x1 - w/ a "L" conversion or x2

[cnc-newb]

after a lot of reading, the x1 w/ a "L" conversion looks like it may fit my needs. most of what i will be making will be out of 6xxx & 7xxx Al w/ the blank size of ~8x5x4.

i would like to convert to belt drive and also cnc. i am not having much luck w/ plans for either of these. i see a lot for the x2 and was wondering if it was that much better of a machine? unfortunately w/ a x2 i would still need to make some changes (like the x2 freak) to get the desired travels, so i am a bit at a loss.

figure i would use one of keling's nema 23 425-495 oz/in 3 axis kits for the motion control.

any comments/suggestions would be greatly appreciated.

[SORCHEROR]

the X2 is way better than the X1,the spindle is alot more beefy,as far as travel i was able to get 9x4 1/8 xy and 10 z out of mine with some minor mods to the casting

[cnc-newb]

Originally Posted by SORCHEROR the X2 is way better than the X1,the spindle is alot more beefy,as far as travel i was able to get 9x4 1/8 xy and 10 z out of mine with some minor mods to the casting

could you post the mods?

[sansbury]

I have an X1 and so far I am very happy with it. The base price of $300 and the ease of resale (you can ship it UPS or Fedex, no truck freight) makes it the cheapest way to get into milling.

425oz motors are wildly oversized for the X1. I am direct-driving my X and Y using 125oz motors from an earlier wood router project. I am still working out backlash which is on the order of .005 but that is with no work on my part to reduce it. Aside from the CNC conversion parts I made it is 100% stock which made it a stupid-simple setup. I used the drawings on this site to build the X and Y bearing blocks and used cheap skate bearings instead of fancy thrust bearings. They are a great upgrade even if you use the handwheels instead.

http://www.theblossers.net/index.php...m449e9dbb67ef5

The Z axis is where you need power but a 200-300oz motor seems sufficient, especially with a belt reduction. I've been trying to move my Z with a 125oz motor (because it's what I have at the moment) but it's not quite enough by itself. All the bigger motors will get you are faster rapids which are meaningless on a mill this size, and of course more expense/heat/power issues. I drive mine with an $80 HobbyCNC pro board and a 24V PSU.

I am not sure what you mean by the "L" conversion. I do have the extended Y base from Little Machine Shop and will probably add the extended X when $s allow. These two mods push you up towards the base price of the X2 but you actually end up with more travel, particularly in the Y. The Y conversion is highly recommended as you get double the dovetail length for any given position which really helps rigidity and you need all you can get.

There is a Yahoo group called hf47158toCNC_Moderated which is dedicated to the X1. I would search there for more info on the belt mod.

Along with the belt drive, I've seen people put treadmill motors in these for more power. My feeling is that the existing motor can probably deliver as much power as the (limited) rigidity of the mill can stand up to, but I've never worked with one modded this way, so take it with a grain of salt.

I've also never worked with an X2 and am generally new to machining so I can't say how much better the X2 is. Anecdotally it seems like people who upgrade from the X1 either stick with a micro mill and go to a Sherline or Taig for the precision, or they go to a "small mill" like the X3 or RF-45.

Right now I am cutting 2D profiles in .500" cast aluminum plate--don't know the grade as I got it in the metal supplier's scrap bin cheap ($2/lb) but have cut plenty of 6061 using up to 1/2" end mills. I do these using XY-axis CNC only (as I'm still working out the Z) so I just run the profile, set the Z depth a little lower by hand, and run the profile again until I'm done. Without flood cooling you need to clear the chips constantly anyway, so no big inconvenience there. So yes, I am also working on flood cooling...

In my case the original choice of the X1 was driven mainly by the price and by the fact that I could CNC it using components I already had on hand. I also needed to carry it down a narrow basement staircase. If you're starting with nothing, the tooling for any of these machines will cost more or less the same. The good news is that tooling can mostly grow with the machine, so if you do upgrade, there's not much wasted. I've spent around $300 already and could easily do it again before feeling close to complete, though $200 is enough to get you started.

[cnc-newb]

Originally Posted by sansbury I have an X1 and so far I am very happy with it. The base price of $300 and the ease of resale (you can ship it UPS or Fedex, no truck freight) makes it the cheapest way to get into milling. 425oz motors are wildly oversized for the X1. I am direct-driving my X and Y using 125oz motors from an earlier wood router project. I am still working out backlash which is on the order of .005 but that is with no work on my part to reduce it. Aside from the CNC conversion parts I made it is 100% stock which made it a stupid-simple setup. I used the drawings on this site to build the X and Y bearing blocks and used cheap skate bearings instead of fancy thrust bearings. They are a great upgrade even if you use the handwheels instead. http://www.theblossers.net/index.php...m449e9dbb67ef5 The Z axis is where you need power but a 200-300oz motor seems sufficient, especially with a belt reduction. I've been trying to move my Z with a 125oz motor (because it's what I have at the moment) but it's not quite enough by itself. All the bigger motors will get you are faster rapids which are meaningless on a mill this size, and of course more expense/heat/power issues. I drive mine with an $80 HobbyCNC pro board and a 24V PSU. I am not sure what you mean by the "L" conversion. I do have the extended Y base from Little Machine Shop and will probably add the extended X when allow. These two mods push you up towards the base price of the X2 but you actually end up with more travel, particularly in the Y. The Y conversion is highly recommended as you get double the dovetail length for any given position which really helps rigidity and you need all you can get. There is a Yahoo group called hf47158toCNC_Moderated which is dedicated to the X1. I would search there for more info on the belt mod. Along with the belt drive, I've seen people put treadmill motors in these for more power. My feeling is that the existing motor can probably deliver as much power as the (limited) rigidity of the mill can stand up to, but I've never worked with one modded this way, so take it with a grain of salt. I've also never worked with an X2 and am generally new to machining so I can't say how much better the X2 is. Anecdotally it seems like people who upgrade from the X1 either stick with a micro mill and go to a Sherline or Taig for the precision, or they go to a "small mill" like the X3 or RF-45. Right now I am cutting 2D profiles in .500" cast aluminum plate--don't know the grade as I got it in the metal supplier's scrap bin cheap ($2/lb) but have cut plenty of 6061 using up to 1/2" end mills. I do these using XY-axis CNC only (as I'm still working out the Z) so I just run the profile, set the Z depth a little lower by hand, and run the profile again until I'm done. Without flood cooling you need to clear the chips constantly anyway, so no big inconvenience there. So yes, I am also working on flood cooling... In my case the original choice of the X1 was driven mainly by the price and by the fact that I could CNC it using components I already had on hand. I also needed to carry it down a narrow basement staircase. If you're starting with nothing, the tooling for any of these machines will cost more or less the same. The good news is that tooling can mostly grow with the machine, so if you do upgrade, there's not much wasted. I've spent around $300 already and could easily do it again before feeling close to complete, though $200 is enough to get you started.

thanks for the info. this is kind of what i wanted to hear. the "L" conversion is, at least from my brief reading, the extended x and y tables. as far as the motors, the 495oz/in motor kit would be $80 more than the 282oz/in and figured they would be more than enough but may split the difference and opt for a 425 oz/in kit for $359 (unless that price is high - it has the 3 driver boards, a break out board, 24VDC/8A psu, 5V psu for a fan so it seems pretty complete). i will probably stay w/ the small mill as i have out of state access to an industrial cnc shop, but somethings i want to mill can't be sent through the mail . for those i need to do it @ home.

so basically w/ your mill, you could put a piece of 8x5x2 Al and have no problems milling out parts to the extent of the blank - correct? even if i used a smaller endmill that is no problem. my only issue may be a liquid coolant setup as this will be indoors - live in a condo w/out a garage but was thinking about an air type of clearing/cooling setup from either a compressor i have or something like that....but that blogger site looks very interesting w/ its enclosure...

could you point me in the direction of the plans for the motor mounts on here? i am assuming they don't connect directly to the bearing mount, but may be wrong.

thanks in advance
newb

[sansbury]

The motor mount plans are at the URL in my original post. You have to click through to a PDF.

I am a little concerned about the size of the workpiece though. 8x5 is one thing- the 2" deep part is another. That's an enormous piece of material on any benchtop mill. You need to consider how much of that material you are going to be removing. I can run 10ipm taking .050 deep cuts with a 1/4" endmill. That's 0.125 cubic inches per minute. Your blank is 80 cubic inches. If your project calls for milling away, say, 25% of that, you're talking a lot of hours.

Also, there is no, I repeat _NO_advantage_ to using steppers 3 times the size needed. At best there is a benefit to having some headroom (10-25% maybe) but past that there's nothing to gain. There are disadvantages. The motor mounts will need to be a lot stiffer to support the heavier motors. They will be slower for a given amount of power so you will end up spending more for higher-power drive and PSU to get the same performance. Smaller motors can actually often ramp and reverse faster since they have less inertia. Bigger is not always better!

One thing that is important to note is that due to the friction inherent in the sliding ways, almost all of the power is used to move the table; cutting force accounts for almost none by comparison. So, don't think that a larger motor will permit a heavier cut--that is dictated primarly by mill rigidity and secondarily spindle power.

My suggestion would be for 125-200oz-in class motors on the X and Y, and a 200-300oz for the Z. I have a 12x20" wood router that rapids at 120ipm using 125oz motors and cheap 1/2-10 single-start acme screws on all three axes. Something about the CNC Zone makes people want to brag about motors big enough to dislocate their shoulders.

As for putting the machine in a condo--you are going to make a lot of mess and noise with or without flood cooling. Chips and lubricant will go everywhere. I live in the city but was fortunate to have access to a basement work area I could set up in. I would not want one of these in my apartment, and if I had to, I'd _want_ it in a full enclosure. Mind you I have an oscilloscope and soldering iron sitting on my kitchen table so I don't scare easily!

Actually the biggest problem with metalworking in the house isn't the mill, it's the bandsaw. Those suckers are LOUD. I only get away with it b/c the girl who lives in between my unit and the basement has a dog with a barking problem. She doesn't complain to the landlord about my bandsaw and I don't complain about her dog. We get along great!

[cnc-newb]

thanks again for the info. i will look for lower torque units. will also save some more $$, always a good thing.

so the plan is the bearing block - that is the mount? i thought that part was just for a bearing not knowing it was the mount too. i just can't see how it goes on w/ a stepper too?? is there any way you can click a pic of yours?

also, is 10ipm something that should be acheiveable? is that high, low or about where it should be for cutting Al w/ this size of a machine?

another question - say i start cutting, can the cnc software pause if it is not close to being done? or is it once you start you need to finish? again i am extremely green w/ this so your patience and knowledge is extremely appreciated

newb

the smallest size i could cut out of would be 7.75x4x1.600 for a finished item of 7.69x3.92x1.45. being able to start out w/ a smaller piece would definitely benefit me

looks like some type of an enclosure it is. so a pair of 185oz/in steppers for the x and y and then a 270oz/in for the z should take care of it ok?

[sansbury]

What are these things you're making, anyway? Figuring in cutting losses I'm guessing you could easily be looking at $50/pc in aluminum alone, depending on how cheaply you can source it. There are suppliers who will supply stock cut to size but this is mainly for the benefit of machining time rather than material cost. If cost is not an issue, make a drawing and find a local machine shop.

Another thing worth considering is casting. You can melt aluminum in a homemade charcoal furnace and use sand or lost foam casting. You can cast the part to within 1/8" or less of final size in every dimension and just machine the parts where tolerances are crucial. This is how engine blocks and all sorts of other "real" large, complex parts are made. I think people think it requires far more expense or skill than it actually does. In terms of the doors it opens it's probably the most powerful metalworking technique out there since it allows you to turn a pile of cheap/free scrap metal into parts in almost any size and shape you want. If you can fit a small sandbox in your backyard then you probably have enough room, though heaven knows you might scare the neighbors a bit

[cnc-newb]

the parts will be all kinds of things including firearm receivers (all legal of course). granted i could buy them for less than making for the most part (when taking in machine costs, time, etc), it is more for the education/knowledge to learn how all the cad/cam/nc works and see it in action. i have read quite a bit and have decided to go the next level and combine it all. this small mill is the right size for my current home so that is why it is a fit . for most of the parts i will probably ask my friend to ship me any extra billet material so i can use that and for the gun stuff, especially items like ar15 lowers, i am sure after my first full billet one i will probably buy a raw forging and start it from there

i am also into different aspects of the rc hobby - again another place where i can just make the parts i want. again, i could just buy stuff but i wouldn't gain the knowledge and for me that is what it is all about w/ this endeavor.

that along w/ just things that i think up of. i can make it in solidworks but that is as far as i can currently get as i don't like to ask my friend to hold up a $80K machine making a small part for me that a ~$1K machine could easily do in my closet.

the casting does sound interesting. out in our little backyard (which is covered in something like a granite sand) we have a bbq that holds a lot of charcoal. it is pretty large and is cast iron. probably 3-3 1/2' tall and ~2' in diameter. has a grille area but quite a bit of room nonetheless and the grill rotates out and it is fully enclosed w/ a mesh all the way around. i really don't know what the technical name is but i have taken my infra-red thermometer out there and the coals shows up @ 1100F - don't know if that is the limit of the thermometer or an error, but it get hella hot. that may be something to look into too. how much heat do you need for how long?

[cnc-newb]

after over a decade of reading/posting on forums, my first double post....

[sansbury]

Yeah, OK, makes sense, though having grown up with over-unders and the occasional 1911, the only time I've seen aluminum used around guns was in the case you carried them in...

Receivers are certainly going to be a good test of skill. It's been a looong time since I took apart an M-16 so I don't recall the pieces exactly but there are certainly a few pieces you want to line up pretty precisely. It won't be fast on an X1 but I'd consider it doable. You might want to start out with wax or plastic or smaller parts while you work out the kinks.

An investment casting (wax or foam) would work very well for this with one important caveat. A homemade casting is going to have slightly unknown engineering qualities due to the much lower degree of process control in a DIY environment. You may mix several pieces of scrap together in the melt and get a completely novel alloy, for instance. An AR-15 receiver is going to be subjected to some force and a lot of vibration. I would proceed carefully to ensure that the receiver doesn't fail catastrophically.

Look for the Gingery Furnace or similar books to get started with casting aluminum. 1100 is damn hot for a BBQ but you need a lot more (1500-1800 IIRC) to melt aluminum.

[cnc-newb]

Originally Posted by sansbury Yeah, OK, makes sense, though having grown up with over-unders and the occasional 1911, the only time I've seen aluminum used around guns was in the case you carried them in... Receivers are certainly going to be a good test of skill. It's been a looong time since I took apart an M-16 so I don't recall the pieces exactly but there are certainly a few pieces you want to line up pretty precisely. It won't be fast on an X1 but I'd consider it doable. You might want to start out with wax or plastic or smaller parts while you work out the kinks. An investment casting (wax or foam) would work very well for this with one important caveat. A homemade casting is going to have slightly unknown engineering qualities due to the much lower degree of process control in a DIY environment. You may mix several pieces of scrap together in the melt and get a completely novel alloy, for instance. An AR-15 receiver is going to be subjected to some force and a lot of vibration. I would proceed carefully to ensure that the receiver doesn't fail catastrophically. Look for the Gingery Furnace or similar books to get started with casting aluminum. 1100 is damn hot for a BBQ but you need a lot more (1500-1800 IIRC) to melt aluminum.

thanks for the info the ar lower would be done w/ a 6061 t6 or higher or from a known source or from a forged 0% unit - wouldn't do that myself, don't want a kaboom . there are solidmodels for all types of guns here - www.cncguns.com very cool site