Cheapy plasma cutters?

[FridgeFreezer]

I've got a few jobs on the horizon that may involve cutting & welding so I reckon it might be a good excuse to treat myself to a cheapy plasma cutter.

I know people have raved about the £80 Lidl ones, but given they only come up once every so often & easily sell out, what's the next best bargain out there?

It would primarily be for relatively thin stuff - LR chassis / bulkhead sort of work, sheet fabrication, likely nothing much above 6mm thick. And yes I've got a good air compressor to run it.

[miketomcat]

I've got one your always welcome to borrow. I've only used it a couple of times but it's ex SimonR.

Mike

[FridgeFreezer]

Thanks but I'm kinda fishing for something that can live in the workshop full time - lots on eBlag under 200 quid, R-Tech want 450 which is a little extravagant but at least I'd trust them on quality.

My view is time saved = money the thing's worth, and given I've likely got a footwell repair to do in the near future I can justify a £150-£200 one to myself and the boss... not sure about 450 as I don't think I do enough fabrication, although the RRC would almost certainly warrant it if I ever get round to it...

[steve200TDi]

Yes, granted it's an occasional use item, but you would have comeback if it were not to work in the next 5 years. 

Eeek, there now £540!

Steve

[Stellaghost]

@FridgeFreezer, John I have a Lidl one, I cannot get away with, just doesn't cut anywhere near thickness of material I was expecting, you can have it if you want it as I'm going to dig my Jasic back out

Regards Stephen

 

[FridgeFreezer]

@Stellaghost what do you want for it? And before you post anything are there any 200TDi parts that @miketomcat needs that we can bundle in the same shipment?

[Stellaghost]

12 minutes ago, FridgeFreezer said:

@Stellaghost what do you want for it? And before you post anything are there any 200TDi parts that @miketomcat needs that we can bundle in the same shipment?

Nothing for the plasma cutter

Parts wise, I've nothing really yet, I do have an engine with bottom end gone, however I'm still running a 200 in Sid, so the engine needs to stay for my own use at the moment, of course that will all change once I have the 1uz fitted

Regards Stephen

[Bowie69]

2 minutes ago, Stellaghost said:

that will all change once I have the 1uz fitted

Chop chop

 

[vulcan bomber]

Friend of mine bought a cheapish plasma cutter to save some time in his workshop, reckons it doesn't and wouldn't bother again and just stick to the 4½ grinder.

[Stellaghost]

I respectfully disagree

Out with the initial purchase cost a plasma cutter saves a fortune in cutting discs, can cut in areas you will never get a grinder in, cuts stuff like stainless and aluminium way easier and also cuts curves brilliantly

It is another one that practice makes perfect, straight cuts need a bit of angle to run along side and hands get steadier with use for other cuts

Regards Stephen

[dangerous doug]

They both have their place. I find the grinder coming out a lot more but as Stephen says, the complex shapes and accessibility can’t really be beaten. Look at it like you have a gas axe but without the bottles. 
 

also, rtech let you do monthly payments at 0%. It’s how I got my plasma and It diddnt particularly hurt

[De Ranged]

21 hours ago, Stellaghost said:

Out with the initial purchase cost a plasma cutter saves a fortune in cutting discs, can cut in areas you will never get a grinder in, cuts stuff like stainless and aluminium way easier and also cuts curves brilliantly

Yep I agree..... and I still use cutting disks lol, with a plasma you only get that nice neat cut if you can clean things first and use a fence/pattern, the surface is consistantly free of rust, paint dirt etc or you get arc wander and in sheet metal/body work you still need to grind and cut what you have plasma cut so you get a neat hole to patch too..... so using cutting disks saves me alot of time over plasma, the other thing is it takes time to setup.... I know its just hoses and a cord lol but often the grinder has the job done before you've even got the compressor full 
For me its conviniance tool its a gas axe that is ALOT cheaper to run.... I use it on complex shapes, large jobs like scraping cars parts or stirp outs, difficult to access areas (just watch out plasma will go through layers unlike an axe lol also a bonus) and 3+mm steel that cant be cut in the bandsaw it is way faster than a grinder then

I can't offer any advice on cheap units lol the cheap ones over here are $300 UKP price lol (Mitech which I did have till it was stolen now I'm running something much better)

What I can give you is a tip on consumables. Tourches that use these style of consumables are false economy seen them called alsorts of designations I think the common one is p31

The electrode wears out very quickly if there is any moisture in your lines, the cup (the bit with the hole in the tip) the hole will blow out and your cut width will get wider with more slag buildup (you can decrease your air pressure this will help stop this but it means your more inclined to get arc wander from contaminates on the surface, or back) If you use your cups to the bitter end lol I'm cheap you will find the hole wears to a slot and it isn't uncommon to have it bad enough the arc is firing off on as much as a 45 degree angle. I've had tips last less than half an hour of use 

I tried several tourches (cheap chinese ones) on my Mitech, that had larger consumables this increased the lifespan of them considerably, further than the unit cost would suggest. My current tourch uses these style of consumables 

they are alot dearer, but I've had it for think almost 2 yrs and I'm only on my second tip and that is running on a 2hp water spitting compressor

 

[robertspark]

plasma comes into its own when you couple it with a CNC table for cutting shapes you design in cad.

these days I tend to use a laser diode to cut the shapes from cardboard or paper first to check hole fitment before wasting steel.   

 

once I'm happy then plasma cut steel and weld.

 

if you ever intend to use a CNC table later, try to find one with a blowback start and avoid the scratch start plasma cutters.   hf start can be used on a CNC table, but not scratch start.  hf start can play havoc with your electronics, hence blowback start.

 

blowback start are more commonly available than they used to be

 

I cannot advise on cheap plasma cutters, but the ones sold by r-tech are cost effective entry point to CNC plasma table cutters that are also hand cutters.

 

air quality is important in cut quality and consumable life, oil in the air stream and water are not good.

 

plasma cutting leads to a hardened edge where the cut takes place, it can be problematic to redrill later as it may / will blunt chocolate drill bits, hence the clean up and prep relative to a grinder can be longer if plasma cutting something you want to later do something else with.

 

top side dross, you are generally moving too fast, or the torch is too high.   normally leads to poor cut through too.

 

bottom side dross, lots of it and hard to remove is cutting too slow.  you will get bottom side dross with perfect cut speed, but is normally comes off very easily (if it's a plate or pattern you can handle, drop it from chest height, flat onto the floor and the dross will mostly break off, otherwise I just hand slide a 1" cold chisel around the back side of the plate very fast and the dross shoots off)

 

[mickeyw]

Footwell and bulkhead repairs -these are the exact jobs I used to justify the purchase of my first plasma cutter. Definitely a worthwhile purchase for this purpose.

Note that if you choose a model that has pilot arc it won't matter how rusty the material you're cutting out is.

R Tech sometimes have "shop soiled" units they punt out at a reduced price 😉

[FridgeFreezer]

Thanks all - Stephen has (yet again) been incredibly generous and shipped me his surplus Lidl unit, so as soon as that arrives I'll be having a play with it. I have a feeling there's a footwell repair on the ambulance in my very near future so that will be a good practical test.

I have harboured vague notions of a CNC plasma being a useful tool but I'm very tight for floor-space already, not to mention time, money, and mental bandwidth !

I'm still getting up to speed with the mill (got a long shopping list for that) as well as having an ever-expanding project list for the 3D printer... these days after staring at a computer screen all day wrangling code I'm finding it hard to muster the motivation to spend all evening doing it too... and with CNC/3D printing if you don't do the computery bit nothing gets made, at least "manual" work you can just go out to the shed and start cutting metal.

[Ed Poore]

If the compressor is living in a not very dry shed / workshop get a drier / filter for it. I've got the 50A R Tech and it really doesn't like sea air from Wales.

Like the Lidl ones it's ambitious on its ratings but will do 10mm reasonably comfortably.

Last time I fired it up it wasn't striking the pilot arc, submitted a support ticket on their website on a Sunday evening. 0930am on Monday I had a phone call from one of their engineers, talked through the problem and he suggested tweaking the spark gap on one of the PCBs. Got it fired up again (although it's back to misbehaving). Oh I should point out it was 5 years out of warranty when I had the 40 minute chat on the phone with them. The support ticket was actually asking about how to ship it back to them to quote for a repair.

So they're good on their support, but I have had a few issues with it but can't complain about their support.

[simonr]

I started with a cheapo plasma - and gave it to BusShed as I could never get it to work well (*see later!)

Then I bought a cheap, used Hypertherm and it was amazing.

Mark (BusShed) said it worked perfectly!  However, his compressor had a huge reservoir.  I later discovered that the evenness of the air supply is critical.  If you have a piston compressor with a small reservoir, the air pressure pulses with the mains frequency.  Since the torch voltage also pulses at 50Hz, you can see problems if the phase of the pulses in the air pressure are in or out of phase with the torch voltage.  The phase is affected by things like the length of hose.

When I bought the Hypertherm, I also bought a cheap used Hydrovane compressor - and I think that's why it worked so well by comparison.

Sometimes people complain about the cost of Hypertherm consumables (roughly £10 per Nozzle or Electrode) where you can buy 100 Chinese ones for the same.  However, there is a big difference!  The airflow through the Hypertherm is much tighter & more cylindrical which concentrates the arc more and gives you a cleaner cut.  The arc being more concentrated also increases the cutting depth for a given power.  They also last a lot longer.

RTech are not bad for the price but their HF Start is too (electrically) noisy for CNC.  I used to have one of theirs too but it was only useful for hand cutting.  The HF Start on the Hypertherm however doesn't cause any upset to the electronics.

In your place, I'd buy a used Hypertherm Powermax 30 or 45 (the main difference is the duty cycle).  I have a 30 now and it's fantastic for both hand and CNC.  It's only 30A, but out performs the 50A RTech and the 60A Chinese one in terms of tidy cut depth.

This is my current (3rd) itteration of my DIY CNC Plasma - you can just see the Hypertherm on the floor underneath.  I get nice cut quality up to 10mm & OK up to 15mm.

P.S. Don't believe the "50mm cut depth" type adverts - they are mostly very optimistic.  For a clean cut, I would bet on about 3A per mm for Hypertherm, 6A for Chinese.

[Stellaghost]

Just received a delivery of these

I get what @De Ranged says however I've used these for 10yrs plus and always got on fine  however I'm not a professional user. This lot cost £24 delivered and will probably last me 2/3 years, granted if I want to cut 8mm I will put a new nozzle in but the consumables are so cheap it isnt an issue if I use a few in quick succession 

Just my 10 pence worth

regards Stephen 

[De Ranged]

2 hours ago, Stellaghost said:

This lot cost £24 delivered and will probably last me 2/3 years

Over that time frame it does sound silly lol.... that lot would last me 3 months 

You got me interested in the economics of changing tourches, on my old Mitech I changed tourches due to damage to my old torch leads (twice, bought bigger consumable torches each time) happens when you break up parts trucks to scrap or strip outs (ifs to solid axle) also the hardest on consumables due to dirt grease and paint causing the arc wonder that blows out the cups  
Going to the P80 series (what my new plasma runs) prices off Aliexpress (including freight).... 
Replacement torch/handpiece only 16 UKP
Torch and lead                                 40 UKP
Consumables 20 sets                      22 UKP (can buy less but price goes way up per unit) basicly lifetime supply for most people given my experiance so far

Replacement P31  (what comes on the cheap machines, one that uses your consumables)
Handpiece only                                 7 UKP
Torch and lead                                33 UKP
Consumables 50 sets                     23 UKP (again can buy less but I like the unit price) this is where it gets murky, I'm guessing this is twice your bag above.... so potentailly 6yrs worth, for me about 6 months... maybe a bit more if I don't let my mates use the plasma lol, without offending anyone on here I'd say your engineering work/achievements are greater than most of the people here..... that says my advice is kinda carp lol 

While I was researching this I bought a spare lead and torch lol If I have a spare the one on the machine will last longer!

 

 

Edited March 22 by De Ranged

[robertspark]

I have bought bits from here but it has been a while, via the slow boat

https://www.riverweldstore.com/collections/trafimet-s45