Thanks. Feels great to be here.
I guess I'm committed now.

Ordered my racks and pinions from TEA Transmissions in Queensland today.

In total I ordered 4 x 2 metre Module 1 rack and 4 x 20 tooth pinions with custom bore (14mm) to suite the Motion King steppers I have. I'm going with direct drive for starters and will add belt drives later if needed.

All this, delivered to Melbourne cost ~$670. A local supplier up the road from me wanted over $1600 to do the same thing (without delivery) !!! I guess it made the choice simple.

Started cutting the rails down to size.

It took me hours!. Still haven't finished. Have to wait till next weekend. Hours of noisy tools and good neighbour relations seldom go hand in hand.

Did the Y rails first. They are a little uneven. Any tips for bringing them in line would be appreciated.

I found that if a used washers to keep the section i had cut through, open then I avoided the nasty binding and kick-back caused every time the blade pierces the through the steel.

In the end I was left with a nice 20mm wide strip of offcut steel. This could probably be used as the clamping strip in 10 20 235. To bad I actually bought a separate strip for this. Oh well.

Finished that job a while ago, hated every minute of it. I intentionally cut mine a little tall so I could sand them down to close to 28mm. I used 1/2 the skate and set it for slightly taller than 28mm with a 2mm 115mm cutting disc plus a 24 grit sanding disc on board. Took friggen ages to get them sanded but the finish is nice and smooth plus they are alot more consistent in height than I could ever get by cutting only. As long as your lowest height is above 28mm you should be fine to use a similar sanding method to get them close to even.

Cheers
Bruce

You are in the good track. To do it more precise, in my opinion, you should use a piece of MDF between the rack and the base, like in my photo: http://www.mechmate.com/forums/attac...1&d=1355120867

To correct the rails use a sanding disk (80 grit) on top of a grinding disk, it must be stiff and sand the rails down to 28cm.

your grinding machine should be more in the middle of the wooden base to have more stability. and when cutting do light passes from start of the rail to the end and repeat till finish... it took me about an hour per rail, without forcing.

Paulo, I think both points (move grinder further back on the mounting block and use gentle passes) are both valid. Initially (see first photo above) I was doing it gently and it was very straight. On the second peice I got impatient and I think a combination of disk flex and possible tilt of the grinder (because it is not further bach on the mounting shoe) caused my problem.

The angle on the right is my first cut. The other is my second.

As for placing mdf under the angle, I don't think it's necessary. I marked my angle iron at intervals along its length and using just the xbeam as a reference it was right on.

Yes, you are right. The first rail is much better. A tip from my mistakes, only advance to next step, grinding the 45 degrees, only after you are sure the cut surface is uniform... :)

Time to make sparks
 

I have spent many evenings reading over the electrical threads as I need to start pulling the control box together. While I now have a better idea of how things go together than when I started I am still a little confused so I am hoping somebody can check over my calculations and let me know if I have understood.

I have
- 5x Motion King 34HS9801 motors - The extra one is for an indexer some day.
- 5x Gecko 203V Drivers
- PMDX-125 BOB
- 2.2kW Chinese Spindle

Trying to figure out the power supply I get:

Power Supply Voltage (DC) = 32 * SQRT(4.1) = 65V

While I have 5 motors, if I use the 5th as an indexer then at any point in time I won't be using all 5 (4 motors for a 3 axis router, only 3 for an indexer since the x axis is stationary).

If this assumption is correct then I only need to consider current draw for max 4 motors which gives:

Max Current = 4 * 4A * 67% = 10.7A

Based on that I need a power supply rated at 65 x 10.7 = 696VA

Looking at the 800W range from antek (since there are no 700W) I assume I would go for a PS-8N63?

Is this enough or do I need to apply Gerard's 1.2 voltage multiplier rule and get a PS-8N77? Or one of the other values in between (66, 67, 68, 70)?

Also for any Aussies out there is there a cheaper local PS alternative (other than building my own which quite frankly scares the hell out of me)?

I have the same motors but now i wired in bipollar parallel, use the 8 wires, and now i changed the power supply for another with more Amperes.

You can size up to a posible parallel consumption.

By Gerard I meant Gerald ... Sorry. That's what I get for posting after midnight :o

Did nothing MM related this weekend because I spent all my free time removing tiny particles of rusted angle grinder dust from our cars :mad:

Was stuck on there pretty good (including windows). Had to use 'clay bar' and a LOT of elbow grease to remove. Fortunately I was able to remove it.

Note to self (any everybody else who doesn't know) DON'T EVER USE AN ANGLE GRINDER CLOSE TO YOUR CAR.

Lesson learned .... I move on.

You need to start a thread on the main board as a warning or something. Very unfortunate.

It wasn't all bad. I learned about clay bars and the car came out of it with a showroom finish... :)

I just never wash my truck so if I get over spray or "stuff" on it, I can just wash it off !! :) !

Why bother? Wash it before you sell it...lol

Wash? Let the rain do the job. LOL