Here is a list of all the postings Nick Taylor 2 has made in our forums. Click on a thread name to jump to the thread.
|Thread: Quality indexable lathe tools|
A couple of weeks ago I bought a set of 10mm Glanze CCMT 0602 tools, also bought an 8mm boring bar from RDG as well as a couple of spare inserts.
If I had only used the RDG inserts I would of binned the lot on the first day, they were terrible. The inserts included with the Glanze tools are miles ahead. I also bought some CCGT sharp inserts which are excellent for aluminium and are good for light finishing passes on mild steel.
If your worried about surface finish then yes you do have to take heavy cuts, and you can't doddle with the feeds either. However I'm getting great results using them, even on some 3inch OD EN19T I have, granted I can't take much more than a 30thou cut in that, but after all it's a 0.5hp 40year old myford.
|Thread: Super 7 Leadscrew|
Yes, I agree not having a gearbox is saving me a lot of trouble here and allowing me to get away with just shimming. I think the idea of loosening and re-aligning the apron will solve the little remaining deflection I have. Looking down the leadscrew whilst closing the nuts you can see the tailstock end of the nut is making contact before the headstock end yet I have clocked the leadscrew to the carriage and they are running true to each other.
Like you say if I want to fit a gearbox a later date then I'm going to have bigger problems.
I’ll report back later!
I think angular alignment is more of an issue than the lateral position now, looking at the leadscrew deflect when I close the nuts I think Robbo's suggestion should remedy it.
My saddle is an older narrow guide style, but the bed is a slightly later hardened PCF example. I’ll try Robbo’s suggestion if I can get in the workshop tonight and see how I get on, I might take the apron off and set the under-strip shims as well while I’m at it, see how I do for time.
Hi Gents, thanks for the replies.
I managed to strip everything down last night, I completely removed both support brackets and the leadscrew.
Tailstock end bearings are in great shape, looks like someone has installed a DIY attempt at the thrust bearing modification to eliminate the lash in the leadscrew, consists of some nicely finished bronze shims and works nicely.
The headstock end bearings are bad, scored and are worn out of round by nearly 3 thou so these will be replaced. I think the issue is someone has pressed the bearings right up to each other and there is no oil channel between them. So… make or buy? I’m tempted to make seeing as the parts from Myford will be £12 and for £30 I could buy enough Oilite cored bar to replace every bush on the entire machine!
Leadscrew is in good condition and the half nuts look new, they’re also setup well. So, I cleaned everything up and reassembled fitting 0.5mm shim between the brackets and bed. Less than 0.15mm leadscrew deflection now however it does get slightly worse the closer you are to the tailstock so I will go with Robbo’s suggestion later I think and see how that works out.
I need to adjust the under-strip shims at the front of the saddle as well as there is a tiny bit of lift showing. So, the saddle may be coming off anyway in the next few weeks.
Again, gentlemen I would like to thank you all for you replies, I’m slowly learning and I thank you for sharing your knowledge.
Just had a poke with the DTI, lateral movement away from bed of 0.45mm when closing the half nuts!
Hi, thanks for the replies.
Sorry I should of been clearer - Martin is correct, the movement is horizontal, i.e the lead screw is moving away from the bed when the half nuts are engaged.
I'll get the DTI out later on and measure exactly how much, then I think I will look at shimming the leadscrew brackets. How do I remove the leadscrew?
My Super 7 odyssey continues!
With many thanks to this forum my new-to-me Super 7 is really coming together. I'm slowly working through the niggles I find.
My newest question is how to remove the leadscrew? I want to inspect, and probably replace the oilite bushes as it turns well but there are tight spots and plenty of crud being expelled from the oil nipple whilst running at speed.
I also have a problem with the alignment. My lathe has a narrow guide saddle on a wide bed. The saddle has been machined to allow it to run on the rear shear (so I'm told). Now the saddle moves perfectly, there is no tightness or slop but obviously the half nuts are not where they should be, and there is visible deflection on the leadscrew when the nuts are engaged.
I’m assuming it will be easier to mod the leadscrew mounts rather than dismantle the apron and try to shim the half nuts?
Thanks in advance,
|Thread: Myford bearing spacer|
Hi Terry, I wasn't aware there were different sizes, I bought direct from Myford and was supplied FAG x-life 7205-B.
My machine is 1974.
Edited By Nick Taylor 2 on 14/01/2017 19:11:11
I've clocked longitudinal movement to less than 0.01mm, when running the oil film builds nicely and like I say there is no deflection under side load and no heat build during high speed running so I'm happy to say they're set correctly.
Took a while to get there though!
Hi Nigel, thanks for the replies.
Think I've cracked it. Don't think I had anywhere near enough preload on the bearings. I've slackened everything off and started again... Twice.
Has been running for about 10mins now with no errant noises, it's like a sewing machine! New bearings and a resilient mount 3 phase motor have totally transformed the lathe.
Earlier on I was trying to find out if the noise was in the spindle or the counter shaft, so I chucked up a short length of 1inch bar and turned it down to 12mm to fit in my cordless drill with the idea of spinning the spindle with the drill and using the 'screwdriver to the ear' method for finding the noise. Unfortunately the cordless drill (a fairly new makita) was louder than the lathe was at 2k rpm and I couldn't hear anything!
Do you mean the split collar on the end of the spindle? Or the left of the two locking rings?
The collar is just nipped up and lines up pretty much perfectly with the scribed line on the spindle. The sound is almost a rattle, I would assume this would tell me that there is not enough load on the bearings rather than a droning or humming to tell me there is too much...
Well the new bearings are in and the machine runs so much smoother and I can put a lot of tail stock pressure on and there is no sign of any movement in the spindle and I've run at 2k rpm for 10minutes with only the slightest warming of the front bearing.
However - there is now a noise that sounds like a tin bucket full of marbles being slung around! Fairly sure it's coming from the new rear bearings. I soaked the bearings in oil before I fitted them and have kept them well oiled during the test runs. I know they don't need to be swimming in oil, they make a very distinctive droning sound when they are over full, but this isn't it.
Seems that I've solved one problem but created another!
Parts have just arrived so I'll get cracking later on if I get chance. Brand new spacer was £3 something... compared to used ones on certain websites for £10+!
The wire 'spacer' that was fitted to mine was 1.54mm and only copper so very soft. Would explain why I couldn't get the bearings set right.. oh and they were the wrong way around.
I'm amazed it ran as well as it did to be honest, if you weren't using the tailstock or the high speeds you probably wouldn't notice it, just hope no damage has been done to spindle or the front bearing.
Yes thanks for the tip - I think this might be why the bearings are in such bad condition, the gap in the home made wire spacer was very big, about 90°, so I think most of the oil was missing the bearings, rather than meeting the top of the shaft and being pushed into the ball races I think it was simply running around the shaft and draining right out the bottom.
Edited By Nick Taylor 2 on 12/01/2017 14:43:06
Thanks for the replies as always.
So, it looks like my spindle problems were genuine - bearings the wrong way around and a Micky Mouse spacer! At least I wasn’t going mad without reason.
Just come off the phone to Myford – they have the bearings and the spacer in stock and it should all be with me tomorrow.
Also, asked about the front tapered bearing as they haven’t been available new for a while and they said there is a batch being manufactured shortly for the small bore super 7’s, they have stacks of the big bore bearings in stock apparently.
My front bearing looks to be showing wear but in good condition, same with the spindle so that’s some good news at least.
Cheers gents, I’m sure I’ll have new questions when fitting the bearings this weekend!
Hi robbo, thanks for the reply. My bearings were fitted with the more open faces of the bearing facing in towards eachother.
Can't see anywhere on any drawings that's actually shows you which way around to fit them.
Evening all, its me again!
I've been fighting with my super 7 spindle bearings recently. I had them set about right for slow speeds (say under 1000rpm) with no runout or lateral play but the front bearing was binding with either tailstock pressure or when run at higher speed.
No matter what I did with the adjustment I just couldn't get it right so tonight I stipped the spindle out to find what I assume is not the standard spacer washer! It's a length of solid copper wire (as found in twin and earth cable) formed into a 'U' and put between the bearings! Both rear bearings are rough and there was a lot of metal filings in the gap between them so I'm going to replace both of them.
Looking at the myford site they seem to specifiy bearings singularly; I thought you could only buy angular contact bearings in matched pairs?
PS - the only spacing washer I can find online is £9! I'm almost tempted to stick the spindle back in to make one....£9 for a washer with a bit cut out?!!
|Thread: Myford motor|
Yep that's pretty much what I've done - I set the accel/decel times to 3 seconds, now have a nice steady ramp up and down.
The DC brake has a lot of different settings like time/torque and the like. It was only cutting in like you say just before stop but was VERY loud. I'll see if I can post a video of what it sounds like, but not sure if I'll get into the shop this weekend - work is getting in the way!
Thanks for all the replies gents, have now taken delivery of a 1/2hp 3 phase resilient mount motor from newton tesla.
Cleaned up the gifted VFD and had a quick skim of the user manual I found online, all wired up and worked first time!
I cannot believe how smooth the motor is, even at full speed there is zero vibration coming through the mounting. Quite a lot of electrical noise so I need to tweak the frequency settings in the VFD I think. It was being used on a planer before so some of the settings are specific to that, very fast acceleration and aggressive braking etc.
Speaking of which I disabled the DC brake because the noise when it activated was horrendous! It’s probably perfectly normal but I have no idea about these things so I’m erring on the side of caution at the moment.
Now just need to get it mounted on the lathe then knock up a motor guard to stop the chips and oil/coolant doing any damage, then it’s a look around for any spare switches I have to build myself up a remote-control panel and sort out the wiring!
Agree 100% on both counts! I find the stuff ruddy everywhere, luckily I have a knackered old vax hoover so its easy to keep up with clean up, but i have started covering my cup of tea now... or putting it on the other side of the garage!
Mounting the lathe back to the wall was a bad idea, like you I would move it if I had the space!
Many thanks for all the replies gentlemen, think I have some 2mm ally sheet which will make a nice motor guard.
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