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View Full Version : Time for a Reality Check and encouragement to New builders.!



JAZZCNC
29-12-2014, 02:08 PM
Ok well I feel it's time to stand up and say something about this Stupidly excessive over building and Micro examining of build process's Ie Epoxy leveling going off on the forum.!!

So first let me say this is little rant is mostly for the sake of those sat on the side lines looking to get into DIY CNC. I'm not having a dig at any one individual and if you have the means to build like this then good luck to anyone doing so.

BUT I feel this flurry of Excessive over building using steel plate etc and the micro examining and unrealistic expectations of Epoxy leveling will be putting people sat on the said lines off building.
While I don't have an issue with over building to some degree the current levels being seen on the forum for the intended use of the machines are rediculously OTT and really not needed. Those doing so just don't know it yet.!

So to those Sat looking in on DIY CNC and thinking to build please don't let these OTT builds deter you from building because it's perfectly possible to build great machine without going excessive on build structure.
Obviously there needs to be some degree of strength and steel is a good cheap material but perfectly fine machines can be built without using it. Aluminium profile for instance is great and easy to work with material it just costs more money. Wood can be Ok if done right but not something I'd encourage.!

Now please don't let this sound like I'm trying putting anyone off using steel because I wouldn't and normally the one urging it to be used.
What I am asking for is a reality Check on the Level of build strength and size of material being used for the Purpose of the machine. Also a calming down and realisation of the accurecy needed for the purpose of use. Ie Wood,plastics etc doesn't need 0.001mm levels of accurecy.

Most OTT machines are being built and used as wood routers with occasional Aluminium use with a relatively low powered 2.2Kw Spindle. The structure is hugely out of proportion to the use and spindle power available which in affect is wasteful. The excess cost could be better spent else where.
The levels of accurecy that are being strived for are really not required for the use the machines are being put too. So again this is time and effort wasted. ( I very nuch doubt they are reaching or able to measure the accurecy they seem to think they are measuring, but thats another story.!!)

Time to get real folks and realise that for DIY use this level of building is just wasteful of time and money.

Message to Newbie's is don't be put off building. Good design and attention to detail along with wise component selection is far more important than a Massively built frame. It can be done relatively cheaply and give perfect results for many years it just needs careful prep and research along with asking lots of questions.

Happy new year building to all.!! (Now I'm going to hide and get my flack jacket on.! :hysterical:)

EddyCurrent
29-12-2014, 02:29 PM
Time to get real folks and realise that for DIY use this level of building is just wasteful of time and money.

You've used this term, DIY, many times before, and what you say about it here is true, but maybe some people are trying to build a 'professional' machine ?

Lee Roberts
29-12-2014, 02:59 PM
Not forgetting that real machinists use steel...not ali! There's no such thing as over built and when I build somthing, I always over build, with in reason of course. Code may say 4x2 but there's no reason not to use bigger if you can.

Build what you want, but be sure it's capable of what you require, as it's about DIY this the only thing left to say is, enjoy doing your project and don't forget, not everyone has a problem having to rebuild once they find their feet and some have that intension anyway, they just may not say that.

.Me

Ross77
29-12-2014, 03:28 PM
Yep, as I have said before you cant easily design every element of a machine without masses of engineering know how and expensive FEA software so the best approach is to over engineer the frame.

Bear in mind that it is often cheap and easy to pickup large section off cuts and the only true freebee is time so building massive frames that take awhile will be a cost saving for most people.

Most of the overbuilding seems to be from advice on here anyway ;0)

JAZZCNC
29-12-2014, 03:52 PM
You've used this term, DIY, many times before, and what you say about it here is true, but maybe some people are trying to build a 'professional' machine ?

Yes I'm fully aware of that Eddy but in which case they are doing it wrong anyway.? 200Kg Gantry with cheap 2.2Kw router is no use or ornament as a professional machine and woe fully under powered for the strength of the machine.
Same goes for anyone building a moving gantry router style machine to mill steel or aluminium to a professional level. Compleltely wrong choice of machine.!!
In 95% of the cases on the forum most are not building with professional intents but to be the best it can be. Which is fine but it can be all that with the components used and still be built with much less strength and fuss.


Not forgetting that real machinists use steel...not ali!

Well that explains why you used MDF then.:whistle: . . . But actually professional machines Milling machines mostly use Cast Iron or Man made composite materials along with aluminium.


There's no such thing as over built and when I build somthing, I always over build, with in reason of course. Code may say 4x2 but there's no reason not to use bigger if you can.

Well depends on the design doesn't it.? Space shuttle wouldn't have got far if that was over built would it.!

My point isn't about over building and the " Within reason" comment is very apapt.!
Those over built machines are not within reason they are well OTT for work they are being used for.

BUT My point is that these builds WILL BE OFF PUTTING to new potential builders and I'm not trying to discourage anyone from Over building "With in Reason" and more trying to encourage and let those sat on the side lines know that it isn't required or needed to build like this to get a very capable machine.

You of all people should be encouraging the same NOT jumping on me.! . . After all this forum as been made what it is by mostly DIY Members.

Neale
29-12-2014, 03:53 PM
If all you want to do is build a good, functional, CNC router, then I absolutely agree with you, Jazz. For example, despite the fact that the usual minimum steel section that people seem to use is 60x60x5 - minimum! - my machine is built from 50x50x3, and it seems plenty strong enough to me. There does seem to be a lot of over-building going on. Maybe I'll be proved wrong later...

As I mentioned in the "epoxy levelling" thread I started, my welded steel frame, with its 1.5mm or so dip in the X rails, would be perfectly usable after one coat of levelling epoxy. No question, and I've said as much in that thread. One of the reasons I have spent time measuring is just to verify that. However, I'm retired, I'm not doing this to make money, and at various times I've described myself as an engineer, a mathematician, and a scientist. Wearing my engineer's hat ("an engineer is someone who can do for five bob what any damn fool can do for a pound") I'm right beside you. Swapping to mathematician/scientist, though, I can't help asking "How? Why? What?" In other words - that looks interesting, I wonder if...? We can apply scientific method to building CNC routers, or at least aspects of their design and construction, and maybe something useful will pop out. Or maybe it won't. Is it useful to suggest, based on what I see at present, that two thin layers of epoxy might be better than one thick one? But that one will be good enough for most practical purposes anyway? You are also quite correct that I don't know exactly how accurate my measurements are, although in the best scientific tradition I've described how I made them, and also tried to double-check the method. Is that better than proceeding in ignorance? My father was always saying, "You do it like that because that's how I've always done it." I've always had a problem with that attitude...

I'm also quite convinced that nothing I can say will change the views of anyone else anyway, but in a nice, quiet, corner of the forum us airy-fairy types can argue pointlessly amongst ourselves without disturbing the real workers :beer:

BTW, I also do listen to other opinions, if they're backed up by reasonable evidence or results. That's why I have a CSMIO/IP-M and three EM806 on order for the new machine to replace the vanilla BOB and analogue drivers I was going to salvage from my old MDF-built router. I wouldn't even bother measuring accuracy on that machine - by the time you've pulled the tape measure to the end of the bed, the starting point has moved...
Oh, and there's a big smiley face to cover this whole post - I just can't find one big enough! I am very grateful to all who have posted here in the last couple of years and from whom I've learnt a lot.

EddyCurrent
29-12-2014, 04:21 PM
I think part of the blame is the way the forum works, the same questions keep cominmg round e.g. MDF built machines.
It would be better if there were discreet sections where discussion could take place, for example, 'Router Frames'
In that section there would be discussion to the n'th degree about frames, new users could take a look and use information to build their own frame to whatever level they wanted. There would be no posts like "MDF frames are shite" because there would be a sub section under 'Router Frames' for that. Same would apply to other components of the machine.
Things like Rails, Spindle, etc. would have their own sections.

Router Type Machines
. Frames
... Steel
... Wood
... Aluminium
Gantry
Bed
Z axis


Edit: I'm thinking back to my Lego machine idea where you pick'n'mix your parts from the various sub sections of the forum.

For example I would submit drawings for my frame and gantry for anyone to download, tweak, build but at the moment I think they would just get lost in the mountain of info.

JAZZCNC
29-12-2014, 04:22 PM
If all you want to do is build a good, functional, CNC router, then I absolutely agree with you, Jazz. For example, despite the fact that the usual minimum steel section that people seem to use is 60x60x5 - minimum! - my machine is built from 50x50x3, and it seems plenty strong enough to me. There does seem to be a lot of over-building going on. Maybe I'll be proved wrong later...

Exactly my point it's more than enough for 95% of DIY builds and you won't be proved wrong I'm 100% sure of that.


Swapping to mathematician/scientist, though, I can't help asking "How? Why? What?" In other words - that looks interesting, I wonder if...? We can apply scientific method to building CNC routers, or at least aspects of their design and construction, and maybe something useful will pop out. Or maybe it won't. Is it useful to suggest, based on what I see at present, that two thin layers of epoxy might be better than one thick one? But that one will be good enough for most practical purposes anyway? You are also quite correct that I don't know exactly how accurate my measurements are, although in the best scientific tradition I've described how I made them, and also tried to double-check the method.

Nothing wrong with Scientific and taking measurements etc but completely pointless if it can't accurately be verified and at this size of machine then it can't be with a spirit level and tape measure!! (Making a point not having a go at you there.!). . . . BUT I can tell you what will tell you 100%.? Cut something with the bugger.!!

If it's out then it will just mean simple case of shimming or adjustment if you have had the good sense to build adjustment into the machine.
This is what I mean about good design beating over building every time at DIY level. Also lets make no mistake we 99% of members are DIY level no matter what those up there own arse's like to think.:whistle:

mitchejc
29-12-2014, 05:33 PM
Jazz, I totally agree with what you are saying. I got on here a few months back with the intention to build a small very sturdy router from alu and after calculating the cost and seeing the nice solid steel builds and not fully understanding remarks like "use larger profile" and "extra weight might be a good", things got out of hand... You over design one bit and then you strengthen something else to be in line with that and before you know it your are caught up in a viscous cycle of adding more strength and weight. The other issue is that parts are MUCH larger in real life than the CAD drawing suggested but at that point its a bit too late. I did not see this coming but to give you a good example, I had to fit a hook to the roof trusses and buy a chain block just to get my gantry on an off my machine while I'm building it, so how wrong is that for a little DIY router. Well, for me there's no turning back now and it will be finished like that and maybe I can do a future version 2 in a more sensible manner.

I wish someone could get hold of a drawing of the Datron M8 gantry and post that on here as a reference of what the ultimate steel gantry looks like. I bet you one does not need a chain block to lift that gantry.

I think classifying the build threads into 4 classes: Wood, Alu, Steel and OTT Wackjob is a good suggestion.

Clive S
29-12-2014, 06:34 PM
Jazz, I totally agree with what you are saying. I got on here a few months back with the intention to build a small very sturdy router from alu and after calculating the cost and seeing the nice solid steel builds and not fully understanding remarks like "use larger profile" and "extra weight might be a good", things got out of hand Etc etc. I for one agree completely that if you're not careful things can get a bit out of hand. Its alright trying to measure to the nth degree in the morning and then when the sun comes out in the afternoon (or in the case in England when the big wood burner gets going) the whole machine has expanded and the first lot of measurements go out the window.:friendly_wink:

I do realise that different people see things in different ways but as Dean has pointed out we have to be careful not to put people off in what is achievable to the average Joe Blogs trying to build a machine in his garage with just basic tools and I would suspect there are quite a few folk out there wanting to build a machine having never even been in a true machine shop.

I could not have built my router without the help of some of the truly helpful guys on here.:thumsup:
So lets keep it light. As this forum is a mine of information and I have met some really nice and genuine people on here.:beer: Happy New Year ..Clive

Ross77
29-12-2014, 06:46 PM
Had a bad Christmas Jazz? :0)

Before this gets really catty would it not be an idea to turn it in to something more positive and usefull like a standard design for a 2.2kw router? Yes I know work size will affect slight sizing but most common size could be used?

Ive been on and off this forum for about 5 years and the same questions and basic mistakes are made time and time again. My pet hate is poor bracing layout and over sized bracing, nearly every initial frame design the same comments have to be made.

Rather then keep on about it I think it would be better to do a little Guide that that everyone can added to, to make it a varied and trustworth source rather than one persons opinion.

Its it more the projects that become large due to "advice" or when large projects are proposed from the outset?

mitchejc
29-12-2014, 07:05 PM
Well said Clive:beer: In the end most of us are building and using these machines for pure entertainment value whether its a little 6"x 6" mdf router with old hard drive steppers or a 3x2m monstrosity, as long as everyone is having fun doing it, all is good. As soon as I have finished this ice cold beer you subtly suggested I'll be back in the shed to continue bolting the battlestar galaxtica together and I sure as hell hope I don't discourage anybody else to pursue there cnc dreams by doing so :-)

longy
29-12-2014, 09:43 PM
Epoxy leveling is a waste of money and time, unless your trying to correct defects in the frame build levels. Your machine levels will move even if it's bolted to your workshop floor and the levels you had yesterday are different today and will be different again tomorrow !

WHY because the ground your workshop is built on is moving very slightly up and down all the time, water levels (hydrogeology) cause the ground to swell and shrink several times per day, the temperature inside and out will contact and expand all materials very slightly so what was once level may never be level ever again.

So unless you need to correct any flaws with frame build levels don't waste your money. Buy yourself a beer and sit and watch the room moving or was that the beer that caused it to move.

All the best to everyone for 2015

Clive S
29-12-2014, 09:50 PM
So unless you need to correct any flaws with frame build levels don't waste your money. Buy yourself a beer and sit and watch the room moving or was that the beer that caused it to move.

All the best to everyone for 2015 I had that problem the other night, you are correct how do you know if its the room or the beer would that be a G90 or a G91 move?:thumsup: ..Clive

Neale
29-12-2014, 10:19 PM
Epoxy leveling is a waste of money and time, unless your trying to correct defects in the frame build levels.

But that's exactly why people use epoxy. Not all of us can build machines without defects in frame build levels (or warps, twists, or other inaccuracies).

njhussey
29-12-2014, 11:06 PM
+1 that's what I've used it for. I couldn't machine the rails flat so wanted a method that i could do the diy way...epoxy was the best way for me.

JAZZCNC
30-12-2014, 01:24 AM
Removed has to Reply in anger means to repent at leisure.!!

HAPPY XMAS and NEW YEAR to ALL.!

Ross77
30-12-2014, 02:29 AM
Sorry you have a bad time Jazz. Look none of my comments have been meant as an attack on you. Whilst forums are really good at helping they are not the best form of communication and a simple difference of opinion can be taken out of context.

I work in design office and we always bounce ideas and comments off each other and the value is working as a team, sometimes my ideas are good and sometimes another persons is better. I don't take it personally its just how it is.

Happy to post up some ideas like i always have when I have the time to be on here.

I really don't want to fall out with people on here and if I do have a difference of opinion then I will give a justification for it and not just say that's "shite". I also only comment on the structural elements that I'm confident advising on. It is also just a difference of opinion and not a personal attack and I think that's the main point and the more opinions the person asking the questions gets then the more helpful it is.

Anyway all the best and hope you can help me out with the bits im not so sure about.

Cheers
Ross

vargai
31-12-2014, 06:07 PM
Whilst forums are really good at helping they are not the best form of communication and a simple difference of opinion can be taken out of context.


Actually you are taking about how you could provide better ministration for the forum members and that is great.
You and the the available data here give huge help for 1st time and advanced builders and you do it magnanimously.
As human beings, we all have our own values, beliefs and attitudes and personally I do not mind both gentle and tougher comments.
Sometime a virtual slap comes in handy to halt i.e the l'art pour l'art design as I did myself.
Regarding to the receivers no one should use only the paste command in design and devolve the responsibility of the result.
All of us have to have common sense to make wise decisions and spent our money usefully.
So this is an exciting great forum and happy to have found here.
So keep your good habit and

Happy New Year to all.

PS: these girls do not prevaricate

https://www.youtube.com/watch?v=up7pvPqNkuU