Charter I.H. Clone build

[Roadstercycle]

Thanks Jay, It really turned out nice. Can't wait to make some chips. A few more pics below.

Hey Dad. Nice job on the mill.

Jay

[Roadstercycle]

OK today worked my butt off getting wiring straightened out and cleaning the shop to put the new one in the corner. Wife and Grandson helped a lot. So the DRO is done, the quill DRO is on and set, just installing the belt covers that a friend of mine whipped up for me, Eddie Paul is his name look him up on You tube or google him, he builds everything from cars to sharks for Hollywood movies. The CNC is in the corner and everything works great. Smooth stepper ethernet works awesome at this point, cut some imaginary parts since I don't have the belt guards on yet. Also got an Edge tramming tool, pretty nice for $100 bucks. You can see all my nostalgic posters that my son Jay has given me over the years, Awesome !!! Here's some pics.

[Roadstercycle]

Well it seems I'm done for the time being. I am going to order a couple more ball nuts so I can build a double ball nut setup. I'm not happy with the backlash of the so called anti backlash ball nuts. Now I just have to come up with a clever way to do it. If anyone knows of any pics of what others have done they could help. Here's a couple finished pics of the machine. I moved the DRO back to the left side with a 12" extension so I could compare the readings on the DRO and Mach 3 screen. Also in the picture is my usb radio keyboard that has a joystick mouse and buttons. Works really well for controlling the machine and quick editing G-code all in one shot. Again this machine is a CNC/Manual mill, you can use it either way you want.

[louieatienza]

OK today worked my butt off getting wiring straightened out and cleaning the shop to put the new one in the corner. Wife and Grandson helped a lot. So the DRO is done, the quill DRO is on and set, just installing the belt covers that a friend of mine whipped up for me, Eddie Paul is his name look him up on You tube or google him, he builds everything from cars to sharks for Hollywood movies. The CNC is in the corner and everything works great. Smooth stepper ethernet works awesome at this point, cut some imaginary parts since I don't have the belt guards on yet. Also got an Edge tramming tool, pretty nice for $100 bucks. You can see all my nostalgic posters that my son Jay has given me over the years, Awesome !!! Here's some pics.

Awesome to have a friend like Eddie Paul!

[jbolt]

Well it seems I'm done for the time being. I am going to order a couple more ball nuts so I can build a double ball nut setup. I'm not happy with the backlash of the so called anti backlash ball nuts. Now I just have to come up with a clever way to do it. If anyone knows of any pics of what others have done they could help.

I only have a couple of pictures of the double ball nut setup. Basically the second nut is spaced from the block and spring washers under the screw head for tension adjustment. Works well but takes some time to get adjusted just right.


Y-axis


Z-axis


Jay

[Roadstercycle]

Jay, thank you. Now I have 3 thoughts on how to cure the issue.

[Roadstercycle]

I used the mill today to do a few things and let me tell you, what a difference between the RF 31 CNC and the I.H. Charter. It's very solid, of course that's my opinion coming from the other mill. I bought a small 4th axis Chinese unit from a company on Alibaba and for some reason I thought it was a 34 motor but it ended up being a 24 motor so pretty much useless for doing anything heavy duty. So I am converting it to a 34 motor and also made up a way to use it as a dividing head so I can cut some splines. I'll have to move the pin setup with the new motor setup but at the moment I did quick so I can get these splines cut. Here's what I did with some pics. Removed the nut holding the belt sprocket and made a dividing plate with 14 holes in it that fits over the shaft and tightened the nut back up. You can make up dividing plates at will to do this, I did a 14 because thats what I need right now for my reverse gearbox setup. I used a small 3/4 by 3/4 piece of aluminum as the pin setup. I drilled and tapped 2 mounting holes then drilled and tapped the hole for the pin bolt to go into the dividing plate holes. The bolt is tapered to go into the plates holes and it locks in really nice. Here's some pics hopefully they are self explanatory.

[Roadstercycle]

OK, an update. I put to more ball nuts in my machine and biased them with the other 2. I used 24 coning washers rated at 81 lbs and put them together so they would be about 160 lbs. I have double nuts now. That fixed all my backlash issues I was having. So word of advise for those of you that are going to buy the Chinese or Automated Technologies ball nuts and screws be advised to buy extra ball nuts if you want your machine backlash free or very close to backlash free. I had about .007 amount of backlash in my X axis. Anti backlash I believe is a sales gimmick there is no way to get zero backlash out of a single nut. My 2 cents.

[louieatienza]

OK, an update. I put to more ball nuts in my machine and biased them with the other 2. I used 24 coning washers rated at 81 lbs and put them together so they would be about 160 lbs. I have double nuts now. That fixed all my backlash issues I was having. So word of advise for those of you that are going to buy the Chinese or Automated Technologies ball nuts and screws be advised to buy extra ball nuts if you want your machine backlash free or very close to backlash free. I had about .007 amount of backlash in my X axis. Anti backlash I believe is a sales gimmick there is no way to get zero backlash out of a single nut. My 2 cents.

To be fair, there is a difference between anti-backlash and zero-backlash. It's the nature of the construct of the screw I suppose, since the nut must me made and the balls sized to adapt to the sight variations in pitch of the rolled formed threads. One reason why C7 is also called "transport grade."

[Roadstercycle]

I agree we are talking about anti backlash not zero backlash, different animals. Most of the Hobby CNC guys go with the anti backlash because of cost so I'm just advising to purchase 2 per screw or the double ball nuts to help get close to zero backlash.

[Roadstercycle]

Today I finally cut some parts and drilled some holes to see if my double nut ball screw setup was worth the time and money. After cutting and drilling various aluminum parts using the milling wizard in Mach 3 and using DRO as a comparison to go back to zero after the cuts and drilling. X -axis came in at .0001 3 times. The Y came back to .0000 every time. So I am totally jazzed at what I ended up with and now I can make chips in confidence that I am nailing the specs. Nothing really needs to be that close that I build but I know I can cut or drill anything and be spot on. Again I'm jazzed. So I hope I helped some people with their build or thoughts of building a machine. I have to say using the I/H/ Charter mill as the base platform really will make a difference in my shop as that 12" Y-axis is the bomb. 8" and 9" will work until you need 9.5" for some stupid little job you can't do or have to flip the piece around to finish, PIA, I know I've dealt with that for years, hated it ! ! ! Jack

[Roadstercycle]

So today I decided to update the little Chinese 4" 4jaw that I bought from China but they are all over Ebay for about $300 bucks. It had a 24 series motor so I upgraded it to a 34 Series for better locking power. I had a couple in stock so that was easy, just had to take one apart and turn the 1/2" shaft down to 5/16", easy-peasy. So I had to buy a longer belt, make a new motor mount and installed my 14 hole indexer behind the belt drive. Since I'm going to be doing a lot of 14 tooth splines I just added it semi permanent for now. It turned out nice and the new CNC performed beautifully making the new motor mount. I'm really happy with the machine. If anyone needs a I.H. Charter Oaks machine I have another one brand new in the box in Southern California. PM me. Here's pics of the 4th axis. Now I have to figure out how to make it work since I've never had a 4th axis before. It will be fun.

[lcvette]

Do you have pictures of the double nut setup? I just ordered a set of double nuts but I can see that the second nut is still a little loose to the fixed nut the way they "link" them. Thinking a preloaded set belville springs is probably a better solution. Just curious how you decided to put it together.

[Roadstercycle]

Do you have pictures of the double nut setup? I just ordered a set of double nuts but I can see that the second nut is still a little loose to the fixed nut the way they "link" them. Thinking a preloaded set belville springs is probably a better solution. Just curious how you decided to put it together.

I'll do a drawing tonight how I did it. I went so fast when I did the double nut setup that they where in before I realized no pictures where taken.

[lcvette]

Awesome, been there, lol.... Sometimes blinders while getting her going is the best way to get it done... Drawing would be very much appreciated! And I'm glad to hear your results are so good!

[Roadstercycle]

OK, since I used 10-24 bolts instead of metric I had the fill the ball nut mounting holes so they would not twist, I don't think they would have but I just made sure. I did this by using 1/4" heat shrink on the bolts, made them a perfect slip fit, lucky on that is all. The way you eliminate the backlash is screw the second ball nut up close and aligning it but not touching the first one. You should have about 1'8 to 1/4 inch gap. When you tighten the screws you will be actually using the ball screw to put pressure on the first ball nut against the mounting block compressing the the coning washers. You don't need much pressure and remember to use blue lock tight. The ball nuts will actually kind of stay close to zero even after they wear as the coning washers will take up the slack for awhile, not forever and then you can tighten the screws again to fix that.

[dracozny]

Ivette, sounds like you have the double nut that is a flanged nut with a shorter non flanged nut by your description. If I'm correct than you will want to remove the locking tabs and insert some shims, alternatively the bellville springs are a good option but you have to remove one of the nuts to install them.

[Roadstercycle]

Well I am setting up my 4th axis and I'm in the lost zone. I have it working and it's moving to the correct position but slow as molasses. It jogs fine etc but just goes to the next potion painfully slow. I've tried a few things to no avail. It's set at 13.33333 steps per degree in the steps on the motor tuning page. The accel and velocity I've played with but to no conclusion. Anyone familiar? Is there a place where you tell Mach that A axis is degrees? Thanks in advance.

[Roadstercycle]

Well it took all day but finally figured out the slow move issue. In the Mach 3 setup you have to check the move by radius box and tell the DRO in settings that the radius is .0001. What a PIA to find that out. Now when I'm cutting a spline it will move to the next cut fast, it was taking forever it seemed before. I'm a happy camper now. Now I'm going to fine tune all the motors and be done and start making chips and reverse gear boxes for motorcycles.

[Roadstercycle]

Did a little mod today to the machine. Love the machine, hated the cheap/cheesy Y axis way cover, it was cracked the day I got it and just got worse. I ordered a Tormach Y axis way cover. It was the widest one they offered and with a couple of modifications works great and made the machine look so much cleaner. I paid about $42 for it shipped. For the life of me I don't understand why all the desktop mill manufacturers go with that rubber mat type covers. I bet in China the Tormach way cover probably costs $5 to manufacture and $10 to buy. So for a few bucks more the manufacturers would have a more professional looking mill. I am so happy about how much cleaner the ways will be and how much more protection the ball screws have. Still have not missed any steps and have been doing a lot of different parts. The difference between my RF31 CNC and this one is night and day.