[sagreen]

More pictures of progress. Notice that the motor for the X ballscrew will not mount flush to the motor mount. This is because the shaft bottoms out in the lovejoy and is short by about 3/8 of an inch. Not sure how george is going to fix this.

Scott...

[CNC Lurker]

That is a good looking machine!

[ihavenofish]

More pictures of progress. Notice that the motor for the X ballscrew will not mount flush to the motor mount. This is because the shaft bottoms out in the lovejoy and is short by about 3/8 of an inch. Not sure how george is going to fix this.

Scott...

your motor shafts are 3/8" i assume? you need to drill a hole through the red plastic part of the coupling to let the motor shaft through. it possible youve swapped couplings on the y or z as well.

[gio666]

some of the coupling have a hole in center and some don't ,the one on the X should have the hole through center,also the screw is ground off of everyone,but your was one of the first 2525 and yours being in box already i didn't put in machine,but machines where made already and changed from 18mm od coupling to 25mm coupling as why the screw hits

[sagreen]

I've changed the address to the Guitar Instructional Video website to one that makes more sense to me long term.

Please visit the new site at RMGreen Videos - Instructional Videos for Woodworking, CNC, Guitar Building

Thanks,
Scott Green
RMGVideos

[sagreen]

Finished construction of the frame and built a stand last weekend. This weekend, I'll be building support for the e-chain and a monitor and keyboard arm on the frame.

[sagreen]

Didn't make much progress over the weekend, but I thought I'd post a few thoughts on the machine...


Pros:
1) I've ran it with my 620oz motors from candcnc and was able to get 800ipm rapids before stall. I think that I will probably tweek this down to about 700ipm max, but thats pretty decent. Have not cut anything to know how fast I can push it through material.

2) The machine is very sturdy and well built. I dont think I will have any problems cutting aluminum with the machine. I'll have to get some tee slot nuts to mount a vice to the table.

3) The ballscrews on this thing are very smooth, and quiet. Even at 800ips, no whip to speak of.

4) I'm using Unistrut for the stand, and if you've not used this stuff check it out. It's ~$18 for a 10 foot length from Lowes, and after I got it all braced up, it is rock solid, and cheap!

Cons:
1) I'm not pleased with the gantry height. I want to run an indexer on this thing, and would like to be able to get it all under the gantry and Z-Axis. I dont think the current gantry will work. George and I have talked about extending the gantry sides.

2) I'm not a big fan of a single ballscrew in the middle of the X axis. Over time I believe that this design will cause flex in the gantry as it reaches the outsides of its travel. If I were building a machine like this from scratch I would use Rack and Pinion on the X axis at least. I have a shopbot with R&P and never have any problems with it. R&P works as good as, or better than ballscrews with no whip or flex at any speed.

3) As I have said before, I dont really like the way the lovejoys are mounted to these ballscrews. Seems that if you have to grind off the allen bolt heads (can never get them back off and save the lovejoy) due to clearance issues this is a design problem.

4) The router will not travel to the extreme extents of the X or Y axises. This is going to cause a problem when you put on an MDF spoilboard and want to surface it. I'll let you know how this goes, but I expect that I will create my MDF spoilboard the same size as the extents of these axises so I can surface it. The problem is going to be getting the spoilboard square to the machine.


Thats about it for now. I'll post more pictures and comments as I go.

Scott...
RMGreen Videos - Instructional Videos for Woodworking, CNC, Guitar Building

[buckeyes1997]

[QUOTE=sagreen;901009]Didn't make much progress over the weekend, but I thought I'd post a few thoughts on the machine...

Cons:
1) I'm not pleased with the gantry height. I want to run an indexer on this thing, and would like to be able to get it all under the gantry and Z-Axis. I dont think the current gantry will work. George and I have talked about extending the gantry sides.

I AGREE!!! Also with the Z mounted as designed the height is limited by Z axis and not travel. If the whole Z was mounted other way the whole axis moves out of the way to allow more height on parts/fixtures.


3) As I have said before, I dont really like the way the lovejoys are mounted to these ballscrews. Seems that if you have to grind off the allen bolt heads (can never get them back off and save the lovejoy) due to clearance issues this is a design problem.

I also agree. I mentioned to George about maybe using helical couplers I had on hand and because the ballscrew threads into the lovejoys he advised it was not a good idea to change to helical.


NICE BUILD LOG!! I am currently modifying my raptorx gantry sides to allow adjustment of the squareness alignment of the X to Y. Mine is very good out of the box with only .060" error over 20" travel, but I know it can be improved if its adjustable.....we'll see.

[ihavenofish]

Cons:
1) I'm not pleased with the gantry height. I want to run an indexer on this thing, and would like to be able to get it all under the gantry and Z-Axis. I dont think the current gantry will work. George and I have talked about extending the gantry sides.

gantry height is always a compromise. the taller you make it, the more flexy it becomes. the newer versions of the machines ar 2" taller, but they use thicker plates. if its just for an indexer, one thing you can do is drop the indexer through the table. youd have to make a clever mounting system and obviously remove the table top.

2) I'm not a big fan of a single ballscrew in the middle of the X axis. Over time I believe that this design will cause flex in the gantry as it reaches the outsides of its travel. If I were building a machine like this from scratch I would use Rack and Pinion on the X axis at least. I have a shopbot with R&P and never have any problems with it. R&P works as good as, or better than ballscrews with no whip or flex at any speed.

the centre mounted screw isnt that big an issue in practice, although it does "twist" if you put a high load on one side. it always bounces back to neutral though, so it becomes like any other flex aspect in the machine, just cut within its abilities and do a light finish pass on dimensionally critical things.

rack would be a down grade. twin ball screws is a better solution and george is working on this. it improves the rigidity of the machine, and also the table. better all around, but of course cost more because of the extra axis.

3) As I have said before, I dont really like the way the lovejoys are mounted to these ballscrews. Seems that if you have to grind off the allen bolt heads (can never get them back off and save the lovejoy) due to clearance issues this is a design problem.

the new machines are totally different and no longer an issue.
the issue with the old couplings is due to the end plate being used to retain the bearing, which means the hole has to be smaller than the bearing, which is only a hair bigger than the coupling. so the screw is ground down. that said, there is really no reason to ever take the coupling off the screw, unless its damage or the bearings blown.

4) The router will not travel to the extreme extents of the X or Y axises. This is going to cause a problem when you put on an MDF spoilboard and want to surface it. I'll let you know how this goes, but I expect that I will create my MDF spoilboard the same size as the extents of these axises so I can surface it. The problem is going to be getting the spoilboard square to the machine.

use a spoil board that fit the travel of the machine, like youd do with any other machine. youve got a table top on there, so there no reason to use an oversized spoilboard.

[sagreen]

gantry height is always a compromise. the taller you make it, the more flexy it becomes. the newer versions of the machines ar 2" taller, but they use thicker plates. if its just for an indexer, one thing you can do is drop the indexer through the table. youd have to make a clever mounting system and obviously remove the table top.

Thought about this, but taking the entire table top off is a time consuming option, mounting it across the Y axis would limit the depth because of the ballscrew. Mounting it along the X would require removal of the entire top. I'm thinking of a big aluminum block to extend the spindle over the 0,0 end of the machine, and putting the indexer mount on the end of the frame. Easier to take off the spindle than the entire table. Has there been any real life test data that show the amount of flex per inch that happens by extending the gantry height?

the centre mounted screw isnt that big an issue in practice, although it does "twist" if you put a high load on one side. it always bounces back to neutral though, so it becomes like any other flex aspect in the machine, just cut within its abilities and do a light finish pass on dimensionally critical things.

rack would be a down grade. twin ball screws is a better solution and george is working on this. it improves the rigidity of the machine, and also the table. better all around, but of course cost more because of the extra axis.

I disagree. I have a 4' x 8' machine with r&p on all axises and I never have a problem with accuracy of this machine. I cut to within .001 on all axises. with no backlash. I cant even get the table or rails level within this tollerance on the XZero. On top of that, ball screws ALL have whip. You can reduce the whip by putting 2525 ballscrews on the machine to slow them down, but you loose resolution in the process. You'll see this when you start having steps on 45 degree cuts (lost resolution), or try to run the machine at any reasonable speed (whip). I can get over 2000 ipm rapids on my R&P machine. You put ANY ballscrew on an 8' long machine, let alone a 10' machine and its going to whip at 500ipm. Any CNC machine's accuracy is based on the least common denominator. Gantry flex coupled with the ability to square / level the machine will be way worse than any backlash delta between R&P and ballscrews. Plus twin R&P would be 1/2 the cost of single ballscrew.

the new machines are totally different and no longer an issue. the issue with the old couplings is due to the end plate being used to retain the bearing, which means the hole has to be smaller than the bearing, which is only a hair bigger than the coupling. so the screw is ground down. that said, there is really no reason to ever take the coupling off the screw, unless its damage or the bearings blown.

What exactly is a new machine? I've had mine for like 3 weeks, and haven't even cut anything yet. Is there an recall upgrade available to retrofit the old machines with the correct design? It is a total design flaw to have to grind down a removeable part to the point that it is no longer removeable.

use a spoil board that fit the travel of the machine, like youd do with any other machine. youve got a table top on there, so there no reason to use an oversized spoilboard.

Thought that was what I said I was going to do...

Scott...

[ihavenofish]

"What exactly is a new machine? I've had mine for like 3 weeks, and haven't even cut anything yet. Is there an recall upgrade available to retrofit the old machines with the correct design? It is a total design flaw to have to grind down a removeable part to the point that it is no longer removeable."

there no recall, theres nothing wrong with the design. you dont happen to like the way its done, but it works just fine. its a non issue. assembly and maintenece dont require you to ever remove the coupling.

the "new" amchines are the beefed up heavier machines george has in production right now. they use much larger ball screw bearings and as such accomodate larger couplings with more room around them.


"Thought that was what I said I was going to do... "

yes, but im saying that this isnt a con of the machine, its a reality for every machine - you can cut anything bigger than its travel.

[gio666]

The machines first had a 20mm OD coupling , but changed them to the 25mm OD coupling ,outer bearing race is 27mm ,so hole in frame is 26mm, I have some 20mm OD coupling coming and will send you some ,but they are not as strong as the 25mm , but I don't know why you would ever have to take of the coupling?
The couplings are spider coupling and not lovejoy couplings, the ones used are the the closest flexible coupling to using a rigid coupling,Helical couplings are know to have backlash under high torque.
I see machines running at 3000IMP with the same single ballscrews as you have ,machines where speed is what is needed,and they have no problems in the window frame machines they use.
The Updated machines now have 37mm hole in the X ballscrew and now have 30mm OD coupling on ballscrew.
Never thought a filed coupling head screw would come a issue,but could change to flat head screws,just can't tighten down as much.
I will have the 3 inch higher uprights as a option on the machines most likely in a week or so.
I have asked ,NSK .THK and Hiwin about R/P and none of them sell them,and they are the leaders in linear motion, But THK has R/P on one of there linear profile rail for the mining field , but price is $2200 for 12 feet
And Scott is right I can get R/P for less then half the price on the ballscrew is ,but i have read in couple threads where it said i use single ballscrew to save money lol when I could do R/P for 1/3 the price of the ballscrews on all axis
http://x0cnc.com

[sagreen]

Picked a couple new toys last week. Picture on the left is a sweet set of wheels that have an adjustable leveling foot built in. You move it into place and then drop the foot to the floor and level. The spindle is 4KW. I've ordered an ER20 collet set that should be here next week as well as inductive prox switches.

Scott
RMGreen Videos - Instructional Videos for Woodworking, CNC, Guitar Building

[sagreen]

Never thought a filed coupling head screw would come a issue,but could change to flat head screws,just can't tighten down as much.

To be clear, this is not an issue right now. I'm not even worried about it at this point. George you dont have to send me a different coupler right now. I just dont like the way the coupling was implemented. The only time this would be a problem is when you want to remove the coupler, which I have not had to do. With the exception of the gantry height, I really like the machine. I've not cut anything yet so the gantry height is not even an issue yet. I'm just calling it as I see it in the build log.

Scott
RMGreen Videos - Instructional Videos for Woodworking, CNC, Guitar Building

[sagreen]

Ok, I've ran into my first snag. I'm trying to mill up a plate to adapt the Spindle to the Z-Axis. The provided Z Axis plate mounts with bolts from the front to the hiwin sliders and ballscrew nut. To mount a normal router mount, you pull this plate off and insert bolts from the back, mount the router mount, and replace the plate on the sliders and ballscrew nut.

So in the pictures you'll see that their is a row of holes in the back of the spindle that accepts bolts. My plan was to build a 3/8" thick plate to attach to the spindle, then bolt the plate to the provided ZAxis plate, then re-install the entire assembly onto the ZAxis. Problem is that I wont be able to re-install the bolts into the ballscrew nut housing cause the spindle will cover these holes. Its possible that I will have to drill into the provided ZAxis plate, and thread some holes to accept the new plate. I sure hate to cut into this thing, but it seems that it is my only option at this point.

Still thinking on this one, and will post what I end up doing. Ideas welcome!

Scott...
RMGreen Videos - Instructional Videos for Woodworking, CNC, Guitar Building

[Zygoat]

i have an idea that might work. a little complicated to explain tho.

in the first picture take the 4 big bolts out. then leaving the carriages (the red things in the second pic) behind; slide the ball screw, nut, and plate all up above the carriages. then you can turn the plate left and right. this should let you get to the back side to screw the bolts into the spindle. ie turn it as far left as you can and install the right bolts to the spindle then do the other side.

then just slide the whole mess back down and bolt it back together.



hopefully you can understand that.

[sagreen]

i have an idea that might work. a little complicated to explain tho.

in the first picture take the 4 big bolts out. then leaving the carriages (the red things in the second pic) behind; slide the ball screw, nut, and plate all up above the carriages. then you can turn the plate left and right. this should let you get to the back side to screw the bolts into the spindle. ie turn it as far left as you can and install the right bolts to the spindle then do the other side.

then just slide the whole mess back down and bolt it back together.



hopefully you can understand that.

zygoat,

Thanks for the idea! the problem is that we are talking about 2 different plates, the one that is bolted to the Z axis, and one that I will bolt to the spindle before I bolt it to the zaxis plate. Basically its and adapter.

I went ahead and drilled and threaded new holes in the plate that came with the machine. I've attached pictures. Now off to create the adapter plate.

Scott...
RMGreen Videos - Instructional Videos for Woodworking, CNC, Guitar Building

[ihavenofish]

Ok, I've ran into my first snag. I'm trying to mill up a plate to adapt the Spindle to the Z-Axis. The provided Z Axis plate mounts with bolts from the front to the hiwin sliders and ballscrew nut. To mount a normal router mount, you pull this plate off and insert bolts from the back, mount the router mount, and replace the plate on the sliders and ballscrew nut.

So in the pictures you'll see that their is a row of holes in the back of the spindle that accepts bolts. My plan was to build a 3/8" thick plate to attach to the spindle, then bolt the plate to the provided ZAxis plate, then re-install the entire assembly onto the ZAxis. Problem is that I wont be able to re-install the bolts into the ballscrew nut housing cause the spindle will cover these holes. Its possible that I will have to drill into the provided ZAxis plate, and thread some holes to accept the new plate. I sure hate to cut into this thing, but it seems that it is my only option at this point.

Still thinking on this one, and will post what I end up doing. Ideas welcome!
[/url]

i just ran into this a few days ago trying to mount the colombo spindle to the square rail z. the solution to me is to thread the 4 reverse counter sunk holes with M8 threads. then you make a plate that bolts to the spindle, and then finally bolt that to the z axis from the front with 4 m8 screws. you can make the plate have a few different positions as the spindle mounting holes are likely 100mm apart.

this solution will work on spindles up to about 80mm wide. im not sure how big yours is. you said 4kw, which is extremely overkill for this machine.

if the spindle is wider than 80mm, youll need to make a second wider adapter plate.

you also need to cut some "relief" on the back side of the mouninting plate, so it wont hit the top ball screw/motor mount.

[jassaf]

I found this online store: R/P

rack and pinion cnc linear ballscrew slides plasma cutter module

The machines ............
I have asked ,NSK .THK and Hiwin about R/P and none of them sell them,and they are the leaders in linear motion, But THK has R/P on one of there linear profile rail for the mining field , but price is $2200 for 12 feet
And Scott is right I can get R/P for less then half the price on the ballscrew is ,but i have read in couple threads where it said i use single ballscrew to save money lol when I could do R/P for 1/3 the price of the ballscrews on all axis
http://x0cnc.com

[ihavenofish]

I found this online store: R/P

rack and pinion cnc linear ballscrew slides plasma cutter module

you missed his point. he meant that the top companies in linear motion dont recomend rack and pinion, not that it wasnt available. only lower end machines use rack and pinion, or ones where ball screws arent feasible(20 foot travels). part of the reason xzero machine are so nice is the precision ball screws. rack and pinion would be a big backward step on these machines.