Fitting a new felt to a super 7 front bearing advice

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Fitting a new felt to a super 7 front bearing advice

This topic has 14 replies, 7 voices, and was last updated 14 April 2017 at 22:39 by Ken Weeks.

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31 March 2017 at 20:24 #291520
Ken Weeks
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@kenweeks58536
I am fitting a new felt to a Super 7 head stock front bearing bush.

The new felt appears to be too large for the hole in the bush.

Is their any special way of fitting the felt?
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31 March 2017 at 20:24 #32943
Ken Weeks
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@kenweeks58536
31 March 2017 at 20:38 #291523
ASF
Participant
@asf
I think you need to insert it from the spindle side. ie the spindle needs to be removed
31 March 2017 at 20:44 #291525
daveb
Participant
@daveb17630
The top of the felt can be trimmed with a craft knife if you forgot to put a pin in the hole before refitting the spindle. You may wonder how I know this.

Just checked Myford drawing, if you remove the spindle, you will see the wick sticking out through the hole in the front bronze bush, pull it out and gently push the new one into the hole. Remove the small grub screw just below the bronze bush, get a dressmakers pin, push the new wick down against the spring until it's just below the surface and then stick the pin through the grub screw hole to hold the wick in position. Squirt plenty of oil onto the wick to soak it, refit the spindle, remove the pin and replace the grub screw. Dave.

Edited By daveb on 31/03/2017 20:48:09

Edited By daveb on 31/03/2017 21:06:34
31 March 2017 at 20:56 #291527
DMR
Participant
@dmr
Is the big bore S7 wick the same as the older/earlier S7 one? I have no idea, but the numbers for the item on their web site are different. Ask new Myford if they have sent you the right, one assuming you got it from them.

To my knowledge there was never a variation in diameter on the earlier S7 and obviously the item should not be a tight fit. The felt you need is on the Myford site as "H68. LUBRICATING WICK A3610/1"

Dennis
31 March 2017 at 22:22 #291549
Ken Weeks
Participant
@kenweeks58536
Hi Guys

Thanks for the replies.

I am rebuilding my MK1 head stock with a MK2 casting,

The felt was supplied by Myford as a "H68. LUBRICATING WICK A3610/1" the large part is quite a bit bigger than the old one I removed.

I now know what the hole just below the bearing is for. Thank you daveb.

I have contacted Myford about it.

Thanks again

Ken
31 March 2017 at 23:01 #291562
DMR
Participant
@dmr
As an owner of both a Mk1 and a Mk2 (as you call them) I would do the reverse to you. The early headstock was far superior to the newer one. Myford changed the design on production cost grounds. If the felt pad you are changing ever dries out, it tends to melt/glaze over and chews the cone bearing. A Mk1 to Mk2 clutch change is a very different story.

Dennis
31 March 2017 at 23:18 #291564
Ken Weeks
Participant
@kenweeks58536
Dennis

You have now put the "cat amongst the pigeons".

The lathe was built from parts as a project it is a mixture of MK1 and MK2 bits.

I was drawn towards the MK1 head stock when I made it but thought the MK2 head stock was an improvement.

In view of your post I am now having second thoughts.

Ken
1 April 2017 at 00:22 #291572
bricky
Participant
@bricky
I have a S7 mk1 and a large bore mk2 I prefer the oil feed on the mk1, one can set the feed rate.

Frank
1 April 2017 at 10:49 #291612
Robbo
Participant
@robbo
Ken

If it helps, the dimensions of the A3610/1 Felt are: ( approximate as it is difficult to measure soft felt without squashing it.)

Thick end 7mm dia, 14mm long

Thin end 5mm dia, 46mm long giving a total length of 60 mm

It is possible I suppose that the one you removed has had all the thick end worn away, this would probably mean it has dried out, but it doesn't seem likely as the spring pushes on the base of the thick part.
1 April 2017 at 13:13 #291638
DMR
Participant
@dmr
Ken,

Just points.

The early S7 mandrel cone has nothing rubbing on it. I do not feed my Mk1 mandrel from the reservoir via its tap (as Myford called it) continuously, I just dribble some in whenever…..there is no signs of wear on the cone from the year 1954, whereas there is visible marking on the mandrel of the younger wick fed one. I renewed the wick on that when I bought it as the end of it was hard and the large diameter not very long, but you have no way of seeing how worn the wick is without disassembling the machine! And on top of all that, a real Myford engineer years ago admitted that the glazing over of the wick was "a real possibility".

The sole reason Myford changed the design was on production cost issues – just consider the different engineering costs in the examples you have. the later wick is certainly not an "improvement".

A point to your "build from bits" statement. One of the last jobs on a new Myford was (still is if the new lot bother) to align the tailstock height-wise. The base of the tailstock was selected from stock to correct any error and skimmed if necessary. You will be lucky if you line up exactly without some shimming or other adjustment of the base piece. Now if your early headstock is a twin for your tailstock, then no problem.

Dennis
1 April 2017 at 17:00 #291671
Ken Weeks
Participant
@kenweeks58536
Hi Dennis

Thank you for the points.

I have been using the same method to lubricate the spindle as you describe but was concerned that it was not O.K.

I take on board the comments about the concerns and draw backs with the felt I will stick with the early head stock seeing as it was cost saving exercise rather than an improvement.

The lathe was finished about 18months ago I did check the alignment at the time and have been using it since with out any problems..

It never fails to amaze me the amount of information that appears when you ask a question.

Thanks to everybody who took the time to post

Ken
2 April 2017 at 08:51 #291749
Sandgrounder
Participant
@sandgrounder
Posted by DMR on 01/04/2017 13:13:02:

The early S7 mandrel cone has nothing rubbing on it. I do not feed my Mk1 mandrel from the reservoir via its tap (as Myford called it) continuously, I just dribble some in whenever.

Dennis

I do the same, if I open the 'tap' I always forget to close it when I've finished turning.

John

Edited By Sandgrounder on 02/04/2017 08:51:48
2 April 2017 at 09:53 #291756
Robbo
Participant
@robbo
Posted by Sandgrounder on 02/04/2017 08:51:09:

Posted by DMR on 01/04/2017 13:13:02:

The early S7 mandrel cone has nothing rubbing on it. I do not feed my Mk1 mandrel from the reservoir via its tap (as Myford called it) continuously, I just dribble some in whenever.

Dennis

I do the same, if I open the 'tap' I always forget to close it when I've finished turning.

John

Edited By Sandgrounder on 02/04/2017 08:51:48

Me too. If I fiddle about setting it to the correct "drip" then I always forget to turn it off, and come back to a tray swimming in oil and the reservoir empty. Half fill the sight glass to start with to get a good start and flush out the bearing, then top up now and then.

Edited By Robbo on 02/04/2017 09:55:03
14 April 2017 at 22:39 #293393
Ken Weeks
Participant
@kenweeks58536
I like the idea of an oil feed to the bearing without the felt but the fact that you either had to lose the setting for the feed or lose the oil as well as forgetting to turn it off was a draw back.

This made me look to change the head stock for the felt type as this appeared to give a more constant lubrication.

Having read all the thoughts and points my post produced I have decided to try the following modification.

I have removed the flow adjusting needle and spring, fitted a male to female adaptor with an ML7 oiler in its place

This should allow me to adjust the flow and be able turn it on and off without affecting the setting.

Time will tell.

Ken
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