Assembly of a HDIY Gantry Kit from Precision Plasma LLC
Precision Plasma LLC offers a gantry kit where the customer performs all assembly to reduce the cost of the kit. It is based on our Heavy Duty line and is named HDIY since assembly is required.
The aluminum extrusions will be drop shipped directly from 8020 to reduce costs. The extrusions and aluminum gussets will arrive via UPS in 2 boxes.
In the small box, you will find the following components:
In the long box, you will find the main extrusions.
Cut open the plastic wrap to remove the extrusions.
The next step will be to tap the ends of the (2) long extrusions to accept a 5/16-18 bolt. No drilling is required since there are holes of the proper size in the ends of the extrusions. This will need to be done on both the 1-1/2" x 1-1/2" extrusion and 1-1/2" x 3" extrusion.
We made a wood fixture for a vice and use an impact wrench since we do this quite often. A tap handle will work just fine since you are only building 1 machine.
Next, you need to cut down the gear rack based on the width of the gantry being built. Make the gear rack 6" longer than the nominal size. For example, if you are building a 5' wide gantry, cut the gear rack at 5'-6".
Next, you will need to apply 3M VHB tape to the gear rack.
The first step is to clean the rack. This is done with alcohol and a scotchbrite pad. Wipe down with alcohol and a white paper towel. Clean until the paper towel stays completely white. Make sure the alcohol is dry before applying the tape. We use an inexpensive wall paper roller to roll the tape after applying to get out the air bubbles and we trim it with a single edge razor blade.
Next, center the gear rack on the 1-1/2" x 1-1/2" extrusion. It will be applied to the flat side of the extrusion and will be lined up with the radius. Mark a line once you have it centered.
The easiest way to apply the gear rack is to peel back only 6" of the tape protective cover at a time. Apply it starting at the line you made. Once you have it attached, lift the unattached end of the rack, peel back another 6", and continue working your way down the extrusion. It is much easier to keep it straight using this method as opposed to removing all of the tape protective covering at once.
The main rail will be shipped with the components directly from Precision Plasma LLC.
Rubber bumpers need to be attached to the ends of the rail to prevent the carriage from running off. They will be attached with 1/4-20 socket head cap scres and will require drilling and tapping of the extrusion.
Center the bumper with the width of the rail and have it flush with the end of the rail. Clamp it in place and use a transfer punch to mark the holes.
Drill, tap, and bolt on the bumpers.
The rail is hollow at this point, so you only need to drill and tap 3/16" thick aluminum.
The assembly of the main gantry extrusion are next. First, drop a 5/6" socket head cap screw into each hole in the v-rail extrusion.
Thread on a 2 projection weld nut onto each screw making sure to have the thread projection away from the v-rail extrusion.
Flip the assembly over and slide the weld nuts into the 1-1/2" x 1-1/2" extrusion. Make sure the gear rack it facing towards the closest v-rail and not towards the other row of weld nuts.
Next, slide the weld nuts into the 1-1/2" x 3" extrusion.
Center the aluminum extrusions on the v-rail extrusion. Use a square to make sure the 8020 extrusions are flush with one another and clamp the extrusions together.
Clamp the extrusions together as you tighten the screws to make sure the extrusions are touching. This will also center the v-rail on the extrusions.
The next step is to attach the stainless tray to support the cable track. Center the pan on the bottom of the 3" wide extrusion and mark each hole.
Slide in a 5/16 weld nut and line up with each mark.
Insert a 5/16 x 1/2" long flange bolt into each hole and tighten to attach pan. Be sure to verify that it is centered between the ends of the extrusions before tightening the bolts.
The main gantry extrusion assembly is now complete.
There are 3 belt reduction units required for the gantry. The assembly procedure is the same for all even though the side plates will differ in shape. They all have the same bearings, gears, shafts, bearings, belts, and hardware. We are showing the assembly of the carriage belt reduction since you need to make a choice at this point. Do you want to have the side cable track on the right hand side of the machine when looking at the Z axis. If so, build the reduction unit to match the following pictures. If you want the cable track on the left hand side of the machine, you will have to build the belt reduction opposite. This will require the 2 side plates to be flipped over when assembling.
First, you want to square up the bearings to make assembly easier. The bearings are self aligning which means they have a ball and socket design. Using the shaft as a lever, place it in the bearing and place the bearing on a flat surface to see if the shaft is sticking straight up. If not, use the shaft as a lever to move the bearing insert so that it is. A rubber mallet is also a good way to make the adjustment.
Place the bearing on the plate and visually center the bearing mounting holes with the corresponding holes in the plates.
Insert a 3/8" x 7/8" long flange bolt into the mounting holes and tighten in place with a 3/8" jam nut. Two bolts are required per bearing.
Insert a 5/16 x 5/8" long flange bolt into each of the perimeter holes and thread on a 1/16 coupling nut hand tight.
Insert the shaft into the bearing of the plate with the cable track tab and have it protrude past the bearing by 3/16". NOTE: On the side belt reduction units, this will be the flat plates (not the formed plates).
Slip on the timing sprocket and belt.
Place the 2 halves together and add the remaining 5/16 x 5/8" long bolts.
Line up the set screws on the flat of the shaft. Center the timing sprocket between the plates and tighten all set screws. Rotate the sprocket to verify that it does not rub against the bearing attachment bolts. If it does, you need to readjust the timing sprocket. If it still rubs, your bearings are not centered and you will need to reassemble.
A 1/2" collar should be added to the output shaft near next to the bearing and then the gear should be added to the end of the shaft. On the side reduction units, the gear hub should be facing the bearing and the gear should be flush with the end of the shaft. On the carriage belt reduction unit, the hub should be facing away from the bearing.
The next step is the carriage plate assembly.
Install the 1/4 x 1-1/4" long bolts through the plate in the holes closest to the flange. Install the concentric bushings as shown.
Add the v-guide wheels and 1/4" flange nuts.
Place the carriage plate assembly on the Z axis and attach with (4) 1/4 x 1/2" long button head screws.
The bottom wheels are held on with eccentric bushings that have a hex for adjusting.
Set assembly on the main rail, install the bottom wheel assemblies with the eccentric bushings, and tighten eccentric with a 9/16" wrench.
Tighten the wheels enough so that you cannot skid the wheel on the rail if you hold the wheel with your hand. Move the carriage assembly back and forth to verify that it rolls smoothly.
Install the belt reduction unit onto the carriage plate flange with (2) 5/16 x 5/8" long flange bolts and nuts. You will also need to remove (2) of the bolts used to assemble the belt reduction unit. Replace the (2) bolts with 5/16 x 3/4" long flange bolts.
Adjust the gear to line up with the gear rack. When tightening the reduction unit to the carriage plate, firmly press the gear against the gear rack.
Install the cable track onto the gantry using 1/4 x 3/4" long bolts through the belt reduction unit bracket and 1/4 x 5/8" long bolts through the stainless pan.
Picture of the front of the assembly.
The end assemblies are made from 3x3 extrusions and aluminum brackets. NOTE: This is the assembly procedure for mounting the cable track on the right hand side when looking at the Z axis. Build opposite if you want the cable track on the left hand side.
Install 5/6 x 5/8" long button head screws and weld nuts in the triangular gussets.
Install them flush with the end of the short extrusion.
Center the assembly on the longer extrusion.
Install (4) 5/16 x 5/8 long flange bolts and weld nuts as shown. These will be used to attache the side belt reduction units at final assembly.
Install the bearing bracket as shown with (4) 5/16 x 5/8" flange bolts and weld nuts.
Install the side guide bearing bracket on the bottom of the assembly with (4) 5/16 x 5/8" button head screws with weld nuts.
Add the cable track bracket as shown with (4) 5/16 x 5/8" long flange bolts and weld nuts.
Install (4) weld nuts in the extrusion one each end opposite the outside bearing plates. Install an end cap once you slide in the weld nuts.
Install the wheel shields with 5/16 x 5/8" long flange bolts.
Install the angle and gusset as shown below with 5/16 x 5/8" long button head screws. The gusset faces the shield side and the angle faces the side with the (4) extra bolts.
There are 3 different wheel assemblies. Top: upper wheel assembly. Center: bottom wheel assembly. Bottom: side wheel assembly.
Install the wheels in the center of the slots. Finger tight is fine at this point since they will need to be adjusted when installing the gantry.
NOTE: The opposite side assembly is nearly the same except it does not have a cable track bracket and the bottom brackets do not have slots for side bearings.
Slide the end assemblies into the ends of the main extrusion assembly. NOTE: These ends are adjustable to exactly match the fabricated frame and rails.
Install the end plates with 5/16 x 5/8" long flange bolts. There is an extra hole in the plate that should face down. This allows the far motor wire to run through the main extrusion of the gantry.
Install the router or torch mount to complete the assembly.
Add the end belt reduction units after the gantry has been installed on the frame.
The HDIY gantry now has an option to make it compatible with the candcnc.com Bladerunner Servo controls package. Due to the length of the servo motors and planetary gearboxes, the side assemblies of the HDIY gantry needed to be modified to allow the servo motors to be mounted under the gantry. The assembly procedure is nearly the same, but the upright 6" extrusion was replaced with a 3" extrusion and 3" x 6" aluminum plates. This allows for a 3" x 3" space in the side assemblies to fit the motors and gearboxes.
Kits are now shipping with a 5" long shaft for the carriage belt reduction rather than the 6" long shaft required on the side belt reduction units. This eliminates one collar and allows for the hub of the gear to be placed next to the bearing. See picture below:
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Assembly of a HDIY Gantry Kit from Precision Plasma LLC
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