You might want to look at a few torque curves to see how much power a inductive stepper makes at speed.
34N - High Torque Stepper Motor
youtube videos of the G0704 under the name arizonavideo99
Dave thanks for that, steppers definitely drop off as RPMs go up. Since the Y and X are nema 34 mounts I can change them out rather easily to something else if the performance does not meet my expectations. I don't run fast while using my machines so I'm not too concerned. If I was going to run fast then I would of went a different way. I am just afraid of being under powered and loosing steps with the bigger, heavier, machine. I have 2 I.H. clones now so maybe the second one I'll go smaller everything and see how it runs. All the parts are ordered for the first one.
Just dawned on me the machine you are most likely taking inspiration from. Here is a quote from him "this thing is scary at 200ipm I wont be running over 50 for rapids"
Yes that is true as I mentioned in an earlier post. And like him I won't and don't run any faster than 50 ipm myself and that's fast for me. His machine is solid and that's what I want. It's way overkill but I won't be worried about being on the edge or the fringe of of missing steps. If I miss a step with this then something has definitely gone wrong. He even admits it's way overkill, but after 3 years running he's not missed any steps. It's crazy I know but really it's no big deal. I'll have fun building it. Pulling the head off today, already removed the X and Y screws.
Where's your thread at for your machine, I must have missed a lot of your build and I'd like to run through it again.
My machine isn't finished but it's right below yours atm
drac, OK, got it, I just thought you got further along than the last post I saw from it. I thought I missed a few posts. Well got the head off and wish I had a bathroom scale for a weight check. It is heavy but I don't have a guess for the weight. I'll go buy a bathroom scale today somewhere. Doesn't really matter but I'd like to know. I'll tell what though my car hoist in the garage is a life saver since I lifted the head off with with chain fall and did not realize it would not go to the ground afterwards. Lifted it up raised one side of the hoist and fixed the issue. A car hoist is worth it's weight in gold sometimes. I use it all the time for projects. I did get the Z screw out too. Looks like I may be able to bore out the Z screw nut to fit the ball screw nut, it's really beefy but I'll have to wait and see, if not I'll make another. Here's some pics.
The motors and power supplies arrived today. Unbelievable, ordered Sunday night from a Chinese company leaving for Holiday and they said they would get them out of their California warehouse before everyone bailed out. I believed them halfheartedly and purchased anyway to roll the dice. Arrived today Wednesday. The 4200 inoz Nema 42 and the 2-1600oz Nema 34 look like a Mother pot belly pig and her 2 babies. The 42 is big for sure.
Here's the pic. The ball screws are suppose to be here Friday from Automation Technology. Looking forward to getting this one done. My Rong Fu 31 is just too small to make the new reverse gearbox I designed for motorcycles. The fun begins this weekend with motor mounts and drive pcs.
OK, things are moving along. I was thinking the biggest issue I can see with someone building up a CNC is not having another CNC to make parts for the new one. Sure makes life easier. Today I CNC out a few brackets for the motors. The X axis has the motor in front of the slide to save room in the shop. It's out far enough in front to be able to put my glass scales between the motor and the table. Both the X axis ball screw bearings will be hidden under the slide on either end, mounted inside on the bracket instead of hanging out, I think it's cleaner looking. I loose a little X travel but I don't think that's an issue since I've used the RF31 CNC for years and never used the whole table on it. Of course it will rear it's ugly head someday I'm sure. Also the Y axis motor will be under the machine in front. I will have hand cranks on the X and Y for convience as I do a lot of quick things so I need it. So here's the pics of what happened today. Oh, I forgot to mention that I was able to nail all the holes and line up pins by using the stock casting pieces as guides. I found that the pins are tapered (at least in the I.H. clone I have) so make sure if you do this that you use a drill with the minor diameter, my outside hole was .250ish and the inner about .220ish. The same with the bolt holes the bolts where about .312 and the holes where .350. So I used a .350 drill to get a nice center then went with to a .312 drill the do the hole. The hole and line up pins fit perfect. So I'm jazzed.
Well a little more accomplished today. X- axis ball screw mount is done, going to do the Y axis tomorrow. The X-axis needed a little massaging to get it right but it turned out pretty good. I actually had to shave a little off the top of the ball screw to make it fit, no big deal though. I realized another reason why I'm building this besides the Y axis travel, my RF31 CNC/mill/drill is such a pain to move the head up and down. Loosen bolts, crank up or down, tighten bolts, it seems I'm constantly doing this while building parts. Such a pain. If your thinking about doing a round column CNC conversion just save your money for a square head column, it will make life so much easier in the long run. Please don't get me wrong I really like the RF31 and I've built a lot of cool stuff with it but I just realized with the new one no more cranking. Here's some pics.
yeesh, you are running circles around me. I'm still boring out the center of a ball nut holder for my X, although admittedly I have only had about 4 hours to work on it. canned cycles are making it less tedious at least.
Todays accomplishments where a lot of fun. Y axis ball screw mount. Also started on the Z axis bearing mount. It came square so I had to put it in the lathe and whittle it down to be round so it would fit in the Z axis top hole. I had a BK 15 when it should of been an FK15 which is round and since all the Chinese ebay sellers where gone for the Chinese new year things where not going to be in the States until March 15th ish. So I just built my own. I also got rid of the front aluminum plate that was un-needed for the front ball screw bearing. I did use the bearing and mount first to drill the holes through the machine so they are exactly true. Tapped them and the bearing and ball screw lined up perfectly. Here's some pics, they are not in order. I also ordered an ethernet smooth stepper today with a 6 axis breakout board combo. (I have a fourth axis I dying to try.) From all the forums and feedback they seem to be the way to go now.
I got the Y axis screw in today. You'll notice in the picture a little discoloration on the free end of it, that is because I annealed it so I could turn it down to the correct size for the bearing. There's no load so making it softer in this area was no big deal and it saved my tooling. Tomorrow the X-axis!!!
Well today I finished the parts and installed the X axis ball screw. So the X and Y ball screws are done. Next is the Z axis, I'm really looking forward to this install because it's all hidden inside the column. The only thing that will be seen is the 4200 in oz Godzilla stepper on top, should be a very clean setup. I may install a couple gas shocks to relieve some of the pressure off the the ball nuts, the 4200 oz stepper really does not need help moving head, I think it could actually pick up my car so 300 lbs is no issue. No pics today.
you won't need them a 2005 ball screw can hold a static load of 4863 lbs it can move 2149lbf, If you went the same route I did with 2505 screws on the Z you could lift your truck with it.
Update, I finished the Z-axis today and very happy with it. Everything worked out as planned. I had to build my own internal coupler for the motor and ball screw as the off the shelf ones where too big for the cartridge assembly I was building. I also made the block that holds the ball screw nut for the Z. It came with a 14mm bolt and when I check it it only had about 3 or 4 threads that where engaged in the stock Z block, talk about living on the edge. I went with a 5/8" course bolt with about an 1-1/4" engagement into the block. I also removed the pins and installed 2 1/4"-20 bolts instead of the pins. After I lined up everything and bolted the block in with the 5/8" bolt I drilled and tapped the block for the 1/4" bolts to make sure alignment was as close to perfect as possible. I used the lower stock bearing support as my anti whip bearing and turned the shaft down just a tad under size so it could move with expansion. I had to knock all the bond type stuff off so the plate that holds the bearing so it could be adjusted. After I bolted up the Z block to the Z axis slide I turn the ball screw by hand all the way down to the bottom by the stock bearing mount, I adjusted the bearing by opening up the mount holes a bit and centering the bearing and tightened it down. Then I screw the ball screw and Z axis slide to the top off the column and tightened the top mount that's under the motor. Feels great no binding. I could of saved a 1/4" up Z travel if I could have waited for a different round bearing assembly but the Chinese new year messed me over on that so I used a square one and made it round as you see in the picture. So by doing this I had to make a 1/4" plate to hold the assembly in. So if you want to do this type of cartridge the number is a FK15 bearing assembly, on ebay. I got the belts today for the X and Y but I blew the measurements so I had to reorder from McMaster, no big deal they have an awesome return policy. Now that the Z is done (a lot of fun by the way) I will take the table all the way apart and cut the Y axis about 1-1/2 inches for extra travel. Then I will decide wether to granite or not to granite. I also bought a new dual fan computer box and power supply to install all the electronics in. I figure the dual fans will keep everything nice and cool and the power supply has 5 volts as an added bonus. If anyones has any thoughts why the 5 volt power supply shouldn't be used for the breakout board please speak up, I thought it was a good idea but I could be wrong. A couple of thoughts for others here. Rule of thumb for aluminum is use course threads. Also most black allen bolts are grade 8 or better so don't be afraid to use them, they are tough. Well here's some build picks. They are not in order.