I have no idea yet but they will need to be very heavy duty to put up with the mess.Quote:
Originally Posted by komatias
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I have no idea yet but they will need to be very heavy duty to put up with the mess.Quote:
Originally Posted by komatias
These are good quality strong, adjustable and waterproof and come in a variety of designs
http://www.aliexpress.com/item/Water...707482221.html
Yes, that would my choice, there are a lot of head options - roller, plunger, lever etc with that switch type.
Need to choose where to mount them sensibly too.
Got the knee back on tonight, new lift bearing makes it silky smooth after years of grinding up an down...
Attachment 18542
Anyone know how to adjust gibs properly? The books just say tighten until you feel resistance but on the knee that could be very tight?
The vise-grips are only there to crimp off the feed to the saddle so i can prime the way lube pipes ;)
Dial/DTI gauge, magnetic stand, and a big lever.
You don't want to adjust it up to the point there's no measurable play as you risk it binding and no room being left for oil, but you also don't want it flapping about.
When adjusting slides that I can't try moving by hand to test resistance, I usually aim for around 0.02mm of movement on a DTI. On older machines, you may need to allow for worn areas, so you ideally want to adjust things at the least worn part of the travel.
How is it measured though - the distance the measurement is taken over will vary the reading etc, is it measured up/down or left/right??
You want to be measuring the lift in the slide (forward/backward movement on a knee), however you need to judge the best way to achieve that for each machine.
For a knee, I'd probably mount a DTI on the side of the body pushing against a feature/block mounted on the side of the knee, and try rocking the knee side to side, and pivot it up/down. You obviously don't want to be measuring the play in the knee nut/screw mounting, so you may need to try levering a few different ways to work out what will work best.
You can also get them from Denco Lubrication (part of the Bijur group of companies) in Hereford (or Cougar Lubrication if you're in the South of the UK), shame I wasn't working there still else I'm sure I could have helped out;)
Nice refurb log Dave, following with interest. I was looking at doing this for work but we're still undecided on retrofit or purpose built....funds will decide!
Got the lube parts from Lubetec, very fast delivery.
Started sketching out my control circuits, change-over from main spindle to bolt-on aux spindle will be done via the respective Mach3 profiles.
Attachment 18546
Luckily the CSMIO has two 0-10v outputs and stacks of digital I/O so i can connect both VFD's up and use mach to decide which motor to start or which limits to look at.
Not being funny (well perhaps just a little) but I would not let mach decide I would definitely tell it which ones to use, the thought of mach going eenie meenie minie mo doesn't inspire me with confidence.. Sorry couldnt resist that!
They're stockists for the Bijur range so should be :)Quote:
Originally Posted by Davek0974
One of the (many) things I've still to do is finish off the control/safety circuits...I've forgotten what I was going to do so probably going to start from scratch again and try to get my head round the subject (I hate electrickery stuff!!) again :) The CSMIO products are good, I'm glad I went with them.
Let me expand...Quote:
Originally Posted by lucan07
I will have two Mach profiles - std Bridgeport & engraving
In profile 1 I have say output 7 defined as active low and no other connection
In profile 2 I have say output 8 defined as active low and no other connection
On the CSMIO each one of these outputs controls a respective VFD these outputs, being active low will come on as soon as Mach has started up and will stay on regardless of Mach reset condition.
So to do engraving I would fit the aux spindle and tell Mach to use profile 2 and so on.
It doesn't actually decide what to do, it just chooses the correct VFD for the profile I click on.
I love the electrickery stuff - I have been cussed many times on here because I try to go too far with system controls etc - I am used to using PLC's and pneumatics at work and it tends to spread to my stuff ;)Quote:
Originally Posted by njhussey
I'll come to you then for double checking my stuff then, I did some programming, PLC and PIC stuff on my degree....but that was 15 years ago and I've forgotten more than I knew...which wasn't much in the first place!!Quote:
Originally Posted by Davek0974
I am doing something similar but with linuxcnc and mesa combo 5i25 + 7i76 so that one profile controls the lathe and the other the mill with one control boxQuote:
I will have two Mach profiles - std Bridgeport & engraving
Sounds good, two machines with one system does seem to make sense when most of the I/O is the same.
Got the ram and knuckle on this morning, also stripped and painted the saddle and head.
Attachment 18561
Also fitted a spacer here as the gear mesh was terrible, way too wide. For the first time in all the years i've owned her, the knee now glides up and down silently
Attachment 18562
Looking lovely Dave, looks so much nicer cleaned up and painted, should turn out to be a nice conversion/restoration.
.Me
Got the head on, spindle in and new oil pipes plumbed in and tested.
Attachment 18580
Also stripped and painted the lower drive housings and scraped out the wax that used to be grease ;)
Looking good Dave, are you fitting new ballscrews you ordered as you re assemble or are they fairly easy to access/fit without breaking down the whole thing again?
Yes, i'm at the stage now where I can't progress until I get the screws. Hopefully they will be here this week before we leave on Thursday for a couple of weeks holiday.
Ball-screws arrived today :)
Managed to start fitting the Y axis one but where the oil feed drilling is in the nut, the pipe hits the knee chip guards so it'll last about 5 minutes :(
I have emailed the suppliers as it looks wrong unless i have it fitted wrong of course but there is only one oil drilling.
How smart am I :)
Not very it seems!
I ordered a ball-screw kit for a Bridgeport with a 9" x 48" table, however, after trying to fit the Y axis again tonight it turns out I have the extended knee model with a 12" Y travel not 9" like normal :livid: :livid:
Still, I've only had it 11 years, never noticed.
The suppliers are being good so far and are looking into getting the bigger version swapped out with my one while i am on holiday.
Aaaargh!
Also ordered up another three replacement bearings for the head - the old girl was in a worse condition than i thought.
Bigger version screw is on the way :)
Note to remember - measure twice, order once ;)
Dave,
out of interest: what paint did you use?
It's from a UK company called Craftmaster Paints, it's their "Engine Enamel" range in Bridgeport Grey.
Its the same company I used for painting the traction engines - the best paint I've ever used :) Not cheap it cost £30 for the 1ltr tin inc postage but well worth it.
Hi all, back again after the holiday :)
Wasted no time in getting out to the shop, started catching up on customer orders and did some work on the mill.
Seems I have ordered a screw set for the Z axis that is far too long - bum :thumbdown::thumbdown:
Will eBay that one for a few quid - its a 20/05 zero backlash unit 360mm long if anyone wants it.
Then i discovered the motor bearings are half-shot :sorrow::sorrow:, a bit of slack and grumble when spun. It will work ok but not sure having come this far if i should refit or replace with something else - options would be repair (expensive), fit a new vfd style motor with shaft extended (more expensive) or throw on a servo motor (a bit more expensive).
Having replaced nearly all the bearings it seems daft to refit the duff motor now - time to think here.
How much could be that motor bearings? it seems cheaper to replace them, right? Aren't they some standard size?
Having done all that work til now, the logic is not to leave anything unrepaired.
I have read some tales as its a US motor and a bit awkward to dismantle, to find bearings size i would have to strip down which risks disturbing old and fragile varnished wiring etc. Not a big issue but could end up in a trashed motor.
The extended/custom shaft makes replacements a total bugger - practically impossible to fit a new motor and re-use the Reeves vari-speed drive system as new motor shafts are far too short.
This was the reason Bridgeport motors are stupid expensive.
So, options - strip and attempt repair.
Fit a servo and dump the Reeves drive but retain back-gear ?
The budget for this job went silly a long time ago - i was not intending on replacing all the ball bearings etc and some of them are £££ so it seems now that an extra £300 or so on a 3kw servo/drive is pretty irrelevant overall.
The servo would likely be the easiest option - just a new mount plate and two pulleys, the repair on the bearings could be the cheapest option but would still leave an inferior, power-sucking drive system on what is now a damn expensive machine.
I'll work some prices out.
What about repairing it on place with graphite or bronze filled epoxy ,Moglice and others? Why dont you check if that's a possibility. It would be dirt cheap
These would be ball bearing races so not repairable in that way.
Ain't a ball screw a ball bearing that could rotate as high as 3000rpm?
I'm losing the plot here Boyan, I'm talking about the bearings inside the 1-1/2Hp spindle drive motor are buggered. ;)
Drop-plates for X & Y servo motors - 10mm, 12mm, 15mm thick ally??
Thicker will be better, but it will depend on servo shaft length/pulley thickness as to what's practical. Some form of box section would be better/stiffer.Quote:
Originally Posted by Davek0974
Regarding the motor bearings, unless the motor has some odd wiring/end cap configuration and/or you damage the windings trying to lever the end caps off, stripping it and replacing the bearings shouldn't be a problem.
Quote:
Originally Posted by Davek0974
I was saying if it works for removing ball screw backslash and the ball screw is in fact a more complex ball bearing , its worth a try at the cheap price of it. How fast this motor moves? 1200rpm? Same as ball screw.
I see as a better idea changing to cheap Dc motor or better servo motor. And why not a cheap modern normal motor , disassemble, weld some shaft and machine it on place. That would be super simple. And a bracket adaptor
I'm going to have a go at dismantling i think, try that first.
A 2.0kw AC servo would be best but a toss-up between money and easy-fit;)
Well, I spent a good few hours trying to dismantle this motor while being very careful not to risk damage, I could not even get the drive disc off the long shaft, seized well on. There is also a pressed-on fan at the top to shift which would likely bend/break so i carefully replaced what i had done and left it.
So my choice is now to build the cabinet and wire for the VFD / motor OR throw one of these in...
http://www.aliexpress.com/store/prod...037588952.html
I have asked the guy for a 2kw or 2.2kw 3000rpm unit but not had a reply yet, seems the bigger servos don't have the speed needed.
Fitting would be easy, but the only benefit i would really see is the easy and accurate speed control - I don't need/want rigid tapping although i think it would be useful for smaller taps maybe - what is needed to gain rigid tapping?? Is it just a setup option or do i need more CSMIO modules??
Pulleys/belt - 44t HTD8 x 30mm should handle it ok.
You'd need an ENC module if you wanted to do rigid tapping.
The motor will most likely run for a long time before the bearings get bad enough to cause issues. If you could get some fresh grease into them, it would most likely make them last even longer and quieten them down.