Member postings for John C

I wanted to replace the angular contact bearings in my Super 7 headstock. The
bearings did not seem unduly worn, but as I had the headstock apart it seemed a
good idea. On removing the old bearings one was stamped RHP 7205 and the other
was R7M LJT25.  The RHP bearing was missing a ball! The Myford description in
the manual is RHP 7205. Searching under angular contact bearings suggests that RHP bearings without a suffix have a 20 degree contact angle. I could not source any of these through a number of bearing suppliers but was able to order a pair through Myford (RDG) sales. They duly arrived and are marked NSK 7205 BEAT 85. The B suffix on many bearingsindicates a 40 degree contact angle. I asked Myford (RDG) directly if these were from the Myford (Beeston) stores and the answer was yes. I also spoke toNSK (UK) who took over RHP. They confirmed that the B suffix indicated a 40degree contact angle, and that they had been supplying Myford with these bearings since 1995.

So it would appear that either the spec quoted in the handbook I used was wrong
or incomplete, or that Myford at some point changed from 20 degree contact to 40
degree. Research into the two angles indicated that greater angles are better
at resisting axial loads - which I have assumed is a trade-off to being less
good at resisting radial loads. However, using some of the formulae provided by
the bearing manufacturers would indicate that the bearings are relatively
lightly loaded, thus the effect of the change of contact angle would not be
significant anyway.

The 7205 bearings were used in MG axles, where the radial and axial loads were
probably much greater than in a lathe headstock.

The exact same bearings are available from RS components.....at a significantly
cheaper price!!

Rgds,
John

Edited By John Corden on 18/03/2013 12:39:36

Any good?:

**LINK**

John

Edited By John Corden on 13/03/2013 09:49:01

I'll also go with M-Machine (above).

No connection etc!

John

Bri, whereabouts are you? RDG are advertised as being at the Manchester Modelling Exhibition in the Trafford Centre tomorrow - you could go and have a look.

John

Agree with Dave B - I had to use an impact driver to undo mine. I made an allen key to fit from one of the bits that came with the tool. Don't forget to undo the tenon clamping screws (thrust screw, part no 2137/No 44 on the parts diagram) recessed into the front of the bed too!

Edited By John Corden on 31/01/2013 07:48:20

John S, can you give a ball park figure for price on your spacers?

Thanks,

John

Ok, Thanks. At that price, no wonder they never sold one!

John

Hi Jason,

I have a Chester 626 - same as the Warco - and am very happy with it. I agree about the quill - most useful. Also the Warco you are looking at appears to come with a DRO. I would say this is a huge advantage which wil make your milling so much easier.

Blowlamp -was your spacer a Myford part or home - made?

Rgds,

John

Nice one Gary!

Rather than start a new thread, I thought I would add some more Outstanding Service awards to this one. That way they are all together and may help people choose suppliers in the future.

First off, Simply Bearings. Ordered a pack of Oilite Bushes Wedneday evening and they arrived Friday morning. Fantastic!

Second, Verdict Repair Dept, Part of MJ Allen Group. I enquired about servicing a no longer produced T8 dial indicator. Kevin agreed to look at the item, subject to the usual fee and the caveat that parts were no longer available. I posted the indicator on Tuesday, had a phone call from Kevin on Wednesday and the item arrived, looking like new, in Friday's post. Again, oustanding!!

And I have to admit, contrary to the many criticisms they receive, Royal Mail did OK too!!

No connection to any of the above, just a very satisfied customer,

John

Hi Richard,

PM me with your e-mail address.

John

I received mine yesterday. Very pleased with the quality, speed of delivery (ahead of schedule I think) and communications throughout. The holders pull up perfectly on my Dixon toolpost - as they should, of course - and the clamp and adjuster screws fit very well with almost no perceptable wobble.

I am hoping the same firm will look at producing T0 and T1 toolholders in the future.......if you are interested, let them know!

No connection except a very satified customer.

Rgds,

John

Edited By John Corden on 06/01/2013 12:20:52

Recieved safely, thanks Jason for taking the time and trouble to organize this. Merry Xmas!!

John

Hi Jason, PM sent.

John

Hi Len,

I agree with all Michael says. I have a standard, i.e.non-vector, inverter on my S7 and it works just fine. When I set up the machine I did use a tcho to verify speeds, but now I just use the full speed figure for the belt configuration multiplied by twice the frequency shown on the inverter. That is, a figure of 50 (Hz) is 100% of full speed, 25 (Hz) is 50% of full speed and so on. Reverse is excellent for metric screwcutting. I still change the belts and have never been worried by lack of torque, although this type of inverter does lose torque at low revs. There has been talk of the motor overheating at low speed due to lack of cooling airflow, but I have never experienced this.

All in all I have found this a very worthwhile mod.

John

Hi Pete,

Watch out for the import duty! That may change the final price significantly.

John

I got mine for a Myford Super 7 from Drives Direct - see ad on the right!  Very helpful company. 

No connection etc...

John

Edited By John Corden on 01/09/2012 18:06:55

Running in reverse is very useful for single point cutting metric threads - but only to move the tool back to the start, no cutting force applied.

John

Hi Mike,

There is a thread on the cone clutch on the Myford lathe Yahoo group:

http://groups.yahoo.com/group/myfordlathes/message/5500

You may have to join to see it, but there is lots of info within the group which would be of use.

John

Edited By John Corden on 30/08/2012 11:55:36

I wanted to replace the angular contact bearings in my Super 7 headstock. The
bearings did not seem unduly worn, but as I had the headstock apart it seemed a
good idea. On removing the old bearings one was stamped RHP 7205 and the other
was R7M LJT25 The RHP bearing was missing a ball! The Myford description in
the manual in the files section of this site is RHP 7205. Searching under
angular contact bearings suggests that RHP bearings without a suffix have a 20
degree contact angle. I could not source any of these through a number of
bearing suppliers but was able to order a pair through Myford (RDG) sales. They
duly arrived and are marked NSK 7205 BEAT 85. The B suffix on many bearings
indicates a 40 degree contact angle. I asked Myford (RDG) directly if these
were from the Myford (Beeston) stores and the answer was yes. I also spoke to
NSK (UK) who took over RHP. They confirmed that the B suffix indicated a 40
degree contact angle, and that they had been supplying Myford with these
bearings since 1995.

cheaper price!!

Rgds,
John