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I have just went through the sites of motor, spindle, etc and they are expensive even from China.Quote:
Originally Posted by silyavski
Ie.only a BT40 spindle would be 2000 EUR in my hand with VAT,etc.
In my present eyes it is too much for 30 kg engineered steel and if I went with this I would make it myself.
Regarding the power I think I would satisfied with about 4 kW
But the main issue is not this and thank you to summarized.
Years ago two gentlemen visited us from a UK company Built Offsite to clarify the details of some modular building.Quote:
Originally Posted by JAZZCNC
Being interested and reading some books about inventors and Technics I told them that the industrial revolution did not begin accidentally in the UK.The only fortuitous was just they came from Shrewsbury where around the industrial revolution had begun.
You are enterprising and advised to reach the high technical level where you are now.
I hope I am enterprising enough no to stop at the difficulties and advised enough to perceive the realistic factors.
The cost is vulnerable issue and the question is over and above: what is different between machine and good machine and very good machine. Purpose+Design+cost+used time+effort and so on -there are many factors are too see and specify the scope.
I do not usually comment on this type of thread, but PLEASE listen to Jazz. He knows exactly what he is talking about and trying to stop you spending money needlessly. Build a good quality router for softer materials and buy/convert a mill for steel. That is my lot, I shall not comment again in this thread. Good luck with whatever you decide. G.Quote:
Originally Posted by vargai
Thank you and you are welcome any time.Quote:
Originally Posted by GEOFFREY
I'm struggling a little here to decide if we have a language barrier thats getting the translation a little muddled or if you are saying "Get stuffed" I'll do it my way regardless.?Quote:
Originally Posted by vargai
Hope it's just language differences but honestly I don't care if not.! . . . Because if your stupid enough to go against good sound advice from several experienced people then more FOOL you and I DON'T wish you Good luck as that would be encouraging someone to waste money and being a born & breed Yorkshire Man I wouldn't encourage even a FOOL to do that..:stupid: . . . . . Just like I won't waste my time or hard learnt experience on FOOLS.!
Normally if someone says that it cant be done then that is like a red rag to a bull and I try to come up with a solution, but now you have brought steel into the equation then I would agree with the others that it will be really difficult as the requirements are at opposite ends of the spectrum.
If it was Diy the you could compromise on the design and use the machine to the best of its abilities but you seem to be saying that it will be a commercial use so that wouldnt really be feasible.
If you did proceed you will need to two spindles.
1. Low speed with high ridigity and power at low speed for steel.
2. High speed and power at high speed for ali.
You would then need 10mm pitch ball screws on high power servo motors with high resolution encoders to get the accuracy. Etc etc.
It can be be done but like the others have said it will be expensive and you will still end up compromising the design. It may well be cheaper and better from a production point of view to build 2 specific machines. Good luck
Have I made something wrong?Quote:
Originally Posted by JAZZCNC
I have started this thread and collected all the information that is necessary to make decision.
I have not buy anything and not gone any direction yet .
The only thing I do I try to make out these info that is just slightly more then just listening.
Quote:
Originally Posted by Ross77
Sorry for late answering. I could have placed this post to a general thread since by going through my one the searching on the good design led the doubt about the primary aim.Quote:
Originally Posted by JAZZCNC
Reading the posts after my latest design I recognized or at least felt the generally weak points. Sorry for seeming stubborn. It is not meant to happen. My tenacity is all about my goals and not the way and method to reach it. It is not easy to abandon a main intent and to say right away yes, or no.
So thank you all who involved for your efforts and advice in highlighting my weakness.
I hope I do not have to turn my back on metal and will be able to build a good router for Al and other softer material.
Hi, I said that I would not post again on this topic, but your final sentence sounds very sensible. G.
Hi Vargai
Don't be put off building a machine, maybe you should proceed and prove us all wrong :o)
everyone is just trying to help you get the best results.
Of course I do not , because the goal is not to prove that is impossible but to build what is possible:)Quote:
Originally Posted by Ross77
Let me ask something I have a doubt about.
I saw your latest general frame design and I am wonder how the steel hollow tube beams bracing react to the machining force on a router .(generally).The seems like "strings" and source of resonance but I have never seen or heard router during operation.
Actually I am wonder of the smallest applicable size ie 50x50x3 showed many times.
It was meant as more of an idea than a finished design. Yes if the bracing became long and slender then it could resonate. They are all different lengths so they would have different resonant frequencies.
It is also the base frame so the bolting down fixings will help with damping.
Like I said it was more of a basic idea, I did quite a few different options and it started getting messy. So look at the bracing for layout and size accordingly.
I plan to build a similar heavy duty fixed gantry mill, better not mention that I want it to cut steel. He he
With a smallish (600x400?) working area and a strong solid fixed gantry machine, I do not see why steel should beQuote:
Originally Posted by Ross77
too much of a problem. My machine (converted commercial PCB drill/router) had a steel section right across the middle of the aluminium table that was used to locate dowelled stacked boards for drilling etc. Careless use by the previous owners operatives has led to to both the alluminium and steel parts of the bed covered in holes and grooves all over the place!!! These have maily been cut with sub 1mm cutters, which probably did end up breaking, but not before inflicting serious scars everywhere. With a slower speed spindle, and the right cutter I feel sure that I could cut steel, but would not need to be greedy with regards to feed speed DOC etc. G.
Strong Fixed gantry machine is the correct choice for larger foot print when cutting steel with correct spindle attached. Moving gantrys will cut steel with correct spindle but are less than ideal unless massively built.Quote:
Originally Posted by GEOFFREY
My router which in the grand scheme of things is weak compared to even lightest duty milling machine as cut steel on the odd occasion and even cast iron. But it's not really practicle or advisable as it knocks the stuffing out the machine and takes an age to cut due to restrictions on feed and DOC.
The whole reason or point of my objections is that one machine can't cut every material correctly and when comes to steel a moving gantry design is not practical due to the strength needed and all that it brings with it to the build. Far cheaper and easier to build/buy to separate machines each designed for it's purpose.
It was not criticism just gathering data for a steel based light weight moving gantry DIY router that can be used in its scope and additionally I can check , try some solutions. I red about HSM spindle and HSM Al milling and aware of that this is also a wide spectrum so I will be happy with the result that a router can give.Quote:
Originally Posted by Ross77
Not forgetting the steel I am planning to attach an easy removable really small, geared spindle driven by the HS one with belt or directly coupled. (EDIT: i see now that the belt not good at this speed) In this method the supposed extension of the original spindle would be only about 60-80 mm and the force not bother the main spindle bearings
With 1:0,5 ratio (12000-to 6000 rpm) and quite enough torque I probably can make a typical steel milling with DIA 4-5 mm mill.
This would be making opening on a flat parts of electrical enclosures ( mainly doors) and mainly Dia 30,5 mm holes for push buttons.
The only problem is that the thickness is 2 mm but I suppose a 3kW spindle can do it with full DOC( the pre drilling- hydraulic method works but too slow and there are other shapes). This will not be bottleneck if I cannot do it just an idea.
pls adjust me if someone has experience.
One question about the steppers:
Normally they do their job and do not care of step loss and go on.
Is there any no too expensive mean, method to persuade them to stop at step loss and not multiply the mistake.
Thanks
I've run a stepper based machine for several years and when configured conservatively it will not loose steps under normal conditions. But if you are looking for something else maybe try EasyServo, its steppers that offer some of the features of servos but still easy to set up. Not sure about how the cost compares to the stepper motors you have in mind. They are basically steppers with build in encoders and run closed loop. They will try to correct lost steps and if they can't they would stop and give a fault signal it the error goes over a configurable amount of steps + some other cool features not really possible on other steppers without encoders. They also have a model for 110-220 volt AC so no power supplies required for those.
Nice video made by JazzCNC of how they work
https://www.youtube.com/watch?v=ZMZdCcLQc4M
Company that makes them
http://www.leadshine.com/category.aspx?type=products&category=easy-servo-products
I got them but my machine is in the build process so I have no idea how well they will work. I have played with them and its easy to get them running and the configuration software also allows many parameters to be modified if need be.
Thanks, just thought there is some DIY made way but it is ok when it is reliable with careful set-up and parameters.Quote:
Originally Posted by mitchejc
As you said the first to "play" and know the new built machine to find its sweet points.
In this thread and (others) you can find opinion of JAZZCNC of easyservo and he says it works excellent.
Little bit expensive but you have them and you can compare the price.
Could you tell this comparing the same torque stepper pls?
Belts are not a problem here. HTD belts are rated for these speeds. Problems are the bearings. Conical roller bearings will not spin so fast. Hence the 6000rpm limit on the spindles they sell. You will have to use angular contact bearings, not roller bearings, so they have to be over sized. Though i am still not sure if they don't use ball bearings on the spindles. You will have to check this and find suitable bearings and i don't see why it will not work. I have thought about that many times, despite what i said before. Plus my gantry on the machine i am building is rock solid. Though you have to have tremendously strong Z, cause 60-80 mm are big difference when we are talking about Z travel. On a router i mean.Quote:
Originally Posted by vargai
One thing to note is that when we say -"this is bad, can not be done, not like that, you need other type of machine" , its not that it will not work. It will work.But not consistently, not for a long time. No perfect finish. Not be able to hold consistently precision. Ruining some element with time , /bearings/, etc. I can drive a city car where 4x4 car goes, but for how long? So actually its not a discouragement, its a reality check. I will be more than happy to see it done. Cause i will do it also.
Why don't you sketch your idea for the spindle and investigate the bearings.
As for the motors you could fit cheap encoder to steppers and then feed the signal to the breakout board/you will need available inputs/ . When out of programmed way, the machine could stop so you don't damage material. I have a plugin on my PC that does exactly that. Though that's not a true closed loop. The closed loop motors will push till all is where is meant to be and stop only if they could not overcome the force. If you decide to go this way, i will send you the plugin. There are cheap normal steppers with integrated encoders. though definetely will be mistake for the sake of encoders to buy some steppers witch are not low inductance.
Just use good PSU, good board and motors and you will not need these. Though closed loop would be nice on a metal working machine.
What spindle are you planning to use? I know there were a few mentioned but cant see which one you decided on.
The thing to remember with spindle bearings is the amount of pre-load they have which affects the rigidity and speed.
Taper bearings with a heavy preload will be super rigid and cut hard materials but will be limited to a low speed. If your milling steel this is what you need.
Angular contact (AC) bearings are similar and the heavier the preload the more rigid they become. Due to the reduced contact area they have a higher speed capability but lower load bearing capacity than a similar sized taper bearing.
So as most of the high rpm (15-20k) router spindles will be using AC bearings then the rigidity will probably be low. This will be the weak link and no matter how strong the machine is it wont be at its best.
Bottom line is you can have a machine capable of both but realistically you will need two separate spindles.
You could always get high end spindle with hydraulic adjustable preload :0)
I have 75x40 precision AC bearings for mine and should get me up to 12k for HSM with adjustable preload and with oil mist lubrication lol.
2,2 or 3 kW water cooled chines spindle fit to a general routerQuote:
Originally Posted by Ross77
The secondary small spindle would be a really light loaded ocassionally used one for the special purpose mentioned.
Short video is attached. The door steel sheet is 1,5 or 2 mm. At issue.That is why I do not want to pay too much attention to it but some searching is not a sin. I will show up some details in the answering to Syliavski and waiting for your comments.
By the way do you have something more then Chinese spindle do not you? from low rpm to 12000
https://vimeo.com/117009926
Here is some sketch and I am almost sure the for DIY use with a short 5 mm flute cutter this spindle is quite strong enough.Quote:
Originally Posted by silyavski
Cutter is clamped by Weldon @6000 it works, lower AC bearings are coupled and after installation it will be preloded
grease lubricant also fine here.
Some safety issue should be considered:
The drive shaft in the ER20 collet should we carefully machined including the pulley to reduce the unbalance.
I would use double key opposite to each other.
Good cover must be done to protect the belt and user.I checked my 170 mm blade Makita plane , it run @15000rpm so you are of course right regarding the belt application. Here ribbed V belt is used so i think 15 mm wide HTD3 is sufficient here.
If you flip the pulley on the mini spindle to the top to skip the belt from the milling area you have to use some adapter plate .
This is not the first thing i make now but probably later Paris is well worth a mass.
http://www.mycncuk.com/attachment.ph...id=14450&stc=1
Some technical info and bearing sizes and data . There are some force calculators there and so on. May be you know them already but let be here on one place.
Here is the 3kw/3.2-4kw i believe also/ spindle with all sizes if you dont have it at hand. I took them personally :-) .This is the original Guanzhou spindle with the 4 bearings and the black rings. Maybe enough place that the attachment could be clamped directly at the spindle there.
Hope that helps. When i have time will sit also and see if i have some ideas.
http://www.mycncuk.com/attachment.ph...id=14451&stc=1
These are the bearings and dimensions of the BT35 spindles for reference:
http://www.mycncuk.com/attachment.ph...id=14452&stc=1
Here is some belt info. If i read it correctly best would be HTD3- HTD5 belt or GT belt even better . Dont be put off by the lower life the figures show. After all one belt is 1-4 euro only. One thing to note is that wider than necessary is not a good idea.
http://www.mycncuk.com/attachment.ph...id=14453&stc=1
http://www.mycncuk.com/attachment.ph...id=14454&stc=1
http://www.mycncuk.com/attachment.ph...id=14455&stc=1
http://www.mycncuk.com/attachment.ph...id=14456&stc=1
http://www.mycncuk.com/attachment.ph...id=14457&stc=1
The general arrangement is really good. Back to back AC's and floating end bearing to allow for thermal growth. Are you making this or buying?
My only concern is that by driving it from the bottom you are increasing the distance from the cutter to the bearings and compromising the design. The belt tension will also pull the spindle off center. Can you drop the bearings down in side the pulley?
I'll try to find my old spindle designs and show you what I mean, I have gone over sized on the bearings so the taper of the collet is inside the bearing.
what size bearings are they? For 6000 rpm have you considered roller taper bearings?
This is of course me being super picky, your design will work but just offer suggestion to maybe improve :0)
I prefer to download 3D model of all stuff and it is not supplied so thank you this and other information.Quote:
Originally Posted by silyavski
I will make my model to go further.
If one use this spindle occasionally only for fine milling in steel(up to 3-4 mm flute small doc) there is no point to make extra attachable spindle except handling the main gently.
When I am right the main DIA of the rotor is 25 mm(suppose the bore of the bearing same) so it has much stronger then my mini spindle with its 15 mm bore bearing. At this case I would not rank the spindle application
based on material but based on load.
There are coated cutter for HSM in steel rated for 7-8k rpm. At this value the torque is about 1/3 of the top ( I will check the curve) so this gives an additional protection for the spindle.
I have an offer for both 2,2 and 3 kW Guanzhou spindle and saw the 2,2 kW is popular among builders.
Does the bigger worth the 200 USD price different on a general router-or the bigger the better?
I am agree with the advice to go step by step. A 700x1000 mm commercial LSM CNC mill has a roomful foot print and it cannot be compressed to my design with impunity.By sitting in front of monitor and doing 3D designs some(me) tend to loose the sense of reality. So I go further with a router and it gives the possibility beside other matl to work with wood that I like too. In the mean time I can check things in the reality. I can reach from A to C through B and maybe it will be shorter way.Quote:
Originally Posted by silyavski
I have to jump in to the electric stuffs first to understand completely this language.Quote:
Originally Posted by silyavski
I revert it later, thank you in advance
My friend is renting a small shop and generally I got him to machine the part,and I will put them together.Quote:
Originally Posted by Ross77
There are a Bridgeport VMC, a Colchester CNC turn and a Hungarian CNC turn. I used to work here but recently after the daily office job I prefer to have a little brake. That is way I would like to have some machines at home where I can work any time that fits to me.
The bearing is 15 mm bore -for an entry level spindle is Ok but any design comes in handy, thanks.
PS: I have adjusted my setting so the vid is already visible at my previous post to you