Ive temporarily wired up my new cheapo spindle and vfd to check all is working and set up the vfd.. Watercooling not connected (just run for a few seconds each time) and unshielded cables. It runs ok, but... The noise! I have a pretty strong feeling that the bearings are shot.. But maybe not? Ive no idea. Attached is a recording made on my phone.. It sounds worse than it is (phone was 10 cm from spindle and exaggerates the high pitch vfd noise) Note: i had to rename the file from. Mp3 to. txt to get it to upload, you will need to rename it to play at 7400 - 7600rpm there is a resonant type squealing, most noticeable when i turn the speed back down. and a lesser one around 11-14000 (didnt note it precisely) Is this "within acceptable". Or is the spindle toast? Can't imagine shipping it back is an option.. Also imagine a bearing change might be impractical (although i do have a motor repair and rewinding shop nearby, dont know if spindles are considered "exotic" in these places?) As usual, many thanks for expert opinions..
What spindle do you have? There are a million different variations. I'm not by my pc to rename the file and won't be anytime soon, but is this the first time running it? How does it feel when you turn it by hand? Often times, the bearings do need a slight break in after sitting. Are you 100% sure your VFD parameters are correct? Is it mounted to the machine? If so, what machine?
Thanks for the reply, its about the 5th time ive fired it up, obviously only for a few tens of seconds each time (probably 1 minute was the longest) since the watercooling is not connected. Its not currently mounted in a machine as i dont have the kit yet.. Lying on my desk. Shaft seems nice and smooth to turn by hand, but doesnt spin for ages when i spin it manually, stops after a few turns. I think the vfd settings are correct, all seemed appropriate settings. i did a fair amount of research and found a very nice pdf that covered the whole setup. Running with 400 hz, current limits etc correct, 8khz carrier frequency.. Now that you mention it i didnt check rotation direction yet, but i guess that shouldnt matter for noise. Photo attached showing the logo etc. Its quite obvious its cheap from the paint job, lack of earth connection, and suspiciously thin wires internally from plug to windings..
It does sound odd to me. Did you spend alot? The idea with chinese spindles is you can buy them and they don't break the bank but I think it might be the spindle lottery sometimes. From what I have been researching in spindles since I have built my diy machine is i have seen spindles bearing are replaceable. Some come with spare bearings. So I guess the quality bearings your spindle has is the question. Maybe you can take it apart. Or you can run it till it implodes. What I would do. Get the water cooling system going! Because there is no cooling maybe its heat related. Even the slight amount of expansion of metal from heat might cause weird noises. After coooling installed and still noisey. I would make inquire to the place I bought it see what the vendor says. <== If nothing. I would see if there was play in the end shaft holding the endmill. None? Just noisy. I would run it see what kind of cuts it makes. If solid then run it till it needs attention. If it has slop in the shaft I would probably figure out how to take it apart and replace bearings. Check wiring. Maybe it not getting 100% juice it needs. Check connections to the power cable feeding it make sure there solid. Maybe buy a back up so you are ready when it implodes.
No, i didnt spend a lot, it was 239 euros for both spindle and huanyang vfd. I chose that model because a) it had an er16 collet b) it was available in europe c) it didnt come with crappy extra watercooling bits i didnt need (already have old pc watercooling stuff to reuse) and d) it was cheap. I kinda assumed that all these chinese spindles were probably from the same factory so didnt pay any attention to the brand (not that i think it was mentioned) Ive generally had reasonable luck with cheap chinese stuff.. Maybe i lost the lottery this time! Im happy to run it till it dies if it cuts ok, but i dont want it to destroy the vfd or fly to bits explosively (scary!). If this risk isnt an issue then ill see how it goes. I could try contacting seller, but i dont expect to get an offer of a replacement just because "it sounds a bit odd", and shipping it to eastern europe again would probably cost more than a new one.
That does appear to be a legit unit with angular contact bearings. I just got to play it. The whine you hear is the electrical current, but you already knew that. The resonance you here at 23s and the screech at 44s are not normal. There is technically a break in procedure, that may take care of it. Get water hooked up to it. Set it to 5000rpm, and just let it run for half an hour. If you hear the sound getting worse, stop and contact the seller. If you plan top do the repair yourself, make sure the seller has agreed to it.
thanks for the advice, ive got some tubing and connectors of the right size for my pump in the post, ill park it until those arrive, then try the break in procedure. ill have to modify the vfd settings to get down to 5000 rpm, the minimum is currently set to 6000. (on that note, ive read conflicting things about minimum rpm for watercooled spindles... those who say 6000 should be the minimum, and others who say, since its watercooled, you can go slower.)
i have found the spindle manufacturer (maybe?) Technical parameter-常州市华江电器有限公司 they say the spindle is rated from 1000 to 24000 rpm.. ive never heard of a spindle being run at 1000 rpm, although ive not got anything beyond "forum level" experience so far. they also say to run-in the spindle starting at minimum rpm for 30 minutes, then increase in 3000 rpm increments with 20 minutes at each speed. here is the chinglish: "In the process of saving and transporting the spindle, the high speed grease status in the bearing will be changed, and the customer should run the spindle under the minimum speed for 30 minutes firstly, then increase 3000 RPM as a shift for each following 20 minutes. If you start running in high speed directly without run-in period, the spindle will cause the phenomenon such as foreign noise, high heat rise etc., and it affects the bearing life. The spindle should be turned on (low speed) for 15-30 minutes weekly for the long term use purpose." hopefully ive not damaged the bearings question is, should i start at 5000 rpm as suggested above, or listen to their published spec and run it at 1000 rpm for 30 mins ?!
Do not run it at 1000rpm! Also, that list technically says 1rpm to 18k/24k rpm. The spindle can run at whatever rpm it is driven at. The VFD is different. If you have ever dabbled with remote control brushless motors, you'll notice that even high end ESCs (electronic speed controllers) have a bottom end. At the bottom end, they stutter at best. They are made to be able to put up with it, but these VFDs running at much higher voltages are not! Let 4000rpm be your bottom end. A lot of sellers even say a minimum of 8000rpm, but that's just to cover themselves. There are different quality levels with VFDs. The HY are the typical hobby units, but even among our community, the HYs are cloned, and there is a significant difference between the two.
Just an update on this: I tried running in at 4500 rpm for 30 mins, then gradually increased speed in small increments over the next hour.. The noises changed a bit and came on at different rpms after that.. Came back to it a couple of days later, and it sounded just like before. I messaged the seller, who asked for a video.. I sent a video showing ths sound from 5000 rpm up to max and back down. He was very nice! Said the factory had checked video and agreed bearings were probably shot.. First, he asked me if i could replace the bearings locally (i guess he had to try eh?). When i said its not possible, and that shipping back to china wasnt going to fly, he proceeded to refund me the full price of the spindle (they dont sell the er16 collet version seperately from vfd, so sending a replacement wasnt an option either). So now ive ordered a new one from a different seller (seems same model, as do all er16 1.5kw ones ive seen). So i now have a spare spindle for free (assuming new one is actually better!) If anyone wants name of seller im happy to share, although they seem to come and go almost daily and use a random-word-generator for their names.
To be honest I've no idea.. Selling it seems impractical (defective, high shipping costs). Itll probably sit on the shelf, waiting for a highly unlikely spindle failure. I might take it to the motor servicing shop nearby and see if they have experience with high speed spindles (they mostly do household water pumps and agricultural stuff, this is south Italy after all). - I would imagine they would have proper tools to change bearings at least..
