[Sturmer]

Hi i am a new one here on forum,but i have degree in Mehatronics i worked on couple of german made machines that were for A3 paper dimensions cuting tables...now i have question...what is the amount of money needed to put in this project to get one A3 cuting table,and what are the mistakes made by the machine if one is made(from cheep parts).I whuld like to make this machine couse i am layzy cutng balsa for my RC projects..and i need some kind of a hobby to fill my time..so if any of u can direct me to one of the forums that covers this cind of machine...or topic..please help...

Best regards Stjepan from Croatia...

[chuckknigh]

You're in exactly the right place.

Of course, all engineering involves tradeoffs and design decisions, but a light weight machine to cut something as soft as balsa wood need not be complicated. Common materials can be put to creative uses, and end up giving excellent results.

If I understand you, you are asking what impact on performance choosing inexpensive components will have. That's a complicated question, but here's a simple answer.

ALL machines have weaknesses, and most of them can be summed up in two words. Flex and backlash.

You can address flex by making your machine as rigid as possible, but realize that there is a point of diminishing returns. In woodworking, accuracy over .01" is rarely needed...truth be known, for most applications in woodworking, .1" is close enough.

Backlash is the "wiggle" or the looseness present between the screw and the nut. A preloaded nut can give a tight fit, but at the expense of additional drag which requires a bigger motor. Again, keep in mind the tolerances you require, and design for those.

Welcome to the forum, Stjepan. It's nice to meet you.

-- Chuck Knight

[Sturmer]

well I am sorry about my poor English...well when i was in school i tried to start this kind of project...but all of my professors seed that the ball-screws are the most expensive...is it possible to make one for about 300 €?(can i use ball-screws of the printers,and their step motors?) Cause i really need about A4 cutting space...?and i still did not catch how do you control this machines?is there any free software?I really don't need big precision..about .1, to .5 mm( oh and...inches are really com fusing to me) just to cut balsa...and some plywood... maybe Plexiglas...but that is just maybe..the primary function is for cutting balsa...PS. I can get access to the one milling table so i can almost all parts make by another mill( A3 is my limitation)...Oh and what are the speeds needed for the cutting head to cut the balsa without spliting it at halve?

PS I am sorry.y if i ask questions that are already answered somewhere in this forum...but this forum is huge...


Stjepan

[tbenefi33]

hi strumer well right now i'm on hold on my project cause it summer time here..lol i have every thing done and all i needs is the electronics and flang bearing So far i got all most $400.00 in the project .Its safe to say you'll probley spend around $600.00 to a $1,000.00.Shop around and look for the cheaper price I'm still looking for some stepper moters.

[tbenefi33]

Hi Dogsione I found a local pc store i might check them out on a dock station.But if i find one i'll let you know.

[chuckknigh]

well I am sorry about my poor English...well when i was in school i tried to start this kind of project...but all of my professors seed that the ball-screws are the most expensive...is it possible to make one for about 300 €?

How good are you at finding/adapting to surplus parts? For example, the old HP LaserJet printers all had a very useful 100 oz in stepper motor in them, which many of us have used in our own machines.

Your professors were quite correct about ballscrews being the most expensive leadscrews. BUT, the precision of ballscrews is not needed for a woodworking router. Their low friction is desirable, but the increase in cost makes it an unacceptable tradeoff.

Many people use standard threaded rod. Bearing supports can be made from RollerBlade skate bearings -- the ID of the standard bearings is 8mm, which is fit by 8mm threaded rod.

A step up in quality, accuracy, and efficiency can be had by using ACME threaded rod.

You're a mechanical engineer -- I've never met a single ME who did not enjoy recycling discarded parts into usable machines.

(can i use ball-screws of the printers,and their step motors?) Cause i really need about A4 cutting space...?

Refresh my memory on the dimensions of an A4 sheet. Metric is fine. I believe it's a standard piece of typing/copier paper, right?

and i still did not catch how do you control this machines?is there any free software?I really don't need big precision..about .1, to .5 mm( oh and...inches are really com fusing to me) just to cut balsa...and some plywood... maybe Plexiglas...but that is just maybe..the primary function is for cutting balsa...

There are a couple of steps. Do you understand the electronics needed? Basically, what happens is that the software reads an instruction to move the X axis 25mm, and then converts that into the needed number of steps. Out the parallel port come electrical pulses, which are received by a driver circuit. This translates those low level signals into something capable of actually driving the motors.

There are some really good programs to interpret the G-Code. EMC is a free program which runs under LINUX, TurboCNC is a shareware program that runs under DOS, and there are a few really good ones which run under Windows for various prices.

PS I am sorry.y if i ask questions that are already answered somewhere in this forum...but this forum is huge...

You're right. This is an amazing site, with an enormous amount of information. It's actually difficult to find the necessary information, without dedicating a week or two to actually reading everything on it.

-- Chuck Knight

[Sturmer]

How good are you at finding/adapting to surplus parts? For example, the old HP LaserJet printers all had a very useful 100 oz in stepper motor in them, which many of us have used in our own machines.

Well i was thinking something like that,well all of my stuff that i made/make is made from scrap...very few things i buy...well i am student which is working to pay of his intuition..and life costs(i am from pretty poor family)but my curious nature is stronger then my low budget so..

Many people use standard threaded rod. Bearing supports can be made from RollerBlade skate bearings -- the ID of the standard bearings is 8mm, which is fit by 8mm threaded rod.
Refresh my memory on the dimensions of an A4 sheet. Metric is fine. I believe it's a standard piece of typing/copier paper, right?

Yes it is standarad printig paper size...

There are a couple of steps. Do you understand the electronics needed? Basically, what happens is that the software reads an instruction to move the X axis 25mm, and then converts that into the needed number of steps. Out the parallel port come electrical pulses, which are received by a driver circuit. This translates those low level signals into something capable of actually driving the motors.

Yes i do understand the electronic part of the machine...i had few of my own concepts but i have terminated them because i did not know how to make software to control the machine... and i was afraid of the mistake it would made....and the software i used in school is simple(cad like)...is there free software which is CAD like?Or which uses DXF formatted drawings?Or that compiles the CAD drawing into code?

hi strumer well right now i'm on hold on my project cause it summer time here..lol i have every thing done and all i needs is the electronics and flang bearing So far i got all most $400.00 in the project .Its safe to say you'll probley spend around $600.00 to a $1,000.00.Shop around and look for the cheaper price I'm still looking for some stepper moters.

well if i use the stepper motors i got from the printers(or some where else) and if i scrap for almoust all the solid stuff,and buy just the electronics what whuld be the price..?

[chuckknigh]

Can you build the electronics, or must you buy them pre-built? I don't know what things cost in your part of the world.

There is a kit in the US, called PICStep, which is only about $75 for a 3 axis setup. BUT, it's a kit. Other well known kits are Xylotex and HobbyCNC, both of which have excellent track records.

I doubt the electronics would cost you more than $100US, if bought in the United States.

You said you're a student. Does your school have an electronics program? Might one of the other students or maybe one of the more open-minded teachers be able to help with the electronics? There are super-simple stepper driver circuits available, on the web...not exceptionally efficient, but the cost is definitely right.

Stepper driver circuits are a fairly common project, in many electronics courses.

-- Chuck Knight

[tbenefi33]

I"ve been eyeballing the kits on hobby cnc also hard alot good stuff about um some said they where eazy to put toghter not sure what the price is on them.I'll have to check the site out i havent been on there awhile.

[joecnc2006]

I"ve been eyeballing the kits on hobby cnc also hard alot good stuff about um some said they where eazy to put toghter not sure what the price is on them.I'll have to check the site out i havent been on there awhile.

I use the HobbyCNC board the three axis is 79.00, yes is very easy to put together with his instructions that are included and he also has the yahoo forum that is helpful. I give it two thumbs up...

[chuckknigh]

Well i was thinking something like that,well all of my stuff that i made/make is made from scrap...very few things i buy...well i am student which is working to pay of his intuition..and life costs(i am from pretty poor family)but my curious nature is stronger then my low budget so..

Noone *likes* to pay full price for anything! And, happily, in this hobby there are almost always other options.

Getting creative with the parts is half the fun of building these machines!

Yes i do understand the electronic part of the machine...i had few of my own concepts but i have terminated them because i did not know how to make software to control the machine... and i was afraid of the mistake it would made....and the software i used in school is simple(cad like)...is there free software which is CAD like?Or which uses DXF formatted drawings?Or that compiles the CAD drawing into code?

It's a multi-step process using the free tools, but it works really well.

Step 1, draw your part in a CAD program, save it as a DXF file.
Step 2, use a CAM rogram to convert it to G-Code. This is a type of programming language that syas things like move the X axis +25mm, and move the Y axis -47mm.
Step 3, run the G-Code through a controller program like TurboCNC. http://www.dakeng.com is their URL, I think. This program turns the instructions in G-Code into the needed pulses to control *your* particular setup. You define that 200 steps (pulses) = 1 rotation, and each rotation is 1mm...that sort of thing. It does the calculations, and outputs the right stuff through the parallel port of your computer.

-- Chuck Knight

[Sturmer]

http://www.dakeng.com[/url] is their URL, I think. This program turns the instructions in G-Code into the needed pulses to control *your* particular setup. You define that 200 steps (pulses) = 1 rotation, and each rotation is 1mm...that sort of thing. It does the calculations, and outputs the right stuff through the parallel port of your computer.

-- Chuck Knight

i know the G-code in high school i had few exams in it....and i used it for couple of my home made projects...so i know how to use it...i am now on collage(i used machines in highschool...i have high school degree in mehatronics this is how education works in Croatia)

Is there any free shematic of full 3axis controller?(part list,shematic and pcb board pictures) so i can buy part by part...
( resistor by resistor )

And i am definitively not interested in buying complete kits...it is just not fun...

hm...i have a another problem...the size and noise...i will probably use it in my room...so...i have pretty old and grounch neighbors...

i have contacted my old professor,and i will probably have the access to the milling machine so i could make all the parts on it...


and i have a another question,what kind of cutting tool i will need to cut balsa?! High speed drill?With a milling head?

[fredmontgomery]

I use the HobbyCNC board the three axis is 79.00, yes is very easy to put together with his instructions that are included and he also has the yahoo forum that is helpful. africansmag
I give it two thumbs up...

It sounds like you have a great background for taking on a project like building an A3 cutting table for your RC projects! Here are some details and advice:
Cost of Building an A3 Cutting Table

Materials Cost: The cost can vary widely depending on the quality of materials and components you choose. Generally, you'll need:
Structural materials (aluminum profiles, steel components, etc.)
Cutting components (blades, motors, linear guides)
Electronics (controllers, sensors)
Power supply and wiring
Software (if needed for automation)

Estimated Range: A rough estimate could range from a few hundred to several thousand dollars, depending on whether you're sourcing new or used parts and the complexity of the design.

Common Mistakes with DIY Machines

Quality of Components: Using cheap or low-quality parts can lead to:
Inaccurate cuts: Poor quality blades or motors can result in imprecise cutting.
Short lifespan: Parts may wear out quickly or fail under load.
Safety risks: Inferior components might pose safety hazards during operation.

Design Flaws:
Structural integrity: Weak frames can cause vibrations affecting cutting precision.
Alignment issues: Poorly aligned components can lead to skewed cuts.
Software integration: Inadequate software setup can result in operational inefficiencies.