To be fair it was crappy jig from M1 Machining. It had a tendency to slip and did not have secure index points. But honestly the cost of a Modulus jig is enough to install a DRO on your mill.

However as far as I know CNC is basically counting the dials (the computer just keeps track of it and does not forget) and must account for backlash or use ball screws. Why don't they connect DRO glass scales to the CNC controller so the computer can just track position by what the scale says rather than being off a bit because of backlash?

Yes you can, but I can say the Modulus jig is a great jig as is the 5D tactical jig, I own both of them as well as a couple of others I have picked up along the way, jigs are a good thing for those who just want to build a gun or two and have no planes to go farther, but there are a few of us that take things to an extreme and continue to upgrade our equipment.  For me, it was just a natural progression of things after I partnered up with a guy that owns a really large machine shop, it is fun to figure out what I am going to build next with my stuff.

With you, it is quite obvious you are on the same path in life that I and a few others are!



The high dollar equipment does not have much in the area of backlash, some of the equipment my partner has starts and stops on a thin blade of grass, but those machines also cost a hell of a lot of money, making stuff that is that precise is very expensive.

A lot of people outfit a G0704 (or similar machine from Precision Matthews) with CNC because it is inexpensive to do so. Outfitting a large machine is much more costly.

But I just thought that if a CNC controller takes input from a DRO glass scale, they can basically rule out backlash altogether. I know backlash can be easily adjusted on the G0704 but unfortunately the adjustment is in a hard to access location, I'm not going to flip my mill upside down just to find it. But I guess for most people using ball screws is worth it (it has zero backlash) but I also read ball screws are bad on manual machines. I've seen people heavily mod their G0704 including milling off the dovetails on the column and adding linear rails. I can't begin to imagine how much it's costing to do it.

We are only limited by the money we have to spend, the machines are out there, but I don't believe many of us really want to invest the money involved.

I know I see Haas mills on ebay all the time and they are good machines. As are Fagor machines like this one:

https://rover.ebay.com/rover/1/711-53200-19255-0/1?type=3&campId=5337559805&toolId=10001&customId=j5ngswhr6600zk8a00004&mpre=http%3A%2F%2Fwww.ebay.com%2Fitm%2F121685540611:g:5M0AAOSwLVZViJSu

This one is actually a pretty good buy.

We are only limited by our bank accounts.

It's more than bank accounts... that's a lot of money for most people to spend on a mini machines, and acceptable results are possible for 1/3 of that price, unless you're making aerospace components or something (in that case you'd spend MILLIONS on each machine). Even if I could afford it, that machine probably weights thousands of pounds and that means I'm not getting that up to the third floor. I also don't have 3 phase powder needed to power it. If it's 2HP or less I may be able to use a VFD to run it, but if it's a lot of horse power, then no.

It's also a lot to spend for a hobby too. Even the most critical tolerance of a firearm doesn't require that level of precision.

FYI, large machines are generally very good buy, as in you can get a 10,000lb giant milling machine probably for the same cost as a decked out PM-25MV (including DRO and all, a little over 2000 dollars). The reason is because very few people, outside of people with an actual industrial location can run that machine. A location with floors that can support that kind of weight isn't exactly what everyone has, and oftentimes the locations have to be built to support the machines (both weight and electricity). About the upper limit for an average suburban home is probably one of those Bridgeports. Since they can't sell to just ANYONE and often people selling those machines want them gone, they're a very good buy as their market is somewhat limited. Bridgeports are still a little pricey just because an average garage could support it, and it's large enough to meet most hobby needs.

Case in point... when I was in Taiwan I bought a 18 inch bandsaw for resawing and other work. Someone sells a 26 inch bandsaw for exactly the same price, maybe a little more but it's close enough. The only problem was my shop was still several flights of stairs up, and so moving equipment weighting over a certain poundage was impossible. Then there's the problem with the saw is probably taller than the ceiling at my shop, so I couldn't get it. I did end up getting a 12 inch jointer that was probably 1000lbs, and it worked great assuming I kept the blades sharp... That jointer cost half as much as my bandsaw.

I probably could have gotten a 1.5 ton Clausing mill in Taiwan for about 1500 dollars, ready to go and all that... Mini mills are actually harder to get in Taiwan than full sized ones.

If I were younger, I would build a bigger shop with the correct power system and have the machines I want to build just about anything you can think of, but I have already retired from one career and enjoy my retirement way to much to invest that much money, besides I have a partner that has just about anything you can think of in the way of milling equipment as well as the guys to help or do anything you can think of.

Mine is basically a hobby shop to build my guns and suppressors every once in a while, but I do like having the ability to machine a reproduction part for an old boat when I need it or a specialty part for a car I am working on.

I spend a couple of weeks every few months with my partner and we discuss new ideas on what we want to do in the future, meet with the buyer for the stuff we make and spend a heck of a lot of time drinking and BBQing!

Works out great for me, cause I know I don't really want to start a new career at my age!

"If I were younger" is my line too except when I was younger I lack the money to really do much as far as location goes. Even now I would love it if I could rent a warehouse type deal with 3 phase and all that, I have no idea how much it would cost, probably more than I make in a year per month. That 1000 dollar bridgeport doesn't seem like such a good buy when it means paying an extra 3000 dollars a month on the space for it...

In.

I made an aluminum plate early on.  Used it to drill holes in the lower to "hog" out some of the material with a drill press prior to milling.  Really cuts down on machining time on these little mills.  But if I'm only doing one or two, it's more enjoyable to just mill the whole thing.  

I made step by step, move by move instructions for how to mill a 15 or a 10 platform.  FWIW,  I walked my buddy's kid through milling his own lower.  He'd never seen a milling machine before that day.  4 hours after he showed up with a box of parts and an 80% lower, he had an assembled and function checked rifle.  He did 100% of it himself. Even assembly.  I just told him how.  Did I mention he's 11 years old?

I'm all about build parties!  Having learned 99% of what I know by doing, opportunities to learn from somebody else in the game are few and far between but always welcome.

I don't know if all CNC uses DRO outputs but some do.

I put DRO on my mini mill for $25 per access.

I got the HF mini mill for $428 delivered and put $75 into DRO

They are accurate to 0.0005 inch

Over kill for a lower

You can do this without spending huge amounts of money that you guys are talking about.

I don't believe any of us have spent huge amounts of money for the equipment we are currently using a few of us do talk about what we WOULD do if circumstances were different.

I only have about $1200.00 into my mill with belt drive, DRO, 10" Lathe, mill light, and all of the tooling.

I'm not just doing a lower...

I'm machining Remington 700 receivers and other assorted parts...

Some added precision helps.

Made a coolant drain table end cap.  

The video my coolant was getting low so the flow wasn't at it's prime.
Also it's screaming so mine your volume before you hit play.


The next operation I ran the thing at 150ipm and it was buzzing right along.  I wish I did a video of that, but pushing the spindle to the limit, I wanted to hover the E-stop and not hold a camera.


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Here is also a power drawbar I made from an air cylinder I got off eBay. The pain was engineering it fit a lever and a fulcum point because the thing was so damn big. Because of the 1.5 HP motor on it, I didn't want pullout so I wanted at least 3000lbs of pressure on the Belleville spring washers.

My first oops.  $50 probe tip snapped when a had a jog run away from me.
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And it plumbed and working

This thing is the bee's knees for tool changing.

Very cool!

As a owner of 4 Grizzly machines - this explains why if Precision Matthew was around when I bought mine, they would have been my choice.

Forget price - the real question is what never ending problems are you willing to put up with for as long as you own that machine, or finally spend even more money (and time / down time) doing your own mods to fix the problems.

That's why this time around, I went with PM rather than Grizzly even though PM machines are twice the price... I pre paid for the PM1228 which has a 1 1/2" spindle bore so I can do gunsmithing. It has a 2HP brushless DC motor, and only weights around 500lbs without the stand. Weight is important since I live on the 3rd floor...

I increased my Y travel to 8.3inches.

I'll bump this thread.

This guy is getting CNCd.

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NICE!  So what are you planning to make?

Me?

Round things.  

(I have no idea)

Better that way.  Sky's the limit.

Should this be moved to the new metalworking forum we have on here?

Didn't even know we had a new section, but it does go well with building as well.

Not a terrible idea.

I just want to buy one of these...

https://www.tormach.com/tormach_pcnc_mills.html?gclid=CjwKCAiAxarQBRAmEiwA6YcGKGy-T50GckpDEZ03z-wwHDaojLS0vWr8xtSL5ZBaH4L5hgaEIH196BoCdQYQAvD_BwE


Maybe some day.

Picked up a used mill, I’m  finally getting there! Bolton ZX45

I ordered a stand from the manufacturer which is on back order, so I have some time to start accumulating more necessary tools etc before I get it set up.

The big one that I’m really not sure about is DRO. So many out there at all different price ranges.

Any input would be greatly appreciated.

Look up this number on Ebay, it is the kit that I purchased a little over a year ago and I have been real happy with them.

142023107663

I have glass scale DROs from dropros.com on my Jet GHD1440 lathe and my Jet 836-3 mill. I've done several lowers and a bunch of other machining with them - they work great.

Leaning hard toward the DroPro seems like a great company and reviews look good, what I can find.

Thanks

I am content with the eBay kits.  I've had mine for about 4 years.  The work well.  Only complaint is the batteries.  I forget to turn them off and run the batteries dead.  They last a while, 6-9 months maybe depending on use.

They are at least as accurate as my mill. As long as they have fresh batteries and the scales are kept reasonably clean, I haven't had any issues with losing my zeroes or anything noticable with incorrect  readings.

Is there a write-up on the ball screw upgrade for the HF mini mill? I'm about to take mine apart again to tighten-up and adjust the lash.

Unless your machine is CNC, don't install ball screws.
The axis' will be too smooth to take hand cuts and will jump on you.

If your machine is CNC then you will definitely want them.

Much of any backlash makes climb milling close to impossible.  This also includes plunge milling.

Too smooth of action and you will want to tighten your gibs to keep it from walking.

Gotcha. Not CNC.

Tag for later

I have the HF versuon and put DROs on it.

Now I want to CNC it

Finally got this used mill I picked up assembled and trammed. I just couldn’t get the front to rear Y axis any closer than .003. Good enough I hope. I tried it in a collet and the drill chuck, both approx same result.

I got a set of cheap endmills off Amazon to play around with. I have scrap plastic and aluminum so that should be a good place to start.

Next is getting the DRO installed.

First mistake was the Factory stand, should have had a sturdy heavy metal one built. In time.

So much to learn........

If you locked the spindle and move table front to back and have a .003" change - that is table flatness - table surface not parallel to the Y Axis ways.

Once you know if the table is flat and parallel to axis motion.

If you have a perfectly flat disc ( we used a brake disc new/old stock for a 70's CB750 before they started drilling them from the factory ) you can tram the head by sweeping the indicator around the circle.

Getting the spindle square to the X Axis is a head mounting ring adjustment. Getting square in Y axis is harder. You need to use shim stock between the base and column.

When you go DRO plan to mount the glass scale on the front of the table. Y DRO can go on the far side from your table locks. You can get a econo quill DRO then use glass scales to read the head height in Z. So 4 total DRO.

First thing you need to do is get that sucker mounted to the floor, in your picture it looks like it is on the Wall!!!

lol!
Actually I think I will mount it to the wall. The stand has a slight wobble, I think a couple angled braces to the wall will be the fix.

I was able to shim the vertical column and am now only about a thousandth out. Just tightening the bolts from snug to tight will throw it out several thousandths, so it was a chore to get it there.

i'm looking into getting my first mini mill, i've wanted one for a while.  I found a PM25 w/ out DRO for sale locally used, guy used it for a couple months on wood and plastic and now wants to dump it.

What's a good price?

What are some things I should look out for?  Is there a Date of Manufacture stamped on the device so i can try to verify his claim on age?

http://www.precisionmatthews.com/

Ask them when they first started shipping that model or give them the S/N - they can likely give you the exact ship date.

Bump before this goes into archives.

Does anybody have experience with this set of DROs?
https://www.amazon.com/dp/B013D1C9JM/?coliid=I31BQQJ93KYOO8&colid=KWKVDTX3GA02&psc=0&ref_=lv_ov_lig_dp_it


On paper, it looks pretty decent for the price.  All pretty self contained and glass instead of magnetic scales.  And it comes with at least some mounting hardware.  Not sure how much will be able to be used to actually mount it.  I'm looking to put it on the Harbor Freight mini mill.

I have had a Central Machinery Micro Mill for years.  I have broken more gears than I care to recall.

This is the only belt conversion I have been able to find.  I just put it on my machine, and I love it.

His kit is superb.  If you are patient when you order, you will be ecstatic when the product shows up.

Belt Conversion Kit

I run the belt conversion kit that I got from Little Machine Shop and have been real happy with it, they put them on sale quite often.  I have a Grizzly mini mill which is the Sieg X2 mill

Unfortunately they stopped carrying the one for the Sieg X1 micro mill.

The above link was the only place I could find that still made the conversion for the X1 micro mill.

Either way I am extremely happy with what I recieved.  The only hard part was relocating the controls.

The guy that I work for just bought a mill from Taiwan that came with one of these.  The mll just came in on Thursday and I have no experience working with it other than turning the knobs. I haven't put a gauge up to it to test it's accuracy either, but just playing with it i found that it's hyper sensitive.

Once the mill is up and running and I cut on it, I can probably give a better opinion.

3 in 1:
How to make a diy mill, with close to 50% of it from absolute crap.
Complete a 0% lower with it.
Upgrade the mill with a DRO (on page 3).
https://www.ar15.com/forums/topic.html?b=1&f=5&t=2109930

Incorrect.