Using a Dremel

[shearder]

Hi All

Well I am new to this forum/site but i have always been intrigued by and also interested in CNC machines.

Well I am embarking on a project at home which will have me building a 737 cockpit. A number of items on the agenda is panels and PCBs. I will be etching my own boards with Ferric Chloride.

Yes, i know, not an electronics site ete etc... However, the reason I have decided to join is that is all else fails i.e. etching of boards or not being able to find someone to engrave/cutout the percpex for me may result in me wanting to build a CNC that needs to be capable of 600mm x 300mm to cut panels and mill PC boards.

This leads me to an important question: How robust would a Dremel be for CNC usage? I have read about too much play on bearings etc etc etc... is it suited to CNC work or plastics and PCBs?? I would rather not have it destroyed but in the same light I don't KNOW i can't afford some fance motor to turn the bits...

It always seems the case - i have been surfing for the last 3-4 hours and always see a mix of stuff and never get down to questions being answered LOL - so, if this has allllllllllll been said before, and i don't doubt it, please humour me. Yes, i am a newbie here but in no way a "newbie" on earth LOL

I have seen some stepper motors i.e. 48 Steps 5V 500mA; 24 Steps 10V 345mA; 24 Steps 5V 625mA; 40 Steps 7.5V 250mA... How does one know what to get? Is more steps better than less? (assumption would say yes) is high mA better? these are simple questions that I don't have answers for...

Thanks agian for any and all responces and my apologies if i have made you swear and question "where does this dude come from" lol

[epineh]

Hi shearder, welcome to the Zone !

There are a lot of electronic guru's on this forum (I am NOT one of them)
For my 2 cents...if it is only PCB's you want then using toner transfer method is a pretty simple and quick way to go, I have a small drill bit adapter that I use in my drill press and use it for drilling 0.8mm and 1mm holes, I have it on the fastest setting that most people will say is never fast enough but it gets the job done.

Once you need to cut out panels and engrave things then I guess you may need to build a machine if you cannot get somebody to do this for you. Do some searching for JGRO and Joes2006 on this forum and you should get some idea of a good place to start.

Knowing the maximum size job you need to make is helpful as this gives you somewhere to start.

I would keep away from Dremel's, I had one, used it once for about five minutes and it died, not exactly the best performance. I have friends with the same story, and it is not like they are cheap either. Even a cheap laminate trimmer will last longer and have better runout in my opinion, bit noisier though.

As for steppers most CNC ones seem to be 200 steps per revolution, if you want a simple and cheap setup to try that won't break the bank, have a look at the linistepper stepper driver, simple to make with very common parts and surprisingly good performance.

Sizing steppers is another topic all by itself, I can't really help you there, I don't use them any more, but there are a lot of threads here that talk about what size for what kind of machine, you will have to do a bit of reading/searching but its worth it.

Good luck !

Russell.

[carvemylog]

A Dremel would probably have too much runout for the size of holes you are trying to drill. I would recommend a Bosch Colt and then adding one of the collets on http://www.precisebits.com/gateways/ColletsNutsHome.htm to bring the runout down.

[DeadTom]

Just a quick curious question as to why you would want a 737 cockpit at home?
I have some misplaced ideas but that seems kind of odd.

[tmadaras]

Hi shearder,

I agree, why a 737? Why not something sporty like a Lear, or a fighter?

If you are going to make your own panels and PC boards you are going to need a CNC router. I make all of my panels from scratch on my home made CNC router and find it both frustrating and rewarding. My working area is 350 x 250 x 75mm and haven't used all of that. (Throttle handles came close.)

I cut MDF, Polycarb, PVC, Delrin, etc. up to 1/2" thick. Drilling all including brass and aluminum. Largest hole 1/4" x 1/2" deep. I do exactly as you plan and etch PCB's then use the CNC to do the drilling.

I also agree that a Dremel is not the way to go although others have used them successfully. A trim router seemed a bit of over kill for the size of the average cockpit work piece so I use a Proxxon IB/E. It's run out is less and it is much quieter than my Dremel. It has never broken a 1/32" bit used to drill PCB's and does a nice job on the 1/8" letters engraved on the panels. The engraving is done with a .5 mm stub end mill.

I do wish my 80oz steppers were just a tad bigger because at times I get a lot of lost steps. (The cause might also be the laptop I use to drive the stepper drive...considered a no no since its parallel port might not be at 5V.)

Hope this Helps.

Terry

Owner of MPX-1 a generic F-16/Lear/Embraer/Cessna cockpit.