my RF-45, and when machining stainless, the key is to keep the cutter chewing - go too slow and the material will work harden quickly and burn up your end mills. The best way to control feed rates is to add a power feeder. Having a DRO that displays the feed rate is also very helpful. I'm not sure I would be very successful machining stainless without a power feeder - consistent feed rates are important with that material. Same goes for drilling stainless - keep plunging, and here too, power downfeed on the quill is very useful for stainless drilling.

 

[Batmanacw]

In my experience, table mass is much less important than adjusting the split-nuts to remove backlash and getting the gibs adjusted properly so the table is restrained from lateral movements during climb-cutting. I routinely climb-cut stainless on my RF-45, and when machining stainless, the key is to keep the cutter chewing - go too slow and the material will work harden quickly and burn up your end mills. The best way to control feed rates is to add a power feeder. Having a DRO that displays the feed rate is also very helpful. I'm not sure I would be very successful machining stainless without a power feeder - consistent feed rates are important with that material. Same goes for drilling stainless - keep plunging, and here too, power downfeed on the quill is very useful for stainless drilling.

I agree.

 

[Pcmaker]

Thanks.

I'm leaning towards the 835 now because of the price and the ease of tramming the tilt and nod of the head.

 

[Batmanacw]

Thanks.

I'm leaning towards the 835 now because of the price and the ease of tramming the tilt and nod of the head.

The Align power feed is sweet! You might want to have them install it. The shims have to be just right. I love my 835 so far.

I noticed tramming is easier when you get it right and leave no pressure on the worms before you snug it down tight.