Re: First Design Build (doing it on the cheap!)
Quote:
Originally Posted by
jfong
Yes that is true.
Very true, you avoid spotting until you have everything properly aligned. The trick with spotting is to avoid going too deep thus weakening the shaft, but yet deep enough to allow the nose of the set screw to seat. There is one advantage to spotting in that it can keep a pulley from walking off a shaft, in other words it holds the pulley axially as well as resists radial movement.
The quick and easy way in the home shop though is to file a flat on the shaft in question. In either case the ideal situation is to have the flat or divot on the extreme end of the shaft to avoid wreaking the shaft. This however isn't possible in many cases thus the goal of minimizing how much material is removed.
Re: First Design Build (doing it on the cheap!)
Good advice. Thank you. Currently building another two machines and I noticed the NSK ballscrew doesn't have a flat on it. However the servo motor does. I can drill a divot on the ballscrew end and any minor adjustments can be done with the servo pulley.
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Re: First Design Build (doing it on the cheap!)
Bit of progress made over the weekend sorry to say weather was nice so my bikes took most of my free time been neglecting them too much lately they need riding and I need the exercise getting old, London Surrey 100 end of July and Box and Neath hills are both killers if you are out of shape and practice. However fixed problem of slipping pulleys before it occured, a bit of testing/tuning first cuts a few slats of 25mm mdf which I have decided to use for first sacrificial bed, had a selection of 2020 off cuts laying around from printer builds etc so using these for clamping t-slots gives me 5mm to skim as needed. Using 6mm Router bit 1st DOC 3mm 2nd 6mm 3rd 12mm MDF using 12000rpm and 1500mm pm feed no problems with cuts. I have used a BOB I was given I think its a cheap chinese import and I appear to be having occasional problems, axis will refuse to operate in one direction, jogging a different axis then frees the original axis to move as required so another BOB on its way, double checking wiring next on to do list, all wiring is CY shielded cable currently all mounted in small pc tower case whilst waiting for cabinet to arrive so may just be everything to close for comfort. VFD is mounted well away from everthing else.
Re: First Design Build (doing it on the cheap!)
Tracked down the problem of my one way axis that corrected after jogging a different axis, I found a link stating there was a problem with opto isolated bob's driving opto isolated drivers which didn't seem terribly convincing, however Tweakie on the Mach3 support forum came back with same answer to above post, so it seems that there is or can be a problem with this. Hopefully new Bob on its way will solve the problem,and the information may be useful to someone else.
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Re: First Design Build (doing it on the cheap!)
And award for plonker of the week goes to ME!! rushed back so I could skim the bed before it got too late, I had trammed it in on an old offcut of ply last night. Set it up to face at 1.5mm DOC at 1.5mpm 6000rpm and it glided around leaving a nice clean finish, straight edge and a CREE to check and a blind man would have been glad to see it. Shocked Who decides wants to play some more and take just 0.2 to see how it goes, fired up the spindle and thought I would try the new hand control thats sat here for a week, DAMN straight down and 1mm ding in the freshly skimmed bed, well it can stay as it is for now until I feck it up again!!! Anyway have to remove the grease nipple on bottom bearing to skim it as it holds just off the edge since I fitted that side.
Re: First Design Build (doing it on the cheap!)
Quote:
Originally Posted by
Louis_Cannell
And award for plonker of the week goes to ME!! rushed back so I could skim the bed before it got too late, I had trammed it in on an old offcut of ply last night. Set it up to face at 1.5mm DOC at 1.5mpm 6000rpm and it glided around leaving a nice clean finish, straight edge and a CREE to check and a blind man would have been glad to see it. Shocked Who decides wants to play some more and take just 0.2 to see how it goes, fired up the spindle and thought I would try the new hand control thats sat here for a week, DAMN straight down and 1mm ding in the freshly skimmed bed, well it can stay as it is for now until I feck it up again!!! Anyway have to remove the grease nipple on bottom bearing to skim it as it holds just off the edge since I fitted that side.
Mistakes happen that is why one keeps his fingers out of the hazard zones. In any event I don't see a ding or any other damage in the pictures, the machine looks to be pretty nice.