Myford thread dial bolt size

Advert

New Replies

Report Bug

Help/FAQs

Myford thread dial bolt size

This topic has 27 replies, 11 voices, and was last updated 23 March 2017 at 15:39 by not done it yet.

Viewing 25 posts - 1 through 25 (of 28 total)

1 2 →

Author

Posts
16 March 2017 at 07:46 #289053
Allan B
Participant
@allanb
I have just bought myself a thread gauge to add to my Myford, but dose anyone know what the thread is in the right hand side of the carriage? It doesn’t come with the bolt, but I’m not to good with imperial bolt sizing and I would like to make a knurled thumb bolt ready to fit.

Thanks in advance

Allan
Advert

16 March 2017 at 07:46 #18456
Allan B
Participant
@allanb
16 March 2017 at 08:26 #289055
Jon Gibbs
Participant
@jongibbs59756
Hi Allan,

The thread is 1/4" BSF but mine is a stud and nut.

HTH

Jon
16 March 2017 at 08:32 #289057
roy entwistle
Participant
@royentwistle24699
So is mine

Roy
16 March 2017 at 08:39 #289061
Nigel Bennett
Participant
@nigelbennett69913
Allan – it doesn't just bolt straight on to the apron; Myford provide a couple of red fibre washers to space the unit off the apron in order to get the graduations to line up properly with the fiducial mark when the half-nuts are engaged. You need to fiddle about and choose the correct thickness combination of washers to do that.

As Roy & Jon have said, it's 1/4"BSF.
16 March 2017 at 08:43 #289063
Allan B
Participant
@allanb
Thanks all, love how much information is on this forum.

I will have a look for a stud and a tap so I can make a thumb whee, I have got numerous washers I can use to get a size, then a bit of nylon I can make a spacer out of as a final fix.

Allan
16 March 2017 at 08:51 #289067
Jon Gibbs
Participant
@jongibbs59756
Posted by Nigel Bennett on 16/03/2017 08:39:21:

Allan – it doesn't just bolt straight on to the apron; Myford provide a couple of red fibre washers to space the unit off the apron in order to get the graduations to line up properly with the fiducial mark when the half-nuts are engaged. You need to fiddle about and choose the correct thickness combination of washers to do that.

….Ahhh, that would explain why mine doesn't line up exactly when engaged then – I have no fibre washers on mine.

Thanks Nigel.

Jon
16 March 2017 at 09:03 #289069
Allan B
Participant
@allanb
Now this might be sacrilegious but would an M6 stud do the same job (me penny pinching as normal with what I have in stock lol

1/4bsf is 6.35mm but it’s always cut a little under for threading so say 6.25mm,it is a 26tpi which comes out as 0.977mm, which is almost an M6X1 stud size, the only thing u would wonder is how much force it needs to take as it would only be holding by 3/4 of the thread area.

Allan
16 March 2017 at 09:29 #289072
Brian Oldford
Participant
@brianoldford70365
Go on, you know you want to do it properly. http://www.ebay.co.uk/itm/261467361177?_trksid=p2057872.m2749.l2649&var=560347081093&ssPageName=STRK%3AMEBIDX%3AIT
16 March 2017 at 09:36 #289075
Jon Gibbs
Participant
@jongibbs59756
Allan,

Well if you're wanting to get into threading (otherwise why else would you want the threading dial on?) then why not turn a bit of the lathe?

The stud is plane 1/4" under the dial body rather than threaded – less wear over time although most of the time it'll stay put I know.

1/4" BSF is 26 TPI and you can leave the half-nuts engaged and reverse the tool out as you'd have to do for metric threads to avoid the threading dial issue.

If you need a 1/4 BSF nut to test fit then borrow one from elsewhere on the lathe. The banjo uses two of them and you could manage without one for a moment or two.

HTH

Jon

Edited By Jon Gibbs on 16/03/2017 09:38:48
16 March 2017 at 09:43 #289078
Jon Gibbs
Participant
@jongibbs59756
You could always buy a die **LINK** or **LINK**

The Chronos price is delivered.

Jon
16 March 2017 at 09:49 #289081
Allan B
Participant
@allanb
OK I have bitten the bullet and bought some BSF nuts and will make the stud to match them, have got some HSS I can grind to the specified 55 degrees.

Allan
16 March 2017 at 10:31 #289089
not done it yet
Participant
@notdoneityet
There are so many options – as long as the thread into the casting fits. Threaded rod, bolt (not favourite), a stud with any thread you choose on the other end, metric, imperial, cycle? Nut, thumbwheel, wing nut. Any combination with the other end 1/4 BSF!

The usual reasoning with studs into cast is coarse in the cast end and (possibly) a finer thread for the nut. With a finer thread the nut gets undone and not the stud and is better for high clamping force applications. This is not a high clamping force application, of course. Think cylinder heads for high clamping force requirement.

Threads wear over time with continued use. The stud is easier to replace than the threads in the casting. Remember also that the thread dial has a clearance hole (for the relevant sized stud). Fitting a smaller stud should not be contemplated, even though you 'might get away with it'.
16 March 2017 at 10:46 #289090
Allan B
Participant
@allanb
OK so if I am going to do this properly, and before the actual part arrives, could someone please measure how long the hole through the the tread gauge is, and also what the ID is, then I will make a stud with 1/4 BSF on one end, M6 on the other, and then a thumb wheel to match

Allan
16 March 2017 at 11:12 #289093
Jon Gibbs
Participant
@jongibbs59756
Here's my stud in situ. The stud is exactly 0.250" in diameter (calipers below). You should be able to tell how deep the threaded hole is on your apron perhaps.

Jon
16 March 2017 at 11:14 #289094
Jon Gibbs
Participant
@jongibbs59756
Posted by Jon Gibbs on 16/03/2017 11:12:45:

Here's my stud in situ. The stud is exactly 0.250" in diameter (calipers below). You should be able to tell how deep the threaded hole is on your apron perhaps.

Link to original image here… **LINK**

Jon
16 March 2017 at 11:16 #289095
Allan B
Participant
@allanb
Jon

Thank you for that, I now know what tonight’s job is 😀

Allan
16 March 2017 at 11:18 #289096
Jon Gibbs
Participant
@jongibbs59756
Happy turning!

Edit: When I think about it, it'd be really strange if the stud wasn't symmetrical end-for-end so that ought to give you everything you need.

Jon

Edited By Jon Gibbs on 16/03/2017 11:20:01
16 March 2017 at 13:19 #289102
Harry Wilkes
Participant
@harrywilkes58467
Posted by Nigel Bennett on 16/03/2017 08:39:21:

Allan – it doesn't just bolt straight on to the apron; Myford provide a couple of red fibre washers to space the unit off the apron in order to get the graduations to line up properly with the fiducial mark when the half-nuts are engaged. You need to fiddle about and choose the correct thickness combination of washers to do that.

As Roy & Jon have said, it's 1/4"BSF.

Thanks for the info Nigel I was not aware that you needed to adjust the fibre washers, when I acquired my S7 in came with a thread gauge but it was not fitted so I'll check it out.

H
16 March 2017 at 16:30 #289120
roy entwistle
Participant
@royentwistle24699
I always thought that the fibre washers were so that it could be engaged and disengaged without using a spanner

Roy
22 March 2017 at 17:31 #290073
Jon Gibbs
Participant
@jongibbs59756
I think Roy is more likely to be right than Nigel, now that I've examined my threading dial in more detail.

The pinion is free to rotate and is held simply with a cap-screw and washer onto the bottom of the indicator shaft. So, it can be positioned anywhere to adjust its position, irrespecitive of any fibre washers.

I think you just need to engage the half-nuts, mesh the pinion, align the indicator with the witness mark and snug up the cap-screw from below?

Jon
22 March 2017 at 19:57 #290100
Richard S2
Participant
@richards2
Posted by Jon Gibbs on 22/03/2017 17:31:39:

I think Roy is more likely to be right than Nigel, now that I've examined my threading dial in more detail. Jon

Seems both can be right !. Myford ML7 Manual mentions the Fibre Washers are provided for alignment of the Dial markings with the zero mark on the Indicator Body (page 28, fig 39).

They (washers) can also serve to provide suitable resistance to permit engaging and disengaging of the indicator with the Leadscrew by hand pressure as many have found to be a handy procedure, but is not mentioned in the Manual.

Regards
23 March 2017 at 08:53 #290158
Jon Gibbs
Participant
@jongibbs59756
Thanks for the reference to the figure in the manual – I obviously don't know that manual as well as I should.

When I look at other indicators on ebay they clearly don't have a capscrew holding the pinion gear on, which would obviously change the adjustment possibilities dramatically.

and

I am therefore beginning to wonder whether my thread dial indicator is either an old one or has been modified because it still seems to me to be much easier to align things by adjusting the retaining screw than trial-and-error with fibre washers that will compress over time. To boot, mine is also missing any fibre washers.

Jon
23 March 2017 at 09:48 #290164
Brian Oldford
Participant
@brianoldford70365
Posted by Richard S2 on 22/03/2017 19:57:41:

. . . . . . . . .

They (washers) can also serve to provide suitable resistance to permit engaging and disengaging of the indicator with the Leadscrew by hand pressure as many have found to be a handy procedure, but is not mentioned in the Manual.

Regards

I'm happy to be proven wrong but I've never seen a need to disengage the indicator from the lead-screw. Surely any increased wear is going to be immeasurable?
23 March 2017 at 11:57 #290179
Philip Rowe
Participant
@philiprowe13116
I also never disengage mine, apart from the rare occasions when removing for cleaning/maintenance my thread dial has been permanantly engaged since 1973 and I can't detect any wear.

Phil
Author

Posts