Currently building a Tronxy X5S and I can't help but feel a bit disappointed with some of the "Out of the Box" design issues with this printer. Saying that, it would appear that the company listen to the feedback as there seems to have been several design changes to the original machine spec.
My first issue was with the gantry carriages. The way the flimsy acrylic is used to pre-tension the V-wheels is diabolical and was bound to fail sometime in the future. The design meant the gantry was really stiff to operate and seemed to be out of square, despite much tinkering with belt tensions and checking of frame squareness etc.
I downloaded and printed a set of the "Mega Gantry blocks" by "Graham01" which looked great. The problem is that it looks like the design of the extruder carriage has been changed and now has a rear mounted belt attachment point which collides with the Mega Gantry blocks.The new design also means the the belt path geometry is out of alignment.
Speaking of belt path, I then worked out that the reason for the stiffness in the motion of the gantry, especially in one direction, was significantly due in part to the utterly crap design of the belt idler system. A ball-race, sandwiched between a pair of fixed penny-washers using spring washers as spacers meant the bearings did not sit perfectly horizontal and caused the belt to ride up and rub hard against the non-rotating penny-washer, creating friction. So they had to go. I downloaded and printed off the corner pulley guides and the gantry pulley guides by "HanCheol" and had a go at fitting them. These are super strong but I had a bit of a problem fitting one of the T-slot nut as it clashed with the frame fixing screw head inside the aluminium extrusion, preventing the nut from rotating and locking.
So, I've had a bit of a remix. I hasten to add that as I couldn't use the mega gantry blocks STL's in Fusion 360, I scratch drew them up but they are based on the original design by graham01. Consequently, the gantry pulley guide is also scratch but of similar design to that of HanCheol.
The Corner pulley guide have had a simple change in that the fixing hole nearest the corner of the frame has been moved a couple of millimetres to clear the screw head. This allows the T-nut to turn and lock into place so an otherwise excellent original design.
The Gantry blocks have had a clearance slot made into the X axis support to allow the rear of the extruder carriage to pass above. The hole for one of the idler pulley screws has been realigned to provide a straight belt geometry between the corner idler and the extruder carriage. The mounting hole is now threaded M5 to remove the requirement of fitting a nut underneath the carriage block. The 2nd idler pulley now shares its axle with the rear inside V-wheel. To avoid preloading the pulley bearings whilst securing the V-wheel, an hexagonal hole is now located in the spindle hole for an M5 nut to be fitted. This allows the screw to be moderately tightened from the top to avoid crushing the pulley bearings but allows the V-wheel nut to be tightened firmly to prevent any play. The gantry pulley guides then had to be redesigned to fit the new configuration of the carriage blocks.
Update. 24 Mar 19. I've added a Version 2.1 for the gantry Pulley supports. The only difference is the addition of a hole directly above the screw which secures one of the T nuts in the top of the gantry (X axis) beam. I realised after printing that this would become a bit of a pain if you need to slacken to adjust the width after fitting all the block wheels. The hole is 5mm diameter to allow for either an Allen key or a pozidrive screwdriver blade to pass through.
Update 26 Mar 19. This is pretty much complete now so I'm taking the "Work in Progress" status off. I still intend to make some motor mounts to replace the crap OEM ones and that will ensure geometry is maintained but I'll update when I get round to it. I'm still in two minds about the limit switch bracket too as I quite liked the adjustment with the screw.
Any feedback welcome.
Update 24 April 19. Motor mounts are now designed and available.These are screw adjustable and maintain the correct belt path geometry whilst providing a strong and rigid mounting for the steppers. the detailed instruction are on the link here: https://www.thingiverse.com/thing:3584805
TECHNOLOGYOUTLET PREMIUM PETG
You need supports just for the recessed bolt holes for the Block pulley support. Print this with the pillars pointing vertically up and support from Bed only.
The same goes for the gantry blocks. Print them upside down on the bed. The only support needed here is for the extruder carriage clearance slot so again, support from bed only.
Print the corner idler pulley supports on their side, with the long foot (The front face of the model) face down on the bed. You will need "Support everywhere" for this one to form the 3rd column. I printed the first set out using 70% infill which was probably an over kill. The current working set were printed with 50% and they feel pretty rock-solid.
Assembly instructions and parts list.
Bits you will need to buy:
Plain 12mm idler pulleys. x 2. https://www.amazon.co.uk/gp/product/B07F3W4TCX/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
Toothed 12mm idler pulleys x 6. https://www.amazon.co.uk/gp/product/B07K8G9LS5/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
M5 x 60mm cap head screws x 6. See note below
M4 x 20mm cap head screw x 2 ( I had these lying around in my screw box).
M4 x 25mm pozi screw x 4 ( I had these lying around in my screw box).
M5 plain nut ( I had these lying around in my screw box).
The rest of the stuff following was recovered from the original components or in the spares with the printer:
M5 spring washers x 16
M5 Nyloc nut x 8
M5 x 50mm Pozi Screw x 2
M5 x 30mm Pozi Screw x 2
M4 x 12mm x 4 (2 will be left over after full assembly)
M4 plain washer x 6
M4 T-Nuts x 8
M6 Penny washer x 2
Aluminium spacer bush x 4
For the corner pulley idler supports:
M4 x 12mm Pozi screw X8
M4 T-Nuts x8
M5 x 30mm pozi screw x2
M5 Nyloc nut x2
M5 plain washer x2
Note. On each gantry block, the M5 x 60 screw which also supports the belt pulley idler needs to be threaded more than the standard twice diameter plus 12mm. (22mm in this case). This is because of the fixed plain nut which allows the V-wheel to be tightened without transferring the tension loads to the idler pulley which shares the same axle. I actually ran a die down a pair of the standard bolts to extend the thread but you can get fully threaded screws if you don't have an M5 die.
The stepper motors will need to be slid out towards the outside of the frame to align the belt path. The important one is the belt portion that goes between the moving X axis gantry pulley and the inside edge of the motor pulley. This needs to be parallel to the Y axis (Frame of the printer rail). The other side of the belt which travels to the corner idler pulleys can be angled as this has no effect on the geometry. I'll get around to designing a stepper motor mount in the future as the ones in the kit are crap.
Once you've printed all the parts you should have a left and right hand gantry block, a left and right hand Pulley support, a left and right hand corner pulley block and the following end stop support bracket from Graham01 (https://www.thingiverse.com/thing:2594291).
- Fit the two m4 x 25mm screws with an M4 plain washer through the horizontal holes in the gantry blocks. Fit a pair of T-nuts and spin them on a couple of turns. These will slide in to the X axis gantry rail rear face.
- Fit two M4 x 12mm through the holes in the gantry block above where the top surface of the gantry rail will sit. Spin on another couple of T-nuts.
- Aligning the T-nuts with their corresponding gantry beam slots, slide each gantry block onto the gantry until it abutts the stop edge. Tighten the 8 securing screws to pull the beam into the fully seated position and then slacken them off slightly. The blocks are a snug fit on the gantry beam so shouldn't fall off.
- Fit the M5 plain nut into the hexagonal hole on the top surface of each block. I recommend using the M5 x 30mm screw to fully seat the nut by screwing it into the nut from underneath and pulling it up snug. Once done, remove the screw.
- Place the gantry assembly onto the Y axis rails and check the rails are central to the clearance slot in each block.
- Next, get the pulley supports for each block. Fit the M4 x 20mm cap head screw into the inner turret. Now "CAREFULLY" remove the innermost M4 x 12mm screw from the top of the gantry block into the beam top slot taking care not to disturb the T-nut in the beam. Fit the pulley support onto the gantry block and screw down the M4 x 20mm cap head screw into the hole from which the M4 x 12mm screw was removed. Tighten and then back off a little.
- I recommend the first wheel axle to be fitted is the one which shares the idler pulley. This is the inner rearmost wheel. Take one of the M5 x 60 caphead screws and fit through the hole in the top of the pulley support. The hole is deliberately snug so its best to screw it in. If you are assembling the left hand gantry block, you will need to fit onto the screw between the pulley support and the gantry block, an aluminium spacer, followed by a smooth idler pulley, followed by a plain M5 washer. This can be a fiddle but one way of making it a bit easier is to push a small screwdriver up from the bottom and assemble everything onto that as gravity is your friend. Then as you wind the screw in, allow the screwdriver to be pushed back out. Screw in the bolt until it protrudes from the wheel well beneath the gantry block by around 3mm.
- Next fit an M5 spring washer onto the bolt, followed by the V wheel. Screw the bolt further in until it protrudes through the V wheel. Fit another spring washer, followed by the Nyloc nut. Tighten the nut until it just bites and then back it off. Now screw in the bolt until the head is flush with the top surface of the pulley support. It's best to hold the Nyloc nut whilst tightening the bolt as this will prevent the plain nut from pulling out of its recessed hole. Once the head of the bolt is flush, fully tighten the nyloc nut to secure the wheel. Check both wheel and idler are free to rotate.
- Now fit the remaining 3 wheels using the same method of springwashers and nyloc nut onto the two M5 x 60mm cap head screws on the outer edge of the gantry blocks and finally the front inner wheel using the M5 x 30mm pozi screw.
- Fit the M5 x 50 screw through the hole in the pulley support and assemble the idler. For the Left hand side, this will be a toothed Idler pulley, followed by an aluminium spacer, followed by one of the M6 penny washers. The screw should be screwed into the M5 threaded hole in the gantry block until it tightens. Do not overtighten or it will distort the pulley support.
- Repeat process for right hand gantry block. The idler pulley assembly will be a mirror of the left hand side. Ensure the gantry rail is free to travel the full length of the Y rails without sticking or tight spots. Once it has been manually travelled several times, fully tighten the screws securing the blocks to the gantry beam. Do a final check of free movement and also ensure the gantry is perpendicular to the Y rails. When the gantry is fully forward, the screw heads at the front of the gantry blocks should touch the front frame of the printer simultaneously.
- The corner idler assemblies are pretty much obvious in their assembling. Use an M5 plain washer between the two idler pulleys. No need to fit washers top and bottom as there are spacers modelled into the frames.