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View Full Version : x3 vs HF 40939



project5k
12-19-2006, 11:44 PM
ok, so here is where i'm at.. im looking at an x3 type machine from harbor freight, and im also looking at the small knee mill that they have... and i just dont know which way to go.. i have parked my cnc router project for now.. mainly due to a more imideate need for a mill... so i have 500 oz/in steppers, and driver boards..... and after reading and reading and researching.. my brain has just bogged down, and i dont know which way to go... I'm looking for suggestions, thoughts, experiences, anything... i really need a cnc mill, and I'm willing to put in the time that it takes to convert one... mainly cause i cant afford to buy one pre-setup...

here is the small knee mill im looing at....
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40939

and here is the x3 type i'm looking at....
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42827

or maby this one?
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93885

also what are the pros/cons of an r8 taper vs the m3?

i have no milling experience.. but know that i have a tendancy to outgrow small tools quickly..

PLEASE HELP!!!!

sanddrag
12-20-2006, 12:17 AM
I would go with the 33686 over the middle one (the 42827). The 42827 is a ZAY, but it is round column, and I dunno, I saw it in the store and it looked a little junky to me. I've never seen the small knee mill in the store, but I saw it on some other web page where some guy bought one, and it looks pretty nice to me. Enco sells a very similar one I believe. Anyway, you gotta consider the round vs dovetail column thing. I've heard the round column machines have rigidity issues when you extend the quill far out (beyond like 2 inches). On a dovetail column, you can move the whole head down.

Runner4404spd
12-20-2006, 06:51 AM
2 things,

1. how soon do you need it? if you can wait a few months, the new industrial hobbies mills will be here. they are the biggest and most well built square column mill on the market. there is a new owner who will be importing these.

2. if you have to have one right away i suggest looking at wholesale tool (www.wttool.com). i'd get the one i listed below. its a little more than the knee mill you showed but has more capacity.

http://www.wttool.com/product-exec/product_id/14840/nm/Geared_Head_Mill_Drill_Machine_w_Dovetail_Column

project5k
12-20-2006, 10:32 PM
ok, i will take a closer look at that unit.. i clicked over to the page and it looks to be a good mill, and i like the larger travels... means once i cnc that sucker i can make more parts in a single setup.. thats allways a good thing...

I'm still hoping that someone can help me to understand the pros and cons of an r8 taper vs a morse3.... i know the tail stock on my mini lathe is a m2, so whats the differences? anyone have opinions on one better than the other? is tooling more expensive for one that the other, or maby easier to find???

Runner4404spd
12-20-2006, 10:34 PM
stick with the R8 setup. MT3 is fine but its not as widely used as the R8. R8 is an industry standard and theres tons of stuff available.

project5k
12-22-2006, 12:31 AM
well thats good to know.. one thing i hate is getting a new tool, only to find out that i went the beta direction instead of the vhs... and now theres no support... hehehe ok bad analogy, but you get the point...

ok, so i'll keep r8 in mind... any other suggestions??

I'm looking to move on this fairly quickly, meaning i want it here by the end of jan. give or take on shipping...

I would really love to get a good used brigy, but something tells me thats just outta my price range... i can make 1400 work, but it emans that i'll have to wait till the next couple paychecks come in to get all the tooling and bits i want... if i go with a slightly cheaper machine, then i can get more pieces now... i guess putting more into the machine and waiting on all the parts would be the better move, at least then i have a better machine and not some 600-1000 pound thing that im not happy with...

where i'm trying to equip a 2400 sq-ft shop, size isnt a problem.. only that it will do the small stuff i wanna do, that i can convert it to cnc eventually, and it has the cap. to do the bigger stuff i wanna do...

sanddrag
12-22-2006, 12:53 AM
If you have the power for a bridgeport, you might consider it. Just a couple days ago I saw a nice Bridgeport with powerfeed and DRO go for $1250 at an auction. You might check out if there are any auctions near you.

project5k
12-22-2006, 02:56 PM
well thats one thing that i have been looking for is some place that might have a auction.. i have a full 200A 220 single phase service going to my shop.. i would hope to find a 1 phase machine, but worst case, i would either have to change out the motor, which is fine.. or have to get a rotary converter... i would almost rather change the motor, i know more about that than i do about the rotart phase converters....

the question is where can i go to look for auction announcements??? the local paper is useless....hardly worth even putting in a hampsters cage....

suggestions?

project5k
12-22-2006, 06:10 PM
also i was wondering about this one....

http://www.wttool.com/product-exec/product_id/14821/nm/6_x_26_Knee_Milling_Machine

Runner4404spd
12-22-2006, 10:10 PM
the main reason i stayed away from this one is the fact that the travels are limited. i had about that much travel on my RF-25 clone. so when i decided to step up the the next logical step was the RF-45 clone. and aaron at IH had the biggest on they made.

project5k
12-23-2006, 02:13 AM
but correct me if im wrong, arent most all the RF machines round column? that just scares me... seems to me that if i get into some heavy cutting that that head will swivel around like the head on my old drill press when its not locked in place....

project5k
12-23-2006, 03:21 AM
ok, so after looking and reading and looking some more and reading and now having a headache... i think i've decided to go with an x3 type machine.. It should do all i need a machine to do, and with all the cnc conversion kits im finding online, seems the way to go.. so, now for the questions...

first, who do i buy it from? there are several sellers, and whats this about the super vs. standard? is the table bigger or something and whats the price diff? who can ship quick, any one have any horror stories on this? who's got the best price?

second, i have 3-500 oz-in nema 23 steppers, and so thats what im thinking of using.. do ya'll see any potential problems with this?

i'm seriously thinking the only way to go is ballscrews... that way once i make the conversion, im done... thoughts?

one thing that i'm a little afraid of is starting into the conversion, and figuring out that i need a mill to do it, and having it all apart.... or are these kits set up so that i wont need a mill to make the conversion?

my thinking is to get the mill soon, and then save up a little for the cnc conversion kit, and in the meantime i can use it manual... thoughts? or should i wait and just get it all at once...never having had a cnc machine, or a milling machine, seems to me that some manual education wouldnt hurt...

any thoughts, suggestions, ideas or brainfarts are needed.. i'm really in over my head, and need some expereinced guidance....

bohica
12-23-2006, 05:45 AM
Having gone through the same thing you are going through, here are the conclusions I reached after a ton of research.

1. Square column mill. I wanted rigidity, and you can't get that in a round column. And using the quill for the Z axis just blows any accuracy right out of the window. Round columns are a forgetaboutits.

2. If you are going to convert, do you have the tools, equipment and ability to complete the project? These conversions are not rocket science, but they are still not a walk in the park either. Generally, you will not need a mill for the conversion. But expect the unexpected. During my CNC conversion, I found the square column base had been milled with a chop saw and was out of square to the ways by 1/8 inch in 2 directions. I had to take this to a machine shop to be fixed.

3. Servos! Far superior in the torque curve. All commercial CNC uses servos, and for good reason. With steppers, you run the risk of loosing steps and not knowing it.

4. Ball screws are the only choice if you ever hope to acheive any type of accuracy or repeatability. Then you have the rolled vs ground camps, but this is getting into the angels on the head of a pin debates.

5. The Super X3 looks like a really nice machine. Remember...whatever you buy is probably not going to be large enough, so get the biggest travel numbers you can afford.

6. Kits vs DYI. After a lot of research, I realized that DYI in a CNC conversion would require way too much of my time, something that is, for me, in short supply. That is why I went with a CNC kit. The only servo kit I found was the IH kit from Aaron Moss. It stood out so far above the stepper crowd that it was a no brainer for me. But it's a function of what you are willing to pay for..servos are much more expensive than steppers.

7. Go with full flood coolant. With CNC, you're going to need it. This means building an enclosure of some type. I spent 7 weeks building mine. There are lots of designs out there, some are simple and others are complex. I'll try to get a pic of mine posted shortly.

Hope this helps. Good luck in your project. Take you time and savor the journey.

project5k
12-24-2006, 12:25 AM
Bohica-
thanks for giving me your thoughts...
1 i agree.. round colum just dosent seem like a logical direction for me...
2 tools, equip, and ability.. I'm good to go as long as i dont need a mill to do the job... I hope that i wont find my machine that far outta whack... but let me ask this.. did you see this before you converted? or only after you started into it?
3 steppers vs servos.. well thats a week long debate in and of itself.. i agree that servos are the way to go if you have the money, and time to set them up.. as i have neither.. and already have the steppers and drivers, this is my only option at this time.. the good thing is that once i get it up and running, and maby make a little $ with it doing odd jobs for friends, then i can afford to upgrade to servos... and if i take a little time to tune the steppers well, then dropping steps shouldnt be a major problem.. i have seen lots of stepper systems, both good and bad, and the ones that were setup right, worked just as well as a servo system.. maby a little slower.. but then again, slower is probably a good thing for me for right now, as im so new to all of this and what not....
4 ball screws are definately the way to go for the long run, but again, being $ limited, i will have to go rolled for now...
5 looking at the x3 seems to be a good machine.. as i have said before, i would love to get a full sized knee mill, but i just havent found one that i could either afford, was in good enough shape to bother with, or wasnt 3 phase.. yes i know i have options on the 3 phase part, changing the motor or going with a phase converter, but this is all just more added cost..... i need to do some more lookng around and see if i can find a 3 phase mill that is cheap enough that i could the add the price of a new motor or converter and then come out at about the same price as a 1 phase to start with.. i have no problem doing the work, and im fully able.. and even look foward to it.. the more i do the more i know and the better i understand my tool.. that all allows me to do better work...
6 diy vs kit.. this is one of the reasons that i was looking at the x3, it seems to me that the kits are much more plentifull for this mill than any of the others that i have looked at... kit is definately the way to go for me.. as i have designed and started building my own cnc wood table router, sourcing and getting all the parts together has led me to believe that getting it all in a kit that someone has allready tried is sooooo worth the added $...
7 agreed, and building the enclosure shouldnt be a major problem for me.. I've worked lexan with good success, and welding up a steel frame for it wouldnt take any time... i envision something with a screen bottom so that the chips can be sepperated from the coolant.. thus it can be reused more easily....and this would also make cleanup easier if the screening system were modular, such that it could be snapped out for cleaning and then put back in...

bohica
12-24-2006, 02:46 PM
No, I did not notice the base problem prior to beginning the CNC conversion. But I never ran the mill, just disassembled it on arrival for the conversion.

Here is the enclosure I built, designed specifically for the IH mill. I had considered installing a screen like you mentioned but instead installed two gasketed cleanout ports, one on each side. The enclosure is finished with a ureathane (sp?) based paint. Nasty to apply but man, this is tough stuff. I liked Aaron's idea of hockey puck feet so this is my rendition of this. I also included vibration isolators between the mill and the mounting pads.

Hope this gives you some ideas.

project5k
12-28-2006, 02:19 PM
thats a good looking enclosure, im just wondering how you will get all the chips out... i see that your drain/return is knotched, that should allow the coolant to drain but stop most of the chips.. you might think about putting some window screen over that to keep all the chips out of your return and pump...

i also wondered about using one of the $10 harbor freight fountain pumps to move the coolant... where the unit is submersable, as long as you keep any debree out of the impeller, i would think that it would move the coolant good enough.. and thier cheap...

bohica
12-28-2006, 03:29 PM
There are two gasketed cleanout ports, one on each side of the mill. When the mill is installed, I will install small screens in areas were chips could infiltrate the coolant. In addition, all coolant will be filtered before it gets to the pump, which is a 500 ghp submersible pump

project5k
12-29-2006, 01:58 AM
ahh ok, i went back and saw that you told me that already, sorry, i missed it first time through... well it looks and sounds like you have really done your homework on this one, its a right fine setup, and i hope to see more pics and maby even some videos soon...

I'm still trying to decide which mill to get... or, really where to get my x3.. i really cant wait till the IH unit comes out in march.. i need it sooner than that... whats your suggestion on where? theres one from harbor freight, grizly, and some others.... are they really all the same machine? or are there some differences? also, i've read that some people have had some problems with the seals around the quill.. have you ever seen this?

phantomcow2
12-30-2006, 07:16 PM
I would have bought the small knee mill, but 750 pounds or whatever was just too much for me. I had to settle for the X3, which by the way is a fantastic mill. I bought mine from Grizzly and had it in 5 days.
I have seen a small knee mill like that, it really is a good size and quite solid.
THe HF and Grizzly models of the same will come from the same factory with a different color.

That big ZAY round column mill is pretty junky if you ask me. I saw one at the HF store in Richmond. Yes it's big and solid, but it's a round column which is an immediate turn off. Also, the general quality and finish looked well below what the X3 offers.

Bottom line:
In your situation, I would get the X3. It's about 1k, so that leaves you some money to buy tools. Tools will end up costing a lot, you will see. It is a small mill in general, but a medium sized mill by bench standards. Buy rolled ballscrews if you are doing a conversion, they are still pretty accurate. I remember reading somewhere that a guy tested the 5/8 rolled type and found a deviation of less than .001".
Buy steppers, it's cheaper and they are pretty easy to setup. I will be posting pictures of my X3 to CNC project. THis project is taking forever, but It has gotten some great progress in the past week.

project5k
12-31-2006, 11:35 PM
yea i already have the steppers and driver boards that i built.. all i'd need is the hardware to actually convert the mill itself... i was looking through the new grizly catalog that i got in the mail a couple days ago, and i'm not 100% sure which one is the x3... can you give me the # on it?

phantomcow2
12-31-2006, 11:42 PM
http://www.grizzly.com/products/G0463

project5k
01-02-2007, 11:16 AM
ok.. i see it now.. man, that just looks like its soo small...

phantomcow2
01-02-2007, 05:29 PM
I never considered it very small. The table is 22 inches wide I believe, it probably weighs about 400 pounds. Grizzly says 343, but htat does not make sense. When New Penn Freight shipped it to me, the shipping weight was 448 pounds. Now there were a few accessories and a plywood box, this was not 100+ pounds.
The machine is about 36" in height.

It is not an industrial hobbies or a bridgeport by any stretch

project5k
01-04-2007, 11:55 PM
yea, and im sure its a fine machine, and with all the different kits out there to convert it i'd bet it'd be great.. im just worried that i'll overload it or end up with somehting thats just too big and wont be able to use it for what i wanna make...
95% of what i want to do is maby 3" by 3", but there is that occasional huge project...

phantomcow2
01-05-2007, 06:22 AM
Well, then by all means I suggest getting a ZAY type. I don't know who is going to carry the industrial hobbies mill, but when it is carried by somebody that is about as big as a benchtop will get.
Penn tool has a pretty beasty benchtop with 9" of Y axis.

1990notch
01-06-2007, 12:52 AM
In case you're interested, Grizzly now has the Super X3 under G0619 for $1295

phantomcow2
01-06-2007, 07:19 AM
In case you're interested, Grizzly now has the Super X3 under G0619 for $1295

But the Super X3 is probably not much of an upgrade for those who wish to go CNC

project5k
01-06-2007, 07:56 AM
I'm looking at that, and i cant see that its the super, whats the specs on the regular vs the super?

phantomcow2
01-06-2007, 12:58 PM
The Super has the capability to rotate your head +/- 90 degrees. It has a slightly more powerful motor, but has a lower spindle speed. It comes with a tapping function, so that your motor is instantly reversed. It does not have any more travel though