I have designed a new badminton load spreader for the Wilson Baiardo stringing machine. It is made from an extremely durable plastic and can be made to order in different colors. Currently I can make it in two colors: Black or Orange Price 37 € for a pair + shipping (varies on destination) - payment via Paypal. Please contact me if you would like to order some for your Baiardo machine
I am using PETG filament and solid infill. It feels extremely solid, like it will last forever I am currently working on a PETG stencil template for badminton. PETG is difficult to paint on ... my idea being that the stencil paint will not stick and ruin the template.
PLA is almost twice as stiff as PETG. which is better in this application. if the support is too soft, it won't serve its purpose.
Actually petg is a great choice, it is stoffer than pla and only outdone by ABS of Carbon Filled filaments. If this thing fails you could check out ABS, but it's more tricky to print (source, i own my own 3d printer) Verstuurd vanaf mijn H8324 met Tapatalk
PLA is stiffer than PETG, but PETG is stronger. In this application, being strong is not the most important. While being stiff is better. If the support flexes then it won't serve the purpose of being a support anymore.
According to a CNC kitchen stiffness test performed with a flat rectangular bar part, the measured values where: Higher values = less deformation PLA - 3300 MPa ASA - 2300 MPa PETG - 1900 MPa It took me 23 revisions (drawings) to get the Baiardo load spreader model right - so changing print material to PLA is easy. I will change the material to PLA going forward. Thank you for the input Kwun
That's very interesting, i work as a mechanical engineer and every single time a PLA part failed the switch to PETG made it better (one prototype was actually a compressive test, quite like the loadspreader) My source at the time was this https://3dprinterly.com/pla-vs-petg-is-petg-stronger-than-pla/ But it's okay if Im wrong and I stand corrected , it's always fun to see more 3d printing applications Verstuurd vanaf mijn H8324 met Tapatalk
Just did a tension test on the PETG version using one my own badminton rackets, measuring the deformation with 5 kg tension as the baseline. Measure from top (outside) of racquet to load spreader bottom (outside), table locked, pulling on a BG80 string on the main start. Tension = Measured length 5 kg / 11 lbs = 28,9 mm 10 kg / 22 lbs = 28,8 mm 15 kg / 33 lbs = 28,6 mm 20 kg / 44 lbs = 28,45 mm So there will be a deformation of up to 0,45 mm at high tension. Keep in mind this also contains the deformation of the racket head. I will print a PLA version and repeat the test.
remember we are talking about stiffness not strength. PETG is higher in strength, ie it will less likely to break, but before breaking, it will deform more than PLA per unit force applied. For an end support / load spreader, we want to have more force spread to more teeth in the spreader. If the material bend and the teeth moves, it will bear less force. providing less support, which is not desirable. The strength of the material don't matter (I don't think it will stress PLA/PETG to breaking point as a load spreader).
How many main strings did you pull to get that amount of deflection? Can you do the same experiment without the load spreader? that will be the absolute worst case. You might have to modify the way you take the measurement as you won't have the load spreader. But this measurement is important as it forms the baseline of everything. All variations of load spreader design will have to be between this worst case measurement and the best case, which is no deflection at all.
I only pulled on the main start. So 2 strings through A1 on the racket. Without the load spreader ... I might have to sacrifice an old racket But I can do a comparison where I use the original load spreader that comes with the Baiardo.
So I completed a very pseudo scientific tension test. The test subject is an old racket with an existing frame crack at the throat at 5 o'clock. I could not convince myself to use my own racket ... wonder why I used the stock, PETG, PLA and without a load spreader. Every measurement was done 2 times (average) at 5,10,15 and 20 kg tensions using BG80 through A1. 5 kg tension is the baseline and the measurements are relative to the baseline. My measurements and my poor job at making a deformation table: ---------------+STOCK(mm)+PETG(mm)+PLA(mm)+Without/Racket only(mm) _5 kg / 11 lbs | 0,00 ___| 0,00 __| 0,00 _| 0,00 10 kg / 22 lbs | 0,30 ___| 0,20 __| 0,30 _| 0,10 15 kg / 33 lbs | 0,50 ___| 0,30 __| 0,45 _| 0,10 20 kg / 44 lbs | 0,40 ___| 0,40 __| 0,60 _| 0,20 ---------------+---------+--------+-------+------ Worst result___| 0,50 ___| 0,40 __| 0,60 _| 0,20 Keep in mind that Stock/PETG/PLA measurements also contain some racket head deformation. My analogue calipers measuring tool is also a source of measurement uncertainty ... and my skills at reading the scale (using magnifiers). My measurements seem to point to the PETG filament as deforming slightly less than PLA. It might be because the PETG filament has a better layer adhesion than the PLA. Within same material you also have some uncertainty coming from colours, filament components etc. More surprising to me is that the PETG actually behaves slightly better than the stock. I suspect the stock load spreader is manufactured using ABS injection moulding ... but this is just a guess
If you are only pulling 2 strings that's not really stressing the support. The purpose of the story is to support the frame portion away from the 12 o'clock.
I really appreciate your feedback Kwun So now I have done another test using 10 strings (A1-A5) on the mains using the Stock ,PLA and PETG load spreaders. At different tensions (5kg, 10 kg, 15kg and 17kg) I measured all three pins on the load spreader (left, middle, right). I do not want to kill my Stock load spreader, so I stopped my test at 17 kg. After a lot of pulling and measuring, the worst results came at 17 kg / 37,5 lbs - with 5 kg being the baseline: (lower is better) Worst deformation middle pin Stock 0,6mm PLA__ 0,6mm PETG_ 0,3mm Worst deformation left/right pin Stock avg. 0,2/0,6mm PLA__ 0,2/0,2mm (I guess I hit dead center) PETG_ 0,1/0,3mm Results appear to be more or less the same as the previous test with the worst deformation being on the middle pin. I am a bit tired after all the testing now ... and I hear the couch is calling me
Thanks for all the work testing it. Good work! It does seems that PLA is less stiff than PETG despite the specifications out there!
Well, there is more to it. If you print with an FDM machine like most DIY home prints you have layers of filament. All prints are at their strongest in line with the layers (XY) and weakest perpendicular to them (Z), so if the "layers are stressed" it depends on how well they melted together. (there is even a trick to this, try to oriënt the print in such a way the layers aren't stressed) . If you print just a bit hotter, the layers can melt together and form a more solid piece. With different setting, for all I know PLA could be stronger, 3D printing is a real rabbit hole Verstuurd vanaf mijn H8324 met Tapatalk
For now I will conclude my test. It was a good learning experience I suspect it is the rounded shape of the load spreader that gives PETG a slightly better behaviour than PLA - simply because the force is not perpendicular like the test in the CNC Kitchen video. I agree to the rabbit hole analogy ... similar to stringing ... the learning process is ongoing I am already using several custom print settings to end up with a good quality load spreader that is comparable to the stock one. I will say that both PETG and PLA should work fine for this application - but in the end the print quality matters. Actually this all started because I could not buy a spare load spreader from Wilson. You have to buy a complete toolkit and that is very expensive. I thank you for your feedback Kwun and jerby it is much appreciated
