Well done, I like that box...was cutting the Vectric monthly project box this afternoon...lots of work finishing it off. Keep the photos coming.

Very nice Anthony!!
I like the Mothers Keepsake Box, nice changes.

Cheers
Tony.

Nice job Anthony, I also have a plasma torch for my mechmate but I havent swapped it in yet. Keep posting pictures!

Cheers
Tim
I'm still climbing the learning curve!

Anthony,

Very interesting that you have a dual-mode MechMate ( wood and plasma cutter). Could you show us some pictures of your plasma set-up? I'm thinking about building my "next" MechMate to be convertible to a plasma cutter.

UNCSA #58 machine has a Dual Z axis for just this use.

http://www.mechmate.com/forums/showt...ighlight=uncsa

I have a separate circuit run to the head for my plasma. I quick disconnect the router and the plasma head clicks in and away you go. I suspend my torch line from the dust collect line so I can use it for other projects. To each there own, just as long as it works :)

cheers,
Tim

Tim,
That is how mine is currently, torch line suspended from dust collector and two separate config file in emc. Gcodes M3 & M5 are connected to different pins on the BOB for different setups. Also Arc OK is connected so that if arc goes out motion stops, plus an on screen over ride button for 'air cuts'. The current mount is similar to K2CNC except mine is laminated chipboard.
The biggest problem with sharing mounts this is that the torch isn't floating to 'touch off' which I feel is a necessity for cut quality & efficiency.
Dual Z's is the go, that way pilot drilling or marking and plasma cutting can be carried out in one operation with gcode offsets (thats the theory anyway unless someone can tell me different).
If someone wan'ts the dxf for the mount I can post it.

I made these boxex out of 6mm (1/4) mdf to test the machine capabilities ie missed steps, bit flex, spindle rpm drop, etc. with out sanding (I hate sanding) the joins.

Nice joints, I hope to be cutting those soon :)

Cheers
Tim

This sketch should be self-explanatory:

Attachment 11850

Quite a few developments have happened this past week.
It started with shed extensions 'approved' and ordered, which means a dedicated area for the MM to contain dust and noise:D.
Got a letter in the mail that said my application for the business name 'Riverland CNC' is approved:D.
Also riverlandcnc.com.au wasn't being used so I grabbed that with both hands:D.
The dxf and picture might explain the cube.

I think what Gerald was suggesting that the "Dog Bone" fillets give a smaller holes than the "T Bone" fillets and may be preferable in some cases. :confused:

also faster cutting, less sawdust, and less filler to make them disappear before painting :)

All the little things you don't think about. Thanks for all your input guys this will help me down the road as well :)

Cheers
Tim

to put a number to Geralds' succinct and intuitive drawing . . .

using http://en.wikipedia.org/wiki/Circular_segment as the basis of the math . . .

r = cutter radius

inset = d = sqrt((r^2)/2) = r / sqrt(2)
this is the amount you must offset x & y to trim the fillet left in the corner

theta = 2 * arccos(d/r) = 2 * arccos( (r / sqrt(2)) / r ) = 2 * arccos(sqrt(2)) = approximately 1.57

area = ((r^2)/2)*(theta - sin(theta))

because the inset cut cuts on both sides of the corner, we double the area

area of cut = 2 * area = r^2 * (theta - sin(theta))

area of non offset cut = (pi * r^2) / 2


ratio of offset cut to non offset cut = area of cut / area of non offset cut
= ( r^2 * (theta - sin(theta)) ) / ( (pi * r^2) / 2 )
= 2 * (theta - sin(theta)) / pi
= approximately 0.36 or about 36%


. . . so . . .
you will only cut 36% of the material using Geralds cut compared to the original cut . . . and your filler material has a much smaller gap to span

cheers

Like I said, building this thing is the easy part lol!

Robin, the red scenario is an empty half-circle, the green has half of an inscribed square filling the half-circle.

The diagonal of the square is equal in length to 2 * r
The diagonal length of a square is sq.root 2 * side length
The area of a circle is PI * r * r
The area of the square is side length * side length

Therefore the ratio of filled vs. unfilled is 2 vs. PI = 2 / 3.1416 = 64% :)

Hey! and 36% + 64% = 100% ! :)

so thats how you travel faster then light??

Gerald, you must be a teacher :)

i only had to tilt my head 45 deg's to see that in all these years i have not lost my knack for figuring things out the hard way :D

Robin, actually I cheated....:o

I drew a 100mm radius circle in AutoCad and then drew a square inside it. Measured the side length of the square and saw it was 141.4mm...an old familar number related to the sq.root of 2. Then it all fell into place.....:)

I did always know that the area of a circle inside a square is about 3/4 of the square area, but that it is exactly 3.14/4 (pi/4), so I did have a suspicion there is a linear relationship to pi for square inside the circle.

Every one else has been designing reduction drives I thought I would have ago.
Mine will be made from cast aluminum and fully enclosed so that I can take advantage of plastic pulleys.
Also I have done away with the laser cut bracket and mounted it to a custom long stud with a large flange to elimiate twisting.
Pictures are of a MDF prototype, the design has slightly changed, they give the general idea.
The image of the reduction on the machine shows it on the wrong side - the reduction housings are universal.

Now, that is the right way to do a belt reduction box :D

It also look like your design can be machine off a block of aluminum :)

i like the reduction design. It will be casted very well in Aluminum. Thanks for sharing.

Hi Anthony

Must be that time of the year for designing belt reductions :).

I like your design, especially the symmetry that makes them universal.
After a few quick calculations I see that 2 x 12 mm plates are never going to make a fully enclosed drive.
Is that why you have chosen casting due to the depth of the assembly?

As an aside if my limited experiences so far with the 4:1 reductions are any thing to go by, you will enjoy having them on your machine.
Just pushing the gantry up the machine when the motors are off is telling me so much more is going on!!

Regards
Ross

Wow! that looks fantastic, I like the closed design.

Ross,
I wanted enclosed for dust and swarf.
It had to be light weight for plasma cutter to help acceleration and using a plastic large pulley will help with weight but also rotating inertia.
My aim is to go from 16 mirosteps to 4 mirosteps = more torque + 5.2:1 reduction = more torque. I then maybe able to lower the amperage without sarificing performance(??).

Anthony