Square Column Bench Top Or Knee Mill ?

GarageWrench

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Looking for some input:

I will be purchasing a mill for my home shop. I rebuild Harley engines and build custom motorcycles. I have a Rongfu type round column mill/drill w/dro and its time for a upgrade. To compliment my mill I also have a Craftsman 101 12x36 lathe. I would love to expand my machining capabilities and maybe even venture out and expand my (very small) operation and take on some job work.

Its difficult to determine if a square column bench top will be all I need, and not need to upgrade in the near future. Need to make my hard earned money work for me, HD truck mechanic by trade and no extra funds to flush down the toilet. I have read just about all I can on this forum (which is awesome by the way) and else where, and I really do not want to purchase a used BP style mill and take the time to rebuild/work on. Time is money, and I know a new mill is my best choice. I have narrowed it down to the PM or Grizzly bench top or the Grizzly G0730 type mill. For what I do and want to expand into I am thinking the smaller knee mill may be best for me. I really need to be frugal with my money and my shop is really packed full, but I can make the room for a knee.

I really enjoy reading all the post here, just looking for some input from all the experience that is here and help me with this decision.

Danny GarageWrench
 
All I have ever heard is, a knee mill of just about any fashion is superior to a mill-drill, square or round column. And that is true. Knee-style mills are more common in industry. If I had my pick, I'd have a knee mill - I've just not got the space for one.
 
Knee mill is far superior to a square column mill. Someone on this website just bought an 8x30, IIRC. I think this is a good choice; reasonable price, made in Taiwan.

I have its grandfather, a Clausing 8520.
 
Tim, Not familiar with that name, IIRC, where do I find info on that mill?
 
Clausing is a famous name in machine tools. The mill I have was built in the 60's. You can find them on craigslist occasionally for $1000-2000. Well liked by hobbyists, but like any used equipment, usually requires some care and feeding. The 6x26 and 8x30 mills were patterned after it. The Grizzly 8x30 looks like a reasonable copy that should serve you well, and is a much better choice than the smaller 6x26 mills.

Again, knee mills are much more flexible and easier to achieve precision results with than a column, IMHO.

EDIT: never mind, just caught your question. IIRC = If I recall Correctly. :D The gentleman in question just bought the mill (Grizzly G0730) we are talking about. You can read his thread and see his pictures here:

http://www.hobby-machinist.com/thre...ed-and-expecting-delivery-friday.34883/page-2
 
That little 8x30 may not be large enough if you are going to be machining cases or heads. You really need to base your decision on the size and type of work you are wanting to do. I recently visited a gentleman that has an older 8x30 type and it is in no way more capable than my larger bed mill. Now if you think you need a tilting/nodding head, then a BP type could be a choice but the little 8x30 head doesn't nod. At least the one from Griz doesn't. But the PM935 does if you can swing that. But then again cutting angles is what tilt-tables are good for. Any given machining problem has more than one solution.

Opinions here are as varied as there are stars in the night sky. :) To get some useful information on this you could help focus this discussion by describing the size and type of work you want to do, and maybe what you'd like to do in the future. Are you going to keep the 12x36 or are you going to upgrade that too? Having machines of similar capacities can be helpful.
 
That little 8x30 may not be large enough if you are going to be machining cases or heads.

Good advice. One advantage of square column mills is they are significantly cheaper than knee mills, so if you are on a budget, and need to mill something large, than they could be the way to go.

The largest of the square column mills is the one sold by Charter Oak. Coolidge will be alone any moment to chime in on this, as he just bought one. :D

You can catch his posts about it on the Charter Oak forum.
 
What Bill said, start with the minimum work cube X x Y x Z that you expect to need. I recommend you cross bench type mills off your list round, square, or otherwise. Go knee mill or for Seal Team 6 level bravado find a used Bed Mill. Used knee mills should be on the table given you want to keep the cost down, if you have time, months to wait for a sweet one to surface and the cash to pounce that would help. DO NOT assume just because you purchase a new mill that you won't have to fix a bunch of crap.
 
Good advice. One advantage of square column mills is they are significantly cheaper than knee mills, so if you are on a budget, and need to mill something large, than they could be the way to go.

The largest of the square column mills is the one sold by Charter Oak. Coolidge will be alone any moment to chime in on this, as he just bought one. :D

You can catch his posts about it on the Charter Oak forum.

Yea, my 12Z is what I was referring to. :)
 
That little 8x30 may not be large enough if you are going to be machining cases or heads. You really need to base your decision on the size and type of work you are wanting to do.[/QUOTE

Yes, I have the means to weld cases and heads, but always need to send out for machine work. It's not the Z or X that is short it's the Y axis on the square column mills that seems to be a little short, most at less than 8". Like someone mentioned, yes I do have a budget and that style mill is much cheaper than a knee with the exception of the knee without the nod function, I guess there will always be that one area where your mill falls short when yer on a budget.
 
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