Build my own milling machine

[TSutrina]

I have been interested in building my own machines since I saw the Gingery designed home made machines: lathe, Mill, and shaper. There are others all made from aluminium castings and steel ways that are flat bars. Gingery-style homemade metal lathe builds | Make: But casting seem to be a complication that doubled the complexity of building a machine. And I do not see a significant supply of aluminum, a second complication.
Concrete on the other hand, stone and sand are cheap and plentiful. Also reinforcement components out of steel are also cheap and plentiful. Casting patters are also typically wood. How to make concrete less likely to fail, crack is understood and the information is available. For example Tyler Ley has many videos on how to keep concrete from cracking. Post stressing concrete is one of the best and easy to do for small items. You can find a bench made with fiber filled concrete with a few theaded rod in plastic tubes bent into a shallow "U" shape to keep the concrete in tension. Two inch thick and like 4 or 5 foot long strong enough for a two pound person to stand in the center. Here is a reinforcement video from Tyler: NASA had a contest to 3D print housing which using Mars materials would be the printing of concrete. This is the video made by the second place team:
Note that the stresses are always highest at the surface of the structure so cast iron components of machines are hollow. Concrete machines also should be make hollow. Say a wall thickness of 2 inch and maybe 3 to 4 inch around the active post stressed steel and the cast in place reinforcement steel. To prevent cracks fibers of steel, glass for concrete or besalt would be used. Bamboo has also been used, plant fibers.

 

[MrMetric]

I've seen that done. It is interesting. I've also taken apart an unreinforced brick chimney that was in the middle of my house. It was the opposite experience of your parents. I live in earthquake country, and let me tell you. I was stunned at how easily that chimney crumbled once the cap was off. Yes, as a composite structure it was strong, but after the the top was off, a few whacks and the whole wall started crumbling away. I don't miss that chimney at all.

Your parent gave a whole new meaning to, "I like this house... I don't want to leave!"

 

[MrMetric]

There are a few 3D printed housing technologies that are being started up. It is pretty nascent, but I personally think that they are really cool. Ditto with ICF (insulated concrete forms). I may do that for a basement sometime if I move. I think that is kind of the cat's meow. Very neat stuff.... You are right, though, concrete is an amazing substance... There are some really nice counters you can make with it. Best of all, it is relatively inexpensive and eminently recyclable.

 

[TSutrina]

I fixed the top of a brick chimney also. Snow, ice, and rain destroyed the concrete holding the bricks together. Took it down to the roof and then rebuild it up. There was not reinforcement in the chimney thus any side forces would put the chimney in tension, break the bond to the bricks. The shape of the Mars structures is to use gravity to keep the concrete in compression. All the Roman stone and concrete structures are design to put the concrete in compression since their is no reinforcement. The majority even in the earth quake prone Italy have survived for centuries and surviving earth quakes. The Mars structures are not reinforced. Fibers could easily be added. Basalt was one of the materials mentioned as well as plastic brought to Mars. Basalt fibers and plastic fibers are both used in concrete to keep cracks small and not growing. Then a person could insert short metal reinforcement into the concrete so long as the nozzle doesn't hit it when the next layer is added. The plastic and metal could be taken from scrap material. The parachute and other landing components are scrap.

Reinforcement is easy to do. Here is the DIY possible table design which is the size more typical of a machine out of concrete. The majority of information is for building and bridges. Civil engineering but it works just as well for smallers structures.

 

[WmRMeyers]

Concrete bridge port milling machine has been built as other big commercial machines. Concrete is typically made with epoxy replacing concrete. Machine Casting – Castinite However actual concrete machines were build during WWII to produce production parts. The base line is patent 1154155 by L. I. Yeomans Sept. 1915 Articles on the web can be found.
The Multimachine Open Source Concrete Lathe Project is a standard concrete machine found on the web. Sorry do not know the full site address: ...

SNIP!

The MultiMachine group is on Groups.io, now. multimachine groups.io Group There are files and photos there of the machines Pat and others have built. I'm a member and moderator there. No cost to join, and not much activity at all these days. It would be nice to have some new members!

Bill in OKC

 

[ajoeiam]

I fixed the top of a brick chimney also. Snow, ice, and rain destroyed the concrete holding the bricks together. Took it down to the roof and then rebuild it up. There was not reinforcement in the chimney thus any side forces would put the chimney in tension, break the bond to the bricks. The shape of the Mars structures is to use gravity to keep the concrete in compression. All the Roman stone and concrete structures are design to put the concrete in compression since their is no reinforcement. The majority even in the earth quake prone Italy have survived for centuries and surviving earth quakes. The Mars structures are not reinforced. Fibers could easily be added. Basalt was one of the materials mentioned as well as plastic brought to Mars. Basalt fibers and plastic fibers are both used in concrete to keep cracks small and not growing. Then a person could insert short metal reinforcement into the concrete so long as the nozzle doesn't hit it when the next layer is added. The plastic and metal could be taken from scrap material. The parachute and other landing components are scrap.

Reinforcement is easy to do. Here is the DIY possible table design which is the size more typical of a machine out of concrete. The majority of information is for building and bridges. Civil engineering but it works just as well for smallers structures.

The stuff holding the bricks together is not actually concrete.
The technical term is 'mortar'.
It is similar to concrete but not the same thing.

 

[Wizard69]

I'm not sure how the original posters build went but hope that he has had some success. I entered the machine too rebuilding industry real early in my career and then moved to automation. In any event that early fist exposure to all sorts of lathes and mills made me think seriously about a DIY build. That was years ago and frankly time and maybe more importantly money never materialized in a way to allow me to do such a build. I look at such a build as a potetnially "fun" project.

There are issues however that can causes serious problems. For one you need superior stiffness even in a small machine to get good results in metal. It is pretty popular to build routers and even there guys struggle to get enough stiffness to get good results you would suffer even more trying to get good results in steel or other hard to machine materials. In a nut shell it would certainly help to have some machine tools to start with to make building robust structures easily. In any event one of the best book series on DIY machine tools was written by Dave Gingery, worth a look if DIY is in somebodies future.

There is a lot of negativiity about DIY machine builds but we are on a forum where guys build engines so I'm not sure if anyone here really has a cause ot complain. As a builder you just need to understand what you are getting into. There is also the possibility of reworking commercially made stuff so don't leave that out.

 

[MrMetric]

LOL... You are right on all fronts.... Fun to make, hard to make stiff, lots of negativity.... and, in this forum, most people will bend over backwards to say, "that is awesome", "good job", "wow... looks really nice... congratulations!" It is the reinforcement that counteracts the rolling of eyes typically provided by our spouses!

 

[SmithDoor]

Looks great

Dave

It might be a little less impractical to make something that would be difficult to buy, either because it’s rare, expensive, or has never existed before - S_J_H’s boring mill, and Jackary’s ‘Stepperhead’ are great examples:

Cnczone boring mill build thread
http://www.lathes.co.uk/stepperhead/

Here’s my more ordinary home made mill, I’d mentioned it on the other, ‘home made lathe’ thread:

View attachment 114885

I cheated and reused many parts I already had.

 

[goldstar31]

For those who want something a bit different the Murad Bormilathe was available. The wrote up is in Lathes.co.uk.
As A DIY alternative, I was always interested in a New Zealand design in a book called Improvements and Accessories for your Lathe with the author J.A Radford.
He called the two items-- Elevating Heads.
For those who want other things, there are delights in and Indexing Attachment for the Lathe and a Worm Wheel Hobbing Tool. Jack is a really different read.


In the Golden 'oldies' lathe variants, I've I've just bought a homemade 'Potts' Vertical slide with a Myford nose and No2 MT arbour and a 9 hole division plate.

Again, Lathes.co.uk has a section on the numerous variants. According to Christmas greetings, JCSteam has one which he was given.
Mine was obviously made from castings and drawings from G P Potts and intially sold by Woking Precision Models who lived under the Forth Road Bridge , North of Edinburgh. It was there that I bought the casting for the Edgar T Westbury Mill Drill which I made up from castings dropped by students at Gateshead Technical College. Later there were improvements known as the Dore Westbury. Continuing the them, Dore Engineering was owned by an Arnold Throp who wrote his Vertical Milling in the Home Workshop. This involves a mention of the Amolco milling attachment and JCSteam seems to have one of these too. He's busy playing with a Hornby train set which he claims is 'for his young son' Believe that if you will.
Just a few bits and pieces to add to a thoroughly interesting post.

 

[goldstar31]

I've just spied a U Tube presentation for the Potts Milling Spindle. Neither are really like my version but nevertheless very interesting. Worth looking at

Best Wishes to all for a better New Year

Norman

 

[TSutrina]

I just viewed the Potts Milling attachment for a lathe mounted to the cross slide. I have a desk Rong Fu RF40 milling machine with a vertical round column like the Potts mill. This means that you can not raise the mill spindle while cutting with the Potts device which limits my use of the mill. If I have to raise the head on the RF40 I have the same problem of loosing alignment due to rotation around the column can not be prevented.

But this article is focused on building a milling machine not using a milling machine or a lathe milling machine attachment. Stiffness and vibration caused motion are the keys to any cutting machine including a router. The gantry style routers all place the cutter off the center of the supporting beam thus cutting forces in any of the three primary directions cause motion in two and likely all 6 degrees of motion, 3 Cartesian directions and rotation in each. Not one of the present gantry approaches places the spindle between two beams or a U channel at the center of the cross section. This eliminates some of the multiple direction deflections, the beam torsional stiffness can be reduced and thus weight.

I think the Maslow router for cutting into a basically flat surface is the most cost efficient and deals with the forces issue the most creatively. It uses the flat surface of the work to locate the face of the router base plate and weight to provide counter torque and a third force for moving in the plain of the work surface.

I have though this a a starting point and by flipping it over and provide a flat surface reference for the router. Vacuum suction and liquid film bearing to hold the router or spindle against the reference with a significant force so weight can be less. The travel of the spindle is the limit of depth possible unless the motor can fit into a cavity already cut while cutting further. And a large flat surface is a problem to create and maintain. Nothing is easy.

 

[hanermo3]

I´m possibly the worlds leading expert on "building a milling machine" ...
having spent around 18000 hours and about 16 years at it, mostly near full time.
My current gear is worth about 100.000 € as insurance replacement value, and for about the 12th time "I´m real close now..".
Grin.

The current version is a full on industrial VMC with a huge volumetric work area, 500 mm vertical travel, 1600 table, 1000 x 500 mm travel, ISO30 spindle.
And the current problem is making a new servo motor mount, because the current AC servo is too small (400 W 1.27 Nm) to move the bridge up/down more than 3 secs, as it uses servo "peak current" rather than rated current.

The bridge is about 500 kg in mass - 2 pneumatic lifters one on each end help reduce the load on the screw.

Building a *good* milling machine is quite hard to do.
Imo.
Ime.

Should have built a smaller one, but now that it´s about running ...
I have commercial uses for it, like making lots of small accurate widgets in one run, like 200-400 at once.