An IH build, base to table

[ozzie34231]

Hi All,
I'm fianlly about to start building my IH mill.
That may sound strange, building an IH, but I bought a headless machine from Aaron before he sold the business. The parts have been riding around in my van for over a year and today I wrestled them out, ( the weight of the column is unbelievable, will my back survive?).
So I've been measuring, figuring, travels, clearances, configurations, etc.

The first question I come up with that I don't have an answer for is the mouting of the base to the table. The table will be a welded up affair from heavy guage 2X2 tubing. The tabletop rails will be placed to fall under each of the four sides of the base exactly enough to weld threaded rod to the sides of the square tubes which will fit into the holes in the base.
On top of the frame I'll place a heavy guage piece of aluminum drilled for the studs, and then I'll J&B around the studs to seal off coolant.

Having welded a similar table before, I know that getting it exactly flat is impossible, at least for me. I can clamp and tack, and do all the right things but it will still be off of flat by quite a bit.

So my qustion to any who read this is:
What is the best proceedure for mounting the base to this not so flat table.

My first thoughts are:
Set it on rubber, either solid or liquid
Shim it the best I can, then tighten.
Set it on J&B weld, let it harden and then tighten.
Grind away at the table until I have it sitting good and then add the aluminum.

I'm listening,
Ozzie

[Cruiser]

Are you going to build a custom head too ? I been rolling possibles on that one myself. on your base when you mount it. make sure to have a good level, and check for any twist, then shim and draw down the nuts. don't require much torque. I had quite a bit of twist to pull out tho. are you getting started yet or still planning

[ozzie34231]

Hi Cruiser,
I started cutting square tube for the table today. I thought I had that size that is about 1/8", I think it's 11 guage, but what I have is about .187"; should make a very sturdy table.
I'm retired but I have a Shoptask and a small business making a specialty item on that, so work on the new mill will go slowly. I am determined to do some work on it every week though.
I have a level that can measure .0001" per foot! Yes checking for twist is a good approach. I hadn't thought of that.
The head has to be built; I have some mental plans. The initial head will be a combination of steel and aluminum. Once the mill is completed I'll re-make the aluminum parts in steel or cast iron. (Milling with a Shoptask is agonizingly slow.)
I have a quill from a Hurco mill with a Quick-Switch holder. I plan to use a timing belt drive with three or four pulley steps and a DC motor with KB speed control coupled to Mach3 with a Homman? board.
I have ball screws for the Z and Y axis, still need the X setup.
The motors will be servos, 75 V., 5.5 A, either 3 or 4 to 1 timing belt setup.
I've spent 7 or 8 years reinventing this Shoptask over and over, so I feel qualified to do a job on this mill.
That's not to imply that I won't need a lot of advise.
Ozzie

[davo727]

Hey there Ozzie, Im interested in what you do with your spindle head. Sounds like a good idea starting with a Hurco quill, so you have a high spindle shaft and bearing assembly and dont have to try and make it yourself. You just need to figure how to make your head and attach the quill. Are you going to use the Ih Z slide? It would be a good time to do a linear bearing setup since you are all apart anyway. Get some 25 or 35mm units off ebay and eliminate the dovetails on the Z. Anyway let us know how its going and remember we like pictures. Dave PS- Cruiser if you are reading: Hows your project going?

[ozzie34231]

Hi Guys,
I'm in Eleuthera for a week so I haven't been in touch.
The Hurco spindle will be bolted to a 1 1/2" steel plate by way of two steel saddles. Behind that will be a basic box.
The Hurco is supposed to be permenantly lubricated, and is rated at 4000 RPM. For higher RPM needs I'll use an additional spindle, mounted to the side and probably driven by a pulley on the Hurco, but that would be well after I get the basic machine going.
I started the support table, I can't believe how heavy this square tubing is.
I also bought a 2 ton engine crane from Harbor freight, ( on sale, $149.00), to lift the IH parts.

I'm interesed in your ideas for using rails rather than the dovetails on the Z.!!!

Ozzie

[davo727]

Its not my idea, Cruiser is adding linear bearings on the side of his Z slide to suppliment the dovetails and Bob W on his site has discussed it http://www.thewarfields.com/cnccookbook/index.htm Here is a pic of 25mm rails and blocks. Bolt the rails to the front of the column, probably have to put a full length precision spacer under each of them to get them out far enough for clearance for the bearing slides. then bolt the bearing slides to the back of your spindle mount box assembly. The smithy cnc mills also have linear guides on the Z axis. It would eliminate all the friction and fun that we get with the Z dovetails. Dave

[ozzie34231]

I went to Bob's site and then the one on CNCZone.
Very interesting but I want to get the beast running and all that work seems interesting, but unproven. I learned from all the work I did over the years on my shoptask that the best planned and executed improvements only give moderate results and at the cost of much money and time.
I wish that I'd sold the machine years ago and bought something better, a milling machine and a lathe.
I'll see how this IH thing goes, but with a minimum of time and expense. If I'm not happy early on, I'll have to talk myself into a B-clone. My feeling is that I can do my size work with the IH I'm building without lots of mods and extras. Even with my Shoptask, I can mill to a thou, and turn better than that. I'd just like to do it faster with less hassel and adjustment (compensation).

Ozzie