Milling machine (PM-25MV)

[noseoil]

I've ordered a new milling machine from Precision Matthews, their PM-25MV model, non CNC stuff or auto-feeds. Wondering if anyone is running one & if so what their feedback is.

It's due in some time next week, so I'm just working on the shop for now, made a stand & getting the area ready for the initial setup. Here's the stand I made, added a bit more reinforcement to the top in the center, but it's mostly finished now.

[jimmontg]

Is that 1/8 inch wall or 16th, .060 wall? If 16th better reinforce it.

[noseoil]

The frame is all 1/16" wall, I added another 1 1/2" X 1 1/2" center piece so, the two 1x1's take the bolts & the center rail takes up the load as well. Has a top in place now, so it should be plenty strong. The machine weighs 250#, so each member will carry 83#, split 2 ways (functionally, load at each end) means each weld on the base will take 41.5# at the ends, or enough to take the load.

Will post back once it's in place & bolted down.

[jimmontg]

Oh I thought it was going to be a bigger mill. Like one of those 400 lb types.

[noseoil]

Just a quick follow-up to the numbers, a 23" length of 1.5" X 1.5" 16 gauge steel with take a load in excess of 900#, if loaded in the center & supported on the ends (actually it's good with 20 ga. tubing, .035"). The two 1" lengths have 1/2" holes drilled in them, so they're weakened a lot. With 3 members to take the load, it should be fine the way it's built, but if it fails, I'll let everyone know. a 23" length of steel tube is pretty strong.

Here's a calculator to use if you just plug in loads. Works pretty well. I used a L/D of 360 for deflection.
http://www.atc-mechanical.com/calcul...al-properties/

[noseoil]

Setting it up, now I just need to figure out how to use it. Always a learning curve with making knives...

[jimmontg]

How many end mills do you have? I have a set of small ones made of carbide. Gradually bought them over the years. Very expensive, but they don't dull with as little use as I give them.

[noseoil]

Just got a small set (5, HSS) from PM with the order. I'm going to send for better ones when I need them. I have a lot of carbide cutters, but they're from years of wood working, not really right for metal. I guess in a pinch I could use a couple of them for aluminum, but it's not the right tool for the job...

[jimmontg]

If made for wood they wouldn't be as beefy or as hard as a metal cutting end mill. Probably good for the softer nonferrous metals though. Heck I think Ironwood or African Blackwood are harder than brass/aluminum anyway. I know they sink in water and can't be stabilized. Desert Ironwood will wear out a bandsaw blade fairly quickly because of the silicate in it. I remember the first time I polished some and with a good magnifying lens you could see the silicate crystals in it. Buffs out really well.

[noseoil]

Ironwood is great stuff, if you don't have to work with it! I had to work with it from time to time in Tucson, but it was never fun. Nasty, dulls any cutters, smokes & stinks, but really is a beautiful wood for appearance.
3rdIW-s.jpg

[jimmontg]

I was gifted a couple of branches of Desert Ironwood and took them to my metal working job to cut on our big bandsaw. The bandsaw was purposed for brass and aluminum, not ferrous metals. I set it up to cut 1/4 inch slabs and when I was done the blade was shot. My boss was rather disturbed by my wearing out a $35 blade so I had to hand sharpen the whole blade with a India Stone. Took a couple of hours, but the Ironwood wore out the blade 10x faster than brass or aluminum. If it starts to smoke then you need to resharpen the tool you're using to cut it, it's dull. The funny thing is is that it dulls everything. Great handle material and I'm going back to AZ to try and score some more, but travel is restricted, so time will tell.
Well worth it though when you see its final finish. I've used African Blackwood, but although it is as dense as Ironwood it seems more moisture absorbent, but that just may be me. I use both and used African Blackwood on a knife handle for my grandson and he thought it was plastic! LOL
Some woods do not need to be stabilized and others do, but the super hardwoods don't and I add the hardwoods like cocobolo in there because of their oiliness, which is minor to me anyway. If using an oily wood for scales be sure and wipe them with a solvent that makes the oily side clean.
Blood wood is very oily and a glue of any kind doesn't want to stick to it, it must be wiped very clean. Just some tips. I noticed epoxy didn't want to stick to those oily woods, just a heads up.

[noseoil]

From today, working on the surface grinder attachment to the 2x72. 2" receiver tube for the wheel & slider. This is the table for feed.

[noseoil]

Glued up the magnetic chuck this morning with G-Flex epoxy, it's a PITA to do. I recommend having a couple of clamps, a block to lay across each one as it's inserted & most of all, some small wedges to lock them in place, so they can't crawl out after they're set into position. It's a fiendish exercise in keeping them in place.

I would recommend mixing the epoxy & laying it into each groove, so it can't set up in the pot too quickly. Then use waxed paper or parchment paper to lay on the magnets, as they're set in the grooves. Slide the block as you go, while moving the clamp a little at a time. as each magnet is set & held down with the block, use the small wedges to line them up & hold them flat. Without a mechanical aid, it's about impossible to get the little bastards to sit in place without moving around on the chuck...