The Home Machinist!

Rwilliams wrote: ↑Sat Mar 10, 2018 12:33 pmI have used the Bridgeport to make some incredible accurate wood joints that never could have been done with a table saw or a router.

I'm right with you there. A wood router is just an incredibly cheap and dangerous milling machine for wood. When I screw up a wood project and need real accuracy to fix it, there is no substitute for metalworking machines.

I recall a woodworking expert talking about tolerances of 4 thousandths and calling it "real precision."

I did ten window frames for my C-30 caboose all at the same time. The wood pieces were all cut with a nice sharp carbide cutter at top spindle speed with no more chipping or tearing than I would have gotten on a router or a table saw and perhaps less as I was able to use a back up piece with ease. When the frames were all glued together I realized that they seemed to be just about the same size. Measurement was not considered at first, but the dial caliper soon had me discovering that the total variance between the ten window frames was only .005. It was a real wake up call as to what I had been missing out on for such a long time.

I kind of wonder how important high speed is when cutting wood. My mill tops out at around 4000, and it cuts great.

Sure...wood dust is a problem, but you deal with it. Not about to have one mill for metal work...and another mill for wood work (we can dream though, can't we?).

Sometimes it's not so much the cutter...it's being able to hold a work piece steady enough to perform the cutting operation. Clamped my cupola caboose roof to the mill table when I modified the roof for a wider cupola. Cut the cupola openings for the window sections as well. Worked great...just had to be careful I didn't crank down TOO hard on the clamps. As Harlock noted...having a shop vac nozzle right there to suck off the chips and dust is great...if you have enough hands.
Can't knock getting nice, straight cuts using a machined table and an X-axis table drive! Carl B.

Thanks for the replies everyone! So only one of you would never do this? I agree with ccvstmr that a mill for metal and a mill for wood probably takes up too much space and money. If you run something they still make parts for like an x2, rf-45 clone, rf-31 clone, G0704 you can just buy new parts as they wear out can't you? I wonder what the wood dust hurts most? The motor, the dovetails or the leadscrew?

When milling wood, I have never experienced burn marks from cutter friction. When cutting wood with table saw and router bits at high router spindle speeds, I have experienced numerous burn marks that often had to be scraped, chiseled, sanded, etc. to remove them. End grain is by far the worst offender in burning as the pores are more exposed to the heat of the rapidly revolving cutter.

The luxury of power feed when milling wood is also something not possible with most table saws or routers. Just the ability to have a nice stable hand crank feed is still better than hand feeding of wood into a high speed cutter that does not care if it cuts wood, air or human flesh. Just the safety factor of having the fingers well away from the point of danger is a true luxury.

My biggest fear of the chips is that they might absorb some moisture in a high humidity condition and cause rust to form more easily. The only issue with friction and wear might be with something with mega mineral deposits like iron wood which will eat most wood working tools with ease.

Rwilliams writes:
> My biggest fear of the chips is that they might absorb some moisture in a high humidity condition
> and cause rust to form more easily.

No need to wait for high humidity. Wood is normally 5% to 15% water.

I use my mill and lathe for the occasional wood project, mostly patterns. Be aware that sawdust from some kinds of wood promotes rust (I believe the tannic acid in oak is one example). Stay away from treated lumber, it is brutal at causing rust.

Dick_Morris wrote: ↑Sun Mar 11, 2018 4:32 am I use my mill and lathe for the occasional wood project, mostly patterns. Be aware that sawdust from some kinds of wood promotes rust (I believe the tannic acid in oak is one example). Stay away from treated lumber, it is brutal at causing rust.

I was about to say that modern EPA-approved treatments should be less corrosive than CCA (which contains metal salts) but a bit of research proves me wrong. Some of the preparations now in use are so corrosive that ceramic-coated nails are recommended because they attack even stainless.

In any case since sawdust is at least 5% water I try to get every bit off my machines. I haven't machined wood vary often: if I ever find myself doing it a lot I'll rig the vacuum to collect the dust as it is produced.

When I work wood on my machine tools, as I occasionally have to, I try to contain dust by covering adjacent tools and I set up a shop-vac nozzle at the point of the cut.
The species of wood makes a great deal of difference. The more acidic the wood the more thorough cleaning is needed to prevent chemical staining and etching if left too long. Oak of any kind is the worst.

I was told from a very good old machinist that some wood mix with oil becomes acidic, but I think this takes time. Our mills have so may hidden areas not easy to clean. Under the table is where I am talking. The old machines and Bridgeport's castings had chrome ways. Chrome ways around the coast line with salt air would rust and pit. The pits get scrape as the table when using it and tear chrome. Then this would make long deep scratches, wiping out the ways after a while. The new machinery today use a different cast iron mix. They are cast, weight for check porosity then rough machine. Then inducted harden, also this ages the casting and re leaves the metal or casting. Also draw to a hardness.Some 50 Rockwell Once this is done there ground to finish size and smoothness for ways. But what this way rubs against its matted casting it sits on is softer. Now wood dust is not a problem on this hard surface but the surface it is mounted to. We had a customer that did not what to spend the money for a Jet Mill and bought a Enco. It was deliver to him and he had to drive the fork lift to unload it from work home. 5 miles away. He receive the new mill unloaded it set it up and wire it in. He mounted the mill vise and tighten down the bolt and found the T slot was lifting up. The table was that soft. Call,and reorder another, but had to go thought the fork lift trip again.
What I am getting at is cast iron is just metal, and as you know cast iron rust fast. If wood is acidic over time and you don't clean those hard to get to places, Your taking a chance. Why is wood working different, No oil use. Only wax and special wax.
I am not sure if this in correct and I have mill wood and turn on my lathe. But you should know and look for problems. As in deep hard to get to spots.
Steve

One of the issues with the woodworking machinery available for the home shop is that it’s just not set up for the level of accuracy many of us desire. And that’s fair enough considering that you can buy a table saw for as little as about $150, and a respectable one for $1000. And the vast majority of woodworking projects don’t require the precision that we machinists are used to.

But just as we tune our metal working machines, good results from woodworking machinery requires the same level of attention. You just can’t waltz over to a router on a router table and zoom a piece of wood through it. Same with taking a cut in your Bridgeport. Both have to be thought out and the proper workholding jigs and fixtures provided. And the learning curve is there too. I’ve butchered as much wood as I have metal, and bled on both types of machines.

My woodshop includes a 60-year-old Craftsman table saw I inherited from my dad. At first I thought I was doing quite well if I could cut to within 1/32 on that thing, but after pulling it apart and zeroing out its adjustments and making up a couple of sleds and other fixtures, I can cut mortise and tenon joints for a perfect fit.

Same with the router. Yes, when handled loose and without practice and forethought it can be a dangerous tool. But used properly, it does the job.

So, in my case, I’ve got woodworking machines which I’ve fine-tuned to do what I want them to do. And as Steve wrote above, areas that need lubrication are not lubed with oil but with compounds intended for such use. While some of you may have solutions to the sawdust problem, I don’t want to take the risk of getting sawdust down into the oily leadscrews and ways of my metalworking machinery. Of course, some folks don’t have the space or budget for woodworking gear so there isn’t much choice in the matter. Just beware of the risk and take care to mitigate that.