Author Topic: S7 plus to connoiseur upgrade  (Read 12106 times)

Offline Bjorn_B

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S7 plus to connoiseur upgrade
« on: September 01, 2015, 07:57:12 PM »
Have not been happy with a few things about my early S7 bigbore.

1: Unballance in spindle (my guess is that the cast cone pulley is to blame). The whole lathe will start a shimmy at higher spindle revs.

2: Odd prime number bullwheel (67t) not really suitable for headstock indexing (have a own built versatile dividing head so I guess you know where I'm thinking of next...)

3: Slippage in the bronze gear/cone pulley press fit, preventing use of the spindle lock for dismounting chucks.

4: Backlash between the bullwheel backgear lever/key and bronze gear creating a disturbing knock sound whenever the lathe is running

This is what I have on the bench right now..


Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #1 on: September 01, 2015, 08:00:12 PM »
There is a seal in the new pulley, propably to keep some oil of the polybelt. A small ring is turneed up and locktited to the spindle bush/spacer

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #2 on: September 01, 2015, 08:01:49 PM »
The new pulleys are machined all over, no raw surface anywhere so perhaps some hope for a better ballance..

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #3 on: September 02, 2015, 09:12:35 PM »
Headstock casting marked for position of bullwheel, will machine a flat and drill for mounting of a detent thingy in this area. I don't know if the detent plunger is possible to purchase yet.

Offline ths

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Re: S7 plus to connoiseur upgrade
« Reply #4 on: September 03, 2015, 01:07:01 PM »
Hi Bjorn, this is an interesting upgrade. I assume that the parts were from Myford? It looks as though you have the headstock off the bed, as well as the gearbox. I seem to remember that the bull wheel was 67 teeth, did they ever go back to 60? My ML7 has 65, but 67 seems fairly useless as a dividing basis. Are the new pulleys cast iron? Hope that this works out well for you. Cheers, Hugh.

Offline Allen Smithee

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Re: S7 plus to connoiseur upgrade
« Reply #5 on: September 03, 2015, 01:35:22 PM »
I'm pretty sure my Super-7B has a 60-tooth bullwheel, and does the ML7R. I was under the impression that the ML7 has a 55T bullwheel.
AS
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Offline Stuart

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Re: S7 plus to connoiseur upgrade
« Reply #6 on: September 03, 2015, 01:51:50 PM »
Ok

My connie has a 60 tooth bull wheel  , don't know where the 67 came from , as Allen said its the ML7 ones that had a 55 tooth one

To the OP are you fitting the correct bearing adjustment nut to the inboard side as it's got a oil seal same as the pulley note Myford think they are both the same until I took some pics for them that's why the description on the site says LH . Note when I rang them about this they said the had very little info about the connie , even Myford Chillwel supplied a S7 handbook with them

Are you changing the back gear shaft as the connie one is a different length to avoid clearance issues

Stuart
My aim is for a accurate part with a good finish

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #7 on: September 03, 2015, 04:51:25 PM »
Thanks!

My very ealy bigbore has indeed a 67t bullwheel, they made them like this but changed later back to 60t.
(See MEW issue 108 and 109)

Parts needed for the change are bronze bushing gear, bullwheel and backgear.

Thanks allso for info on the oil seal in the bearing adjuster nut, I will modify mine to make room for a seal. Without the lathe I will have to do it on the mill with a boring head, it has slow quill autofeed for boring, that should work out ok.

Have checked the backgear/levershaft assembly in place and there seems to not be any problem. Everything seems to line up fine with the spindle gears.

Yes, the headstock is off for the moment, will make preparations for a detent mechanism for bull wheel indexing. (Mill a flat and drill for a pair of mounting holes, the detent thing will propably be home made later)

Offline Stuart

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Re: S7 plus to connoiseur upgrade
« Reply #8 on: September 03, 2015, 05:19:44 PM »
It's the same style of lip seal as on the pulley, you need it to keep the poly belt dry

Mine stays nice and clean ,

Are you fitting new AC bearing ? I have fitted a matched pair of SKF ones around £180 for the pair , I measured the split shim and deducted 0.05 mm and obtaitain some shims to make up the distance and fitted these to the shaft then you are able to lock up the adjuster on the shaft tight with a known pre load no guessing involved then you can do the lateral adjustment I find one slot back from spindle locked is about right , the I build up the speed and monitor the temp and adjust if needed .

The shim idea came from Grayham Meek

Myford did not fit a matched pair when the built them and mine failed in the first week after del. from the works ( note I live five miles from the old works) so they sent out a fitter to sort it , but those failed about the time the went under so I sorted it out myself

Good luck

Stuart
My aim is for a accurate part with a good finish

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #9 on: September 03, 2015, 06:13:18 PM »
Thanks Stuart! Ive got quite new bearings in it, old ones gave up last winter so I will use theese until knackered. Took a look at the seals, 45-55-4 are the dimensions, buggered up my sleeve on shaft bushing idea so i will machine a new shaft bushing/spacer to fit the seals when the machine is together. in a drawer i found a pair of new bearing adjuster nuts I forgot about. Ordered them when the vearings gave up because I was at the time playing around with the idea to fit taper roller bearings but gave that up and forgot about it.  :shrug:

Now, what kind of tooth form/dp/module could this be? Need to machine a worm for this one day. New 60t bullwheel.. It is not clear by the picture but the diameter (across tooth peaks) is 107,2mm
« Last Edit: September 03, 2015, 06:28:27 PM by Bjorn_P »

Online Jo

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Re: S7 plus to connoiseur upgrade
« Reply #10 on: September 03, 2015, 06:56:45 PM »
My guess is a slightly undersized Module 1.75.

Jo
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Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #11 on: September 04, 2015, 09:24:42 PM »
Thanks Jo!

measured the gears a bit more today, the bull gear and backgear mesh at a centre distance of 66,13mm (60t/16t) if this is any help to understand the pcd of the gears. Will look into this a bit later..

Meanwhile I did put the headstock casting on the mill today and machined a mounting space for a index plunger.

The headstock is back on the lathe at the moment for an alignment check. Result is that with the bed level (no twist), the spindle seems to point towards the front at about 0,02mm per 100mm (mt test bar, test indicator and precision level used). Needless to say, phone battery died, so no photo of the setup tonight. Is this acceptable or should I try to aim for zero deviation? The bed is still in quite good nick (induction hardened)

Cheers
/B

Offline steamer

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Re: S7 plus to connoiseur upgrade
« Reply #12 on: September 04, 2015, 09:35:56 PM »
Hey Bjorn,

.02mm/100mm forward is a bit much.   Should be more like .02 / 300mm.     It should also....ideally, point "up" at the end by about the same amount.

It's important that it point forward by a small amount.  that way under a cut, your lathe will face concave, never convex.

Mine is about .0005"/12" or about .012mm/300mm.

It gets really hard to reliably measure that on the smaller lathes as they tend to be a bit flexible.

http://www.modelenginemaker.com/index.php/topic,369.0.html



Dave
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Offline steamer

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Re: S7 plus to connoiseur upgrade
« Reply #13 on: September 04, 2015, 09:40:44 PM »
http://www.modelenginemaker.com/index.php/topic,369.0.html

You can start on page 35 where I was starting to align my lathe headstock..

Dave
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Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #14 on: September 04, 2015, 09:48:21 PM »
Thanks for your input Dave!

I will try to correct the front/back alignment to narrower specs (seems quite straightforward to do), have not measured up/down more than a quick traverse, but it seemed more or less level, I will verify this tomorrow.

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #15 on: September 04, 2015, 10:18:52 PM »

Offline steamer

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Re: S7 plus to connoiseur upgrade
« Reply #16 on: September 04, 2015, 11:39:24 PM »
Thanks Bjorn, she's a sweetheart!   Very accurate, and.....NOW.....brand new!

Dave
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Offline ths

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Re: S7 plus to connoiseur upgrade
« Reply #17 on: September 05, 2015, 12:31:50 PM »

I'm pretty sure my Super-7B has a 60-tooth bullwheel, and does the ML7R. I was under the impression that the ML7 has a 55T bullwheel.
AS

Definitely 65 teeth on the ML7. Hugh.

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #18 on: September 05, 2015, 04:48:42 PM »
Got the spindle to within 0,01mm/200mm in direction upwards and about 0,02mm/200mm to the front with some light scraping of the headstock casting underside, there where some high spots there. This can be improved upon, but I won't this time.


Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #19 on: September 05, 2015, 04:50:02 PM »
Spot the fault... :headscratch:

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #20 on: September 05, 2015, 04:51:33 PM »
Much better! :cartwheel:

Offline steamer

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Re: S7 plus to connoiseur upgrade
« Reply #21 on: September 05, 2015, 05:14:38 PM »
Looking good!!!

Dave
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Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #22 on: September 05, 2015, 05:20:58 PM »
Thanks dave, bashed a pinky (finger) installing the clutch shaft the second time, need sympathy.. And a pint.. :DrinkPint:

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #23 on: September 05, 2015, 05:45:53 PM »
Hi Bjorn, this is an interesting upgrade. I assume that the parts were from Myford? It looks as though you have the headstock off the bed, as well as the gearbox. I seem to remember that the bull wheel was 67 teeth, did they ever go back to 60? My ML7 has 65, but 67 seems fairly useless as a dividing basis. Are the new pulleys cast iron? Hope that this works out well for you. Cheers, Hugh.

Hugh! Yes, myford parts all over, did cost an arm and a leg but I will never be happy with the lathe as it is and parts will certanly not be cheaper and perhaps not even available sometime in future. Pulleys seem to be cast iron, but machined all over, no raw surfaces anywhere. Will have it up and running sometimes next week it seems, first job will be to tackle the oil seal issue.

Offline steamer

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Re: S7 plus to connoiseur upgrade
« Reply #24 on: September 05, 2015, 06:14:39 PM »
Thanks dave, bashed a pinky (finger) installing the clutch shaft the second time, need sympathy.. And a pint.. :DrinkPint:

You have my sympathy!    but you might have to buy your own pint.... :lolb:

Couple of years ago, on our "Thanksgiving" holiday, my inlaws came to our home, I was preparing the dinner that day, so I got up early to get that done, and then spent an hour in the shop before they arrived.    I was out there for 15 minutes...when  wrench slipped, and my hand hit the tool post cutting the index finger badly.   I wrapped it up, ate our holday dinner, then went to the hospital and got 6 stitches!     ...Our "babies" will bite us given half the chance.... :ROFL:

Dave
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Online Jo

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Re: S7 plus to connoiseur upgrade
« Reply #25 on: September 05, 2015, 06:23:56 PM »
...did cost an arm and a leg .

:lolb:

Myford spares are actually cheap: If you compare your lathe's original Myford bed wipers at £8.86 a set and Mr Silky's at £122 you will realise how much of a bargain Myford spares are ;)

What ever you do don't ask about the price of a set of headstock bearings for either Mr Silky or the Gamet bearings for the Colchester  :hellno:

Jo
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Offline Stuart

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Re: S7 plus to connoiseur upgrade
« Reply #26 on: September 05, 2015, 09:57:18 PM »
Mega moths  :stir:

Stuart
My aim is for a accurate part with a good finish

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #27 on: September 06, 2015, 06:56:57 PM »
One nice thing is that all parts get a soak in the washclam (small parts cleaner). And as one tends to oogle Bright and shiny things more I found something I never noticed before: Mystery stud post in the "backbone" of the belt housing (upper right corner). Does anyone here know what this was intended for? Ignore the small holes on the side, they are for my work light...

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #28 on: September 09, 2015, 05:52:04 PM »
Inboard bearing adjuster nut modified and seal installed (52mm dia and 4mm deep step machined for the seal, the bore was taken out to 45,5mm the whole way trough. I allso machined a new spindle bushing (45mm o.d. instead of 44mm to suit the seals). It seems that a GHT headstock dividing thingy upgrade kit is on it's way from Kirk..  :ThumbsUp: (have a versatile dividing head)


Now: :DrinkPint:

Online Jo

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Re: S7 plus to connoiseur upgrade
« Reply #29 on: September 09, 2015, 06:06:24 PM »
It seems that a GHT headstock dividing thingy upgrade kit is on it's way from Kirk..  :ThumbsUp: (have a versatile dividing head)

:Doh: And I have a spare set of those bits in the garage and no Myford any more :shrug:

Jo
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Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #30 on: September 09, 2015, 06:20:11 PM »
Quote from: Jo

:Doh: And I have a spare set of those bits in the garage and no Myford any more :shrug:

Jo

Oh dear...  :headscratch:

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #31 on: September 12, 2015, 07:01:49 PM »
Done! It's way smoother than before, with less imballance. I did discover that the clutch centre is wobbling around a bit and that does give some imballance yet. Have to look into that soon, the last time I hate the clutch apart I had a hell of a time getting it back together so I'm a bit reluctant..

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #32 on: October 03, 2015, 05:07:06 PM »
Here we go again, making the ght headstock dividing thingy for my lathe as it at last has a "normal" bullwheel. Normal in tooth count that is, not in tooth form. With help and info from Kirk at Hemmingway I found out that the worm for connoisseur lathes is to be cut with a pitch of 0,2154 inches. Calculations of possible geartrains soon saw the need for a 47t gear.. Great! No such thing in my drawers, not listed at myford or the usual sources either.. And its a prime number, not found on my division plates for the dividing head I rather use on the mill. So, a new division plate was drilled (bless the DRO pcd funtion) and a gearcutting session started.

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #33 on: October 03, 2015, 06:24:27 PM »
Btw, geartrain: 47 30/55 50. This will be, interesting...

Offline steamer

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Re: S7 plus to connoiseur upgrade
« Reply #34 on: October 04, 2015, 10:23:22 AM »
What pitch is the gear Bjon.    I have some 16 dp. 47 tooth gears
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Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #35 on: October 04, 2015, 11:28:17 AM »
It's a myford changegear, 20dp 14,5pa. I have a complete set of involute cutters for those so i can add to the collection when need arises, as it just did.  :stir:
Back to the bullgear worm, linear pitch is calculated to 5,47116 mm after correction for the helix angle. With is geartrain and box set to 8tpi I will get very very close to that. I wonder if this is classified as abuse to the leadscrew, I need to go easy I guess.. :thinking:

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #36 on: October 08, 2015, 08:36:30 PM »
Started cutting the worm for the headstock dividing attachment today. In fear of straining the leadscrew to much, a very low speed and light cuts.. But the quite agresive geartrain seems to work out  :cartwheel:
I could have bought a worm for the connie bullwheel at fair cost from Kirk but sometimes the journey is the reason rather than the destination.

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #37 on: October 16, 2015, 06:52:59 PM »
Soon done..


Offline Don1966

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Re: S7 plus to connoiseur upgrade
« Reply #38 on: October 16, 2015, 07:24:23 PM »
That's some very nice work Bjorn. You will enjoy using it as much as I do. It's a very handy tool to have in your collection. By the way if you don't have it yet, I made a spreadsheet to do the calculations for you. I am attaching it to this post. You may even improve it. It will calculate the Micro Attachment dial setting and is also a stand alone for the different division plates.

Regards Don

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #39 on: October 16, 2015, 08:10:57 PM »
Thanks Don! I allready have laminated charts for the vdh, but this is a welcome addition. Btw, this connie bullgear is really something odd, how about a 14,6506 dp with a 20 degree pressure angle?

Worm is cut to this spec, hence the need for a 47 t changegear, to make that changegear i had to make a new dividing plate..  :wallbang:

Offline Don1966

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Re: S7 plus to connoiseur upgrade
« Reply #40 on: October 16, 2015, 11:06:28 PM »
You could of made it with the 60 hole and micro attachment or am I missing something here.

Don
Never mind you didn't have the dividing head done yet...duuu :toilet_claw:
« Last Edit: October 16, 2015, 11:28:42 PM by Don1966 »

Offline Bjorn_B

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Re: S7 plus to connoiseur upgrade
« Reply #41 on: October 17, 2015, 08:09:11 AM »
Thanks for your comments Don. Seems I'm replicating much of your work  :happyreader:

Yes it would not be much of a problem problem making ithe gear on the versatile, but the dividing head I have on the mill is a lot sturdier and making a new holecircle is allmost a doodle with the pdc function on the dro. I never got quite round to finishing the versatile as I bought the mill around that time and it came with a very nice quality dividing head. This is why I don't have any nose adaptors, collets and so, only the smooth bore with copper pads. Another spindle would be nice , for ER collets.

Next thing on the agenda is some sort of milling spindle for the toolpost and/or vertical slide. The Quorn grinding spindle could allso find use on a toolpost grinder setup. How to power theese things is what bothers me now: Old school ac motor? Brushless motor driven from a 900w power supply via r/c speedcontroller/arduino? Other possibilities?


 

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