Hey guys new member. advice needed

**Kitwn** · 21-11-2020

I don't know the cost of steel in dear old Blighty, but you're looking for RHS (rectangular hollow steel) prices. Here in Australia you could buy an awful lot of it for the equivalent of 600 quid but we dig it out of the ground over here so it might be cheaper! Aluminium on the other hand costs an arm and both legs. I built my machine from steel scavenged off the local tip but that is not the recommended source. Other UK forum members will know more about the likely cost than me.

There are several build logs on the forum which show good designs for welded frames (mine is NOT one of them). If you can already weld, brilliant. If you can't, it's easy enough to do an adequate job and a cheap welder is adequate. You are not building the Forth Bridge and some fairly scrappy looking results will be good enough. You can hide all sorts of sins with a grinder, car body filler and paint. have a look at the pictures in post #5 of the following thread for the proof of that!
http://www.mycncuk.com/threads/13904-Kit-s-Machine

With a steel frame and gantry and a low cost, if temporary, controller you should expect to have most of your immediate budget available for the mechanical components of rails, ballscrews, belts and pulleys etc. and the motors, drivers and power supply plus spindle and VFD.

One very important way you can save money is to consider if you can reduce the cutting area you WANT to build to the cutting area you NEED to build.

**Doddy** · 21-11-2020

Just consider that many of the accessible online metal stores factor in delivery on their prices. Talk to a local supplier - you might be surprised. Also if you happen to be passing any fabricators it might be worth enquiring (I approached a fencing fabricator and they knocked up (welded) a 100x100x4 box section top-frame for a bench, 1600mm x 750mm for a ton... which I thought was pretty good, and flat to less than a mm (as best as I could measure). Also, when sourcing Argon for welding I did speak to a one-man band who showed me around his workshop - a bit of a chat suggested I could buy steel from him cheaper than the usual online stores. Lastly, I bought a load of 100x50x5 box section, a convenient 1.6m long from a fabricator off eBay - was only 20 miles to collect. 6 months later I found similar for sale 20 miles in the opposite direction - turned out they'd bought from the first guy. Keep your eyes open. If you can weld, then you can build a frame pretty cheaply.

**JAZZCNC** · 21-11-2020

If you find your local Steel stockholder you'll buy 80 x 45 x 4mm wall in 7.5mtr lengths for about £60+vat. Depending on size 1 or at most 2 lengths will get you the base frame.
For the aluminum for the Z-axis and other areas of the machine, If you have any local engineering places nearby it's worth calling in and asking if they have an offcuts bin. Often what they call scrap pieces we call a Z-axis and they will sell you it at scrap value or if you drop on right bloke a few pints.
Drop on the right place and you might get steel off cuts their too.?

With £1200 it's just about doable to build a decent machine if you are careful and don't waste money buying the wrong stuff. Like has been said stay away from any electronics kit as they are nearly always made up of rubbish and poorly matched.

Linux CNC with a BOB will get you going cheaply like as been said and then it opens up a whole world of expansion if you move to Mesa, it will also open up a whole world of head-scratching as well depending on your skills and temperament learning to speak all thing Linux CNC but to kick you off cheaply it's perfect.

The secret to the successful building of a good machine is to NOT RUSH or BUY ANYTHING and always ask before buying because often someone will point you to a cheaper or better option.

If you take the Build route then the first thing to do is start a Build thread, even before you lay paper to pen, and ask ALL your questions in this thread. Don't start new threads asking questions because they get lost with time, keeping all your questions in one place makes it easier months later when your looking for reply. It also keeps your thread high on the trending list where you are more likely to get replies.

Good luck and don't waste money on those rubbish Kits as you will regret it.

**tankproof2** · 21-11-2020

Ok, my foot is off the buy pedal.

i have looked though this forum and see 2 ways of doing it. 1 steel welded frame, 2 Epoxy Granite my question whould be, which is the best/ most cost effective? for a 1.2 x .75m machine.

i will start a build thread now and get cracking on the cad.

thanks for all the help, Tank.

**JAZZCNC** · 22-11-2020

Originally Posted by tankproof2

Ok, my foot is off the buy pedal.

i have looked though this forum and see 2 ways of doing it. 1 steel welded frame, 2 Epoxy Granite my question whould be, which is the best/ most cost effective? for a 1.2 x .75m machine.

i will start a build thread now and get cracking on the cad.

thanks for all the help, Tank.

Ok, that's easy, Steel is the better and cheaper choice for a machine this size. Why.?

Epoxy granite would be the stronger machine but would cost far more money by the time you have built a substantial mold for it and bought the materials, then you have the weight of the thing, it would be VERY heavy.
Then you have to consider the machine design.! Moving gantry or Fixed.? Epoxy granite would require you to build a fixed gantry otherwise you'll be into BIG and expensive motors to shift all that heavy mass around on a moving gantry machine.
Then you have the size, Fixed gantry would require roughly 2x the area for one of the given sizes.

The best combination is a steel frame with the rail surfaces epoxy leveled to give you better accuracy with the least hassle.

When you are looking at builds pay attention to those that put the rails on high sided frames with the gantry sat directly onto the carriages. This is the stronger design for your needs with cutting aluminum.
If you want a good example of what can be done with basic tools then check out Joe's build. There is many other's similar as well which use this style of the frame design and very well made.

**tankproof2** · 22-11-2020

Ok i will go ahead with steel construction, sorry i wasn't able to find Joe's build could you please send me a link, Tank

**tankproof2** · 26-11-2020

Ok, so i have done some research and come to some conclusions. but i have a few questions.

i have found multiple options for a few things and would like to ask which is best

spindle- they are all around the same price but with different vfds but which is the best?

https://www.aliexpress.com/item/3225...c00DrQIm1&mp=1
https://www.aliexpress.com/item/3298...c00DrQIm1&mp=1
https://www.aliexpress.com/item/4000...c00DrQIm1&mp=1

steppers i am thinking nema 23 and these are the options i have found which is the best?

https://www.welectron.com/JMC-iHSV57...ed-Servo-Motor (this one comes with integrated drivers but is about the same cost as the other with a CW8060 driver)
https://www.cnc4you.co.uk/Stepper-Mo...H401-03-Nema23

drivers-

i am thinking of going for a way over kill driver to give me head room for new/ more powerful motors

options are the cw8060 https://www.aliexpress.com/item/6127...archweb201603_

or cheap out and get some https://www.aliexpress.com/item/3291...c00DrQIm1&mp=1

my question is what is the best cheap stepper right now?

as far as voltage goes i am thinking 48v but is this too high?

**JAZZCNC** · 26-11-2020

Ok well the first spindle is the better choice because of the VFD, It's made by Huanyang and is well tested on 10,000's of machines, the other two are copies and lower quality, that said even the huanyang isn't the best quality in the world but I personally have fitted 100's with less than a handful of issues so wouldn't hesitate to fit one or recommend buying one.
The Black one I've only fit on a couple machines and wasn't impressed with them, the white one I've no experience other than I know someone who had one and it blow up after 7 months.
The spindles are all the same. One other thing to mention is the water pump.! These pumps included in the kits are 230V Mains powered and DONT have an earth which isn't cleaver in a submersible pump IMO. I won't fit them.!

Motors:
The first motors with intergrated drives are not steppers they are DC servo motors. Never used so can't comment but 180W isn't a lot with only 48Vdc and won't suit a large machine.

The second motor is a run of the mill stepper, nothing special.

Drives:
The CW8060 are not very good drives at all and certainly NOT going way over kill.? 80Vdc drives are what you will need for a decent sized machine to get the higher feeds you'll want.

The cheaper Dm542 are ok for a small machine but are limited on the Max voltage at 50vdc, for a large router like what your planning then you'll want to be running your motors with around 60-65Vdc to get the best speed and torque from them.

Now personally I wouldn't fit any of these because they are basiclly OLD technology, Newer Closed loop motors with Digital drives are much better and won't cost much more money.
Also look for drives that provide AC input and it will save you the trouble of building a DC power supply and a little money.

However, why are you even looking at buying this lot when as far I can see you haven't even decided or designed the machine yet.?
You are a long long way off needing any of this and while it's tempting to buy so you can test on bench all your doing is wasting warrenty and they will learn you very little.
Also, without knowing the Mass etc of the gantry you could easily buy the wrong size motors/drives.

Again I'll advise you to NOT BUY ANYTHING and say go do more research on the motors/drives and why voltage is very important. But only so you have a better understanding of why getting this part right is so important and not so you are better armed to buy now. Only buy when you need or close to needing them.

**CNCRY** · 27-11-2020

Hi Jazz - hope all is good. Sorry to thread hijack, just read your comment about the 230V pump - while running mine today I remembered I'm still using one of those potential death traps with no earth submerged in coolant! From what I can tell (no details with it) its probably 3000L/Hour flow rate .
Do you recommend a better 230V pump or 12/24V versions? Thanks
Ryan

**JAZZCNC** · 27-11-2020

Originally Posted by CNCRY

Hi Jazz - hope all is good. Sorry to thread hijack, just read your comment about the 230V pump - while running mine today I remembered I'm still using one of those potential death traps with no earth submerged in coolant! From what I can tell (no details with it) its probably 3000L/Hour flow rate .
Do you recommend a better 230V pump or 12/24V versions? Thanks
Ryan

To be honest I just use 24Vdc pumps that they use for solar heating, they are cheap and safe. Plenty of them on Ebay.