Hi Gully - Looking good but why isn't the gantry a box? You'll need the stiffness? Peter
It's been a long time comming but I'm back building a new machine.
I find my Little Joes CNC is just a bit too small for me now and I would also like a more rigid machine
so I can push it harder
I will use my Joes to cut the required parts for the new machine where needed and then depending on budget either
strip it for parts for the new machine or put it up for sale.
So if anyone is interested in purchasing it when the new one is finished let me know.
New machine specs:
900 x 900 x 165mm cut zone
Steel tube frames for gantry and base
1605 ballscrews with linear rails
1.5Kw ER20 spindle and VFD (currently in use on my Joes)
Starting with the gantry build
Frame is 65x35x3mm RHS, The gantry end risers at this stage will be 18mm marine ply with stock aluminium C channel extrusion spacers to make them into box sections
Have designed it all in Rhino 3D so I don't expect too many dramas fitting it together
also have all the parts on hand which is a change for me
This wont be a quick build due to time and budget constraints, but at least I've started
Gully
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Striving for medeocrity..and achieving high scores!
Hi Gully - Looking good but why isn't the gantry a box? You'll need the stiffness? Peter
Hi Peter,
Thanks for dropping by.
I agree a box section would be better, and I started out that way but as things progressed I found a C section just worked better in the design
I have used this same welded tube C section method of construction on other jobs and found them to be very very stiff in shorter lengths of up to 1400mm such as this gantry. it also allows me to run the ball screw on the front and keep the Z axis within 5mm of the gantry face
For a machine that will generally only ever cut timber and plastic. I'm going to take the Pepsi challenge on this as it keeps the design compact. (you can always say I told you so later on if I don't like how it performs under load
Gully
Striving for medeocrity..and achieving high scores!
Hi Gully - for timber/plastic it will be fine. And it makes space for the drive. Looking good. Are you going to machine the top/bottom surfaces parallel for the rails or just do the best you can with the welding and assembly? Peter
6 cars on the Z axis?
Thanks Peter,
I should have also added in my last post that I have 6x8m surplus to requirement lengths of 65 x 35 RHS gathering dust in my steel stock and I want to use it up.
No there will only be 4 cars on the Z . Not sure why it has 6 in the image. I must have forgot to untick an old layer in Rhino
Would be nice to skim the top and bottom surface but don't have the equipment to do it myself or the budget to have someone else do it.
Plan A is put it together and shim as required then see how well it all runs
Plan B will be a thin epoxy leveling layer to both surfaces
Gully
Striving for medeocrity..and achieving high scores!
Let the games begin!
Crappy weather day here in Melbourne, add that to being in lock down means I get a bit of time in my workshop
Today's plan was to cut some MDF parts on my Joe's to build the welding fixture for the gantry, cut down the steel notch out the ends and run it through my sander to level out the faces a bit better
Then mark out and attach the ball screw mounts along the center line.
Not a big list but it has taken all day to get to this point
Will try to cobble up the welding fixture after work this week if its not to cold in the workshop
Gully
Striving for medeocrity..and achieving high scores!
Hi Gully - Where do the handrails go? Doesn't Melb mean cold and ourne mean wet? I'm in the northern NSW warm and wet today Peter
Hi Peter,
Yes your name translation is correct although the 'ourne' can also translate to miserable instead of wet.
You had me going with the hand rails? then I looked at the background shelf in the pic.
Saving them for me old age I am.
Gully
Striving for medeocrity..and achieving high scores!
Hi Gully - I was down Melbourne a few years ago for a weekend and living on the Gold Coast at the time I didn't have "warm" stuff. So I went into a men's store and bought a big fleece lined knee length jacket to go watch the footy in. Was great while in Melbourne but have not been able to wear since. Every time I put it on I break out in a sweat about 120 secs in!
Unfortunately age catches up a bit quick. I have had to put up hand rails for when my wifes mother visits. Sees 95 and slowing down... Get stuff done while you can....Peter
Hey nice work there looking great ,for my X rails I used 50x25 x3 tube with a 6m x 50 flat welded to it then had them wash ground together as a pair then stuck the lin rails on that stopped the flex for sure .
Hi InMesh,
I have done the same type thing in the past on jobs for others and it works really well.
My own build unfortunately doesn't come with a budget (any budget for that matter) that will allow for that level of precision construction.
But hey, I'm stepping up from MDF, pipe rails and skate bearings (which I should add has provided me with a very reliable and accurate machine for what I use it for)
If I can achieve the same level of accuracy or better in a bigger and much more rigid machine then I will have met all the criteria that I'm aiming for.
For those who are interested my old Joe's build log is here https://www.cnczone.com/forums/austr...0-cnc-cad.html
Gully
Striving for medeocrity..and achieving high scores!
Hi Gully - Looked through your first build very NICE! I'm sure this build will be light years ahead of that one. I've just started on my bench for my next machine. see for design and now build thread https://www.cnczone.com/forums/diy-c...gineering.html Peter
Thanks Peter,
The Joe's R2 CNC really is an excellent design based on the materials used to build it. I've been very happy with my version
Had an ADO today. Its not like I can go anywhere, so out to the workshop and pushed along with the gantry build.
Clamped the pieces up tight and as square as you can ever get tube into the welding fixture to lock the parts together and gently welded it to avoid warps
Sorry only took post welding pics
I'm happy with how straight it turned out, might just get away with shims rather than epoxy
Rather than drill and tap for the linear rail, I'm considering using flush nutserts to give me some extra thread depth
Gully
Striving for medeocrity..and achieving high scores!
I used to use plusnuts every day at work. Also some limited use of rivnuts.
I've never used flush ones. Are those just countersunk a bit to make them flush?
Alternatively, you could stitch weld some flatbar about the width of your rail on there. But you said you were happy with how flat things are now, and you probably wouldn't be after doing that. And you would be changing your design.
The PITA about nutserts is if for some reason you misthread the screw a bit when starting them, they can spin. And once they start to spin, you can not get that screw back out without some serious messing around.
I wonder if this technique would work for you:
If you search for "thermal friction drill" on EBay the bits are available. Obviously not something you will do with a hand drill, but if you have a mill available, or even perhaps a drill press, who knows...
EDIT:
I forgot to mention, they also have ones that give a flush top, without the lip (even though you could just grind off the lip).
Hi Gully - order some fine thread bolts vs using the nutserts? The rail has to be absolutely tight to the foundation. Nutserts seems to be a step away from being really really connected to the section? I suppose you could solder them once placed? Peter
Rod Webster
www.vmn.com.au
In the video below, he's using a Bridgeport mill
Another option is to drill and tap a long piece of flat bar, at the correct spacings, make the holes through the tube through holes, and put the flat bar inside the tube to act as a single nut for all your screws. Might take a bit of effort to get it aligned initially, but I can't see how it wouldn't work.
The flow drill might be more fun though.
EDIT: It won't work if you have any inside tube seams under where the rails mount. I had a better look at your design....
Last edited by NIC 77; 07-17-2020 at 04:57 AM.
Hi - The long strip with threaded holes works really well. Have done this on a patient lifter under the car rails. Adds stiffness and is easy to do. Yes the tube fin can be an issue. Peter
Flow drilling!
Oh my giddy aunt on my budget I would need to sell a kidney.
Never been a fan of tapping light wall tube, I have used nutserts / rivnuts whatever you like to call them locally to hold down linear rails on tube in the past and they have been rock solid as long as you drill the correct size hole for them, nor have I managed to ever strip one out. (stripped out plenty of holes tapped in light wall tube though DOH!)
I always drill for a light friction push/tap into the hole set up (helps if your drill bits go up in .1mm increments) if you only drill to the nearest .5mm you can encounter issues such as turning under load if they aren't pulled up correctly.
Gully
Striving for medeocrity..and achieving high scores!