Thanks Erick,
If it'll hold thoes big servos of yours, it will sure hold these 116 ouncers.
I'll go with a bearing on the non motor end only, with a 1/4" gap between the shafts for flex. Think I'll leave a little gap on the outside of the bearing for lead screw expansion, because the rubber hose will keep it from moving along the shaft axis.
I like thoes clamps, both small and strong. I'll try to find a source in Austin.
Hager
Erick
When it's time to make chips, I would like to cut the gear that you show in (Post #154 ) http://www.cnczone.com/showthread.ph...5&pagenumber=7
That would be a neat thing to show off. We all need bragging rights.
If you can send the cad file and the GCode also, and what else I would need to run it, so I can start getting an idea of that portion of the system. I have Turbo Cad 7.0 and just downloaded CNCTurbo.
Hager
My email address is hh1957cv@sbcglobal.net
That's a really inspiring design. I've been waiting for my HobbyCNC plans & parts to arrive. Like just about everyone else who buys plans, I've already been thinking about the changes I'll make.
My plan is the same as yours. This is #1 of 2. I had though about #1 being a real budget model. But if I did that, #2 would only be as good as the accuracy of model #1. Catch 22
I have some bearings already. For rails, instead of gas line like yours, I'm going to get some 4 foot lengths of cold rolled steel and drill and tape them for a center support.
David J. Morrow
David,
Having plans will be a definite time saver, you can only glean so much from looking at machines. I really thing I'm exceeding the length limit of the gas pipes, but I'm gonna gamble. Have already placed center supports under them and will add bracing on the outer sides to keep them from spreading.
If 66" is too long it will be a simple matter if unbolting the end plates and moving them in and reducing the table size.
Good luck with yours when it arrives.
Hager
Machine Update
Here’s a few things that were completed this week.
Turned the Acme screws down for the bearings and threaded the ends.
Made bearing retainers, and today made a router bracket, out of some good sized pieces of aluminum I picked up at the recycle yard, it’s pretty crude so don’t look too close. They already had lots of machining on them and holes, but enough left to make a pretty good mount, see 2nd photo of back side of bracket and all the cutouts.
Had a laugh today on me today, went to Sears and bought a new metal cutting blade for my band saw, brought it home and went to put it on the say and realized that they had welded the blade backwards, the teeth were going in the wrong direction. Took it back to Sears and showed it to the salesman, he looked at me and grinned took the blade and twisted and turned the inside to the outside, and the teeth were the proper orientation. Told you I was a newbie, Guess the other times I changed blades I just got lucky.
Last edited by Mr.Chips; 01-25-2004 at 12:21 AM.
Here's the other side of the router mount. Lots of cutouts and a couple of holes but still enough left to make a functional mount.
I tried making this very thing out of 3/4" MDF, like the rest of the machine.
Cut the large "cross-grain" cutout.
Bandsawed it into two parts, to get it under the drill press more easily.
Then drilled the 1/4" "with-the-grain" holes for the tightening bolts.
Just before the drillhead pops out the other side, each piece of MDF split, just as pretty as could be.
But you saw that coming didn't you? :^) I ordered a chunk of some kind of plastic to try next.
Your machine looks great, thank you.
--
Dan
Nice job on the mount. Even looking closely it looks like a great job.
Eric
I wish it wouldn't crash.
Dan,
MDF is some pretty unique, special, trashey, grate material all in the same package, depending on the application.
The top and bottom layers are tougher than the inner plys. I say plys because all the inner fibers are parallel to the surface. Take a chisel and attack it between the plies and it will split pretty easily and straight just as you experienced.
When drilling parallel to the surface there is quite a bit of force trying to split the stuff. All the woodworking tips say to place a clamp at that point to hold it all together. This method may have worked for you. Oh and back the bit out frequently to keep the dust from building up between the hole and bit, this further agrivates the splitting issue.
After the hole is drilled and in use it might not split because you will be tightening on the end grain so to speak. To bullet proof it you could put some bolts on either side of the bolt, holding that MDF sandwich together.
Good luck and keep at it.
Hager
Curious
I don't want to hijack this thread but I have a question which I think will be a good addition to this. I have been working on machine tools on and off since I was 17 or so. I am real impressed by the home grown desing and build units I see on this site.
The MDF designs are perplexing to me. What can or do you do with a machine made of wood? To me it would seem too flimsy. I have had MDF furniture which I hate and the stuff is real brittle in bending or forces on edges which are not normal.
I cannot imagine that such a machine could be accurate to less than +/- .010" and that tolerance would grow with age.
I don't want to discourage anyone I think the learning is probably very valueable and I applaud the amount of work. Please enlighten somone who has a hard time understanding the finer points of a mahcine which isn't controlled by Fanuc.
Thanks
If you are used to metal cutting mahines that cost in the $30,000 and up range I can see your point. The point here with these machines is to cut model airplanes and such. Also like you said to learn something. A guy in his garage can't make an acurate machine from Steel or Aluminum because he doesn't have the tools. Like most folks who have hobbies we improvise with what we have or can afford.
The choice is to have a working MDF machine, or find another hobby.
Small, well designed MDF machines are stiffer and more accurate then you imagine. And, we are cutting wood after all.
Eric
I wish it wouldn't crash.
I had the same concerns when first seen these machines, but a lot of guys have built them already using this material, so I thought why not, it will be cheap, I will learn something and it will at least cut/router mdf, ply, balsa, and at the very worst I will still be able to modify it to cut decals.
I have the capabilitys and equipment to make a machine in alluminium and that will come later, but what attracted me and others to these projects was the simple construction in mdf.
If Mdf is properly supported and the wood itself sealed, I have no doubt it will do it's job for a long time.
Ever tried lifting a 1" sheet of 8'x4' MDF ? It is a two man job and has nothing to do with the size.
Lifting 1"?
I get help at Home Depot loading the 3/4" 4X8 sheets onto the flat bed cart, HEAVY and unwieldy. Then too i'm 64 which doesn't help that much. Have it rough cut there, so I can handle it when I get it home.
Hager
Lifting 4x8 sheets? Not a chance. I have em cut it down right away, and I load up the small pieces. Usually 2x4 or 2x6.
Mike...
Originally posted by Mr.Chips
Lifting 1"?
I get help at Home Depot loading the 3/4" 4X8 sheets onto the flat bed cart, HEAVY and unwieldy. Then too i'm 64 which doesn't help that much. Have it rough cut there, so I can handle it when I get it home.
Hager
Ever tried lifting a 2inch sheet? Four men is not excessive.
How was that aluminum router mount made? Do you have a milling machine?
wishin' I had some serious machining capability for my project.
Owen
I cut the router mount out on my Sears Craftsman band saw, using a metal cutting blade. It is normally a wood working tool but it cut the alum just like wood.
I also trimmed many of the 1/2" pieces of plate alum on the table saw using a carbide blade. Lots of people on this forum said that they had done it and it works. Be sure and wear a full face shield when cutting alum on a table saw.
Hager
routalot
Did'nt know you could get 2" I can get 32mm (1 1/4") OK
My loca supplier does 30mm,40mm and 50mm. It depends on how keen you are to earn a place on the chiropractors Christmas card list......
Y Axis design
Below is a design I am seeking opinions on, I’m a newbie and don’t want to go too far off the deep end if it’s bogus.
I am trying to shorten the area taken up by the Y and Z axis which would yield a larger X axis work area for a given table size. Usually the Z axis is either mounted in front of or behind the Y axis. The router bit would be located directly below the center of the Y axis. Not sure if there would be any mechanical advantage in having the router/Y axis alignment.
One concern I have with the router mounted this way would be that the router mount must be longer than it typically would. Router mount shown in Brown and is 3” thick, 4.5” wide and 8” long.
The Red piece between the router mount and the Z mount is 1.5” thick, 4.5” wide and 16.5” long.
The drawing is shown in side view, the four squares are 80-20 extrusions, they make up the Y axis of a moving gantry design. I wanted to use four to spread the support out over the Z axis mount.
The Y axis rails are 1” in diameter, and the Z rails are 0.75”
Candid comments will be appreciated.
Hager
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