Design & Build of Lanky - A Ozzie 8x4' long gantry router

Hi,
to my knowledge this spindle (Jager 5.5kW) was not available at the time I bought mine. Had it been available I might have bought it rather than the new Dake (Chinese) 3.5kW spindle I did buy.

Looking at the torque speed curve the Jager is rated at 30,000rpm, that is to say that is its lowest speed at which it attains rated power (100% duty cycle, or S1). It's rated torque is therefore
1.8Nm. That is a lot better than my existing little 800W spindle (0.3Nm) but still very much less than my new Dake spindle. The new Dake will do 40,000rpm but its rated at 10,000rpm
and its S1 torque is 3.34Nm

I have been using my little 800W 24000rpm spindle for ten years, and its been great. I use it particularly for circuit boards. It would be nice to go faster than 24000rpm.....but not a deal breaker
either. It would also be nice to have more power, but again I've been able to use 800W to good effect for ten years. If there is an area where my 800W spindle is deficient its torque at
low speeds...it just does not have decent torque at low speeds and therefore VERY limited when it comes to cutting steel and stainless.

This new Dake spindle has ten times the torque and at under half (10000/24000) speed of my 800W spindle. I'm thinking that being water cooled I could expect rated torque (3.34Nm) at one
quarter of rated speed, ie 2500rpm, which would be good to drive a 12mm tool in steel. You would still have to be careful, 3.34Nm is by no means a surfeit of torque....but you can drive a 12mm tool in
steel and stainless quite happily if carefully at 3Nm.

I have decided I really don't need the extra speed (40,000 rpm vs 24,000rpm) nor do I need the extra power (3.5kW vs 800W), but what I really want is more torque at lower speeds....
so I think the Dake is a better choice for my needs which is coincidentally faster and way more powerful.

Jager is such a bloody good name as are the RegoFix toolholders, certainly has bragging rights over any Chinese made spindle.......but bragging rights don't really make better parts....do they?

Craig

Hi Craig - I have nothing against 2nd hand parts. But when I design a machine its designed for production. Which means the supplier has to be able to supply one or 100 parts, prefer 1000 parts. If someone askes me to do a Rolls Royce bespoke job and the budget is there I'm happy to use appropriate parts... I used to work next to a company that did gold plating, gold recovery and stuff. It had a triple gated entrance with cameras and detectors and guards... Maybe I could get them to plate the chinese spindles.. value adding? Peter

Hi,

how many of these things do you expect to make? Be realistic here....all very well to make a machine production ready but have any of your designs been repeated?

I would guess a new Jager spindle (5.5kW, HSK32) will be north of 10000Euro. What is being offered is the same spindle AND ten RegoFix toolholders for $2000USD, that is something like 1/4 to 1/5th
of new price. Present that option to your customer, according to the Ebay ad there is two available.

If your customer wants a spindle in the 30,000rpm to 40,000rpm range for continuous operation this Jager would be ideal.

As I pointed out I am more interested by increased torque at slower speeds which indicates a different choice.....but sure hard to pass up on Jager quality.

Quite frankly there is not a Chinese spindle made that can hold a candle to Jager.

Craig

Hi Craig -There are 3 Scoots in the wild. Scoot is production ready. How many would you like? I'd like to sell 1 every month that would give me confidence to start moulding/casting parts vs fabricating them. In regard to parts there is always a range from Rolls Royce to Chery in terms of cost and performance. Just have to find the balance point that suits the customer...
Here's Matt I helped him commission the latest Scoot, he's a happy customer...He built it in 70hrs not bad for a chippy that had no electronics experience.. 16hrs to do the electronics. If you use the Knighthawk that reduces to 10mins... Peter

Rome was not built in a day.

Hi All - I have been looking at the stack height of rail and cars vs ballscrews and std nut housings. Only one is equal which is using a 30mm rail/car and a16mm ballscrew. The next build will use this combo to make things a bit simpler. I was thinking of making my own nuts or doing this different to fix this issue. But I like the idea of the 30mm rail/cars. So it should work out fine.... I'd like to get the 15mm rail/car to agree with something but that looks like a spacer or a special housing... Peter

30mm seems over engineered for your build.
Check the torque ratings of your cars against your expected forces and choose accordingly. A couple of machined spacers for the ball screw mounts or the ball screw nut housing seems a simple solution.
Making your own nut housing is not out of the question either. I have done this on a manual mill.

Hi Rod - I don't think 30mm is too big for a 2.6x1.8m bed machine. Initially it was only for the Z axis rails, but by the time you add spacers (which I dislike, extra things means extra compliance) the height is the same and the space used is the same (as the 16mm ballscrews define the basic space requirement) so why not. Plus its extra stiffness so all good. The cars are a bit wider than my usual 20mm but that's OK. 20mm cars are 44mm wide and 30mm are 60mm wide so the Z axis is 32mm wider no big deal... Another machine I'm trying to shrink, so want to use 15mm rails/cars and 12mm screw. That requires a spacer or I have to reorganise the drive relationship somehow, that's a wormy 5 axis project.... But I'm slowly marching towards good solutions. Peter

Hi,
I would agree that 30mm rails/cars is outsize relative to the anticipated load. Having said that there is no penalty with using larger more rigid parts other than cost.

I do think however that 16mm balscrews are too small.

Craig

Hi Craig - Its only for the Z axis which is a 550mm long screw so 16mm is fine. Peter

Evening all - I have been working on a B axis for Lanky and Epoch. I'm in the design polishing stage at the moment after a week of chasing my tail with lock nuts... But it has come together and now to really finalise the parts so I can move onto the saddle and gantry...Peter

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