Yes Sharma, the one seen in picture is about 300 Oz-in but I am not going to use it on X/Y axis (may be Z only). Below is the one I am going to use for X/Y.
Attachment 6954

Anyhow, I have these so i am just going to use them and later replace them for better performance if needed.

Nothing interesting to report this time as I am in the process between BBB (Beg/Borrow/Buy) for the welder. So to kill time, browsed through plans again and found missing parts that I could do and then assembled & tested motor drive.
Attachment 6959

One drive tested ..
Attachment 6957

Worked without smoke so started assembling more of them ..
Attachment 6958
Five more in the making, total 6 as I make smoke sometime :)

Anil,
You are making your own drives. Nice. Did you do the board layout yourself?

What's the total cost of one driver ?
As far as welding is concerned ? I got cheap welder at INR 1800 and learned welding, and my MM is still holding :)

Next is squaring the plate sides !! Can anyone suggest how to do that as i don't have any clue on how to clamp the plate on sides ?

I have a suggestion, drill and attach your tube to the back of the plate
and then put the tube in the vise and machine the sides....I think that would make it easy to do and keep things square since you could machine both sides with out taking it out of the vise....
thanks for the shout out about the belt drives...
//chopper

Are those LM18200 H-bridges on that driver? Of the 55V 3A limit variety?

Ah cool, all this time i was only thinking how to get the plate held vertically, never thought it could be milled sideways in horizontally as well (though I did that few times it didn't clicked this time), so dumb of me :p

Those are LMD18245, yes same 55V 3A .

Heath, I did the layout myself (in Eagle) as I wanted single sided boards.

Z-plate squared and drilled
 

Initially thought I'll be working only weekends on MM but I find myself working a bit almost daily after getting back from work :) must be addiction sort of .. Finally squared all edges of z plate today
Attachment 6970
DRO to rescue for drilling ..
Attachment 6971
Drilling complete, 2 dowel holes are drilled 5.5 mm and reamed to 6mm
Attachment 6972

Gerald, my plate thickness is little more than 8mm, is it better/worse than standard 6mm ? If needed i can skim/grind the face opposite to countersunk to get it to correct thickness. Thanks

the thickness of the plate wont matter as long as the angles on the side are ground or machined to the correct angle so the V wheels fit that is all that matters.
//chopper

Thanks Chopper, for that matter it applies to all rails not just z-plate. As we are on this I have another doubt about grinding using skates, if the grinding plates are not bent to correct angle the final output is going to suffer ? I am not yet on that stage but I don't find any discussion on setting the angle correctly !! or it does not matter somehow ?

there are several ways to do it, you can use a scrap piece and check the angle,
or you can grind the rails and check the angle as you go ( you will be making many passes to get to the end so you will have time to make adjustments as you go ) and adjust the angle to match your wheels, either way will work, also if the angle is not exactly the same as the wheels it wont be a big deal as long as they are consistently the same over the length of the rails, but the closer to the correct angle the better...when grinding what I did was set the grinder up and take a pass of each side of the rail to form the V and then adjust the height and repeat, you will see the V start to form
and when it gets large enough you can set one of your wheels on the rail to check the angle, then you keep grinding until you have about .020 thousands of an inch flat left on the top of the rails you will need to check the specs on that number to be sure I am going by memory and I could be wrong on the .020
//chopper

Thanks, so the way is to adjust as you go and visually. I thought there was a was to do it instrumentally that I might have been missing :)

Chopper what do you mean by ".020 thousands of an inch" !! that seems to be nothing (.02 / 1000 = 0.00002 inch), maybe a typo, I'll check it while I am at that step. Thanks again

you will need to check that measurement in the plans I thought it was .020 ( this is the flat on the top of the rail not the angles you will be grinding you do not grind the rails to a complete point)
but it could be .040 or so....
also if you are using the skate that comes with the laser cut kit which is the same one I used there are adjusting screws on the skate to adjust the angle.
I measured mine visually, but if you have an instrument to measure the angles with I would use that. it has been a while since I built my machine and I cannot remember the angle I think it was 90 degrees if that is the case you can measure it with a square, or you could make up a measuring device of your own but it still ends up being a visual thing, and that is why I used the V wheels
//chopper

Thanks chopper, yes it make sense to use roller for checking.
Made last part for belt drive, the shaft and tested for fit (don't have welder yet so just clamped together everything), everything seems to fit nicely.
Attachment 6996
Note : the motor in pic is just for tests and not going to use for MM :)

looking good.....
I tried to make the design simple so it is easy to build,
looks like you have it mastered, I am interested in feed back when you are done on the belt drives to see how you like their performance.
//chopper

I haven't them welded yet !! I feel these are going to work fine chopper. I am sure going to report the outcome.

Something to keep me busy weekend- Steel
 

Ordered the steel for table today and going to get it tomorrow so as to keep me busy this weekend.
All steel is uncut, full lengths of 20 feet except main beams (3"x8") because those were only available in 40 feet a length.

My plan is to cut it using chopsaw or cutoff wheels with grinder. Lets see if that's achievable or I have to get someone with flame cutter later.

With this the real fun begins and the part I am most afraid of ..

Tried to assemble the grinding jig but the wheel does not fit, its too big ! My grinder is 5", is the jig designed for only 4" grinder ? Am i not doing it correctly or do I rush for a 4" grinder :confused:
Attachment 7013
Attachment 7012

I knew it, this part is not fun !! :p

After looking at related threads, realized my mistake. The jig will only take 4.5" grinder !! Tomorrow go and search for 4.5" grinder.

Anil - kindly PM me the details of your timing pulley ( spec and cost)

RGDS
Irfan

Irfan, PM sent

Welding Y-Car problem
 

Gerald please help, while welding Y-Car, I end up with gap on both sides where bent part of 10 30 422 meets 10 30 455, pictures below. I think the 51 deg angle is not bent fully, please guide me what to do with the gap !!
Attachment 7086
Attachment 7085

Meanwhile I keep cutting and preparing steel for the table...
Attachment 7087

Just push the thin plate closed with 2 fingers and weld it . . . .while the thick plate stays vertical.

Thanks Gerald, but I am not able to move it by hand, its hard (mine was cut from 3mm thick as the laser company didn't had 2mm plate in stock). Foolish I am, tried to fix by blow of hammer and the gap widened :o .

Then you need to apply force with a clamp. Once you make the first small weld, check it all for square again. You can put a spacer block (or even the spider) in the center and then put clamps right across both sides and pull them in together.

OK, great, I'll get clamps of that size and try, Thanks a lot

Another problem I created is missing table offset w.r.t beams while welding main beams to cross members, Luckily not yet welded table legs so going to grind open the welds for re-welding. Any other option do I have other than opening and re-welding ??

Its not that I was not aware of offset but I was so focused on aligning/leveling/centering everything that I even centered the table and beam :)

Table Welding completed today :) No photos for this as I work in small room and not able to capture the whole table with my camera.
Attachment 7193

Welding was not that hard, I guess the rail cutting & grinding is the harder one :p

Hi Anil,

good work till now. I think everybody leaves the rails till the very end. Me too.
Good luck with your build

Claus

Thanks Claus, I don't have space so now as the table is done, somehow I have to cut and grind the rails on it, in fact everything now on is going to be done on MM table as It already filled up all the space.

Started with next major part, the Rails (with of course skate method). For me the only option is to do it inside and the only working space I have is MM table. Here is my setup for cutting..
Attachment 7264
The only thing I had and can trust for flatness was this Granite tabletop :), got the permission to use it with a promise that the first thing MM is going to do will be a tabletop.
Attachment 7265

Only a small portion cut and its all mess inside already ..
Attachment 7266

Check for fire risk . . . . that table on the right looks like it has some rags, paper & chemicals on top or underneath? It will also be easier to clean up if you clear all the stuff off the table first.

Thanks Gerald, I am clearing all that stuff now before going any further. Anyone reading this please take all the care and do it outside in open ( I had to do it this way as I don't have other option)

Cutting of rails done :)
 

Cutting of angles to 28mm completed, next going to level and smooth the top of the rails flat a bit with grinder and then grind V :)

Used 10 discs because could not utilize the whole discs as the angles were 65mmx65mm. One tip to add here (may be its already said) is to level and get the disc parallel to cutting surface, otherwise disc is caught in groove and may break and wear fast.
Attachment 7272

I was lucky enough to just cut all of them with what i had (10 discs) as you can see i had to break last a little part of rail as the last disc was not enough to cut through :)
Attachment 7273

In t1st pic, look how small my lathe looks in comparison to MM table

So you consumed all discs we purchased :)
Just to add I got another bigger pulley from M. bazar.
You also need to check angle for v cutting.
(Note - I was with Anil on 23.11.09 together we explored market)

We purchased only 5 that day, I needed another 5 and got them later :), Yes I had a thought about the angle before and asked the question in this thread, will keep in mind to get the angle match rollers to best i can, thanks for reminding.

Wondering today how fast time passes while working on MM, its been a month since started MM build :)
Well, little more progress as the rails grinding completed, no pics for this :( but yes a nice pic of grinding a little V on hand as a reminder to be more cautious and respectful with steel & machines.
Attachment 7376

Moving on to gantry, drilling the pilot in flat bar, y-rail and gantry tube all in one go by clamping together.
Attachment 7374

And finally a welded gantry:D, small twist but seems fine.
Attachment 7375

No, room is always not as dirty as its is now :eek: this is a pic from last month when I started the build.
Attachment 7378

And Yes I do have a lot of help available :)
Attachment 7377

Hello Anil,

sorry about that V-Cut in your hand. As a doctor I usually have always a medi kit around, but I think it will be cured by the time I arrive!:)

Greetings
Claus

See, tapping threads is child's work . . . :)