Milling Steel on a Mini Mill

[jonesrick]

Largest practical vise that can be used on an LMS 4199 is 3”, so your blade is 2x the width of the jaws, is a relatively large part.

The 500W motor is the only option for this mill (I have a 3990, which is basically the same mill without DRO’s & spindle interlock and a few frills that I have added over the years). While I’m very happy with my mill, I should have saved a little more and invested in one of the LMS or PM bench mills for larger work envelope, increased rigidity and a quill in addition to the moving head for Z-axis work, which is my recommendation for your mill. Yes it will cost significantly more, but the mill is just the beginning of a wonderful, long experience of exchanging money for more tools.

Thanks very much for your insight. Why couldn't I do my bevel cut along the x-axis? That seems doable according to the YouTube videos I've watched

 

[jonesrick]

You will need a pretty good torch to heat a piece that size up to the red-hot temperature needed to harden it. You could be looking at some additional expenditures in order to achieve what you want.

I'm going to look around my area to see if anyone does heat treating. Thanks for the advice.

 

[ChazzC]

Thanks very much for your insight. Why couldn't I do my bevel cut along the x-axis? That seems doable according to the YouTube videos I've watched

You would mill along the X-Axis, but you will have -1/2" of the blade hanging over each end of the vise; also, it's going to be tilted in the vise to cut the bevel, which will make for interesting work holding. Even though it is 1/2" thick, you will get some deflection (although for this application that would probably be OK).

I have a small (4" x 5") tilting table that I would use (see – more stuff to buy); the ends would still be unsupported, but only 1/2" on each end.

 

[John TV]

I’m coming to this late, but it might be worth checking to see if there is a Makers Shop or something similar in your area. They might have the equipment and advice to use it safely.

John in Minnesota


Sent from my iPhone using Tapatalk

 

[jonesrick]

You would mill along the X-Axis, but you will have -1/2" of the blade hanging over each end of the vise; also, it's going to be tilted in the vise to cut the bevel, which will make for interesting work holding. Even though it is 1/2" thick, you will get some deflection (although for this application that would probably be OK).

I have a small (4" x 5") tilting table that I would use (see – more stuff to buy); the ends would still be unsupported, but only 1/2" on each end.

I've seen videos of how to mill bevels. I believe they use angle blocks. You are so right about the the "more stuff to buy" remark. The initial cost of $1800 for the 4190 soon balloons to near $3,000 after buying a vise, collets, collet chuck, end mills, and such. Hate to say it, but I'm seriously re-thinking this purchase. For that kind of money, I could buy a whole new wood chipper and an extra set of blades, and still come out ahead. Not to mention buying the steel, milling, tapping, and beveling it successfully, then heat treating it, blah, blah, blah.

I really do respect the skills of a machinist, hobbyist or pro.

Thanks for your interest, Chaz.

 

[ChazzC]

I've seen videos of how to mill bevels. I believe they use angle blocks. You are so right about the the "more stuff to buy" remark. The initial cost of $1800 for the 4190 soon balloons to near $3,000 after buying a vise, collets, collet chuck, end mills, and such. Hate to say it, but I'm seriously re-thinking this purchase. For that kind of money, I could buy a whole new wood chipper and an extra set of blades, and still come out ahead. Not to mention buying the steel, milling, tapping, and beveling it successfully, then heat treating it, blah, blah, blah.

I really do respect the skills of a machinist, hobbyist or pro.

Thanks for your interest, Chaz.

Don't give up: just spend a little more time thinking about other applications for your mill (and lathe).

For your chipper blades, do a search for local machine shops or custom grinders who could fabricate the blades for you at a decent price. If you can wait (which you apparently can), they could work a small job in when they are slow and keep the cost down. 25 years ago a small business I was consulting for needed a old shear blade sharpened, but since the shear was used they had never had it done before. I searched for Machinery repair" and found a shop that could do the work - they didn't have a website, but back then that wasn't uncommon.

Another suggestion: I'm not familiar with your chipper details, but could you just grind the bevel using a 4" angle grinder?

 

[RaisedByWolves]

Yes, I would buy the tool steel, cut it, bevel the blade, tap the holes, and then harden it, which I have no idea how to do (hint). My blades are 150x50mm and about a half inch thick.
Thanks for your response.

Having made my own chipper blades under controlled conditions up to and including hardening and tempering them I have to strongly recommend you do not heat treat these as your first foray into this realm.

If left too hard or unevenly tempered they could shatter and ruin your machine, the users or both.


High speed shrapnel is not your friend.

 

[verbotenwhisky]

We keep talking about heat treat but I would think the proper 41XX alloy might be better, 4140 annealed is a fairly tough stuff without heat treat.

 

[jonesrick]

Don't give up: just spend a little more time thinking about other applications for your mill (and lathe).

For your chipper blades, do a search for local machine shops or custom grinders who could fabricate the blades for you at a decent price. If you can wait (which you apparently can), they could work a small job in when they are slow and keep the cost down. 25 years ago a small business I was consulting for needed a old shear blade sharpened, but since the shear was used they had never had it done before. I searched for Machinery repair" and found a shop that could do the work - they didn't have a website, but back then that wasn't uncommon.

Another suggestion: I'm not familiar with your chipper details, but could you just grind the bevel using a 4" angle grinder?

I sharpen and tone the knives frequently when I'm using the chipper, about two months out of the year. After two years of doing this they still look and perform very well. But at some point they'll need to be replaced. I'm either going to go the machinist route, or I might possibly try changing out the rotary wheel with another company that can provide me with the proper customer service. Compatibility is the key issue there. Can you run a 24" Frontier wheel on a chipper sold by Titan Attachments? I suspect I can, but I have to do the research.

I wish I could join the machinist ranks. I still watch a lot of YouTube on the subject. Very interesting stuff. But I'm not a machinist. I'm a hobby farmer
with minor skills and minor pocket cash to get to where I would like to go.

 

[homebrewed]

I've seen videos of how to mill bevels. I believe they use angle blocks. You are so right about the the "more stuff to buy" remark. The initial cost of $1800 for the 4190 soon balloons to near $3,000 after buying a vise, collets, collet chuck, end mills, and such. Hate to say it, but I'm seriously re-thinking this purchase. For that kind of money, I could buy a whole new wood chipper and an extra set of blades, and still come out ahead. Not to mention buying the steel, milling, tapping, and beveling it successfully, then heat treating it, blah, blah, blah.

I really do respect the skills of a machinist, hobbyist or pro.

Thanks for your interest, Chaz.

I gather that you are thinking ahead on this, which gives you the opportunity to look around for a used mill. Often they will come with various accessories, so you'd be ahead cost-wise there, too.

Even if you are a small farmer, when something that's critical to you getting your land prepared, maintained, crop(s) harvested, etc., breaks you are looking at a time window. You miss that window, you have loss. Low to 100% of your crop, it will be noticeable. Repairing whatever is broken is an additional (and often unexpected) cost.

There are reasons that farmers, whatever scale of farming they're doing, often have a lathe, mill and welding setup. If they were only using them for one thing that only needs doing every so often they wouldn't do that, no way it pencils out. On a farm there's always SOMETHING that needs fixing.

Some things to think about.