Looking for advice on a small (ish) mill

Crutches56

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Greetings everyone! I'm looking to buy a (relatively) small mill and lathe. I own and run a small atv/motorcycle repair shop. I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts. The lathe would be mostly small stuff, under 3" in diameter. I worked a at a place that manufactured welding equipment, and I had the chance to learn all the machinery there, and I love doing that type of work. I was able to program and run some big Haas mills and lathes. We had a tormac cnc mill that I loved. We had a big ganesh, but never ran it, but I spent a ton of time on a grizzly lathe (8"? 9"?) and a manual grizzly mill (26" wide x 8"? Table).

I have 2 main questions, 1: what do you guys suggest for tools. And 2: does anyone have any they're trying to sell? I can probably only spend up to $1500 on a mill setup right now, unless I wait until like July, then could spend a bit more. And lathe will have to wait until next year. I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it. Also have looked at grizzly 0760 (but just the machine is about $2k delivered with no vise, no collets etc....)

Thoughts?
 
Avoid a round column mill.

The work envelope is not so great and you are limited by spindle travel.



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I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts.

... I can probably only spend up to $1500 on a mill setup right now.

I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it.

Thoughts?

In an ideal world, yes, avoid a round column mill. However, you have a budget of $1500 and your stated goals are not complex.

Crutches, are you sure about the Jet? I know they make a JMD 15 and a JMD 18 and I suspect the mill in question is an 18. If so, it will weigh close to 400# without the stand and has a 3" diameter quill with 5" of travel so it is, in fact, a really good heavy duty drill press. It will flycut quite well and handle most any small motorcycle part. I own an RF-31 which is essentially the same machine and after upgrading the bearings, it has under 0.0001" of spindle run out. I know what this machine can do and other than the issues common with the round column mills, it is quite a capable machine. It may suffice and earn you enough money to upgrade to a knee mill at a later date and I would consider it.

Depending on its condition and tooling, $950 may be high. I would take a dial test indicator and a magnetic stand and check the spindle run out. Run the machine on high speed for about 15 minutes and then check to see what kind of concentricity you can get out of the spindle. If it is the thousandths then that right there is your ammo to get the price down. If those spindle and drive sleeve bearings are stock then I would bet money the runout will be anywhere from 0.001 - 0.003" or more. Tell him that replacement bearings will run about $300.00 and the labor to install them will run close to $150.00. See if he'll take $500-600 instead. You never know. If he plays hardball then just walk away. If he bites then the cost for the drive sleeve bearings will be under $30.00 for the pair. The spindle bearing OEM replacements should be under $150, possibly much less. Angular contact bearings can be pricey but I did mine for about $100.00. Not too bad.

If you are not sure how to check concentricity then say so and we'll tell you how. I believe that in your situation the machine has to earn its keep and for your simple needs, that Jet mill drill would work just fine in my opinion.
 
I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts.

Don't try to fly cut cylinder heads with a mill weighing less than 1000 pounds (and 2000 pounds is better).

The lathe would be mostly small stuff, under 3" in diameter. I worked a at a place that manufactured welding equipment, and I had the chance to learn all the machinery there, and I love doing that type of work. I was able to program and run some big Haas mills and lathes. We had a tormac cnc mill that I loved. We had a big ganesh, but never ran it, but I spent a ton of time on a grizzly lathe (8"? 9"?) and a manual grizzly mill (26" wide x 8"? Table).

I have the big brother of the 6*26 (as a 8*30 G0730) and love using it (although it's not a Bridgeport....)

I have 2 main questions, 1: what do you guys suggest for tools. And 2: does anyone have any they're trying to sell? I can probably only spend up to $1500 on a mill setup right now, unless I wait until like July, then could spend a bit more. And lathe will have to wait until next year. I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it. Also have looked at grizzly 0760 (but just the machine is about $2k delivered with no vise, no collets etc....)

Stay away from round column mill/drills.
 
I don't know why people put down round column mills so much. Sometimes it is all one can afford or fit in the space they have. And if care is taken they will do the job for what the OP is looking to do. I know because that is the type of work I have done on a round column mill with no problems. The only time he will need a larger mill, that I can foresee, is for 4cylinder heads as they will be too long for the travel of the round column mills. As far as fly cutting he should only be taking minimal cuts just to clean the heads.
 
Save up and buy a decent mill. I've seen huge Bridgeports go for a $1000. Just a pain to move and feed them 3ph.

The Precision Matthews Pm727m is priced good for a small gear head unit. I think it's around $1500 new, can't remember. I've been happy with mine, I got the DRO version with the stand. It's better than the Grizzly version imo.

DROpros sells small mills too. With a low budget your better finding one used on Craigslist if you're familiar with the machines and can identify the boat anchors.
 
How long are the heads you are going to fly cut??? To properly make a fly cut pass you should start and stop with the cutter past the edges of the head. Sooooo, if you do the math. If you total the length of the head and diameter of the fly cutter. That is approximately the table travel you need. And don’t assume a 48” table travels 48”. It does not! It’s much less!!! Doing a 1 cylinder head may not be a problem on a mid-size mill? But I would carefully check out table travel first...Dave
 
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Amazing amounts of work has been done on the round-column mills since the 80s! there's a reason they're still sold and purchased today. Most people that down them usually have no direct experience and simply repeat others giving the same (ill?) advice. But yes, by all means, if you have the funds and you don't care to learn how to keep the z-axis alignment when dealing with short and long tools (that's the biggest and perhaps the only complaint on these) which takes all of 30 secs if you know the technique then buy a square column mill. Otherwise, if you're getting a bunch of tooling etc they can be a great bargain...
 
So I got curious to see what the round-column mills are going for in my area and while they're all over the map ($600-$1500+ depending on what they come with) I particularly found this ad very interesting so I took a screenshot of it to post here. Also on youtube look for user cuppajoe, google Rick Sparber - among others who have had these for many years and have done good work on them. I'm in the process of converting mine to CNC...hopefully soon, if I can just stay focused on one hobby at a time.

RF30CLad.JPG
 
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