[Coogrrr]

Well I have started gathering all my parts to build my first CNC machine based loosely on David Steele's belt driven plans. I say loosely as I am using 4 axis an all steel fram solid rails with linear bearings etc etc. Pics all the way and I will beg for and give freely, help.
(group)

Here is the frame which was 4 x 1.5 channel steel a bit rusty til i cleaned it. I have it primered and holes taped in one side and then larger holes on the other to allow for adjusting the rails to square.

[Coogrrr]

I know this is out of the go cheap locally method for David's plans but I choose some linear bearing and rails to handle X and Y and Z axis these are solid 20mm bars with "c" shaped linear bearings they are sold as "cnc" bearings in fact.

http://www.vxb.com/page/bearings/CTG...rMotionSystems

I am using the blocks on each end and to support the middle areas I am useing a piece of angle cut to hieght and screwed to the steel channel. This will give a wider support then a screw/bolt and will be easier to make and mount then drill/tapping the solid round bar.

This rail set will give a better connection to hook to so I dont need to thread through "gas" pipe and I wont have to manufacture the skate bearing solution either.

:withstupi

[thkoutsidthebox]

I'll be watching this closely, can't wait to see how you add in the 4th axis. Do you have any pics of the changes from the Solsylva plans, or perhaps jsut tell us them?



Best of luck with your build.

[Coogrrr]

The end channels are there so I can do a drop plate and mount the 4th axis from end to end stepper on one end and a screw/bearing adjustment thing I havent thought up yet to squish the other end.

[Coogrrr]

So now with the primer on and the holes drilled I mounted the rails with bearings onto the frame. :banana:

I think the angle at 1/3 spacing under the rails will give more than adequate support but I will test deflection at wieght.

[Coogrrr]

I just got all my flatbar and angle aluminum. NOW to start on the Y axis mounting sizeing etc etc....

[Coogrrr]

Little frustrated with not having all the right drill bits... I am looking for a solution that will drill 7/8 and 1" holes into aluminum?? anyone..?? anyone..?? Bueller?? anyone?????

[thkoutsidthebox]

I'd suggest buying the right bits! hehe.

Looking good already.

IMHO any TiN or TiTN bits (Gold coloured coating) will give you long and dutiful service in your aluminium. Thats what Im using, and Im off to buy some more bits tomorrow. I dont have an 8mm wood bit so had to stop working om my router until tomorrow.

[Coogrrr]

I am not using "gas" pipe for my rails as I went with solid steel and linear bearing from vxb see previous post. I needed a way to secure proper hieght across the length of X and Y and hated the thought of drilling and taping round stock so I came up with this concept.

The aluminum is 1/8th or 1/4th and the part touching the rail will be slightly concave to mate to the 20mm rail. The part on the frame is bolted down but sloted for adjustment. Hieght adjustment is in the form of shims if need be but I plan to cut these to the exact hieght of the pillow blocks on the ends. The blue arrow in the last pic points to the open end of the linear bearing and how it clears the support bracket.

What ya think? will work wont work?

[Coogrrr]

oh BTW I borrowed a set of 1" and 7/8 drill bits for the 4 stupid holes I need to cut. WOOT!!!

[Oce]

Good job Coogrr! I'm going with the same thing from vxb, keep us posted about how the support for the roundbar works out!
Have you taken any notice of the amount of play in the bearings?

[Coogrrr]

well if I grab one I can say that there is at least a little .002ish play but I am using 2 on each and every axis/rail so 4 for each 2 left and 2 right.

With a angle strung between then my gantry plate comming down to that it should be very square and tight.

In fact the more square they are the less they drag so the object is to get them aligned very well.

I will let you know more when I get that done and pics will follow.

Coog

[Coogrrr]

I am not using "gas" pipe for my rails as I went with solid steel and linear bearing from vxb see previous post. I needed a way to secure proper hieght across the length of X and Y and hated the thought of drilling and taping round stock so I came up with this concept.

The aluminum is 1/8th or 1/4th and the part touching the rail will be slightly concave to mate to the 20mm rail. The part on the frame is bolted down but sloted for adjustment. Hieght adjustment is in the form of shims if need be but I plan to cut these to the exact hieght of the pillow blocks on the ends. The blue arrow in the last pic points to the open end of the linear bearing and how it clears the support bracket.

What ya think? will work wont work?

IN ADDITION!!!!!

The support will be cut and made exactly same in dimension for hieght x 3 per rail so that the ends and the middle are set to same height regardless of support (pillow) blockat the end or anything that might make it hill or valley during the length. I may stick to one with the Y, and there wont be any on the Z so its only 3 of them to get to within .0005 or so...

[Oce]

Thanks for the reply Coogrr, it's great to have someone with the same ambition and ideas at the 'zone, looking forward to seeing more of your plans and work.
I will start ordering next week, and then we can exchange plans and ideas along the way!
Have you given any thoughts about the gentry?
cdsgraphics posted this earlier, I was thinking of going with something like this, since I'm planning a long z-axis, and need maximum stiffness i the gentry...
http://www.cnczone.com/forums/showthread.php?t=30167

[Coogrrr]

I saw that one and another like it that is the cutty shark unit. I am wondering whether or not I may try that or another type of setup I will start drawing something and or think of what I am going to do as I am most certainly about to go there.

I think it would be great to share info and help each other as many do here! If I can answer anything I will!

Sorry for the time delay the cold weather of the last 2 weeks has made it very hard to go out into the shop. I am now back on track. I also had alot of time to work on the electronics so these are nearly set already. PICS inbound soon!

Coog

[Oce]

I've started doing some calculations on how much a gentry would bend, but it takes some time to do it in between studies..
Hopefully you come up with a good design Coog
My Keling steppers are on the way btw !

[Coogrrr]

I've started doing some calculations on how much a gentry would bend, but it takes some time to do it in between studies..
Hopefully you come up with a good design Coog
My Keling steppers are on the way btw !

Awesome and to add to your steppers what motor setup you doing? I have a xylotex and a SureStep setup the heavy duty SureStep is going on this unit the Xylotex is for the second unit that will be built smaller and all aluminum but VERY strong and precise as it will be for milling aluminum directly.

I would suggest the Xylotex setup unless your steppers are bigger than 2.8phase amps then I would seggest a different solution (upon request).

I would also recommend this regardless of anything you do.
http://www.cnc4pc.com/Multifunction_CNC_Board.htm

has the opto isolation has allllll the input output additional hoockups for estop etc etc..

I am working on building a remote Jog/E-Stop/Pause/Spindle etc controller for use around the machine. This little board makes that hookup simple.

just my .0002 worth

[Oce]

Thanks for the tip Coog, I'm currently looking at drivers, found some similar or better than gecko for a better price, think I will go with that...
Will make a thread when the project is coming along..

[Coogrrr]

Well I finally got em mounted and only have a few more wires to go. The parallel card is where the multifunctio board will go and I will have to redo some of the wires but at least I can get this going.

Tomorrow the Gantry should be done and mounted with only the Z axis and steppers left!

Heres some pics again.

Coog

[thkoutsidthebox]

Coog, that is one nice controller setup you have there. Well done.