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Gerald_D
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Username: Gerald_d
Post Number: 213
Registered: 11-2005
| | Posted on Sunday, August 27, 2006 - 04:11 pm: | 
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The very basic thing to do is to decide for yourself what size of MechMate you want to build. You need to pick your own X,Y travel distances that you want to achieve and then my drawings will say "cut the rack to length Y plus 150mm" or something like that. The basic MechMate design will work with a fairly wide range of x-table_lengths and y-gantry_widths, but a narrow range of z-slide_heights, being essentially a machine for processing board materials...
Which brings us to the point that you need to know what size boards you want to process, and indirectly, what board you want to use as the table surface. Then you need to decide if you will have twin routers and how far apart they will be in the y-car. The plans will focus on a single router sitting off-center in the y-car, with a big dust hose using the space that others might eye for a second router. But I will give a priority to those building a MechMate similar in configuration to what we built in 2005/2006.
Back to board sizes....in South Africa, MDF is sold as 2750mm x 1830mm boards (9' x 6'). Masonite, Melamine-face chipboard and lots of other stuff also comes as "nine_by_sixes". Plywoods are not that popular, but they come in smaller sizes in any case (2440x1220 or 8x4). apparently the board sizes in America are narrower and gantries can be limited to 5 foot, but here a 5 foot gantry is very limiting.
In the plans, I will give dimensions of rails, racks, gantry beams, etc. as X_plus_1234 or Y_plus_567 where X and Y refer to spoilboard size. The MechMate will be capable of moving 50mm (2") more in all directions. ie. a 100mm (4") diam cutter will travel just clear of the spoilboard, while a smaller cutter can have up to 50mm (2") breathing space off the edge of the support/spoilboard. (Only valid for a single router).
Out of curiosity, what board sizes will you guys want to be cutting? |
Mike John
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Username: Mikejohn
Post Number: 56
Registered: 12-2005
| | Posted on Sunday, August 27, 2006 - 06:31 pm: |
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My board sizes are 2070mm x 2800mm |
Gerald_D
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Username: Gerald_d
Post Number: 216
Registered: 11-2005
| | Posted on Sunday, August 27, 2006 - 06:48 pm: |
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Mike, how typical is that around Europe? Would you be interested in a gantry that managed to cut across the 2070mm? |
Mike John
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Username: Mikejohn
Post Number: 57
Registered: 12-2005
| | Posted on Monday, August 28, 2006 - 06:41 am: |
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Its very typical for mainland Europe.
I'm not certain for the UK.
To date I have never needed anything larger than my table size (1206mmx2560mm), and feel that lengthening the gantry might introduce an element of 'slop'.
The problem for me deciding size is that, at the moment I put 3 'pallets' up at a time for one common tasks, and have just enough room at 1206mm, so feel 1300mm would be nice. But then, am I going to want 1350mm later on?
At the moment I would stick to 1300mm.
How about the length?
Your trick cutting two side pieces from one 6m [ channel for my table saved a lot of money, making the 2560mm cutting a good choice. Does 'rack' come in certain standard lengths?
I already have my welder/fabricator standing by (my son), and a lazer cutting firm as well.
So I am awaiting the final plans with great anticipation. 
.........Mike |
Pete Wood
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Username: Pete_wood
Post Number: 3
Registered: 07-2006
| | Posted on Saturday, September 02, 2006 - 06:08 pm: |
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I love this forum. Just like Mike, I can't wait to get started.
I am based in the UK, so tomorrow I will see what size boards are most readily available. |
Gerald_D
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Username: Gerald_d
Post Number: 228
Registered: 11-2005
| | Posted on Saturday, September 02, 2006 - 06:20 pm: |
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I know you guys can't wait, but there is some progress with drawings - while I'm not fiddling with other subjects on the forum |
Gerald_D
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Username: Gerald_d
Post Number: 244
Registered: 11-2005
| | Posted on Wednesday, September 20, 2006 - 06:58 am: |
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Board sizes in UK
Board sizes in Australia
more Australia
Valchromat coloured mdf sheet size 2500mm x 1250mm |
David Rosenbleeth
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Username: Dave_r
Post Number: 11
Registered: 07-2006
| | Posted on Thursday, September 21, 2006 - 02:50 am: |
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From Above:
I know you guys can't wait, but there is some progress with drawings - while I'm not fiddling with other subjects on the forum
Reply: Time flies when you're having a good time!!!  |
Bojan Regouc
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Username: Bojan
Post Number: 2
Registered: 10-2006
| | Posted on Wednesday, October 04, 2006 - 08:45 pm: |
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2070mm x 2800mm |
Gerald_D
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Username: Gerald_d
Post Number: 256
Registered: 11-2005
| | Posted on Wednesday, October 04, 2006 - 09:08 pm: |
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Bojan, would you want a machine to cut full-size or half-size sheets? In other words, have you got workshop space for the big sheets and can you load the sheets with one or two people? |
Holger Erendi
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Username: Holger
Post Number: 1
Registered: 10-2006
| | Posted on Sunday, October 15, 2006 - 06:39 pm: |
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Hello Gerald,
Nice job with Mechmate!! You got me to rebuild my PRT, I will try to make mine to cut in Y direction 2100mm. |
Gerald_D
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Username: Gerald_d
Post Number: 305
Registered: 11-2005
| | Posted on Sunday, October 15, 2006 - 06:51 pm: |
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Hi Holger, good to see you here! The 2100mm in the y-direction should be no problem. The MechMate you see in the photos is 1900mm y-travel for cutting boards up to 1830mm wide. Even with the longer, heavier gantry, we have a similar speed/acceleration to the old PRT 1300mm gantry. You might have to set your "ramps" a little bit slower for that long gantry, but you will still have a good performance. |
Gerald_D
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Username: Gerald_d
Post Number: 306
Registered: 11-2005
| | Posted on Sunday, October 15, 2006 - 07:07 pm: |
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If the MechMate were restricted to four table lengths (X) and four gantry lengths (Y), it would appear that most of the market could be served by the following capabilities: (max board sizes)....
X dimension equals:
1850mm [6.1 ft]
2500mm [8.2 ft]
2800mm [9.2 ft]
3660mm [12 ft]
....or would a 3050mm [10 ft] be a more popular length?
Y dimension equals:
1250mm [4.1 ft]
1530mm [5 ft]
1850mm [6.1 ft]
2070mm [6.8 ft]
(The design allows for 50mm [2 in] extra travel beyond all edges of the above board sizes) |
Mike John
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Username: Mikejohn
Post Number: 90
Registered: 12-2005
| | Posted on Sunday, October 15, 2006 - 07:51 pm: |
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Gerald
In manufacturing cost terms, is there a great deal between a 1850mm gantry and a 2070mm gantry?
Or for that matter between a 1250mm and a 2070mm?
It seems to be no more than the cost of the longitudal lengths of steel. All the cross pieces and end pieces, the Y carriage, all the manufacturing, the number of cuts and actual assembly, would all be the same.
And I guess this applies to the x direction.
Doubling the length of the table isn't going to double its cost, apart from maybe material. (I say maybe as you need 3 pairs of legs for a 2.5 m table, only 5 pairs for a 5m table.
I recognise you need twice the length of rack, but everything else remains the same.
So, what is the most economical way to go?
If I had the room, I can imagine loading one end of the table with a full sheet, let it cut, move to a sheet on the other end, then change the first sheet.
..........Mike |
Gerald_D
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Username: Gerald_d
Post Number: 307
Registered: 11-2005
| | Posted on Sunday, October 15, 2006 - 08:17 pm: |
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In manufacturing cost, you are right, it costs very little to up the size. (steel tubes, racks, cables, cable chain). But, the bigger the table, the more you have to walk to get around it. Getting small parts off the table are also an issue. (our 8x4' table is seldom climbed on - the 9x6' is climbed on often) If the table needs a vacuum system, then size matters a lot. A dust collector hose over a big area is also more difficult to handle. |
Mike John
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Username: Mikejohn
Post Number: 91
Registered: 12-2005
| | Posted on Monday, October 16, 2006 - 07:22 am: |
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Now I have to stop Roxana reading this!
She will want the biggest table possible to make me walk as far as possible. The thing is, if the table is so big that it is too close to the wall on any side, will I even be able to get around the table!
Just how big is your table?
............Mike |
Gerald_D
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Username: Gerald_d
Post Number: 403
Registered: 11-2005
| | Posted on Wednesday, November 08, 2006 - 06:46 pm: |
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2750 x 1830mm [9 x 6 ft] board size - the movement is 50mm [2"] more on all four edges. |
Bill McGuire
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Username: Johnnydoughey
Post Number: 1
Registered: 11-2006
| | Posted on Tuesday, November 14, 2006 - 08:02 am: |
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Here in the US, plywood comes in 48" X 96", but Melamine covered particle board is 49" X 97"... don't know why... |
Greg Waggy
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Username: Gawnca
Post Number: 46
Registered: 11-2006
| | Posted on Tuesday, November 14, 2006 - 08:08 am: |
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Bill, maybe for the same reason you can't find a 3/4" shhet of plywood any more, they are 15/32nds or something on that order. The 48" x 96" is a standard by which ceiling heights are and use to be stud centers in interior walls. As for the 49" by 97" maybe they have to build in a fudge factor for sloppy construction work or poor building materials. I know a 2" x 4" (3.75" x 1.75") stud has more water in it than a sponge floating in your wife's ketchen sink. Heck they'll spit at you most of the time when you hit them with a hammer. |
Gerald_D
Registered
Username: Gerald_d
Post Number: 451
Registered: 11-2005
| | Posted on Tuesday, November 14, 2006 - 08:18 am: |
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Aren't those "odd" sizes because of some metric systems creeping up on you? A 2.5 meter board, ripped down the center with a 5mm kerf will give you 2 boards 49.1" wide.....
20mm is slightly thicker than 3/4".....
18mm is popular in some metric countries, slightly thinner than 3/4"........ |
vadeem
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Username: Vid1900
Post Number: 13
Registered: 10-2006
| | Posted on Wednesday, November 15, 2006 - 09:05 am: |
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The 49x97" sheet as found with MDF, is used so that even with the loss of the saw kerf, one can still get, for instance, two 48x48 pieces.
It indeed comes very square from the factory. |
Gerald_D
Registered
Username: Gerald_d
Post Number: 493
Registered: 11-2005
| | Posted on Tuesday, November 21, 2006 - 02:49 pm: |
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What is the smallest MechMate off the plans? Well, I am very tempted to do a 1200mm [4ft] gantry on a 600mm [2ft] table for making signs at home. In this case I would call the gantry x and the table y.
That gantry would easily transfer to a 2400mm [8ft] table if I want to sell it. I think there comes a point where one considers shortening the table instead of the gantry, since 95% of the MechMate's "engineering" and sweat are in the gantry (and control box) and not in the table. Tables are almost consumable/disposable - unless you are heavily invested in vacuum holddown. |
Greg Waggy
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Username: Gawnca
Post Number: 78
Registered: 11-2006
| | Posted on Tuesday, November 21, 2006 - 03:18 pm: |
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Gerald, Then what you are saying, build the width you want but the table length can be expanded. The gantry is the moving part(s) that have the milling motor/router attached? |
Gerald_D
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Username: Gerald_d
Post Number: 494
Registered: 11-2005
| | Posted on Tuesday, November 21, 2006 - 03:31 pm: |
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Everything of any complexity sits on the gantry (the moving part). ALL the motors, ALL the switches, ALL the cables/wires (except one ground wire), etc. The static table only carries a pair of rails and racks.
The logic is that you build the gantry in a small corner of the garage, get the x-motors to turn, get the y-car to run, get the z-slide to move. etc. Thats 95% of the sweat. THEN you build the big table and explain to your wife that her car now has to sleep outside. |
fabrica
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Username: Daya
Post Number: 65
Registered: 10-2006
| | Posted on Thursday, November 23, 2006 - 05:48 pm: |
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Gerald I have started on the base table. In all parts which use 50 mm dia round pipes can I replace them with 2"x1" 3 mm thick box iron . Is their any special reason for you to suggest round pipes. |
Gerald_D
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Username: Gerald_d
Post Number: 502
Registered: 11-2005
| | Posted on Thursday, November 23, 2006 - 05:56 pm: |
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2"x1"x3mm box section will be perfect. You also need a piece 490mm long for the Z-slide.
I used pipe for two reasons:
1. I had some pipe lying around that wasn't going to be used for anything else.
2. The sawdust doesn't collect on top of round pipe - the machine stays cleaner. |
fabrica
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Username: Daya
Post Number: 67
Registered: 10-2006
| | Posted on Thursday, November 23, 2006 - 07:23 pm: |
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OK then I will go with the box iron option. |
Sheldon Dingwall
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Username: Sheldon_dingwall
Post Number: 17
Registered: 08-2006
| | Posted on Monday, March 19, 2007 - 04:11 pm: |
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Gerald, I'm thinking 2' x 4' too. Or possibly smaller, say 20" x 40" with a dual Z. |
Gerald_D
Registered
Username: Gerald_d
Post Number: 1162
Registered: 11-2005
| | Posted on Monday, March 19, 2007 - 05:42 pm: |
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Sheldon, I would make the gantry long (40-48") and table short (20-24"). It is easier to lengthen the table down the line if you want to go bigger. Also, the access to the job is easier with a long open X. (See this post above)
Also, I would build such a small table quite high off the ground. And give the table a sturdy vertical front "apron". This is for clamping vertical work where you need to do end work - like drawer sides. |
Frank Dixon
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Username: Pamarine
Post Number: 1
Registered: 05-2007
| | Posted on Friday, May 11, 2007 - 06:08 am: |
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Ok, time for another newbie. I am interested in building a CNC Router for 5052-t3 Aluminum Sheet, Acrylic, Lexan (Plexiglass), and wood. I like the look of your MechMate and was wondering if it could be scaled for a 60" x 60" table. Also, was wondering what kind of price range building such a table would be. These are my basics for now, and I can guarantee there will be many more. |
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