Hi K....for the record....a machinist of advanced years maybe.........experienced ....OK.........CNC literate.....hardly, but as machinery is machinery and parts of a machine move as good as the components they are made from, what you buy and expect to work is another story.......taking out a mortgage for a hobby is one way to go.
The point I wanted to get across for a person with perhaps little experience of actual machinery build,even though he has 15 years on a machine, is that there are machines that are not all that ideal for conversion and spindle tapers that are not ideal either.....no matter who fits one on a machine.
So....the round column type........2 out of 10 for an ideal machine.
3 Morse taper spindle.....1 out of 10 for an ideal tool retention system.
The main point is, if that's all you have and want to afford....well, a mill is a mill no matter what form it comes in.......that was my experience too, but for choice, it's as I stated.
BTW, back in the 80's Taiwan made mill drills with round columns and flooded the market with them.....theywere called Taiwanese terrors due to the amount of gunge in the bearings and badly fitted dovetails etc.....but they were sought after because they were dirt cheap.....eventually they got better as the importers sent their people to Taiwan to rev them up a bit in the quality control.
The last bad point for mill drills round or square column is that with the quill for the Z axis move you have very little travel and a difficult method for moving it..........making the head the Z axis move is another problem along the way. but that is par for the course with a manual mill retrofit.
It's a leap of gigantic proportions to consider fitting linear rails to the column for Z axis travel........only if it's a square column type, but that's a gigantic leap forward for a CNC retrofit.
As far as the throw away parts are concerned.........everything bar the basic castings is really throw away.......people retrofit for CNC not to go the other way so there is a throw away aspect to consider in the cost.
Ian.
Hi......I just wanted to add that machinery and tooling form Taiwan is now considered to be top class.....ask me how I found out that one.
When I went to our local machinery dealers to buy a dividing head, they were quick to pont out that one of the models was made in Taiwan and the other one in China.
Anyone getting into the machinery market has to start with economy of input until the pot is boiling and they have retooled to make things better..........the fact that things improve with age is very true for automobile designers and builders and the same applies to machinery startup companies.
A lot has happened in the design of machinery in the last 40 years........back then CNC wasn't even thought of as a home hobby outlet but the design of the early manual machines hasn't changed at all.....retrofitting one is now an uphill battle if CNC is the desired outcome.
Ian.
You seem to class Morse Tapers below a round column in terms of desirability but with no justification? There are many, many old machines, US, British, European that used Morse tapers and turned out good work for nearly a century so why the put down? If its a personal dislike - that's fine but declare it as such otherwise you just arbitrarily condemn machines as scrap / obsolete to a potential starter machinist looking at this thread!
Hi k.....as far as Morse tapers are concerned, they do NOT belong on a mill........they are best used on drilling machines where you have all downward forces and a slot in the side of the spindle to hammer a drift in to remove the tool.......having a Morse taper and a drawbar does not make them better.
Mills work best with the ISO 30...40...50 etc non stick tapers and R8 is next in line for preference.,,,,,and don't even mention 3C or 5C as a tool holding system for a mill spindle.
Morse may have been widely used in the last century, but so were horse and carts.......both were extremely functional in their day.
Personal choice does not come into the matter, I cannot imagine, given the choice of 3 Morse, ISO 30 or R8, why anyone would ever consider 3 Morse.
A Morse taper relies on the slow taper to hold the shank in the spindle..........if a drawbar is employed the tendency is to freeze the taper in the spindle.........don't ask me how I know about that aspect.
If the "lucky find" machine happens to have a 3 Morse, then you have to put up with it's inadequacy, the same applies to dovetails, Acme threaded screws, Imperial screw pitching and columns/heads that tilt to allow angle cutting.
Ian.
Re: I am a newbie need help on cnc conversion.
Reply with Quote
