[Jparker1983]

First off thank you guys for listening. I have been machining for 15 years and want to get into doing some things for my own. My Father in law died a few months back an had his own machineshop with a bunch of grizzly g1007 mills and I would like to do a cnc conversion. I have to say I have looked into it and I am so confused. How do you know what motors to get. How do u know what ball screws to buy. How do you mount it all. If anyone could give me some guidance on how to understand what I am trying to do I would be so appreciative. Thankyou again.

[handlewanker]

Hi, first you have to have some knowledge of machines and how they're constructed......just working on one doesn't mean you know how it/they are constructed.

The point is what actual 15 year experience d you have?.....all manual?

Re-building a manual mill means you need to be able to take it apart and modify certain parts to enable the CNC retrofit parts to fit and work.

To start off, what machine specifically do you intend to rework?......not all mills are constructed the same and the interface for various motors and ball screw faces might mean a certain amount of machining.

You also have to contend with the spindle/tooling method as many mills have 3 Morse taper and that is a dead in the water start to any project.

The most important aspect is the condition of the slideways, as if the mill(s) are worn in that area you won't get smooth movement and the stepper motors will struggle to move a tight slide that has to be tight to keep it on track.

Retrofitting a mill that is unsuitable for CNC work.......IE, one that has a quill and 3 Morse taper spindle would in my opinion put it way down the path for any kind of expenditure as opposed to buying in a new mill that has a lot more going for it and is in pristine condition mechanically.

The fact that a quill type mill has very short travel in the Z axis means the head must do the Z axis move and that is another headache in the making due to the weight of the head casting and the head dovetails that give rise to a phenomena called "head nod".

If you don't have a mill with R8 or ISO 30 spindle taper.......give up on that mill and look elsewhere.

Also, what kind of work load and type are you contemplating?

Edit......I just remembered.......how much disposable income do you have as it's a money bin in the making once you get hooked in a build and can be considered as a one way path to poverty once you start investing in tooling etc.......especially as the new man at the top wants you to buy USA only and not Chinese.
Ian.

[109jb]

For those that don't know, a G1007 is a round column mill that has a fairly large table. My father had one many years ago. I would guess the table is about RF-45 size. It should have a R-8 taper on it.

Having said that, it is a pretty good candidate for a CNC conversion, except that it is a round column. A round column has the disadvantage of only being able to CNC the quill and raising the whole head generally results in lost position reference. For this reason round column mills aren't as popular for cnc. I CNC a smaller round column and it was good experience, but I wouldn't do it again.

If you do decide to CNC a round column mill, there have been some that have added ways to raise the head and maintain alignment. If you don't do that you will have to get creative with tooling so that the tools for a job are all pretty close to the same length. In general, I would not recommend a round column for CNC, but they do work and I made a bunch of parts on mine.

As far as motors, for a round column, I would not even consider servos and would stick to steppers. The steppers for the table would be similar to the RF45 threads and can be anywhere from 640 oz-in to 1200 oz-in NEMA 34 size. The quill could be another 640 oz-in.

On the ballscrews, you just kind of plan them out yourself from what you have. The thread on my little harbor freight round column should give you a start. Not much detail, and there are much better build threads, but you can check it out here.

http://www.cnczone.com/forums/bencht...cnc-forum.html

[Jparker1983]

Hey man thanks a lot. I also have 2 Jet 16 12 speed mill drill mills. Would they be better to cnc. When you say round column what do you mean. When I put the quill down it is round so I am guessing thats what you mean. On any of these mills do you have to make your own brackets to mount the motors to your machine? Also for the ball screw do you have to take yours out of the mill and make a new one yourself or does someone sell them. I am sorry I am so confused. I have been doing manual and also cnc work on mills lathes and 5 axis machines. I am proficient in mazak but also know gcode and most cam software. I am using this cnc I build to make golf putters and other golf training equipment, I set my own tolerances but mostly plus or minus 5 thousands.

[GITERDUN]

[QUOTE=Jparker1983;1996798 When you say round column what do you mean. When I put the quill down it is round so I am guessing thats what you mean. [/QUOTE]

HUH?? You have been machining for 15 years?

[Jparker1983]

Ok. I only came here for help not some dick ass being a prick. SO go away..

[109jb]

The G1007 head is supported by a round vertical column that is bolted to the machine base.

There are machines now that have a "square" column that has a vertical dovetail slide arrangement. When those machines are converted to CNC the quill is simply locked and the entire head is moved up and down on the slide.

[handlewanker]

Hi....short answer to your endeavour is.......stay away from the round column types....also 3 Morse spindle ones too.......the end result for those types is never anything but mediocre at best and is just money spent without real value attained.

You're going to be spending a whole lot more to do the retrofitting exercise so you might as well realize on your existing assets ......sell them on etc.....and invest in one that is more suitable to your needs...which hasn't been stated yet........at any rate, most of the moving parts of a manual bench type mill will be scrapped when it is CNC'd

As i said before......with the new buy in the US policy suggestion from the top of the heap beaurocratic advisors, any foreign imports currently in the country will soon be bought up......that will make any retrofit using existing Chinese cheapies a whole lot nearer to buying a complete brand new Tormach or whatever rings the bells.........I can see the hobby getting a lot more out of reach for the economy tool buyers that just want to cut metal for a week end hobby pursuit.

If this isn't helpful to your needs, consider it a guideline to how not to spend money that doesn't produce a result........CNC is a mode that is very distant from manual machining and relies on accurate co-ordination of machine parts and electronic features working in harmony with each other........and we haven't even started to get to the electronics, control mechanisms and software you must have.

With a CNC machine you only have to push the green button to make it happen......that is the only user interface that happens when the machining cycle is initiated,....anything down the line that doesn't add up just makes scrap.

BTW......the top of the class linear rails going by the name of Hiwin will not be available to the US in the very near future unless Hiwin relocates and uses US labour and materials etc.
Ian.

[arizonavideo]

"BTW......the top of the class linear rails going by the name of Hiwin will not be available to the US in the very near future unless Hiwin relocates and uses US labour and materials etc.
Ian."

Good grief , you really think that linear rails are going to be outlawed? We don't have a dictator we have a House and Senate that some times passes laws. It generally takes years to get something passed and if it does its a compromise between the two parties.

I will bet you that next year at this time I will still be able to get rails for about the same price. A year after that if they come from China there might be a import tax on them greater than what they have now. The EU adds 15% to most everything already and I bet you like that tariff.

If your so sure rails are going to "not be available" and excessively expensive and your so sure of yourself then buy $10,000 worth and make a killing re selling them. You could corner the market all by yourself. There wont be a tariff from your country to ours so your in just the right place to show us all how correct you are.

I know you love to argue about stuff like this but really if you reply please explain the EXACT process that the USA is going to force all rails to be made here.

[handlewanker]

LOL........I don't want to argue the toss one way or t'other......the point is your guy wants to make EVERYTHING in the USA......he actually did say that.

Well that may look good in his mind to win votes, but first he needs to recreate the infrastructure to actually manufacture the goods that at this moment in time, those foreign countries supplying your needs, have had at least 40 years of non competitive marketing and also made your workforce unable to produce the goods I mentioned.

The good news is......the party leader only has 4 years to make the miracle happen before the country gets tired of the bull and changes the party lineage again....as they always have done.

I don't think a mere 15% tariff is going to be a useful Bandaid approach to your problems.......the supply chain is so long that just cutting the end a bit will not have any effect at all.....it's that deep rooted.

The main point is.......if he applies a tariff, you still won't be able to manufacture the goods as the home market won't tolerate the low quality crap and high prices you'll have to charge just to get to the starting line..........any volume still coming in will offset the manufacturing capability of any stasrtup venture.....and it will be a startup venture now you have no manufacturing facilities to think of.

I think when the dust settles and a tariff has been decided on. life will go on as usual, but you will also have to tolerate a tariff on the dwindling exports you now have left......it cuts both ways........I just can't imagine what a 15% tariff is going to achieve....it's such an insignificant amount but will cause inestimable ramifications to your economy without creating new industry.

BTW, we don't buy machinery or tools from the USA.....the shipping cost is too high for goods that are imported by you from China and rebadged or just sold on.....LOL
Ian..

[jfong]

I'm not sure I would consider Hiwin "top of the class". If some kind a future china tax ever happens, you could always get better quality linear rails from THK, IKO, NSK, Bosch, Thompson and others. So many linear motion suppliers worldwide.

[handlewanker]

Hi......if you can fault a Hiwin linear rail....... and I don't know by what standard you would be doing the analysis...... you're also faulting any other part of the machine you bolt them to.......sometimes being too pedantic can be perfectionism for no better cause..........you can also buy the best rails and still get no better results in the end.
Ian.

[jfong]

I never used a Chinese Hiwin rail before. I've read there is a good chance of getting a fake on eBay so I don't even bother to search for that brand. I've used plenty of THK, NSK, IKO profile linear rails. All very high quality with THK my personal favorite. Given the choice, I would choose Japanese over Chinese for linear motion products. Just my opinion.

[handlewanker]

Hi, to be truthful, I've never bought or used a Hiwin brand linear rai, although I have a CNC mill that has linear rails fitted.... (unknown brand)..........so was only commenting on the possible price hike that is possible if the rumoured 35% tariff on foreign imports to the USA comes into being.

I doubt whether any of the brands you mentioned are made in the USA as most firms wanting to minimise their production costs and maximise their profits at sourcing or producing offshore anyway.

The biggest worry will be that those firms supplying the CNC needs by importing will now find it impossible to make ends meet and go under.

Correct me if I'm wrong........I think HIWIN is a Korean firm, not Chinese, making the profile linear rails.
Ian.

[jfong]

Hiwin is Taiwan (Republic of China)

The fake ones are made in mainland China (People's Republic of China)

[DonKes]

Isn't there a political branch of cnczone?

Don

[handlewanker]

Hiwin is Taiwan (Republic of China)

The fake ones are made in mainland China (People's Republic of China)

Thanks.....my mill was made in mainland China, so probably the linears are home brand too.......I have to wonder what a Chinese linear differs from a .....a.........gee batman, I think they're all made in the far East or somewhere like it.....LOL.
Ian.

[handlewanker]

Hi....getting back to the thread, perhaps a budget figure would make a good start point.......that is if the mill in question is going to be the donor for the CNC retrofit or a more suitable one bought outright with better specs.........that would be determined by the size of work intended.
Ian.

[jfong]

Thanks.....my mill was made in mainland China, so probably the linears are home brand too.......I have to wonder what a Chinese linear differs from a .....a.........gee batman, I think they're all made in the far East or somewhere like it.....LOL.
Ian.

As a machinist you should know better. Are you now implying that all Far East manufacturing in different countries are made to the same high tolerance and quality control.

A video I saw on Chinese made linear bearings, which someone purchased for a 3d printer, there was metal swarf still inside the bearing block. When he rolled the carriage, you can hear the crunch and grinding. Lol.

[kawazuki]

......stay away from the round column types....also 3 Morse spindle ones too.......the end result for those types is never anything but mediocre at best and is just money spent without real value attained.

You're going to be spending a whole lot more to do the retrofitting exercise so you might as well realize on your existing assets ......sell them on etc.....and invest in one that is more suitable to your needs...which hasn't been stated yet........at any rate, most of the moving parts of a manual bench type mill will be scrapped when it is CNC'd.

For a machinist of advanced years / experience you do spout some crap some times! 'Round Column conversion' - i'd tend to agree although I have no practical experience to confirm one way or the other. Morse Tapers against R8 for CNC makes what difference? They both will hold any tool, collet or drill when suitably sized and a Morse has more taper in contact with the spindle so could be said better for load bearing? Tormach will supply a CNC machine using an MT3 taper for their TTS tooling systems with ATC - have they go it wrong as well? As regards throwing the majority of moving parts away - since when? Maybe a couple of bits - no reason why a CNC can't use std Acme screws and nuts! Ball screws and ball nuts will replace a few more but the essential machine is still retained. Stop being a Machine Snob - not everyone wishes to invest 000's of $$$ for their first CNC machine which they may not 'click' with and prefer manual operation.