Machine rebuild time - options...

I built an MDF router based on plans from build your cnc...then adapted & improved it. The machine never ran as well as I would have liked - mainly due to alignment issues and a damp/humid environment.

I've now moved house & have more workshop space to play with. Shortly after the house move my disassembled machine got soaked due to a leaky workshop roof...I now expect the previous alignment issues to be even worse and am thinking about possible ways forward.

My first thought was to get the machine assembled again & set up as best I can, then use it to cut new parts for a better MDF machine.

But i've now started thinking about the possibility of using aluminium profile instead.

I've found guides for 80-20 profile but not a lot else...it also seems that 80-20 isn't easy to get in the UK.

Looking around i've found numerous sources for other sizes eg, 40-40, 40-80, 45-45, 45-90....i'm wondering about the suitability of these for the job in hand & whether there are any plans or guides out there using these profiles....also would the resulting machine perform better than an mdf one?

My current machine roughly has a cut area of 4'x2'...i'd like the new version to be the same, or a smidge larger.

If anyone can give me any input on this i'd be grateful - good sources for ally profiles, plans, guides etc

Thanks

Tom

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But i've now started thinking about the possibility of using aluminium profile instead.

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living in the damp old uk it makes a lot of sense to me to upgrade from mdf

i cant see any reason to use 80/20 if you cant find any... there are lots of other t-slot profiles and suppliers, i bought from valuframe (kind of pricy but they had the sizes i was after)

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i'm wondering about the suitability of these for the job in hand & whether there are any plans or guides out there using these profiles

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it might be worth finding a build on this forum that you like and twist the builders arm a bit to get him to give you his drawings and guide you through any of the pitfalls he experienced (what kind of cash are you willing to splash on rails and screws?)

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also would the resulting machine perform better than an mdf one?

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on a like for like build id buy myself a hat and eat it if it didnt:wink:

if you copy a design from this forum you will be able to see the kind of work thats being done on that machine

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Originally Posted by CraftyGeek

I built an MDF router based on plans from build your cnc...then adapted & improved it. The machine never ran as well as I would have liked - mainly due to alignment issues and a damp/humid environment.

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Best thing to do is wait for the 5th of november then BURN IT.:heehee:
The only place in CNC for MDF is to be used as spoil board.!! Even then I'm reluctant.

Seriously now you'll be far better of using Ali or steel the result will be machine massively more ridged and accurate and wont shape shift in front of your eyes every time you show it a cup of steamy coffee.!

Personally I'd go with steel due to it being far cheaper than profile. . . Don't have to be a welder and With just a few key tools like drill press etc it's very possible to build an accurate and repeatable machine. . . Welding will help speed the job up but Not required.

What sort of size cutting area and what material do you mainly want to cut.?

Edit: Opp's scrap that bit didn't see the 4x2 bit.:redface:

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Originally Posted by JAZZCNC

Best thing to do is wait for the 5th of november then BURN IT.:heehee:
The only place in CNC for MDF is to be used as spoil board.!! Even then I'm reluctant.

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I agree entirely. Perhaps keep the MDF as sacrificial piece.

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Originally Posted by JAZZCNC

Personally I'd go with steel due to it being far cheaper than profile. . . Don't have to be a welder

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The frame for my machine is the first thing I had welded (done some brazing before but that's about it)... it's not fallen apart so all is good! Aluminium is a good choice for the gantry due to the lower density.

Thanks for the response so far.

Over the last few years i've done loads of research into mdf based machines...it was only 18 months ago that I finally had space to build one after collecting electronics etc over a period of years.
So i've had a learning curve already - ultimately I can see that mdf is going to limit me (as well as annoy).

Right now, after having a quick look into material costs a bit more closely, I don't think I can go for a new full ally profile build as I simply don't have the funds. From a quick glance - ally box & steel box don't actually seem to work out that much cheaper.

My current thinking now is to start upgrading my existing machine into more of a hybrid - then keep upgrading as & when I can.

The biggest problem I have at the moment is the main table/base - it just isn't up to the job. So i'm thinking about making some sort of metal frame for the table - then attaching the rest of my current setup to that.

Tool wise I have most hand held power tools (inc angle grinder & jigsaw) with a circular saw mounted as a table saw & also a router table....no pillar drill. I plan on getting a better table saw & also a chop saw at some stage soonish as well.
I have very little experience working with steel...i've done much more with aluminium & would be more confident working with it as a result.

As welding isn't an option - how would you suggest creating an accurate solid frame out of box stock?
I have a metal supplier near me that could in theory cut pieces to length for me - but how best to join them?

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Originally Posted by CraftyGeek

Right now, after having a quick look into material costs a bit more closely, I don't think I can go for a new full ally profile build as I simply don't have the funds. From a quick glance - ally box & steel box don't actually seem to work out that much cheaper.

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Box section steel is half the price of Ali box section, I pay around £20 for 7.5mtr 50x50x3

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Originally Posted by CraftyGeek

As welding isn't an option - how would you suggest creating an accurate solid frame out of box stock?
I have a metal supplier near me that could in theory cut pieces to length for me - but how best to join them?

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Using plates Drilled and bolted to the frame.! . . . Thats why a decent pillow drill is so usefull, almost essential if you want an easy life.

http://www.mbsitem.co.uk/

Not cheap but very stiff, advice is free. I use them a lot for business. They will cut it to the length you want, drill and tap, even will acually design it for you, even put it together. You can also download the profiles and send them a CAD drawing. But, not cheap. It depends what you want at the end of the day.

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Originally Posted by JAZZCNC

Box section steel is half the price of Ali box section, I pay around £20 for 7.5mtr 50x50x3

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You'd be surprised. I know when I priced a project earlier this year, there wasn't that much difference in price for the box section that I needed. It was all the brackets that bumped the price up. I still went for the alloy though, as it was lighter with less flex which suited the application, and the company cut it all to length so all I had to do was bolt it together, which saved me a lot of time.

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Originally Posted by m_c

You'd be surprised.

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No I wouldn't 50x50x3 Ali is £35 plus vat + Del (Ali warehouse) for 5mtr and as of 2 weeks ago when I last bought some 50x50x3 steel box section was £21 for 7.5mtr. Inc Vat.! (Delivered thou it's only next village so don't count really. .Lol)

That's ok if you have the equipment to deal with full lengths, and need the full length.
But if you don't have the equipment, or don't need a multiple of 7.2m, then price difference can be totally different.
It all depends on what equipment you have and what you need.

I can work with either, but not everybody can.
If you don't have a pillar drill, scribe, centre punch etc. then that's something else you need to factor into the cost, and look beyond the basic material costs.

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Originally Posted by m_c

That's ok if you have the equipment to deal with full lengths

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Equipment = hacksaw (takes a while but it works), or get the supplier to cut it. The place I got mine from cut it without charging, and also gave me a load of free bits :). I worked it out so that each piece would fit in the car, then did the rest of the cutting myself to make sure it was accurate. If I recall correctly the 60x60x3 steel box section I got was £25 for 7.5m.

Sell the spare on eBay, it goes for lots there!

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Originally Posted by m_c

If you don't have a pillar drill, scribe, centre punch etc. then

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Then get one ... you're not going to get very far in life without a pillar drill. Well... I wouldn't! Surely you would need both for aluminium or steel.

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Originally Posted by JAZZCNC

No I wouldn't 50x50x3 Ali is £35 plus vat + Del (Ali warehouse) for 5mtr and as of 2 weeks ago when I last bought some 50x50x3 steel box section was £21 for 7.5mtr. Inc Vat.! (Delivered thou it's only next village so don't count really. .Lol)

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Also to get the same strength in Ali you'd need more than 3mm thick...so comparing like with like would make the difference in price even greater. Also I think Tom was comparing aluminium profile to steel box, and profile is a lot more expensive than box (though also significantly stronger for the same outside dimensions).

Two weeks ago... does this mean you've started the next machine?

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Originally Posted by m_c

That's ok if you have the equipment to deal with full lengths, and need the full length.
But if you don't have the equipment, or don't need a multiple of 7.2m, then price difference can be totally different.
It all depends on what equipment you have and what you need.

I can work with either, but not everybody can.
If you don't have a pillar drill, scribe, centre punch etc. then that's something else you need to factor into the cost, and look beyond the basic material costs.

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Well yes and no really.? Cut to length and small quantity's usually come at a premium and has you said the brackets etc required come out expensive.
Most steels stockist's will cut to size for a few quid more.

On a like for like basis then Steel box works out cheaper by about half and IMO again on like for like dimensions basis steel is far stronger.

Yes pillow drills can be expensive but again they are not essential and jigs can be used to good affect.! . .Just takes longer and harder to achive accurecy as easily.
A pillow drill so useful in every aspect of building a machine I would recommend it being one of the first tools bought for building one.
Things like scribes,centre punch etc I consider minimum tools and to be honest anyone who try's to build a steel or Ali machine without them would shouldn't be trying because there not equiped enough.?
Also with the money saved you could probably buy a cheap stick welder and learn a new skill along the way.! . .:dance:

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Originally Posted by JAZZCNC

Yes pillow drills can be expensive

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Mine was about £50 from Tesco, probably 8 years ago now. It's not particularly fast if you want to start drilling big holes in steel/aluminium, but it does work and for <=6mm it's perfectly good. Now I use the milling machine for any 'significant' drilling.

I'm amused by your spelling of pillar drill.

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Originally Posted by JAZZCNC

Also with the money saved you could probably buy a cheap stick welder and learn a new skill along the way.! . .:dance:

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Mine was just a cheapo 160A welder from Aldi. Think it was £35, might have been less.

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Originally Posted by Jonathan

Two weeks ago... does this mean you've started the next machine?

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Nope that beast will be 100x100 filled with sand and built like a brick shit house.!! . . . Was for steel door at work to stop thiefing bastards.!!

One other great tool and cheap thats quick for cutting steel is 1mm micro cutting disc's in angle grinder, go thru like hot knife in butter, they also easily go thru hardened rails and Pad locks.!

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Originally Posted by Jonathan

I'm amused by your spelling of pillar drill.

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Ye I'm ready for bed. . Lol . . . . also didn't goto school much.!! . . . Or should say didn't arrive at school much some how always got lost and ended up in my uncles workshop. :redface:

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Originally Posted by JAZZCNC

Was for steel door at work to stop thiefing bastards.!!

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Originally Posted by JAZZCNC

quick for cutting steel is 1mm micro cutting disc...easily go thru hardened rails and Pad locks.!

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Surely the logical conclusion from those two statements is that the thieves just need a 1mm cutting disk. :clap:

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Originally Posted by Jonathan

Surely the logical conclusion from those two statements is that the thieves just need a 1mm cutting disk. :clap:

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Yep but what more can you do.? . . . The Health n safety gestapo won't let me wire it to the mains like I want to. . . . . .They don't like shot gun wired to PIR either miserable bastards.:thumbdown:

Actually been told by a steel fab shop that if you put plywood behind the steel it dulls the thin blades and they have hard time cutting thru.? . . . Don't know but I've done it for sake of £20.!

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Originally Posted by JAZZCNC

Also with the money saved you could probably buy a cheap stick welder and learn a new skill along the way.! . .:dance:

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Don't get me started on cheap arc welders. They're horrendous to use, and produce good quality welds. Far better to spend a bit extra for a MIG, and get something easier to use and more versatile.


But getting back to the original posters question, yes it will be fine to upgrade/replace in stages.
Might not be ideal, but there's not any set rules on how diy machines should be built (other than the laws of physics that is!)
As for the types of profile, download whatever specification sheets you can find (I used the sheets from http://www.aluminium-profile.co.uk/), and compare the load capacities to find something suitable.

Thanks for the replies chaps.

I didn't realise that you could get a drill press so cheap - looked at some on Machine Mart earlier...there's a branch just down the road from where I work, so i'm tempted to go that route.
I already have scribes/punches etc - thats not a problem.

Regarding the brackets for creating the frame - can anyone point me in the direction of some suitable candidates?

Going to look into the price of steel box in this area....i'm assuming that you're all referring to mild steel & not stainless?

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Originally Posted by CraftyGeek

Regarding the brackets for creating the frame - can anyone point me in the direction of some suitable candidates?

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It all depends on what you're trying to join, but flat plates, or sections of angle will work depending on how/where you want to join sections.

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Going to look into the price of steel box in this area....i'm assuming that you're all referring to mild steel & not stainless?

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Yes, mild steel, unless you're suddenly got lots of money burning a hole in your pocket!

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Originally Posted by m_c

Don't get me started on cheap arc welders. They're horrendous to use, and produce good quality welds. Far better to spend a bit extra for a MIG, and get something easier to use and more versatile.

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Well don't get me started on cheap migs. . .Lol
Cheap migs are usually low powered and useless for welding thick material (Above 3mm). Cheap migs come with crappy wire feeds, crappy regulators and tiny stupidly expensive gas bottles.
If you want to weld thicker material you need high power mig with decent wire feed and larger gas bottles other wise your wasting your time with a Mig IMO. . . . .Thou I do agree they are very versatile if you have decent one.

Cheap stick welders with decent quality rods can weld thick steel with excellent results with a little time and practice. Far better and lot cheaper than a cheap mig for thicker material.

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Originally Posted by CraftyGeek

Regarding the brackets for creating the frame - can anyone point me in the direction of some suitable candidates?

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Just order a length of wide flat plate then mark cut to shape and size using the angle grinder with the micro thin cutting disc's I mentioned before. Very quick and easy.

The combination of Pillar drill, Angle grinder, decent elec hand drill with a few basic tools like sharp scribes etc is all you need to make a very strong frame.

One good piece of equipment I recommend buying is set of transfer punch's like these. . .http://www.rdgtools.co.uk/acatalog/info_1791.html
They make transfering holes from one piece of metal to the other very accurate and easy.!! . . .Very good when making multple brackets etc.

I'm liking the punch set...I think I'll get myself one of those.

When you say micro thin cutting disk..what thickness are they? I have some 2.5mm discs already...how would they do?

Got a quote earlier for 50mm box steel (3mm) it does work out a lot cheaper, so I'm going that route.

Need to get the workshop sorted, then get on to designing the frame.

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Originally Posted by CraftyGeek

When you say micro thin cutting disk..what thickness are they? I have some 2.5mm discs already...how would they do?

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Originally Posted by JAZZCNC

tool and cheap thats quick for cutting steel is 1mm micro cutting disc's

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2.5mm is bad as it has to remove a greater amount of material, so the cutting force and wear on the grinder is higher and it's not as fast.

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Originally Posted by CraftyGeek

Need to get the workshop sorted, then get on to designing the frame.

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Design everything before making, else you'll likely regret it.

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Originally Posted by CraftyGeek

When you say micro thin cutting disk..what thickness are they? I have some 2.5mm discs already...how would they do?

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2.5mm are the older standard thickness cutting disks. Nothing wrong with them if that's what you already have.

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Originally Posted by Jonathan

2.5mm is bad as it has to remove a greater amount of material, so the cutting force and wear on the grinder is higher and it's not as fast.

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I wouldn't call them bad. They were used for many years as cutting discs.
And how does a thicker disc increase cutting force on the grinder?
You shouldn't be forcing the disc into the metal anyway, as all you do is cause extra heat, wear the disc quicker, and put unecessary strain on the grinder.

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Originally Posted by m_c

I wouldn't call them bad. They were used for many years as cutting discs.

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I should have said 'worse' or 'sub-optimal' instead of bad.

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Originally Posted by m_c

And how does a thicker disc increase cutting force on the grinder?

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The steel is cut by the disk generating friction which subsequently melts it away. If the disk it wider the area in contact is greater, therefore for a given feedrate you have higher friction and thus a greater force. Can also argue it with wider disk must require more power, and since power and torque are related by the simple formula, more power means more torque and if there is more torque on the disk the only way that can occur is from a greater cutting force. This site says 'thinner ones will put far less strain on your machine, create less sparks and give a quicker and cleaner cut', which is basically the same thing:

http://www.ultimatehandyman.co.uk/Me...ting_metal.htm

Could probably find a better reference... but not now.

Jonathan, do you ever think that you overthink things too much?

If you're using a wider disc, feedrate isn't going to be the same. You could try and make it the same, but you'll need far more force than a multiple of the disc width difference, which then results in the disc wearing away quicker than it would normally (or clogging if you really push it), and most likely overheating the grinder.
Plus using a proper grinding disc for grinding puts far higher loads on a grinder than cutting, and if you're wearing grinders out, you're either doing something majorly wrong, or you want to buy better ones.

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Originally Posted by m_c

Jonathan, do you ever think that you overthink things too much?

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I probably just did yes, but not having used one much myself I can only really judge from theory and finding sources.

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Originally Posted by m_c

feedrate isn't going to be the same. You could try and make it the same, but you'll need far more force than

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Of course...So it depends on which the limiting factor is - the force / wear on the grinder or the power output for given duty cycle.

I'll leave it at that as I fear I'm going a bit off topic.

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Originally Posted by CraftyGeek

When you say micro thin cutting disk..what thickness are they? I have some 2.5mm discs already...how would they do?

Got a quote earlier for 50mm box steel (3mm) it does work out a lot cheaper, so I'm going that route.

Need to get the workshop sorted, then get on to designing the frame.

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Well they will do if you have them but the 1mm thickness disc's really make light work of it. . . .Like these http://www.arceurotrade.co.uk/Catalo.../NEW-Abrasives
I don't even bother using an hacksaw to cut bolts etc anymore because these are just thin as hacksaw blades and slice thru bolts in seconds with perfect cut.

Edit: Ha ha ha . .The things we numpties will Argue over..!! . . . Thou it's nice to know it's not just me who argue's with Jonathan.!! . . . .Thou I agree with him completely on this occasion, less width = less friction obviously means less power & force required.!!. . Thats gota be a first eh Jonathan. .:lol: