Here are some threads for adjusting the beast...

Setting the Y-axis square to the X-axis
http://www.mechmate.com/forums/showthread.php?t=231

Setting the Z-slide square (perpendicular) to the table top
http://www.mechmate.com/forums/showthread.php?t=2553

Seating the Y Gantry on the X Rails - correcting a twisted gantry
http://www.mechmate.com/forums/showthread.php?t=663

Enjoy ;)

In thread t=231, Melissa, I hope you have ideas on how to make "a" thin sheet of MDF that's the full length of THIS table, rigid enough to flip over intact.

t=2553 router's already trammeled.

Hi Steve,

Thanks for the links. What I was wondering about is if you have home/limit switches how do you overide them to bump the mechanical stops to true the grantry with the steppers. It would seem if you tripped a limit it would stop before bumping the mechanical stops. Maybe an overide button in Mach?

Gary

Gary,
If you read the first post in t 231, Gerald suggests that auto squaring the gantry on a MM is not possible or at least not probable. He suggests that after squaring the X/Y that the squareness of the gantry will stay that way unless you hit something or run the gantry off the rails. I have found this to be quite true. I have limit switches on my machine and I rarely hit the hard stops. If I need to square the gantry I would disengage or power down the motors, pull the grantry to the hardstops, which are set to make sure the gantry is square, and while holding the gantry to the stops, engage/power up the motors. This will lock the gantry square. I will run the gantry over to the limits, which trip, override the limits, and run the gantry pass them.

Thanks Steve,

That is what I was wanting to know. I remember reading that the motors held the gantry square once turned on, but just didn't know how everyone was squaring their gantry when first turning the machine on. I knew by rolling my grantry by hand that this was causing some out of square and that the machine would have to be checked when first turning on.

Thanks again, Gary

Thien Baffle, completed
 

Some more photos of the Thien dust separator:

Attachment 12231
Attachment 12232

With it connected, I had to do something with all the sawdust from surfacing the table. I felt like a vacuum-cleaner salesman, as I proceeded to empty the bag onto the floor, and then vacuum it up: :D

Attachment 12234
Attachment 12233

The result is that the vast majority stayed in the Thien separator -- I couldn't tell if any made it through to the dust collector's bag. Mission accomplished!

More clamp knobs. I used a two-part toolpath. The first part made the holes in the middle. I then inserted screws with washers, to hold down the knobs during stage 2.

The second toolpath cut the round base of the knobs, and then the handle part. With the knobs attached with screws, I didn't need to bother with tabs to keep them secured.

Attachment 12235

click-together boxes
 

My first attempt at click-together assembly. The box is made of 1/2" plywood. The fit was bang-on, and the tabs make assembly much easier, as it self-aligns. More about boxes below :).

Attachment 12236
Attachment 12237

Squaring the gantry
 

My brother Camille was visiting recently. He helped me align the gantry, among other things we built using the mechmate.

We found it challenging to square the gantry by incrementally adjusting the shims. In fact, at one point, we adjusted it square. However, the direction we adjusted in, brought one of the X motor bolts into contact with the rail, which we discovered when pushing the gantry by hand, and encountering resistance. We quickly reset the shims on that side of the gantry (nearest 0,0), and made all further adjustments on the far side.

The method we eventually employed was to place half the gantry on blocks, and measure the required offset directly. Note the circled areas, and the wheels sitting aside :eek:.

After making these adjustments, the results were verified by cutting two sheets of plywood, as per Gerald's squaring instructions.

Attachment 12238
Attachment 12239

Attachment 12240

broken clamp
 

The MDF clamps have been doing surprisingly well. In cutting about five sheets of plywood, we only damaged one clamp, and that was by hitting the tip sideways while unloading a sheet. In normal clamping use, they're great!

Attachment 12241

More Boxes
 

With the gantry squared, we now had two sheets of plywood, about 25mm narrower in both dimensions. Hmm... what to make... more workshop boxes, obviously!

A full sheet of plywood, clamped on the table. Two sets of boxes were made from $13/sheet "sheathing" plywood. One set was made from $23/sheet "G1S" sanded, which was totally worth the extra $10, just for the fact that it was FLAT!

Attachment 12242

Cutting box parts:

Attachment 12243

Attachment 12244

Attachment 12246

Releasing the parts, cutting the tabs with a jigsaw. This was easier and more predictable than a chisel.

Attachment 12245

The first batch of boxes. I'm astounded how well these came out, given they were built with the cheapest grade of plywood available.

Attachment 12247

Second batch, two different sizes. The taller ones are the same size as typical "banker's boxes".

Attachment 12248

Around this time, we had a visit from Rob and Hannie, two Dutch boaters from New York, who were moored at the canal near our house. Rob needed a step-stool for their sailboat, and my boxes were exactly the right size. So, my first sale of a MechMate-produced part :D.

Attachment 12249

Nice work Melissa. Any chance we could get some close up photos of your dust foot, pvc pipe and the mounting? I ask because I am just getting a dust foot under construction. Thanks.

I think we need an additional criteria for a serial number - show a pic of your first sale to a happy customer.

Good stuff there!

Melissa, did you use screws and glue to assemble the boxes?

Excellent display of a MM in use. Well done Melissa. You might want to start saving all those cut off scraps for the wood stove. Winter is coming soon!

Love to see a machine making things - anything in fact. Well done.

A hint for you on removing your parts from the sheet. At the Maker Faire I saw some CNC people cutting their parts free using a straight cut router with a ball bearing guide.
Make your tab only thick enough to hold the part, even something like 3-4mm is fine then run the bearing guide along the smooth edge to release the part.
It leaves a beautiful router finish where the tab once was.
A a benefit it is also very fast to do.

Regards
Ross

Hennie: polyurethane construction adhesive, clamped during cure by brads shot from a pneumatic gun.

Sean: we had quite a bonfire out back. The next morning, the coals under the ash were still hot enough to ignite plywood. (And what does a Floridian know about winter anyways? Oh, right, all the snowbirds who come down from Ontario tell you stories.)

Ross: did they do that on a spoilboard, or in free air like we did with the jigsaw?

For any inquiring minds, we used 4x8 ft plywood instead of table-sized MDF. 4x8 was big enough, and the remaining scrap was plywood rather than mdf and thus usable for other projects (as you see above, with those boxes).

I leave my tabs 1/2" long and 1/4" thick. The G code goes back and cuts them out last. Very little resitance when cutting them. Part doesn't move and very little sanding, if any

Melissa,
A thought on strengthening the ends of your mdf clamps. The guys who build the mdf routers have used thin cyano adhesive to give additional strength to mdf , maybe this would work for your clamps as well?

Yes Steve, the machine should, and can, remove the tabs. A bit of smart programming is needed, but this is worthwhile for repeat jobs.

For reference here is how the tabs are removed with a trimmer.
http://www.youtube.com/watch?v=0C2CrzTKalE.
Watch the video to the end and you will see how quickly it can be done as they unstack the cut sheets.

Regards
Ross

You have the machine to make boxes that don`t need glue or screws to assemble

Camille,
I grew up just outside Cleveland (Akron really) I and have had my long winters of wet and really cold snow from Lake Erie. That's why I moved to Florida! :)

Sean,
Come to Canada, we will show you a real winter. :)

Oh, were not going start the "well, it's really cold up here!". I spent enough time in NewBrunswick, Calagary, Thunder Bay and Toronto to know real cold! Again, That's why I don't even own a winter coat anymore! :)

Hi Ross,

I cant figure it out unless it's a short bit with bearing on top. And it rides the edges while tip is cutting tabs?
Some very short bit like this one?
http://di1-2.shoppingshadow.com/imag...te+and+Pat.jpg

If there is a bearing, it is typically at the bottom (else it can gouge), but sometimes it is just solid carbide with a blunt bottom. see: http://www.google.co.za/search?um=1&...1500l2-3.2l5l0

If you are going to do a lot of trimming invest in a Festool edge trimmer or a Lamello edge trimmer.You can do really fine adjustments on them.