BP clone CNC is Finally done!

[triberman]

I haven't posted in a long time, I've had my head buried in my project. It's getting late so if this post makes absolutely no sense I apologize.

I just wanted to say thanks to all the folks that have posted here. I pretty much started from scratch as far as knowledge, but finally ran my first production job this weekend on my mill. The dog seems to have mixed feelings, he starts walking in circles when I use larger drills that make some noise.

I also have to give Tom at Rutex, Dwayne at Elrod Machine, and Magmotor two thumbs up for making good products and standing behind them.

I got the alliant casting from work, and brought it home piece by piece. The column was the only part that needed an engine hoist to get off the pick-up. The new head is a WEBB, from Millheads.com and I used Rocksford ballscrews.

Then I sanded and rough filled the pitts, and painted it with 2 part rustoleum epoxy. I must say the paint was impressive, it's available from MSC. The epoxy seems to get harder and harder over time. I think it was the marine grade..??

I'm not much of a welder but somehow the monitor/keyboard holder turned out ok. A co-worker welded the main beam for me. I used piano hinge for the door, it works good for arm support while programming and keeps chips out when I get crazy with the airhose. I used thrust bearing washers for the two pivot points, they seem to work good for movement and rigidity. An all in one extension cable for the mouse, monitor, and keyboard worked good to get enough cable to reach the PC.

I'm right at 81 volts after pulling a couple windings off the avel trasformer. I wasn't aware that more than 18" of wire from cap to drive is a cnc sin, so I had to do some re-work...live and learn.

Not using shielded cable for my limit switches was another snafu, but the debounce setting in Mach3 is keeping the noise from interfering until I can replace it....or not.

I will say the double shielded cat-5 and printer cable from L-com made all the difference in the world for communication stability, I would recommend them if you cant find the right length cables. They had d-shielded 12" cat-5 cables that worked great for my setup.

The mach3 software is awesome and I plan on buying it soon. I will need more than 1000 lines of code and it's a bargin for what you get.

I'm getting about 100 IPM on x and y, and z seems 100+ but I haven't checked it. Backlash is still set to zero in mach3, and I'm getting about .0007 to .001 depending on the axis. The encoder covers I made at work.

The R-8 collet rack is cheesy, but it works good and made good use of the extra wire duct.

Here's some of the sources I used in case someone may want to know.

Magmotor, U.S. Digital, Rutex, Dell, Allied Electric, Digikey, Mcmaster Carr, Msc, Rocksford, L-Com (awesome double shielded cables), Millheads.com, Mach3, Avel for the transformer, using Bobcad 20 for cadcam.

I hope this isn't too many pics, if so Let me know.

PS:PLZ don't make fun of my encoder wiring cheat-sheet on the inside enclosure door.

[ShayArnett]

nice and clean Good Job!!

Lets see some parts you've made.

[svenakela]

Awesome!

[Adobe Machine]

Good, solid work...Know how much time and effort one of these conversions take..just seems there is never enough time to finish. Very nice machine !

[UKRobotics]

Wow, youve done a good job there. This has given me a lot more confidence with my project now. I recently purchased a bridgeport series 2 interact 4 - the 2.5ton beast. Looking at it now in the barn, it is rather daunting, but I'm sure in time I will reach my goals.

The plan is to use the current servos and encoders, but rip out all the old controls/drives and replace with modern pc based stuff, rutex drives and mach3.

Out of interest where did you buy your machine cabinets and epoxy paint ? I'm not famillier with MSC .. do they have a website?

Also do you (or anyone else) have any tips for rust prevention ? My bridgeport is currently situated in far from ideal conditions - arround the corner in an open fronted 'L' shaped barn. At this time of year especially it is particularly moist in the air, and in just a few days of putting it there a lot of rust has suddenly appeared on the table and slide covers.

I have emptied an entire can of WD40 on it, the next thing will be to polish out any visible rust, clean up the machine as best possible generally, paint the paintable bits and then grease all the exposed metal parts. Appart from keeping it covered with a tarp and keeping everything well oiled is there anything else I can do to help prevent rust which isnt going to cost the earth ?

The biggest problem i think is with condensation rather than direct moisture from outside.

**Edit** - Forgot to ask .. What motors are you using (voltage, cont current, stall current ) and what size/rating is your transformer, cap and bridge rectifier ?

[triberman]

Thanks for the comments!!

I'm sure there are things that could have been done better, but I'm happy with it. Here are the requested specs :

Servo's Magmotor C40-E-400FX. Specs can be found here:
http://www.satcon.com/products/pdf/motors_c40.pdf

Transformer: Avel Lindberg 1000va 30v + 30v 16.67A torroidal transformer

Caps are 12,000 UF x2

Can't remember the rectifier specs or supplier, I'll check tonight.

http://www1.mscdirect.com/CGI/NNSRHM

http://www.mcmaster.com/

http://www.alliedelec.com/

http://www.l-com.com/home.aspx

http://www.digikey.com/

http://avellindberg.com/transformers/y23_range.htm

[gus]

That is an awesome job

re: triberman Why? Aside from graphics, the heidenhain control on your machine is superior to most pc based stuff. Newer high quality [ie copley] drives would help sharpen accel but otherwis, why not just use it and enjoy it?

[triberman]

MSC has Starrett M1 spray which is good. But Rust Guardit from Kleen Bore is even better for rust prevention. Once rust starts it's hard to stop, you may need to scrub the surfaces lightly with maroon scotchbrite, clean, then coat with preserative. WD-40 does a poor job.

http://secure.armorholdings.com/klee...chemicals.html
http://www1.mscdirect.com/CGI/NNSRIT...PMT4NO=6124448

[gus]

woops meant that to be addressed to ukrobotics about the heidenhain

[UKRobotics]

Thought it might have been.

See my rant here Bridgeport Series II Interact 4 & Heidenhein Problems . Perhaps if heidenhein had been just a little more helpful then my opinion would be different.

The problem is, its 20year old electronics,a lot has changed in 20years; plus a lot of the parts are as rare as rocking horse poo if anything else were to fail and thus will cost a fortune to repair. As it is, heidenhein want £1600 to fix my TNC150, the screen is burnt badly if i wanted that replacing i'd be looking at an additional £400 ish. There is also a possibility of a spindle drive fault. I think this may have been caused by the faulty heidenhien but i dont know. So i could get the heidenhein repaired only to find somthing else needing to be looked at, costing more money still. Then theres the issue of adding a 4th axis, i dont think there is an option to do that with the current kit, and even if it was possible the expense just for the electronics to drive the axis doesnt bear thinking about. And the icing on the cake is that using it as is would mean running it on 3 phase, which is not gaurnteed to be viable in the long term so i'd rather have somthing on single phase.

The plus points for going with a retrofit. Everything would be new, thus more reliable, cheap and easy to replace if anything went wrong. I would have assembled the system from scratch and therfore would have a far superoior knowledge of how it all works making troubleshooting problemes in the future much easier. A modern desktop pc is a lot of processing power for little money, it wouldnt take much work to put it all in a neat box with a filtered air supply, handwheel, custom keyboard, and/or touch screen. Gigabytes of storage over kilobytes, high res colour screens, high speed networking over rs232 i could go on an on and on. Appart from the risk of the unknown and length of time invoved I see no other disdvantages for a retrofit at all. Not to mention it will all run happily on single phase power and will cost less to retrofit EVERYTHING (except the servos and encoders) than just to get the heidenhein box fixed.

An interesting side note, i saw a sticker on the heidenhein saying it is serviced used replacement. So if £1600 gets you a box of 20year old technology which doesnt even last 4 years, heidenhein will have to look for customers else where, cause they sure wont be getting any custom from my direction unless some things drastically change over there.

As for the rusting i have bought a special sanding/polishing wheel which is designed to remove surface rust without damaging the underlying metal. To be honest most of the rust has appeared on the unpainted surfaces anyway. The paint is just a bit tatty in places and could do with a new coat. I realise wd40 isnt ideal, but it did the job as a temporary quick fix. I will polish off all the visible rust, then heavily grease all the non paintable parts and degrease + paint the paintable bits. Then i think building an enclosure arround it might help to keep moisture out. - I have two smaller cnc's which are box type units (think mini vmc without the atc) when the air is damp, the outside casing can be dripping with water, yet everything on the inside remains dry; so perhaps this is the way to go for the bpt.

[gus]

the control is absolutely set up for 4 axis, right on the front. See my other posting

[dserratt1]

Do you hav any photos of how the Z axis ball screw mounts to the quill?
or maybe a copy of the instructions, and also the motor mount.
I am doing a bp mill but I don't have standard size motors so i will need to modify elrods mount. I have some 850w brushless motors but the mounting is about 20mm larger then nema42
Thanks