[Dougie085]

How much do you think the steel would cost to build a 4x4 cutting area router? The aluminum was going to cost something like 1500-2 grand of course that was for a 8x4. What is the cutting area on yours?

[contactirfu]

for my 4x2.5 machine, teh steel cost me around 300USD, also if u r goin in for a 4x8 machine, have you looked at www.mechmate.com - free plans available.

Hayden I hope I am not Hijacking your thread.

[Dougie085]

Yeah I'm sorry just had a few questions.

[Haydn]

Hi Dougie

Some steel I cut with a hacksaw, some with a bandsaw (at a local engineers) and some with a chop saw like Irfan said. Most of the joints in my build are not length accuracy dependant so a hacksaw was fine and a quick tidy up with a file. I recommend to not use a carpenters square for marking out, most carpenters squares are only vaguely accurate on one face, use an engineers square not too expensive and a good investment. The essential tools I used (a lot from ebay - saving a fortune) are

6" engineers square (bought new)
12" engineers square (bought new)
50" grade A engineers straight edge (ebay £40, saved about £400 there! I checked it on a surface table at a local engineers)
0.01mm finger dial gauge (mitutoyo new ebay)
0.1mm finger dial gauge (mitutoyo new ebay)
dial gauge magnetic base (bought new)
150mm digital verneer mitutoyo (ebay)
starite precision engineers level (ebay)
marking scrib
marking blue
center punch
decent tap and drill set

I spent less than £100 on steel, I saved a fortune by going to the steel stockholder and buying offcut lengths for a few £ here and there. Normally I would have had to have bought 3.6m or 7.2m lengths. Takes a bit longer to build as you may wait for the sizes you need to show up but I was in no hurry. I soon learned who worked which day at the stockholder as some people would give me a much better price than others (how much for that lot? ermm £15 - oh ok, I disappear with the steel, the £15 goes in back pocket for beer!).

I used a pillar drill and a cordless dewalt drill driver for the holes, a decent drill bit is what counts. Some holes were tapped with a machine tap in the cordless, the rest by hand you'll discover muscles in your arm and wrist that you never knew existed after a few hundred holes! You may have some problems drilling and tapping on the seam of box section steel, orientate your section to avoid this as much as you can.

Just my two cents worth and hope it's useful

Good luck

Haydn

[Dougie085]

So saying my budget is ~2000 USD give or take a couple hundred. Do you think it's possible for me to build a steel machine with this? I would like at least a 4'x4' cutting area. I was planning on using high torque steppers even for the aluminum machine so that really wouldn't change too much. Probably 1260oz steppers with gecko drives. The bearings are what I'm a bit concerned about. The linear slide bearings are quite expensive and I haven't been able to find the right lengths on ebay yet. Do you think a V Bearing would work on these? Or maybe a pole bearing with some decent quality bearings? I'd really like to use the slide bearings so maybe I'll look more. I was originally going to do a 4'x8' table so maybe going 4' shorter will save enough to use the linear bearings. Going to reread over your thread a bit now see if I missed anything.

[Haydn]

You maybe could do it for about $2K. I think the bearings are down to what you can achieve on your budget. You could use round bearing shaft (like my Y) but you would need to fully support it and orientate them so the load is distributed evenly. Ebay is getting thin on the ground for cnc parts. Try
http://www.pro.com.sg/Z-HTM/LM-Guide.htm he has used rails and bearings etc
Take a look at www.larkencnc.com they use bearing shaft on their machines. An 8x4 machine would cost $1K+ for slides then you need ballscrews etc so that would be your budget gone. You could use V bearings, I never have so cant advise you there. I'd say what you use depends on what you expect to get out of the machine - engineering tolerances or woodworking tolerances, in that sense don't buy what you don't need unless the extra spend is worth it in the long run, my Y as point of note - I couldn't find ebay rails for it and couldn't afford new at the time, I built it so I could upgrade to rails as funds for rails became available, I have ordered some. You could save a bit on steppers you may not need to go that big maybe 960oz (a bigger stepper can take longer to accelerate so poorer performance) but that depends on the mass of your gantry/load you want to move. If you go the lead screw route maybe use the bigger motors as lead screws are typically about 30% efficient compared to a ball screw at about 90% so you may need to consider losses in your system.
My machine cost me £1800-2000 so $3500-$4000, you could do it for less than me as you have a lot more suppliers in the US and a lot more ebay items which people will not ship to the UK. If you can get a pair of rails for whichever axis at a decent price buy them and then you started, thats what I did (I remember telling myself "**** i'm committed now!").
A note on second hand rails though, if they have been used in an orientation different to how you intend using them they may not be as smooth as you hoped!

Hope this is of some use!

[contactirfu]

hayden, kindly post the pictures of the eng squares you have or the link from where you bought them.

I need to know the difference b/w the carpenters square and the Engineers ! suppliers here dont undersand what the difference it makes and just blurt that a square is a square. what ever u buy.

It will of great help to me to get the right ones thru showing thm some pictures at least.

RGDS
Irfan

[Haydn]

Here is a picture of squares similar to mine. Mine are by Moore and Wright in the UK, you should be able to pick up these from any engineers supplies from many manufacturers, I bought mine in my local engineering supplies shop. Good makes are graded, Grade A being the most accurate and expensive, unbranded squares often do not have any indication of their tolerances, some are good some are bad, I have one I bought years ago for setting the fence on my planer - it was out by 0.5-0.75mm over 150mm length took me a day to work out why nothing would fit together, I use it as a small hammer now!
(nuts)

The blades are usually thicker than a joiners square which makes it easier to run a dial gauge along when setting out.

[contactirfu]

Ah, got it!

my carpenter square looks exactly like those just itis black and probably way out of accuracy.will try to post pictures over week end.

Thanks again for your valuable inputs hayden.

[jrace2718]

Haydn,

Your machine is fantastic. I am starting one myself and I had a couple questions:

1) With your X being driven from the middle as opposed to the sides with 2 screws, do ever get any racking if taking a big cut? If you did it over, would you drive X with 2 screws?

2) Do you have any problems with dust on your X rails and bearings?

Thanks!

[Haydn]

Haydn,

Your machine is fantastic. I am starting one myself and I had a couple questions:

1) With your X being driven from the middle as opposed to the sides with 2 screws, do ever get any racking if taking a big cut? If you did it over, would you drive X with 2 screws?

2) Do you have any problems with dust on your X rails and bearings?

Thanks!

Machine has been running for a year now and I have had no problems. I havent noticed any crabbing/racking I doubt very much I would consider driving with two screws. I have seen plenty 8x4 maachines with one central screw. The second screw can induce as many problems as it tries to solve.

All my bearings are dust sealed with wipers etc. I clean them off with a compressor and vac at the end of the day. I will be boxing in the x screw when I re do the gantry, I have new profile rail for the y axis. I have decided to lower the height of the gantry as I don't need 6" travel in z, and add a little more mass and stiffness.

Hope this is of use

Haydn

[Haydn]

After a few months of saying i'm going to fit new profile rails to the gantry, I have decided to beef the whole thing up. I strapped another 35kg of steel to the gantry as it is and it still ran absolutely fine, so I will be rebuilding it and adding more mass. If anyone is interested in the epoxy technique I used and wants some kind of pictorial construction of the new gantry I will see what I can do. I have already epoxied the new beams for mounting the rails. I've increased the size and length of these from 60x40mm to 80x40mm with 4mm wall.

Haydn

[contactirfu]

Hi Hayden,

Nice to hear that u are going in for that upgrade!, I am interested and so are many others who might come by this thread, to see hoe u epoxied the steel! Pls do post the pictures and if u have a video then youtube it.

RGDS
Irfan

[pumelloman]

Hi Hayden,

I've been lurking around your thread for some time now, and built a Solsylva 25x37 Router. I'm mostly building a CNC for the education, as I am an engineering student, rather than for the actual CNC itself. So I'm starting to think about building a machine out of steel. I have access though to a milling machine, and I live in Canada so shipping from the US isn't as crazy. But I still plan on doing something similar to your build, using epoxy instead of welding.

I guess I will be going through your thread very carefully, and I will definitely follow through on your suggestions for the tools. I mostly have Habor Freight/Princess Auto tools at the moment, so I will go around an acquire the tools that you listed before.

If you could, I am really interested on what epoxy you used, please post your technique for epoxying ^^

[Haydn]

I used two different epoxies. A high spec engineering steel epoxy was used for critical joints, branded as Devcon in the UK, this is a slow setting epoxy - 16hr cure time (they also do liquid steel and fast cure epoxies). I use this for joints that need specific alignment that can't be done in 5mins such as the beams that the x rails are mounted on. I use a cheaper general purpose steel epoxy for general joints and for mounting the rails on, this is made by Unibond and is called Metal Repair for Good in the UK. This cures in 10-15mins is easy to work and has good compressive strength. Neither of the epoxy steels contract as they cure, this is very important for obvious reasons.

Devcon is available in the US

http://www.devcon.com/products/produ...ndid=1&catid=2

I use Steel Putty (A) and may be using Steel Liquid (B) in the new gantry. The steel liquid can be cast and is recommended for levelling machinary surfaces etc.

Haydn

[Haydn]

Back from some time away from here as I've been a bit busy. Haven't done much with the new gantry as I haven't had time. I'll get round to that asap. Just got married too. The woman who was making our rings decided she couldn't do them anymore - three weeks before the day! Decided to make my own with the cnc. Came out a treat, so here thay are. Made in white gold and machined using a 0.2mm dia tapered ball nose cutter. Machined flat and then rolled into rings and joined. Look better in reality than in the pics.

H

[contactirfu]

COngrats on your marriage to karen -

Have a good and beautiful life ahead!

now your wife will always have a softer heart on your cnc hobby!

Enjoy!

RGDS
Irfan

[CNC Rocks]

Hello Haydn.

Can you post some information about the work envelope and the footprint of your cnc router please?

Thank you.

[Haydn]

The router has a footprint of approx 1160mm x 1700mm. x travel is 1280mm, y 880mm, z 150mm. The footprint includes the length of motors. These are not exact figures as i'm not near the machine but pretty close.

H

[Jason Marsha]

Congrats Hayden,
The rings look really good, I am sure your wife is pleased with the results. Since the cnc played such an important role then I suppose you will now have free reign when you want to upgrade.

Jason