Bulldog Laser Cutter v200

Buildlog.net 2.x Laser Assembly Instructions

Prerequisites

Read these instructions completely before ordering any parts. This is a very advanced build.You need medium to advanced level electronics skills. If you don’t understand how to quicklycheck continuity, measure voltages safely and understand things like how a voltage dividerworks, you might destroy expensive parts or kill yourself. You should have good mechanicalcommon sense for how tight to make bolts to where they will stay tight, but not damage thethreads or parts. Torque values for screws are not given here. You will need good computerskills like how to install software and do detailed setup of programs.

License

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Collaboration

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Safety

All aspects of safety are up to the builder. If you do not feel comfortable in this role, do notstart this project. The items list are below are just for your consideration and are not meant tobe a comprehensive list of safety issues.

Eye Damage



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The laser beam is invisible and intense enough to cause permanent eye damage at any power level. Everyone in the room should be wearing safety glasses whenever the beam could beon. Intense bright light can occur when cutting or engraving some materials. Laser safetyglasses do not block this light. This is similar to a welding torch. Do not look at this intenselight.

Electrocution

You will be wiring direct AC line power that can injure or kill you if you contact it. A typical CO2tube runs at 10’s of thousands of volts. This can arc several inches during operation. Stay atleast 6” away from any tube electrodes or wiring during operation. Make sure the the frame isgrounded. Test grounding of frame and skins before applying power any time any change ismade to the assembly.

Moving Parts

There are several rapidly moving parts in this design that could move without warning. They




could pinch, entrap or crush body parts or clothing.

Make sure any controller or controller software is running before applying power. Controlsignals can often be in an unknown and dangerous state when not under software control.Power down the laser before closing any software.

Fire Hazard

Fires inside lasers are common. Never leave the laser unattended when power is applied.Keep a dedicated fire extinguisher near the laser. The beam could also reflect or otherwiseescape the enclosure and cause fires outside the enclosure.

Toxic Fumes




Many materials can cause highly toxic fumes when cutting. Fully research all material beforecutting them. Use a high volume exhaust blower to move all fumes outside the building. Theexhaust system should run at a negative pressure at all points inside the building so leaks pullair from the room rather than push fumes into it. Check local laws to see if additional fumehandling requirements are needed.

Some of the fumes such as chlorine gas can be extremely corrosive and damage expensivecomponents of your laser.

Purchasing

I strongly advise against ordering all parts at one time. Do not order the tube and powersupply until a few weeks before you need them. You might realize you are in over your head.The tube does have a shelf life. You may learn things along the way that will allow you tomake smarter purchasing decisions.

The BOM lists Misumi pre-assembly t nuts because they are cheaper. You will forget to installsome trapped nuts and may want to add your own customization. I suggest buying about 25extra pre-assembly nuts and about 25 extra post assembly nuts. These can be installed after




the frame is assembled.Even if you buy all the kits, it does not include everything. I only supply custom parts andthings I can buy in bulk to help save you money. You will need a few trips to the localhardware store along the way to finish the project.

Timing, Schedule and Work Area

I am sure a group can build this in a day or two, but realistically expect it to take severalweeks. Setup a work area that will remain free for several weeks. You will need easy accessfrom all 4 sides, so a table about the size of the laser (1000mm x 600mm) is ideal. A smallopen perimeter on the table around the laser is helpful to set tools and parts while working onit.

CAM Controller

The default controller for the build is Mach3. There is a free demo version of Mach3 that willget you through the initial testing. EMC2 will work as well as Mach3, but this document willreference Mach3 only. This will only address the specific issues of Mach3 required for theinitial setup. Mach3 has scope well beyond the initial testing and setup of the laser, that notaddressed in this document. Once testing is complete you can switch to an embeddedcontroller.

Tools & Supplies● Laser safe glasses for everyone that will ever be in the area of a power laser.● Fire Extinguisher.● Screw Drivers (some really ones small for terminal blocks)● Digital Volt Meter with conductivity checker.● Wire cutters.● Razor Knife● Wire Strippers.● Soldering Iron.● Pliers.● Wrenches.




● #10-24 Tap.● M5 .80 Tap (Optional - see Gantry Assembly Instructions below).● Allen Wrenches (Metric and English)● Tape Measure (with metric scale helps)● Carpenters square.

● Sandpaper.● Super glue.● Thread lock (removable)● Large black permanent marker (Sharpie)● Oil, rust inhibitor (Starrett M1 is good)

Drawings

This document should be used with the drawings to assemble the laser cutter. This documenthelps with the general order of assembly and has tips on how to do it, but the specific detailsof each assembly and the hardware used is on the drawings.

Kits

When you receive the a kit you should check for damage and inventory the parts. Report anyissues so they can be corrected as soon as possible and will be less likely hold up a buildstep.

Some of the machines plastic and wood parts might have a little rough edge or parting tab.




You should clean them up with sand paper and/or a razor knife so they are ready to use.

Electronics assembly

The electronics assembly will be partially assembled to allow some initial testing of the driversand motors. It is good to get familiar with this part of the build early. If there are problems oryou have questions, you can start working on them in parallel with the rest of the build. It isnice to have a working electronics setup when the build is ready for them.

Assemble the electronics module

The electronic module is designed to be built outside the frame for ease of assembly andwiring.

Assemble Electronics Bed and Mount Electronics1. Assemble the base and rear of the electronics module. Use the corner brackets to

connect the two pieces together.2. Attach the power outlets and power entry module to the rear panel. Note the

orientation of the parts.3. Attach the DIN rail.4. Assemble the terminal blocks to the DIN rail.5. Install jumper assemblies on terminal blocks to electrically connect like colors together.6. Attach the 24VDC power supply.




7. Attach the stepper drivers.8. Attach the interface PCB.

Wire the primary power1. Solder wires to the power entry module.2. Connect ground to green, line to black and neutral to the third color.3. Connect power outlet to terminal block.4. Connect 24VDC power supply to terminal block.5. Make sure power switch on the power entry module is in the off position. Install a

power cord.

Test primary power1. Keep hands clear of all wiring. Test wiring at this point by flipping on the switch briefly.

Look for LED on 24VDC power supply to light.2. Switch off and remove power cord.

Wire stepper motor drivers:1. Wire stepper motor drivers to 24VDC power supply and to interface board per the

schematic.2. Set stepper motors for 8 microsteps and 1.5amp current.3. Reapply power like before to see if LEDs on stepper drivers light.4. Remove power.

Main Frame Assembly

The frame should be as square as possibleUse a large carpenters square to insure this. When assembling some of the initial largepieces this can be difficult, so get it as close as you can, then come back later with the squareto readjust.

T-NutsThe design tries to use as many low cost pre-assembly t-nuts as possible. These nuts must




be inserted from the end of the extrusions. Since the ends of many extrusions get covered byother extrusions during assembly, you must insert the nuts as you go. The assembly drawingfor the frame lists to counts per extrusion on the second page. Take your time and follow thedrawing. Forgetting nut proves to be very frustrating to builders who rush the frameassembly.

Assembly Tips.I find it easiest to firmly attach the bracket to one extrusion, install the other screw and nutloosely and slide into the mating extrusion. It is easiest to do those that align with the end ofan extrusion. One side of the cast brackets has two small protrusions. These go into the slots

and help resist rotation. Choose which way to orient these in areas where a rotation forcemight occur.

Frame Assembly OrderThe following order of work is recommended for easy assembly of the main frame.

(The accompanying image is looking from the rear left corner of the frame toward the frontright corner. Front, Left, Right, and Rear are stated as if looking/working from the front of themachine.)




*Install Feet and bottom Skin1. Roll the frame onto it’s back.2. Tap the bottom of the (4) corner extrusions with a #10-24 tap. The size of the existing

hole is fine as a pilot hole.3. Bolt on the bottom skin. Be sure it is oriented correctly. Look for the two closely

spaced holes for the end of the cable carrier to be on the right side of the central area.Install each screw just enough to grab a few threads. This will allow it to slide around a




bit to get all screws. Once they are all engaged center the skin and fully tighten.4. Now install the feet.The threads on the feet are probably longer than you want. I cut

mine down by about half.5. If you are using a Y axis cable carrier, you should install one end to the bottom skin.6. Return the frame to normal orientation and adjust the feet until the frame is level.

V Rail Assembly (Read completely first. Glue dries too quickly to read as you go.)

Note: Thes instructions describe my method. Tim Wehr did an excellent video of his methodhere.(http://www.buildlog.net/forum/viewtopic.php?f=4&t=406&start=40#p2853)

The v rails are glued to the extrusions. You should use a glue that will go on with an evenlayer. I used a gel super glue and that method will be detailed here. Try to get the “highimpact” type if you can. I used (2) 2g tubes of glue to glue all rails.

1. Thoroughly clean all the oils off the v rails and extrusions using mineral spirits orsimilar solvent. Make sure they are completely dry before continuing.

2. Mark the start location of the v rails on the extrusions with a pen or light scratch. Thisneeds to be done first because the gluing will go quickly and you will not have time to



http://www.buildlog.net/forum/viewtopic.php?f=4&t=406&start=40#p2853)


measure.3. Test Fit the v rails. They are usually quite straight, but be sure they lay flat on theextrusions and are not bent in any plane or twisted.

4. Place an extrusion in front of you on the table. The shorter rails are easier, so startwith a Y axis.

5. Turn a v rail upside down.6. Quickly lay a wavy bead of glue along the wide underside of the v rail.7. Flip it over and place it on the extrusion with a slight wiping motion that would push the

glue towards the corner of the v rail. The v rail must perfectly register itself on thecorner of the extrusion.

8. Push it hard against both surfaces to make sure it is right. You only have about tenseconds to get it right, but it should only take 1-2.

Do this to all v rails and let them sit overnight without stressing the joints at all.

Note that each Y rail is different. They are mirror images of each other.

If you get any glue finger prints on the v rail, clean them off. Used a Scotch-Brite cleaningpad. Avoid damaging the rails. You should re-apply a light oil to the rails to prevent rusting.




Z Lead Screws (build four)

Three assemblies use an 8” threaded rod and one uses a 10” threaded rod.

1. Install the bearings into the bearing plates. You may need to press them in a little.2. Install one retaining screw into each of the bearing plates.3. Install one screw and nylon locking nut per assembly.

a. Install the ¼-20 short height nylon locking nut onto the shaft. These nuts aredifficult to install by design. The easiest way to install it is to install two nonlocking nuts onto the other end tightened against each other so they will notmove.

b. You can now use a wrench at each end to move the nylock nut. Use a bearingplate assembly (nut towards pulley) and a pulley to determine how far to go.The shaft should stop just flush with the bottom of the pulley. The pulley shouldnot rub the nut in any orientation, but check that and rotate a flat on the nuttowards the pulley if required.

4. Tighten the pulley set screw onto the thread rod. Once it is tight, back the nut down toclamp the bearing tightly between the nut and pulley.

5. Thread the table lift plate onto the shaft with the nut on the side of the pulley. Theupper bearing block “floats” on the threaded shaft, so just slide it on for now.

Install Y rails

The Y v rails can now be installed into the frame.

Note: Slide the (4) t-nuts into the lower slots of the rails for the Y axis belt brackets beforebolting to frame.

1. Install the left one first. Install it as close to vertical as possible.




2. Install the right Y v rail. This rail location will get tweaked for the width of the gantry, sojust get it close.

3. Install the last remaining frame extrusion that goes horizontally just in front of the tube.Be sure to add eight t-nuts in for the z lead screw assemblies and the tube brackets.

Install Z lead screw Assemblies

The main assembly drawing shows the location to assemble them. You want to install thenas close to vertical as possible. If they are not vertical, they will try to move the tablesideways as it moves up or down. This puts stress on the parts as they fight each other. Thebearing plates can be squared up to the frame by using a block against the extrusion.

1. Install the Z lead screw assemblies in the locations indicated on the assembly drawing.The longer two rods go in the front right and the rear left.

The belt will be installed later.

Assemble Table

Build the table per the assembly drawing. Note that the shorter extrusions butt into the longerones. Either screw the table surface to the frame for a more robust assembly or use doubleface tape or glue for a smooth top surface. Don’t forget the two t-nuts that need to be insertedinto each of the shorter pieces before you assemble the frame.




Install Table

Lower the table lift brackets to low and equal height. 90mm above the bottom is a good value.They don’t have to be perfectly equal because fine tuning needs to be done later anyway.The table is going to be slid in from the side. Put (1) screw, washer and t-nut into eachbracket loosely. The t nut is on the top. Now slide the table in from the left side. Slide it ontothe t nuts. See the dimension on the final assembly drawing to see how far to slide it in.Square up all the brackets and fully tighten.

Install belt and tensioner

Assemble Laser Carriage

1. Assemble the v wheels by pushing pressing the bearings into the delrin wheels. Isuggest putting a little super glue on the inside of the delrin wheels. Give the bearingsa wipe to make sure there is no oil on the outside surface. Make sure no super gluegets in the bearing. You should do all 9 wheels at this time.

2. Install the front (2) v wheels as shown on the drawing. The Delrin part of the wheelhas a step (see below) on it. Make sure the step faces away from the plate on all

wheels.3. Fully tighten, but not so much that you damage the nylon spacers.4. Using a permanent marker, mark the side or point of the spacer that is closest to the

center hole. You should mark all the spacers at this time. It is handy to visually see the




rotation position of the eccentric spacer after it is installed.

5. Install the rear v wheel as shown on the drawing.6. Rotate the eccentric spacer so that the v wheels are as far apart as possible (mark

faces out).7. Tighten the bolt slightly so the eccentric spacer can still be rotated. The long nylon

spacer is used to activate the limit switches.

Don’t install the optics at this time.

Cross Section Showing Wheel Step

Gantry Assembly

Assembling the gantry has a lot of steps. Please be careful to follow them in order. It will save




you a lot of time and effort.

1. Slide the laser carriage onto the gantry. The single wheel side (rear) goes on theshorter v rail.

2. Slide in (2) post-assembly* t-nuts for the idler pulley assembly on the back slots.

*Post-assembly t-nuts are used because they are shorter than the pre-assembly nutsyou use for nearly everything else. The pre-assembly nuts do not line up correctly withthe mounting holes in the idler assembly and the limit switch bracket. The nuts shouldbe oriented so the short sides of the nuts face each other to get the holes closertogether.

3. Slide in (2) post-assembly* t-nuts in the back bottom slots for the limit switch bracket.*See explanation above.

4. If the gantry extrusion was ordered with tapped ends, you can skip this step. Tap thefour end holes in the 2040 v-rail extrusion with the M5 .80 (or #10-24) tap. The existingholes are fine for tapping with either tap. If you use the M5 tap, you can use the M5socket-head screws you use for the rest of the assembly. If you use #10-24, you willhave to use #10-24 screws instead. Choice may be determined by which tap(s) youhave available. You also use the #10-24 for the frame leveling feet.

5. Install the (2) end plates.a. Install the screws until they are almost tightb. Set the assembly on a flat table. This will help keep the assembly square while




tightening the screws.c. Slowly tighten them until they are all tight and the assembly sits square without

rocking.6. Tighten the rear v wheel on the laser carriage until it is snug, but the eccentric spacer

can still rotate using a wrench.7. Rotate the eccentric spacer to bring the wheel in contact with the v rail. You want it

just tight enough that there is no play in the fit. If you can hold the assembly verticallyand the carriage just barely holds it’s position it is good.

8. Fully tighten the bolt without further rotation of the eccentric nut. Be sure to check themotion of the carriage as you slowly tighten the bolt. It often increases clamping forceif the screw was at all angled when it was loose. It should run smoothly. If there arebumps, investigate and correct. It is usually misplaced glue or a scratch in the rail.Buff out the problem until it runs smoothly and quietly.

9. Install (2) upper v wheels per gantry side bracket. The steps in the v wheel should beaway from the bracket.

NOTE: The lower wheels are installed after the gantry is installed in the enclosure.

10. Install the motor.11. Slide lens carriage over to the motor side.12. Align the center of the belt area of the pulley with the belt clamping cutouts in the lens

carriage.13. Install the X axis limit switch. Before you lock it down, adjust it so it activates just

before the v wheels would go off the end of the track. The switch should be adjusted




so it activates, but if it did not stop the carriage, the limit switch bracket acts as amechanical stop.

14. Create a twisted pair of 22awg wires XX.X” long**.**Not sure of the exact length required. I started with 60” and will update wheninstallation in machine is complete.

15. Solder them to the common and normally closed terminals of the switch. The two endterminals should be the normally closed ones. The middle is used for normally open.Verify with your DVM.

16. Strip 0.10” of the other ends of the wires and use a DVM to verify that the switch isnormally closed and opens when the switch is activated.

17. Tuck the wires into the bottom rear t slot and run them down to the motor bracket. Usea slot cover or cut small strips of 3mm craft foam to insert into the t slot as a retainer forthe wires.

18. Install the Y axis limit switch. Wire and test as you did on the X axis switch with a xx.x”** long set of wires.**Will update this when final measurements are complete.

19. Install the idler bracket parts.20. Loosely attach to gantry.21. Cut a piece of open ended belt 60.0 “ long (already cut in the BuildLog.net kit).22. Clamp one end to the motor side of the lens carriage so the teeth of the belt point up.

Let about 0.50” stick out the other side.23. Wrap the belt around the motor pulley, then around the idler bracket.24. Clamp the other end to the other side of the lens carriage. It is easiest to do this if the

carriage is near the middle. You should have about 1-2” sticking through. You cantrim this down when you are happy with it, but you might want to wait until the motionis fully tested. The clamping screws are easier to attach if the belt is loose. you cando this my moving the idler bearing in. Do not over tighten or you may damage the belt. The teeth on the belt will not allow it to slip.




25. Make sure it is the right length where the idler pulley can tension the belt. You arelooking for about 4.6lbs of total tension on the belt.

The rest of the assembly, especially the lower v wheels will be after the gantry isinstalled in the cabinet.

Test Gantry

Now is a good time to test the motion of the gantry.1. Connect the motor to the electronics module and use Mach3 to test it. Be careful not

to crash the lens carriage into the ends.

Align the Y V Rails

The distance between the Y v rails needs to be exactly the same as the distance between thev wheels. You will be using the assembled gantry as a gauge to do this, but be gentle, untilthe Y axis is aligned you can put a lot of stress on the wheels and rails.




1. Start by making sure the left side v rail/extrusion is fully tightened and square with therest of the frame. The right side v rail needs to be able to move a little side to side.

2. Near the front of the Y axis, set the left set of wheels on the left Y rail assembly.3. Lower the right side to determine the location of the right side. Get the right side as

close as possible then lower the right side of the gantry.4. Keep tweaking the right side until it is as perfectly aligned and parallel to the left as

possible.5. Move the gantry towards the front and back a few times to verify the alignment. There

is not much to keep the gantry square at this time, so be careful to keep itperpendicular the the Y rails.

Install Lower Gantry V Wheels

1. Once the right side rail is square and tightened, slide the gantry so far forward that thetop front v wheels drop of the v rail. This will give you extra space to install the lower vwheel.

2. Install the lower wheels onto the gantry brackets with the wheels as far a part aspossible (mark on spacer points down). The step on the lower v wheels is towards theoutside, just like the upper wheels (double check one more time)

3. Now slowly push the gantry back evenly until the v wheels engage the v track.4. Adjust the tension on the v wheels by rotating the eccentric spacer.

Install Y motor, belts and pulleys.

1. Install Y motor plate. There is a little protrusion off one side that is used to set theposition against the upper cross member.

2. Bolt the motor to the bracket.3. Attach a shaft coupler to each side of the motor. Use set screw to attach to shaft.




4. Assemble and install the rear bearing assemblies. Install them so the can still slide onextrusion the align them.

5. Cut (2) straight ¼-20 threaded rods to 13.25” long.6. From the side slide one through a bearing assembly.7. Run a ¼-20 nut about ¾” onto the motor side of the rod.8. Now thread the rods into the shaft coupler.9. Align the bearing assembly so the that shaft is square with the frame.10. Fully tighten to the frame.11. Install the front idler bearing assembly loosely to the frame where you will still have

about ½” of movement to the front to tension the belt.12. Cut a piece of timing belt to 38”.13. With the gantry located about the middle of the Y travel, attach one side of the belt to

the rear side of the gantry bracket.14. Loop the belt around the rear pulley, then around the front pulley and then to the gantry

bracket.15. It is easiest to now loosen the belt by moving the front pulley toward the gantry while

attaching the belt screw.16. Repeat the last few steps on the other side of the gantry.17. Tension the belts by moving the front pulleys forward. Again, you want about 4.6 lbs of

force on the belt.18. On one side of the motor, lock down the shaft position with the threaded nut on the

shaft.19. Now use a square or other means to get the gantry square. You can also use a gauge

off the front of the frame to make sure both ends are equal distance.20. Once the gantry is square, lock down the second nut.

Install Electronics Module




1. Place the electronics module inside the frame.2. Bolt it to the frame.3. Ground the module to the frame with a direct connection from the ground terminal

block to the frame.

Test grounding of frame

1. Attach one probe of a continuity meter to the ground terminal on the power entrymodule.

2. Touch the frame with the other meter probe all over the frame to make sure it isconnected to ground.

Test motors

Install front skin

When installing skins, just get each bolt started then move to the next. The t slots and ovalholes in the skin will allow it to slide around a bit. This makes it easy to catch t nuts that tendto slide around a bit when loose. A strong magnet is also helpful to slide nuts around wheninstalling skins.

1. Bolt front skin to frame.




Install control panel

1. Bolt the completed control panel to the frame.2. Place the E Stop switch in the off (in) position.3. Turn the power knob all the way down.4. Connect to the Laser Interface PCB.

Install tube brackets

The rough location of the tube brackets is shown on the top level assembly drawing. The finallocation might need to be adjusted based on differences between tubes.

NOTE: Make sure the nylon screws do not protrude into the center area, so the tube can slidein smoothly.

Move To Final Location

1. If the machine is not in it’s final location, move it now...before the tube is in. You donot want to move it much when the tube is in.

NOTE: Flexing or impacts could break the tube. If you want to continue to build, just removethe tube before moving and realign.

Install Tube

1. Carefully slide the tube in from right side.2. Once the tube is in the proper location, turn the adjustment screws by hand to center

the tube.3. The screws should just contact the tube so it cannot move. Do not put and pressure

on the tube. I don’t know how much pressure the tube can take, but you can probablyeasily break the tube by light hand pressure alone.

The threads in the tube bracket tend to be tight so it does take some strength to get then in,just make sure that is not going against the tube. I like to point my water fitting up so bubbles




tend to get washed out easier.

Attach Water Supply.

The cooling system is located outside the enclosure and it provided by the user. It can be aspecial designed system with radiators and fans or simply a large bucket. The tube is about20% efficient at full power so multiply the tube wattage by 5 or more to determine how muchpower you need to dissipate.

Your tube documentation should say how much coolant flow is required. When choosing apump, be aware that the flow stated may be without and restrictions. You may need tooversize the pump a little. In general most people use cheap submersible pond pumps. Theeasiest way to measure the flow is to run the water through the system and into a bucket ofknow volume. Time how long it takes to fill the bucket and do the math.

Wire tube

Tube construction varies, so you should refer to the documentation that came with your tubeand power supply to make sure these instructions comply with the requirements of your parts.There are many wire attachment talked about on the buildlog.net forum. The only universallyagreed item is that you should never attempt to solder to the electrode on the tube. It willcrack the tube or destroy the seal. I like to bind the power supply wires to the using very finewire.




1. Get some bare tinned copper wire in the 34 awg range about 4 inches long perelectrode. I usually get it by stripping stranded wire and using one of the strands.

2. Tie one end of the thin wire to the tube electrode at the beam exit end.3. Strip the ground wire from your power supply to the same length as the exposed part

of the electrode. You may need to extend this wire. This is OK to do using wire ofsimilar gauge, but never extend or splice the positive wire from your power supply.

4. Lay the stripped portion of this wire along side the tube electrode and use the fine wireto bind the wire together. Keep it tight and work your way to the end of the electrode.

5. Wrap the connector with tape. I strongly recommend silicone self fusing tape.6. Repeat the process for the positive lead from the power supply to the mirror end of the

tube.




Test grounding of frame

Give the frame another test to make sure it is grounded. You want to make sure that if anydangerous voltages contact the frame they are shorted to ground through the frame and notthrough a person touching the frame.

Test Tube

Danger warnings here....

If this is your first time, you are going to be amazed at the power of the beam. It will instantlyburn anything in it’s path. Be very careful.

1. Fire at a target like a thick piece of wood. Keep it close enough to the tube so it is sureto hit the target, but far enough away so smoke or debris will not contact the exit mirrorof the tube.

Install Mirrors

1. The first step is to do your best to get all the mirror centers as square as possible withthe frame.

2. Install the gantry end mirror in the center of the mounting slots and as close to 45° asyou can get it.

3. Use the mirror adjustment screws to move the mirror out evenly about 1/16”. This willgive you some adjustment forward and back when aligning the mirrors.

4. Now loosely install the lens carriage mirror. When attaching the mirror holder, be sureit is mounted so it is exactly perpendicular to the beam. Otherwise, the beam willangle slightly towards the front or back when it shoots down towards the table.




5. Use some sort of reference plane to make sure the center of the mirror is aligned frontto back with the gantry end mirror. I suggests moving the gantry to the front of theenclosure and using a front horizontal extrusion.

6. Install the mirror at the back of the enclosure.7. Use the adjustment screws to move the mirror 1/16” out.

8. Adjust the mirror so it is aligned with the center of the tube and the gantry end mirror.

Align Mirrors

Warnings:● You are going to be firing the laser with the mirrors unaligned. Be very careful.● Make sure everyone has laser safe safety glasses and you have a fire extinguisher

ready.● Never have your hands within 6 inches of the tube when firing it. In many respects, an

unfocused beam is more dangerous than a focused one. It has a very smalldivergence angle and will carry dangerous amounts of power density very far. It couldeasily start a fire or do damage far across the room and you might not immediatelynotice.

● Always fire the laser at something (target) that will absorb the laser energy in front ofeach mirror until you are sure it will hit the center. I like to use small wooden blocks,some people like to use thermal fax or calculator paper.

1. Place your target in front of the first mirror the beam will hit.2. Manually fire the laser and observe the mark made.




3. Keep adjusting the screws on the tube until the beam will strike the center of themirror. Ideally the beam is perfectly horizontal and square with the frame, but it is notrequired. Since the first mirror never moves, the beam should always hit the centerand the mirror can adjust for the out of squareness.

Note: Do you best to keep it square to limit the amount of adjustment required. The low costmirror mounts move the mirror center as they adjust, so you do not want to have to adjustthem too much.

You are now going to adjust a mirror to a moving target. While you want to hit close to thecenter of the mirror, that is not the ultimate goal here. The goal is to adjust the beam so it isperfectly square and does not rise up, down, left or right along the length of the path. If itdoes, you beam may still strike the workpiece, but your shapes will be distorted and not thecorrect size.

1. Move the gantry close to the rear.Place a large target in front of the gantry mirror.

2. Adjust the rear mirror until it would be close to the center of the mirror.3. With the target attached to the gantry move the gantry to the front.4. Make another spot and observe the difference. If the far spot is lower, it means the

beam is dropping along the path and needs to be adjusted up.

There are many strategies, but mine is to● Make a spot close to the mirror you are adjusting




● Then move to the far end and adjust until you are close to the first spot.

Since the first spot was not made exactly at the mirror you are adjusting, it is also off,so it helps to over adjust a little along the line between the two spots. This willcompensate the first spot also.

Do the “first spot...far spot...adjust” routine over and over again until both spots or righton top of each other.

If the resulting location does not hit the mirror in a decent location, you have to move themirrors. No amount of adjustment can fix mirrors in the wrong location.

The first alignment of a machine can take well over an hour. Once the mirrors are in the rightlocations, future alignment checks can be done in less than 20 minutes.

Install Rear Skin

1. Attach the duct flange.2. Slide the grommets into the slots. The slots allow the rear panel to be removed without

disconnecting the cooling system.3. Bolt the panel to the frame.

Upper Rear Skin

1. Install this with all screws except the hinge screws. The hinge will be installed withthe top cover. Be sure to align the hinge nuts with the holes before you install theskin, so it will be easy to install the cover later.

Top Cover




1. Assemble the top cover per the drawing. When assembling the frame be sure topre-load trapped nuts for the window and cover stops. Be careful not to damage thewindow when installing. It could crack if you over tighten the screws. You mayconsider using removable thread lock on the screw instead of over tightening.

Tips

Moving the laser. Be very careful moving the laser. Slight twisting of the frame due to unevenlifting or a bump could damage the tube. I always remove the tube when moving the laser asignificant amount.

Options

Assist Air




Assist air does two primary functions.● The first is it keeps fumes off the expensive lens. Some fume are corrosive or sticky

and will shorten the life of the lens.● The second is it cleans smoke from the beam path allowing more energy to reach the

workpiece.

Cable Carriers

The axes have provisions for cable carriers. They are not required, but clean up the wiring alot. Unless you have wiring or air hoses running to the laser carriage, you only need a Y axiscable carrier.

Z Motor

The laser is designed to use a manual Z axis, but an optional Z motor kit is available. Thisconsists of a stepper motor, stepper motor driver and the necessary mechanical parts tointerface it to the existing Z lift mechanism.

Relays

The DIN rail is over sized to allow additional item to be added like extra blocks and relays.The relays can be used to control external items like assist air blowers and exhaust blowers.Inductive motor type loads should use relays rated for three times the running current. Largemotors should use a contactor designed for motors.

There is a relay control board available that is designed to run 24V relay coils. These arecommon coil voltages for industrial automation type relays.










Documents

Bulldog Laser Cutter v200