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View Full Version : Creating a "manual" to describe the MechMate build process


Gerald D
Thu 05 June 2008, 00:10
Copied from another thread:

We agree that a manual is needed, this "forum" is the nearest thing to a manual that we are going to have, and I am not going to give up in my effort to get this forum to look like a manual. . . . .

dmoore
Thu 05 June 2008, 00:32
A comprehensive manual/video would be a fair bit of work. Would you be open to someone producing one and selling it at a profit without restriction on it's format or content?

Thanks,
david

Gerald D
Thu 05 June 2008, 00:48
Yes, I would be open to that. As long as I can sort of expect the "2.5% of sale price, or 5% of profit, whichever the higher" and take a back seat while you promote it in this forum's "Market Place". If I don't like the content, I delete mention to your product from this forum....and stop the expectation of the small monetary consideration. :)

dmoore
Thu 05 June 2008, 08:16
I'll give this some consideration when I build my second MechMate. If JoeCNC and the others can sell just drawings and a BOM for $50 to $100, than a complete manual with videos shouldn't have a problem selling.

dmoore
Thu 05 June 2008, 14:17
. . . . the "manual" that you gave up on writing.

In case anyone wants to pick up where I left off, here is the outline and a few sections completed. NOTE: This has NOT BEEN VETTED AND SHOULD NOT BE USED FOR A MECHMATE BUILD! This document more than likely contains MANY errors - no need to point them out as I wrote this before I built my MechMate. Photos have been excluded:

The following is a compilation of information that you may find helpful prior to a MechMate build or when you start building the MechMate. It is comprised of select information, tips and photos from the forum (http://www.mechmate.com/forums (http://www.mechmate.com/forums)) and other locations on the internet.

2. Pre-build
2.1. What is a MechMate?
2.1.1. The MechMate is a 3-Axis (X, Y, Z) CNC machine based on the design of the commercially available ShopBot. MechMate isn’t an actual commercial CNC machine for sale but instead is a set of free plans from which you can build your own version of the MechMate.
2.2. Who designed the MechMate?
2.2.1. Gerald designed the MechMate and has graciously passed on his knowledge and plans for the greater good of the CNC community. Gerald build the original MechMate for his own person use to improve upon issues that he found when trying to upgrade his commercial ShotBot system. Gerald resides in the town of Fish Hoek which is near Cape Town, South Africa. His company is CAM Craft.
2.3. What does it cost to build a MechMate?
2.3.1. As this is a do-it-yourself project and each build is not only different but built by people all over the world, it can be sometimes hard to pin down an exact cost. Costs also depend on the amount of work outsourced (cutting and bending steel parts) and additional tools you may be required to own to complete the project (welder, metal cutting, lathe, drills, taps, etc). The general range of build costs, if built to the plans as designed, are about $5500 to $7000 USD including steel, parts, motors, controllers, control PC and basic software. This cost does not include tooling/cutters or design/CAD software. Costs are dependent on the quality of items the builder wishes to purchase and cost management of the builder (reusing existing parts, shopping on eBay).
2.3.2. Prior build cost estimates:
2.3.2.1.
2.4. What are the MechMate specifications for speed and accuracy?
2.4.1. As the MechMate is not a commercial available machine and that each builder alters the specifications to meet their own personal needs, the speed and accuracy of each MechMate differs. Prior to building, you should determine the requirements for the work that you intend to do with the unit. If you will be performing intricate engraving, work in materials that can not have machining marks sanded out (plastics) or other precision work, the trade off is speed to gain the accuracy you will need. Accuracy and speed is largely determined by the motors, gearing, rack/pinion, motor driver and wiring.
2.5. What size material can I cut with the MechMate?
2.5.1. The MechMate plans allow easy adjustments to the overall size of the unit. It could be built to cut 4ft x 4ft sheets or it can be designed to cut 5ft x 10ft sheets. Material thicknesses can be from 3-4 inches to as much as 24 inches. Using the standard plans, there is generally about 3-6” of Z-Axis travel.
2.6. Why you should not build the MechMate
2.6.1. If you have never had experience with a CNC machine, you may find value in building a smaller, simple CNC machine first in order to learn the terminology and gain skills necessary make your build a success. If you plan ahead, you can purchase many items that will transfer over to your future MechMate machine - drivers (Gecko’s), CNC control software (Mach3), motors, computer and design software (CAD, V-Carve) all can be transferred over from a smaller CNC machine to the MechMate. The starting point to learn about simple to build hobby CNC machines is http://www.cnczone.com (http://www.cnczone.com/). The MechMate is a commercial grade CNC machine that may be more than you need to accomplish your goals.
2.7. What major skills and tools are required to build a MechMate?
2.7.1. Welding – you should have a MIG or TIG welder and be reasonably proficient in its use. Due to the tolerances required, you will need to know how to manage distortion in parts caused by welding and how to manage and minimize those distortions. If you have never welded prior, it would be highly advisable to seek assistance from an experienced welder.
2.7.2. Steel cutting – While many people will outsource the laser/plasma cutting and bending of some or all of the plate steel items required, you will still need to be able to handle and cut large structural steel beams. A chop-saw may provide all the cutting you need for this project and may require a plasma cutter, band saw or other means of cutting.
2.7.3. Drilling and tapping – The MechMate requires many very accurate holes to be drilled (and often tapped). You should have accurate tools to accomplish this task.
2.7.4. Lathe – A small number of parts on the MechMate will need to be built using a lathe.
2.7.5. Software – You will need the ability to use Windows and configure applications in Windows.
2.7.6. Electrical – You will need to be able to understand basic electrical principals.
2.8. What materials can I cut with the MechMate?
2.8.1. This issue is dictated by the power of the router or spindle, the speed you need to cut, the accuracy you require in the final product and the tooling and coolant systems. Generally the MechMate is designed to cut wood (plywood, blanks, MDF), foam, aluminum and plastic sheet goods. With additional systems, it is also possible to build the MechMate to cut with Plasma or Laser – though these are not covered in the design documents. If you are milling steel or other hard, non-sheet metals, the MechMate is not the appropriate platform.
2.9. What is the MechMate Mamba?
2.9.1. The Mamba is the second, updated version of the original MechMate.
2.10. I live in the United States but the plans seem to be in Metric units – can I still build it?
2.10.1. Yes, a number of US built MechMates have been built using inch bolts, steel, gears and other parts. In most places on the plans you will find there are two values listed – one for metric and another for inch. In some cases, you will simply need to adjust the metric sized items, holes, bolts, etc to the closest inch equivalent. It is possible to build the entire MechMate using imperial/inch parts and materials.
2.11. Where can I see detailed photos of the MechMate?
2.11.1. Right here: http://www.mechmate.com/forums/showthread.php?t=171 (http://www.mechmate.com/forums/showthread.php?t=171)
2.12. Where can I see video’s of the MechMate in action?
2.12.1. The big MechMate built from scratch: (Front of dust foot removed): http://www.youtube.com/watch?v=hGVQQf_iQpI (http://www.youtube.com/watch?v=hGVQQf_iQpI)
2.12.2. What was originally the 8x4' Shopbot is now fully converted except for the X-rails, x-racks and x-pinions: http://www.youtube.com/watch?v=uGQ2J4GgXkg (http://www.youtube.com/watch?v=uGQ2J4GgXkg)
2.13. Before you get started…
2.13.1. While this guide is intended to serve as a starting point, it would be highly advisable to print out the entire set of prints, then review each print until you understand exactly what the intended part is for and how it fits into the overall design. It is also advisable to review ALL the threads on the MechMate prior to starting. Plenty of mistakes have been made in the prior years of builds and you can save yourself the trouble of making the same ones by reviewing the forum. Additionally, you will often find exact answers to your questions – what type of motor works best? What if I want larger Z? Can I use a different motor controller?
3. Base Table
3.1. Determining the size of the table
3.1.1. The first step in building your MechMate is to determine the size of the material you need to cut. It is from this number that all the remaining X and Y values will be based. It is important to note that, in the plans, you will see references to “X + 555 [12.1”]” – this refers to the largest material (in this case in the X) you will need to cut. For example, a part dimension may be listed as 8 feet + 12.1”, 8 feet being the largest material size you will cut. Also be aware that designed into the plans is over-cut. So, even if you design a MechMate with X=8 feet and y=4 feet, the actual total area the MechMate will be able to travel is 8’ 4” feet (X) by 4’ 4” feet (Y) (2 inches/50mm on each side). Factors to consider when determining your overall cutting area:
3.1.1.1. Overall size and weight of your machine. Plan for not only the size of the machine but clear space to walk around the machine, space for the control box, space to load and unload materials and material/sheet storage. Be aware that a 4’x8’ cutting area will result in a base that can weigh over 800 pounds. Also, bigger isn’t always better – building a MechMate in the US, where we normally have 4’ wide sheets, building it to have 5’ of Y would just mean that you now have to lean further over the side to pull off parts or fix a problem. Additionally, with additional X and Y lengths, there are floor space issues and weight issues.
3.1.1.2. Largest size of material to be cut. If you will be cutting surf boards out of 10ft long sections of foam, plan for an X length of 10ft. Keep in mind that materials vary by region and country and don’t always follow “standards”. As an example, in the US, most plywood products are 4’x8’ but MDF, a common material cut by CNC, is actually 49” x 97”.
3.1.1.3. Reference: http://www.mechmate.com/forums/showthread.php?t=63
3.2. Completely welded vs. partially welded/bolted table
3.2.1. The MechMate base table has been built in two major configurations – completely welded and partially welded and bolted. Of course there are advantages and trade offs to both, they are:
3.2.1.1. Completely Welded:
3.2.1.1.1. Advantages: Stronger, no chance of loose bolts due to vibration, more tolerant to out of level floors, less costs and faster to build, the plans detail the step-by-step process for fully welded
3.2.1.1.2. Disadvantages: Very hard to build and flip over (the base is built upside down), move from location to location (over 600 pounds), requires doors large enough to fit through when moving, hard to correct/shim errors in original build, harder to make future improvements (conversion to Plasma cutting bed)
3.2.1.2. Partially welded and bolted:
3.2.1.2.1. Advantages: Able to be disassembled into component parts and in certain cases, moved by a single person – this can be important if your MechMate is in a basement or other enclosed area. Able to change out bed (plasma cutting). Ability to correct for mistakes in original build.
3.2.1.2.2. Disadvantages: Additional cost to install fasteners, build time is increased to drill and tap holes. Can become loose over time. You’ll have to devise your own design.
3.2.1.2.3. Comment from Gerald on bolted tables: “Suggest you weld 2 pieces as per drawing 10 10 310W, but then bolt drawing 10 10 300W instead of welding”
3.3. Materials required for table build
3.3.1. Main beams (X axis) Drawing: 10 10 322
3.3.1.1. “C Channel” or “C-Section” steel. Box tube could be used but would hamper your ability to bolt items to it – not recommended.
3.3.1.2. Height of channel: 5.9” (150mm) to 7.8” (200mm). Width of flange (top and bottom): 1.9” (50mm) to 3.9” (100mm). In the USA, it would normally be available in the USA is a depth of 7” x a flange width of 3.6”. Note that the height of this beam will determine how high your Z axis (along with the height of your spoil board, etc) is and the overall height under the gantry. If you are working with thick materials such as expanded foam, take this into consideration. The original MechMate beam height is 180mm. 5.9” (150mm) should result in about 6” of Z travel. Also consider that if you go Over the 7.8” (200mm) height for the beam, you can run into support and vibration issues.
3.3.1.2.1. Samples of common USA standard “MC Shapes” can be found here: http://www.sss-steel.com/refpdf/10-11.pdf
3.3.1.3. The Y-beams supports (cross bearer) will attach to the bottom of these two beams, forming the base of the table. The tops of the beams will support the x-axis rails.
3.3.1.4. The ends of the beams are cut at 60 degrees but are done so for aesthetics and can be 45 or 90 degrees.
3.3.1.5. Since this section of steel may be expensive, determine if it is possible to build two beams from a single stock size (in the US, beams and channel generally come in 20 foot lengths + an inch or two).
3.3.1.6. If you will be choosing a bolt-together base, be sure to purchase channel with parallel flange and not tapered flange which will be easier to bolt together.
3.3.1.7. http://www.mechmate.com/forums/showthread.php?t=271 (http://www.mechmate.com/forums/showthread.php?t=271)
3.3.2. Cross Bearer Beams (Y axis of base) Drawing: 10 10 302
3.3.2.1. Height of channel 2.99” (76mm). Width of flange 1.49” (38mm).
3.3.2.2. USA standard size would be 3” x 1.938” with a web that is .312” thick
3.3.3. Legs to support main beams Drawing: 10 10 332
3.3.3.1. Height of channel 2.99” (76mm). Width of flange 1.49” (38mm).
3.3.3.2. USA standard size would be 3” x 1.938” with a web that is .312”
3.3.4. Diagonal support tubes/pipe
3.3.4.1. 1.18” (30mm) OD Tubing with .11” (3mm) wall thickness
3.3.4.2. USA standard size would be 1 1/8” with OD with .120” wall thickness
3.3.4.3. Square or box tubing can be substituted but may collect more dust due to the flat surfaces
3.3.4.4. Reference: http://www.sss-steel.com/refpdf/24.pdf
3.3.5. Conversion of a MechMate to Plasma - http://groups.yahoo.com/group/CncManualPlasmacutting/ (http://groups.yahoo.com/group/CncManualPlasmacutting/)
3.3.6. Sheet goods storage below table:

http://www.mechmate.com/Forum/messages/2/44.html
3.4. X-Axis rail systems
3.4.1. Two rail systems – pro’s and con’s
3.4.2. Cutting and grinding rails
3.4.2.1.
3.4.3. Using pre-made rails
3.5. Base table build tips
3.6. Photos
4. Gantry
4.1. Materials required for gantry
4.2. Welding sequence for drawing 10 20 400 W:


The notes on the drawing state:

1. Lay the two Cross Member Tubes 01 20 440 D across a firm workbench with the DRILLED HOLES AT THE BOTTOM. Clamp the tubes to the bench with 4 large g-clamps. (Construction starts upside down)

2. Using an accurate spirit level, framing square, shims and the sub-weldments 10 20 450 W as distance gauges, get the tubes very precisely in position BEFORE any welding is done. They must be level, parallel and square to each other. Use the framing square from one tube over to the other to get the ends in line. Keep within 1mm tolerance.

3. Put in TACK welds (small!) in the following sequance: A1, B1, C1, D1, A2, B2, C2, D2, A3, B3, C3, D3.

4. Un-clamp gantry from bench, gently turn it over, re-clamp and check square/parallel/level again. This is (almost) the last chance to correct "propellor twist". (shimming the rails is the last resort)

5. Lay full welds 40mm long in pos. 4 where the (now) top of the cross member meets 01 20 456 B. The rail lies over this position and the weld must be ground flat down to be flush with the top of the cross-members. Keep to the ABCD sequence hereafter. . . . . .

6. Lay welds 15mm long from opposite pos. 1 up to the tip of the gusset (marked as 5). Same size weld at pos. 6 . Un-clamp and turn gantry over.

7. Join welds 1 and 5 together. Join welds 2 & 3 together.

8. Turn gantry on its edge and do 20mm welds opposite pos. 6
4.3. Photos
5. Y-Car
5.1. Assembly instructions and tips
5.2.
6. Z-Slide
7. Motors (steppers)
7.1. Motor Selection
7.1.1. Non-Geared (direct drive)
7.1.2. Geared
7.1.3.
7.2. Motor Mounts
7.3. Springs
8. Rack & Pinion
8.1. Rack Selection and Purchase
8.2. Pinion Gear Selection
8.2.1.
9. Rollers and Bearings
10. Laser Cutting Steel Plate
10.1. What parts need to be cut and bent?
10.2. Purchasing pre-cut and bent parts
10.3. Issues with outsourcing cutting/bending
10.4. Inch/Metric plate size issues
11. Wiring and Cable Management
11.1. Wiring Diagrams and Sample Photos
11.2. Cable requirements/specifications
11.2.1. Recommended cable quantity
11.2.2. Cable suppliers
11.2.2.1. US Cable Suppliers
11.2.3. Recommended Data/stepper cable requirements
11.2.4. Recommended Router cable requirements
11.2.5. Recommended Spindle cable requirements
11.2.6. Recommended Grounding requirements
11.2.7.
11.3. E-Chain
11.3.1. Where and what to purchase
11.3.2. Installation/placement issues/orientation
11.4. Limit Switches/Home Switches
11.4.1. Homing/squaring the X Axis with Mach3: http://groups.yahoo.com/group/mach1mach2cnc/message/35535
12. Dust Management
13. Vacuum Clamp Down Systems
14. Control Systems
15. Stepper Controllers/Drivers
15.1. Recommended controllers
15.1.1. US controller Suppliers
15.2. Configuration of dual X-axis drivers
15.2.1. Wiring of input signals
15.2.2.
16. Power Supplies
16.1.
17. Software
17.1. CNC Control Software
17.2. Design Software
18. Initial setup and fine tuning of a MechMate
18.1. How to auto-square the MechMate

isladelobos
Thu 05 June 2008, 17:09
Good Big book.
Hey David, you need a holidays :cool: :D