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As above, and also the collets.
This place seems far cheaper than anywhere else, but it says only available when you purchase a machine...
http://www.prototools.co.uk/Kress_Mi...W_p_18538.html
Also, is this the best spindle in it's price range?
Thanks in advance...
Marchant Dice seem to have the Kress market sewn up. They also sell the collets.
I'd spotted them. Didn't realise they did sets of collets though - they're much better value. I think I'll need a 6mm, 1/4" and 1/8" collet.Quote:
Originally Posted by pavlo
Jonathan if you want to spend that sought of dough on a kress why not consider a Chinese spindle drive? much quieter and better choice of collets? feedback on these units have been very favorable on the net unless anybody else has experience with them?
I thought that would end up a lot more expensive for the spindle and driver? Just had a quick look and the cheapest I found was £250...maybe I'm missing them - please could you link me to the one you're thinking of?Quote:
Originally Posted by 2e0poz
Yes it would cost more but cheaper in the long run. Like a lot of people they use or buy a cheaper option to start with and end paying out again for something better....save your pennies? all good things come to those that wait :-)
Hmm, I thought by getting a Kress spindle I would be getting the better option! At the moment I'm using a router that was £6 from the local car boot sale. I guess I'll have to try and save pennies...that's a LOT of pennies though. I got my milling machine for £300 and yet that spindle costs a similar amount, which is more useful...if only my student loan was bigger!Quote:
Originally Posted by 2e0poz
Very true....I paid £700 for my Bridgeport and then to date probably spent about another £1000 on tooling for it over the space of a year. I've brought it up a few times on here the about saving your pennies before rushing out to buy the first thing that comes along. It is very frustrating but it at leasts gives you time time whilst saving to make sure you spend your money wisely? at the end of the day yo have a working machine and router you can screw up whilst your getting used to it. I'm not saying a spindle drive is the best option as the kress gets good reviews but why have silver when you can have gold?
Jonathan http://www.cnc-plus.de/Spindles---Accessories/Spindles/
Its £128 inc vat plus shipping but i agree with 2e0poz that the Chinese spindle would be the better option in the long run.
Why, well the minimum speed is 5K on the Kress but i read on the zone of people using the Chinese spindle being used at 200 RPM
also the speed would be fully adjustable within Mach UNLIKE the Kress
Also a lot quieter than the Kress
Phil
Thanks for the link, though I think you've both persuaded me now. Persuaded me to wait at least.Quote:
Originally Posted by M250cnc
I'm not too bothered about <5000rpm as my brushless motor spindle will do up to 6000 at much higher power. Having said that I don't know what the runout will be like. Maybe I should make it, flog it and then buy the spindle you're suggesting.
What power rating do you think would be suitable? 1.5kw? I take it they're rated by input power, not output - if so what is the efficiency?
£700 for a Bridgeport sounds good. They had two at school (sold 1 last year :mad:), no comparison between them and my milling machine...I'm jealous!
My mill was 300, plus 20 and 2 cups of tea for them to deliver it. Another 20 for a massive milling vice, and yes...lots lots more on tooling. Not bad considering it's £800 new:
http://www.chronos.ltd.uk/cgi-local/...225C#aCMD1225C
Well i would go for the 1.5KW as that is 2HP like i say someone used his at 200 RPM and they can run up to 25K also the higher the HP the more expensive the inverter.Quote:
Originally Posted by Jonathan
Phil
I might be buying one of these sooner than I thought. My really cheap router stalled today for no apparent reason, and emmited a little smoke. It still runs, so the motor is fine but I think the collet chuck is damaged. It's not holding the cutter on centre now.Quote:
Originally Posted by M250cnc
When it stalled I couldn't stop everything fast enough so it bent the 8mm steel bar that I was using to extend the length of the cutter - shows how powerful the steppers are to do that!
Anyway, I think I'll get this one from this seller:
http://cgi.ebay.co.uk/1-5KW-WATER-CO...item3cb17211ec
It's the cheapest I can find. He's not got much feedback though...
Maybe get a 2.2Kw one:
http://cgi.ebay.co.uk/2-2KW-WATER-CO...item3a61c3d4cf
Or is that overkill?
Does anyone here have a dimensioned drawing of one of these spindles? What does the 180mm length correspond to exactly - as in does it include the chuck/wire etc?
Smaller?! Why don't you want one for your current router?Quote:
Originally Posted by chip
I'm already designing A/C axis head for it:
Jonathan i think you need to learn some safety. Extending the lenght of the cutter using an 8mm bar seems an extremely dangerous thing to do. You are not wearing any safety gear (Full Face Shield) would be a good idea and ear defenders, i know to my cost how stupid it is not to wear ear defenders .Quote:
Originally Posted by Jonathan
My guess is centrifugal force took over and bent the bar not the power from the stepper,there is a reason that the cutters are not too long, and that is for safety/stability reasons. I'm sorry if i seem to be having a go at you personally but you seem an accident waiting to happen.
So this rant is also aimed at the people who think machines running at high speed are safe, they are not especially when you modify them to be even more dangerous.
The last thing people on here want to hear is of you having an accident or anyone else for that matter.
Rant over
Phil
Sorry I was ambiguous. The 25mm length of the extension piece that was in the router is 8mm, and that's what bent. The rest of the bar was 12.7mm. It wasn't centrifugal force...what happened was the router stalled and started only spinning at a few rps whilst gantry was still moving at cutting speed. That meant the cutter holder was basically bent by the X axis motors against the face of the MDF it was cutting ... naturally it bent at the weakst point. I hit the stop buttons pretty quickly, but evidently not quick enough. I underestimated how much extra force it put on the cutter having it 50mm further out.
I've used the same 'extender' in the milling machine lots of times before, admittedly at a lower rpm - yet similar feedrate so probably similar cutting force. If it wasn't for the router stalling I think it would have been fine - I wonder why the router did stall? It had only been going about 30 seconds. I've dismantled the router and checked the brushes/bearings and they all seem fine.
I was wearing saftey glasses and ear defenders - got the latter for Christmas! I agree that one should be conscious of saftey with these things (hence my recent thread about dust extraction!)...I once witnessed someone at school on a lathe (identical model to yours incidentally) put a long piece of 1" steel tube in the chuck to face the end, but didn't support the other end. As you say, centrifugal force took over and bent the steel tube to 90degrees, and smashed the cover off the lathe headstock that protects the autofeed gears shearing a couple of M10 (ish) bolts in the process. The teacher was NOT happy! We had health and saftey in the workshop drummed in to us since the very beginning - using lathe when I was 12.
'accident waiting to happen.'
Is there something else I've said that makes you say that?
My rant over...
Your youtube videos show you holding parts while being routed and about to break free from the surrounding material, do you call that safe ?Quote:
Originally Posted by Jonathan
50mm extension is just way too long and are you are gonna admit its made of soft steel
Here is a pic of an extension i made for a Makita 2HP router , on the left is the original nut and on the right is the extension, the extension is the same diameter as the shaft so SAFE anything less is dangerous.
New rant over.
Phil
I agree that's not the best of ideas - I don't think I'm the only person on youtube guilty of that, though that's no reason to do it. I was careful in that case not to put my fingers close to the cutter. I made sure the last cut was very light and plenty of clearance so little chance of anything unexpected. Generally I do put tabs on the parts which are routed out at the end to avoid that, or in the case of PCBs stick them down with double sided tape. On the milling machine I've put a bolt through the part in the past to stop it escaping.Quote:
Originally Posted by M250cnc
It was made from 316 stainless steel (not nice stuff to machine, work hardens), though I'll admit that was mainly because that's what I had at the time. I made it 8mm as that's the biggest collet the router can take. The nut and collet are separate parts on my router, so it would be tricky to make a mount like yours.
The safety things I won't have much idea is where there's a difference between manual and CNC machines since we only had a very small CNC router/engraver at school...
Jonathan there is a saying expect the unexpected. Another is act in haste repent at leisure.Quote:
Originally Posted by Jonathan
Ask Trend Routers if they make an 8mm router cuter that projects 50mm from the collet and see what they say. I have had a few close shaves myself so i know what i am talking about.
Phil
Point taken, I looked a couple of hours ago and only found one - a 66mm long cutter with 1/4" shank.Quote:
Originally Posted by M250cnc
I'm sorry if in my last few posts I've appeared to think I know more than I do about this. I do value your advice as you clearly have a lot more experience than I have. This discussion has made me think more about what went wrong than I would have otherwise. Still I think there was more to it than the tool extension, since had the router not stalled then I think it would have been fine - it was cutting fine before it stalled.
Maybe the extension put a larger bending moment through the router spindle, effectively trying to twist the inner race out of the bearings and they overheated? Seems plausible if the motor is running ok but the spindle is out of whack.
I don't think Jonathan can complain considering how much he paid for the router as it was never intended to be used as aggressively.Quote:
Originally Posted by TheChunk
Increasing the effective length of the cutter will exert more bending action on the spindle, which now seems to be bent. This is in an even more dangerous condition and the end could just fly off with serious consequences.
Jonathan regards to your original question i would stick with 1.5Kw as your machine has some flex issues which you yourself have mentioned, going for an even more powerful motor will allow you to think you can push it further than it wants to go.
A machine is only as strong as its weakest link.
That price you found does seem to be too good to be true btw.
Regarding cutter length Trend do indeed make 8mm shank cutters in the length of 60mm + square ended but even Carbide cutters are mounted on HSS shanks.
HSS cannot bend, only break that is what makes them a safer bet than an extension made from anything other than HSS which Trend will not make that type of extension as it would be dangerous.
It may be good to see if trend have some videos of when it all goes wrong.
The British team going for a new LSR of 1000MPH the wheels will be going around 10000 RPM they have to to be made of exotic metals as they are likely to explode, centrifugal force is an extremely potent force indeed.
Phil
Yes exactly, it was only £8 or so from the car boot sale so it's not a big loss. I would have liked it to last a bit longer though as now the router might be out of action for a while whilst I save up/sell a few bits for the proper spindle. Maybe I can get a loan from the Bank of Mum :lol:. I just wish my chuck for the brushless motor had arrived - it's been ages.Quote:
Originally Posted by M250cnc
I'll check that with the indicator today.Quote:
Originally Posted by M250cnc
Ok, I will do. It's still twice the power of my milling machine and I've never run out on that. As you say the router is not as rigid as the milling machine, so I can't see it being able to use more power. I may well lower the gantry to help with the rigidity issues.Quote:
Originally Posted by M250cnc
I'm trying to machine a block of MDF thats 3 sheets of 18mm glued together. I need to cut to about 50mm deep...maybe I'll have to do it one sheet at a time then glue them together.Quote:
Originally Posted by M250cnc
im all for the saftey :) however in my opinion every good engineer exercises a bit of art to get the job done
if we didnt push the limits and test the boundries we would still as a race be swinging through the trees eating bannanas
id go for the home made extension... however, at router speeds id keep my distance and one finger on the e-stop :)
I checked my router with dial indicator. It's now holding the cutter at an angle such that there's more runout the further you get from the chuck. I'm not going to try running it like that - clearly not safe.
I've just looked it up and found that the ER11 collet chuck will only hold up to 7mm diameter. That's not good enough for reasons detailed in the last few posts! I'll have to get the 2.2Kw spindle as it has ER20, so up to 13mm. I can't accept only 7mm since to make wind turbine blades, the main reason I made this router, I will need cutters protruding perhaps 4" from the spindle - unless I use A axis.Quote:
Ok, I will do. It's still twice the power of my milling machine and I've never run out on that. As you say the router is not as rigid as the milling machine, so I can't see it being able to use more power. I may well lower the gantry to help with the rigidity issues.
You can get bits designed for slot mortising - see the second cutter down at http://www.amanatool.com/bits-fv/45500.html or http://www.machines4wood.com/mall/pr...sargeant/CM103Quote:
Originally Posted by Jonathan
I've used them on a manual machine to cut beech and they worked well but you need a light final finishing cut due to the flex.
On the other hand, one of the big advantages of CNC is that you can stand well away from the scene of the accident :smile:
Problem with standing well away means I'm too far away from the stop button!
Those cutters look useful, but still a compromise. I'm cutting 50mm deep to clear the material around a mould.
A secondary emergency stop button?Quote:
Originally Posted by Jonathan
Maybe a dead mans handle style one so all you've got to do is drop it as you run away :-)
Not much to pay for safety http://www.trend-uk.com/en/UK/produc...mm_collet.htmlQuote:
Originally Posted by blackburn mark
Good idea.Quote:
Originally Posted by FatFreddie
Jonathan on a machine your size you just need an EStop on every corner. Hitting the button should cut power to everything except the PC and you should not rely on the PC to do this it should be hardware based.
Phil
That collet extension is similar to what I made, except I held the cutter in with 2 grubscrews to keep the diameter down...the whole idea was to extend the cutter without the extension colliding with the material above.Quote:
Originally Posted by M250cnc
Yes I'll sort out the Estop buttons soon. Two should be enough considering where I'll be standing...
If anyone is looking for a Kress have a look here http://www.damencnc.com the owner Kevin Damon is extremely helpful, his turn round time from order is 3 days to the UK