Rainbows | 17/04/2017 09:55:53 |
658 forum posts 236 photos | Me and some friends were talking about building a CNC mill/router.
Has anyone used the green spindle heads from aliexpress?
In particular was looking at these two spindles Was just wondering if anyone here and had them and what their general customer satisfaction was. Any having to disassemble, clean and reassemble like people tend to do with chinese mini lathes?
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JasonB | 17/04/2017 10:09:36 |
![]() 25215 forum posts 3105 photos 1 articles | Max speed rating looks a bit low if you are using it as a router particularly item one. |
mike T | 17/04/2017 10:38:35 |
221 forum posts 1 photos | In both cases the BT30 tool holder appears to need a drawbar and manual tool change It does not look like there is enough internal room for a lever action quick change pull button mechanism. Are there any quick change spindles listed? Mike |
Andrew Johnston | 17/04/2017 10:40:29 |
![]() 7061 forum posts 719 photos | Maximum speed ratings are a bit slow for a CNC mill, let alone a router. Andrew |
mike T | 17/04/2017 11:08:03 |
221 forum posts 1 photos | Andrew, Jason My EMCO F1 CNC mill has a BT30 spindle with a quick change tool lever. The maximum speed of the spindle is only 2,500 RPM. It eats steel, brass and aluminium fast enough for my needs, even down to 2.0mm diameter cutters. Yes, a faster spindle would be nice for really small cutters but in my opinion 2.500 RPM is more than adequate for most model engineering CNC mill work. You always need to reduce speed for cutting steel and other hard materials Mike |
Rainbows | 17/04/2017 12:12:37 |
658 forum posts 236 photos | I was wondering why the rpm rating is so low. I can't think thats the maximum bearing RPM? However I was thinking of making an attachment for when its being used as a router which would be a epicyclic gear box that would take the 3000/6000 RPM BT30 to 20,000RPM or so on a ER collet. For quick change I was thinking a pneumatic tool to pull in the draw bar. Seen it done on bridgeports atleast. |
Andrew Johnston | 17/04/2017 12:14:38 |
![]() 7061 forum posts 719 photos | Posted by mike T on 17/04/2017 11:08:03:
Yes, a faster spindle would be nice for really small cutters but in my opinion 2.500 RPM is more than adequate for most model engineering CNC mill work. You always need to reduce speed for cutting steel and other hard materials Quite so, but it's all relative. I run 10mm three flute carbide cutters at around 2500rpm in low carbon steel. The last time I CNC milled a HSS toolbit I ran a 6mm cutter at 3000rpm. For aluminium I'm limited by the top speed of my CNC mill, about 5100rpm. I have just fitted a high speed spindle to my mill. On the first real job I ran a 1mm cutter at 24000rpm and 350mm/min in bronze. Even at 24000rpm each part took nearly 4 hours, so it wouldn't really have been practical at lower speeds. The CAM program was estimating around 20 hours at 5000rpm. Then again I'm impatient and don't like waiting. Andrew |
mike T | 17/04/2017 13:01:18 |
221 forum posts 1 photos | Andrew, As you say it's all relative. If you are intending to mill with larger cutters then the BT30 mill head running below 3000 RPM is quite adequate. However if you really need to be operating at 24000RPM, then a self contained high speed engraving motor/spindle with a tiny ER collet would be more appropriate. There are lots of water cooled engraving motor/ spindles to chose from in the Bay. A 4 hour 24000 RPM or a 20 hour 5000RPM machining job, does not sound like 'normal' model engineering work to me. Ha ha. Mike Edited By mike T on 17/04/2017 13:04:54 |
Rainbows | 17/04/2017 13:20:29 |
658 forum posts 236 photos | Jesus what was the part you were making? And I read the common high speed chinese spindles will do steel but wear out pretty fast compared to when they just get used for wood. Still considering which of all the spindles to use. Such is the issue of wanting to use big and small cutters and wood and metal on the same machine. Edited By Rainbows on 17/04/2017 13:25:11 |
JasonB | 17/04/2017 13:26:25 |
![]() 25215 forum posts 3105 photos 1 articles | It was the bevel gear for his model traction engines governor, have a look back at what did you do or workshop progress threads. I also wonder how well the plan ball bearings run, for that sort of money it would be nice to have taper roller bearings |
Andrew Johnston | 17/04/2017 14:43:12 |
![]() 7061 forum posts 719 photos | Posted by mike T on 17/04/2017 13:01:18
A 4 hour 24000 RPM or a 20 hour 5000RPM machining job, does not sound like 'normal' model engineering work to me. Who said I was normal? The high speed spindle is self-contained (ER11) and not quick change, which has the problem of not being able to use tool tables. To save people the bother of looking, here are the parts mentioned; as Jason says 16 tooth 16DP bevel gears for my traction engine governors: When starting in CNC milling I used relatively large cutters with commensurately slow speeds. Given that my CNC mill is not the most rigid of machines I eventually fell in that maximum metal removal rates were best achieved with smallish cutters running fast and at high feedrates. Although my CNC mill has two belt driven ranges, the basic drive is via a VFD. So more spindle power is available at the higher end of the speed ranges; equals better metal removal rates. Andrew |
John McNamara | 04/08/2017 16:36:29 |
![]() 1377 forum posts 133 photos | Hi Rainbows Just noticed your post re BT30 spindles It would be nice if the manufacturer offered them with a quick change mechanism. Regards |
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