Hi Dave,

All looking good there, I know how hot it can get in Brisbane.
My grandfather lived out in Brisbane a long time ago, I stayed with him when Cyclone Wanda hit.... can't remember when that was.. 1975 I think ! a long time ago.

Any way I've been busy drilling the Z slide, should have that all completed this weekend, then its on to the welding of the spider.

Good luck with your build.

Cheers
Andrew

So i've got a bit more done recently, although not as fast as i'd would of liked but I haven't disapeared.

I now have the y car and gantry all welded up. the spindle has arrived, vfd is on order, my V bearings have arrived, and I've almost finished cutting down my rails to size ready to grind the V into them.

the rails I've cut so far have a .25-.5mm variance in height straight from the cutting discs. I'm hoping doing a grinding pass on them can smooth that out.

what variation is acceptable in the heights across the rail?

and is needs be is it ok for me to grind them down to 27-27.5 to get them perfect?

http://daveshotit.com/mechmate/Gantr...602_124428.jpg

http://daveshotit.com/mechmate/Gantr...602_124441.jpg

http://daveshotit.com/mechmate/Table/Build_14_Table.jpg

We all have unscheduled breaks in our build time. It is inevitable. Just stay with it and it will be done.

Ok so i have a question.
I may have screwed the 1st X rail that i started cutting last night, note to self dont rush things at the end of the day to get it in before light fades.

I went out to continue this afternoon and have found that i must have been sleeping while cutting and have a 600mm section that has been cut to 24.5mm

Is this going to be a throw away angle now, or can i still get away with 24 if using the metric rail?

thanks
Dave

I checked on my MM & it seems that you can get away with 24mm rail, but the slot on the swing plat will be pretty close to the bottom.
IMHO, just dump the last rail & start a fresh. those angle doesn't cost an arm or leg, take that as a practice round :)

Also make sure your grinder set-up hasn't changed so you don't do it again. Maybe something loosened.

Another option is to change to hardened V-rails and and adapt as the cut off height needs to be lower to use the hardened V-rails. The cost is more but gives a long lasting running surface. Here in the US it was less than $300USD for me to do all of my axes. Only problem is you have to cut the rails with a cut off wheel. Tooth blades will not even mark the running profile only the mounting section is soft. I do not know the availability in your area so I would agree with Ken that new angle would be the best option.

Dont make the same mistake I did, be sure to use a large base melamine jig instead of just the laser cut plate with 4 bolts and take at least 25-30 passes on the cut. Very light cuts until you see smoke on the other side.