Cutting quiexxxxx nevermind #104 - Kansas USA
 

Looking forward to building my MechMate! I'm a avid woodworker and a passable welder with a son who welds like a madman. Looks like sonny has some welding to do.

Welcome to the group !! Looking forward to your build.

Welcome to the group Jim!

Browse the forum, read the PDF's, browse the forum, read the PDF's ask question... read.... you will have some fun there with your son.

Ries

hi welcome to the forum.

Thanks to everyone for the encouragement.

Sighting the line - Kansas USA
 

I started on my control box. I also received my laser cut parts and have machined some parts on my Logan 10" lathe. I purchased a gear blank and intend to try my luck at cutting gears out of it. :) I have attached a few pics...

Good luck Jim, I just finished mine, had a great time building it. There is a wealth of infomation and very knowledgable people on here that will help in a minutes notice, it is what made my build so enjoyable.

Jim, is that a South Bend lathe? :)

No, it is a Logan 10" toolroom lathe. It's on the small side but I still find plenty of uses for it.

That is a sweet lathe. Did you restore it? Or was it that cherry when you bought it?

I am currently looking for a nice lathe, but I want a larger one. I have a 10x22 Grizzly that has worked great for what I paid for it.

I just want to work heavier material and these Logan and South Bend machines are a good buy if you learn what to look for when you buy one.

Yes, I did a total teardown and restore when I first got it. Nobody told me about the fact that quality tooling costs many times the cost of the lathe. I might not have one if I knew ahead of time. :)

Jim we have a 10x54 Clausing Lathe at work and I bet it has never chucked up anything over 10 inches. If you did the restore you it turned out great. I am almost finished rebuilding a old Bridgeport Round Ram. I am just waiting on the motor to get rewound.

What is your plan on chucking up the gear stock?

Haven't thought about it much. I have a 6" 6 jaw that might work if I use some shim stock. Or maybe just center it up in my 4 jaw. Do you have any ideas?

Jim,
welcome and good luck
bit of advice for ya, 4 jaw will work to dial that blank in, take some old copper wire and strip it back about the length of ea. jaw and slide that baby down the teeth and chuck away. 3 or 6 jaw wont hold it concentric because of the 20 teeth on blank.
another way is to bore out a heavy walled pipe, slit lengthwise then chuck back up on it
carefully bore to the dia. of blank, when you release it should let you slide the blank in to the sleeve and you should run centered( mark the jaw of the chuck and the sleeve with marker so you can return to the same place in the chuck) kinda wordy for me

Jim
Thanks for the ideas. I am going to try the wire method and see how close I can get to concentric. I used the slit/collar method to cutoff the excentric bushings so I may end up doing it that way if the wire method does not work good enough. :)

Jim
Are you building a MM?

Anyone have a US source for the c channel washers shown in this thread on the second page most of the way down?

http://mechmate.com/forums/showthread.php?t=1385&page=2

McMaster-Carr has the washers

http://www.mcmaster.com/#washers/=664vff

Jim - Most folks make these. You can drill holes in the wing of a c-channel drop then use your grinder to cut them out. Turn them around and you have a washer that matches your channel.

http://www.mechmate.com/forums/showt...7&postcount=32

Jim- I have not started mine yet, I'm still in the procrastination stage.(design stage)
I've logged about 200 hrs of thread reading and decided I'm not to smart!!!! There are some folks on here that are. Speaking of design, I'm considering the use of ball screws, possibly one on each side for x-axis, driven by one motor located in the center, with timing belts to each side, driven by a 3 or 4 to 1 reduction, can I have feedback on why that won't work, also I really liked the builds done with I-Beams, seams a little stouter to me.

Russel, is that old mill called a "M" head, I think I owned one once upon a time but it seams to me the collets were hard to come by?(not R-8)

Jim it is a M-head with a MT2 tooling. Not hard to come by but not as easy as R8 or new collet systems.

Jim
The first thing that comes to mind is cost. Ball screws aren't cheap. I also think you will have pretty long timing belts which will have to be pretty tight due to their lenght. You will also lose the flexability that two motor drives gives you. Timing two ballscrews vs simple adjustments in Mach3. I'm thinking the mechmate design is solid as is, that is why I am sticking pretty close to plan when it comes to drive arrangements.

russell, seams to me mine(which i dont think i ran) had a 3 pc split collet thing that went together inside of the locking nut, but it's been alot of yrs. good luck with that build i am sure you will enjoy it.

Jim, I'll be honest, I don't know the mach control at all, but if that were the issue a guy could put a motor on both ends. the prices i've seen on some of these links tells me that ball screws aren't as pricey as they used to be and i don't think they need to be huge (.75 or .875) but I agree, can you syncronize the ball screws? The length of the timing belts would only be about 26 inches

Cheap ballscrews have cheap seals and they jam up after being exposed to lots of dust.

In addition to Geralds comment above. Would You Might Need a SPINNING - NUT due to the length of the screw in the X axis (even Y if you ask me). Due to there is a high risk of that the ballscrew begins to wobble. That - and reconstruct the design (or buy a spinning nut) takes both more time and costs significantly more $ $ $. Thats my opinion (and experience) in order to obtain the same reliability in design as MM has.

For what it's worth do other DIY hardware / designers pursue to use the R & P.
In there later creations, so it seams as its cost effective..And if anything happens, it is very easy to repair to a low cost. For me was MM's use of the R & P a strong advantage.

Hope it helped you..!

/oopz

New Guy from Kansas
 

Managed to get a little shop time in this weekend and was able to get the pinion gears cut down. Need to drill and tap for the set screws next. I plan to use two set screws 90 degrees apart. Anyone else used this approach?

Jim
BTW, the wire method worked great. I was able to indicate the gear blank down to 2 tenths before boring for the shaft. Thanks!

Hi Jim,

One question, where did you get the gear blank?

Dennis

McMaster-Carr, search for gear rod.

looks good Jim,
if you indicated them to .0002 you didn't need me,
but if you do alot of 4 jaw work take some of that dykem i saw in the picture and paint the chuck key holes on jaws 1 and 2.... makes changing parts out much easier
i agree with your set screw plan, are there flats on shaft? if not when you set in place take the root dia. drill into that hole and drill about .05 dp that will set that setscrew so she won't let that gear spin on the shaft... and if your gear has enough meat on it put a second screw on top as a lock screw.

Those gear rods come in 12" lengths, so there is plenty of material to make your gears longer and provide space for a second row of set screws:

Happy Easter everyone! I hope to work on my controller this weekend but I have also begun to lookfor steel and hav a question. The plans call for 7" c-channel but I can only source 8" locally. It seems to me that I should be able to use 8" provided I get a similiar per foot weight and width. It would also yield additional Z axis travel with no interference. Any cons that I have not considered? Anyone else done this?

8" channel is fine. You can thicken your table top by 1" if you think the z-axis is getting too flexible, but the the standard z-axis should still reach the table.

Gerald, thanks for the reply. I was pretty sure but it helps to get other input. Also, thanks for the great design and website, I would not have done this if not for knowing this great resource was available.

Controller Works!
 

Hello from Kansas! Hope everyone had a happy Easter. I have been working on my controller for the past month and it is mostly complete. By mostly complete I mean that I have one axis moving under computer control. Since I am having to purchase things as the cash is available I focused on getting the x axis running. Then it is a simple matter to purchase additional Gecko G203 drives as finances permit. I went with a slightly different component arrangement as I wanted to build a controller that can grow to 6 axis control in the future. I purchased six heatsinks on ebay but only used two of them for this controller. By cutting them in half and mounting them vertically I am able to accomodate six gecko drives. I cut a section of fins off and mounted the bridge rectifier to it along with the dc power bus. I also incorporated a 12 VDC power source that powers the BOB and also powers the E-Stop circuitry. I did not like the idea of putting 110VAC out on the table if not necessary. Next, I'll focus on welding the car assy. I posted some pictures of the control box.

While I have not posted for a while I have managed to get some work done. My y-car is welded and primed, I have purchased all of the required fasteners, started on the rails, purchased the V-rollers, and purchased some steel for the table.
My work on the rails so far consists of cutting the height down to 1.1 inches using my mill/drill. Since the mill/drill could not cut the entire lenght of the rail down to height I had to cut the rail in several sections resulting in slight steps where the movement was made. After the entire lenght was cut to height I used a file to remove the "steps". Next, I will cut the 45 degree angles using the grinding skate.
I decided to use I-beams instead of C-channel because I found the I-beam at a good price and, as it turns out, better accuracy. My next step of table related construction will be to assemble the gantry.
I did not get many photos but I have attached a photo of the I-Beams as they wait for more work. Enjoy!!

Hello All!
After getting my grinding skate setup to grind a true 45, I finished grinding the 45 degree angles on my Y rails. I started with the Y rails (shorter of the two) in case I fouled one up I would have less work to redo. I clamped the Y rails to my I beams for stability and proceeded to grind. The grinding was not that bad just repetitive. Tonight I took a v-wheel and, with some pressure on it, rolled it along the lenght of one of the Y rails and noticed that it felt slightly rough and noisy so I spent the next hour and a half sanding the 45 degree surfaces on both Y rails. I used a cheap machinist v block which has a machined 90 degree valley built into it, and adheisive backed sandpaper to sand the 45 degree surfaces smooth. I cut strips of each grit of sandpaper and stuck it to the walls of the 90 degree valley on the v block. Then I let the v block ride inverted on the rail and used a sanding motion to sand along the lenght of each rail being careful to keep the v block in true contact with the rail surfaces. After each pass the sandpaper was loaded with sanding debris so I removed the sandpaper from the v block, cut the loaded portion off, and re-applied the sandpaper to the v block. I started with 80 grit and worked progressively through finer grits until I got to a 600 grit. When sanding with the 600 grit I used wet/dry sandpaper and a small amount of oil. This gave me a very smooth finish and the v roller now rolls without any roughness. It also reduced the noise made by the v roller by 80 or 90 %. Now, on to the x rails...

PS: over the weekend I went to a surplus yard in Wichita and, among other things, I scored a great deal on a set of all metal, heavy duty feet for my mechmate. :)

Have not posted for a while but I have been working on my mechmate. I was able to source most of the metal (70%) for the table for little or no cost by checking salvage and being patient. In some cases I had to use short cutoffs but my son was able to weld these short pieces into long sections. I am building a "bolt together" version consisting of welded sides and bolt on cross members. I used 4" square thick wall tubing for the legs and 2" square tubing for the smaller cross braces and diagonals. My design incorporates a open front that will allow me to store material underneath the table. At this point the the table is built and assembled. I completed the drilling of the X and Y rail assemblies and drilling and tapping the I-beams. This allowed me to mount the X rails so I could start the gantry construction. I hope to complete the gantry over this weekend.