Author Topic: Myford Countershaft Stuck With New Bearings And Shaft  (Read 3002 times)

Offline steamer

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #30 on: January 07, 2024, 11:37:03 AM »
With the oil reservoir between the bearings, reaming will not be a problem    Oilite is a sintered bronze that has been impregnated with oil    It's intent is to provide lubrication of some form for bearings that don't get lubricated very often.      This is not that case.

In this application they will be fine.....mine were reamed and are running fine after 10 years  ( 3/4 shaft)

He is where he is,  lets not confuse this any further.

Dave
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Offline Jo

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #31 on: January 07, 2024, 12:02:23 PM »
Yes agreed Dave (Steamer).

The other Dave (Bluechip) just pointed out he has a S7B not the smaller ML7. His counter shaft has oil cups where the pic of this countershaft shows oil nipples which need to be squirted in with an oil gun.


I think reaming (with a reamer or ball) isn't going to make any difference to their effectiveness as these originally would have been oil lubricated bronze bearings so blocking some of the pores by reaming just leaves you with more bronze surface more like the original, the bore just needs to be the right size.

Jo
« Last Edit: January 07, 2024, 12:45:14 PM by Jo »
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Offline steamer

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #32 on: January 07, 2024, 12:37:04 PM »
From the Myford store under spare parts

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Offline AlexS

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #33 on: January 09, 2024, 06:26:21 PM »
Sorry for late reply.

Yes the ML7 has some room for oil when feed in between the bearings. I think I need then a proper oil gun. Now I turn in and out the nipples to feed some oil now and then. Old bushes got really hot when using the machine for a time.

Jo, the OD of the old bearings where 22.030 both sides .0012" at 0 degree cold in the garage.

After building and converting a Chinese mill to 3 phase motor, transmission and set up electra for both the mill and for the ML7 a frequency converter. I thought replacing a few plain bearings would be a piece of cake!

But for the next time I know better to look for. I recently take over a used variable reamer for someone who sell lot more tools. Best way would indeed use the proper bearings. But if buyed from Myford shop it self I am not sure if they than wil fit wel or also need modifying.
The guy who sold the bearings said, don't modify the shaft, only the bearing. He said, I do this everyday with reaming and little bit of coarse sandpaper. Best would be to turn the size in a second lathe and re-impregnate the bearings. Now I don't work at a company where a lathe is available, more reasons to see if the machine park can be expanded in future.

If it was for example a rare motorcycle engine big end plain bearings I would look for different bearings or methode. It should be better than it was, before it could almost lock up when the bearings heat up.

Now I would try to ream them and get a oil gun!

Offline steamer

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #34 on: January 10, 2024, 03:47:22 PM »
Sounds good     The reason people are having difficulty in getting oil in is its a closed volume    to get some oil in   air and oil needs to come out!.    It the space was vented it would be much easier.   
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Offline AlexS

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #35 on: January 11, 2024, 04:06:21 PM »
Ah yes!

it is indeed not a drip feed lubrication like the spindle bearings. I saw a drip system installed.

Offline AlexS

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #36 on: January 18, 2024, 06:43:03 PM »
Well! Monday reamed the bearings. I notice that bearings where not proper aligned. Could only reamed them from both sides and try to guide the reamer with a taper bush pressed in other side.

To get the shaft freely spinning it need some more (looser) work. I have read that this is a common thing when the "swing head arm" is not set up correct with two screws and could bend when force act on the shaft.

But! Yesterday turn a bush for my Kawa Z1 to fit original exhausts. I did not tighten the engine belt too tightly. Immediately noticed fewer vibrations in the swing arm and headstock! And after making the bush no warm area around the bushes!

Only looking for a oil feed gun.

Offline Charles Lamont

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #37 on: January 18, 2024, 09:08:41 PM »
I have read that this is a common thing when the "swing head arm" is not set up correct with two screws and could bend when force act on the shaft.
It is a pity none of us (myself included) thought of that. I would not be surprised if misalignment of the two ends was the cause of your problem all along. I think that casting is mazak or something similar, and if the two belt tension adjusting screws are not properly adjusted, the casting might well delvelop a permanent twist over time under the belt tension load.

Offline steamer

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #38 on: January 19, 2024, 04:16:36 PM »
Well! Monday reamed the bearings. I notice that bearings where not proper aligned. Could only reamed them from both sides and try to guide the reamer with a taper bush pressed in other side.

To get the shaft freely spinning it need some more (looser) work. I have read that this is a common thing when the "swing head arm" is not set up correct with two screws and could bend when force act on the shaft.

But! Yesterday turn a bush for my Kawa Z1 to fit original exhausts. I did not tighten the engine belt too tightly. Immediately noticed fewer vibrations in the swing arm and headstock! And after making the bush no warm area around the bushes!

Only looking for a oil feed gun.

Progress!     Machine repairs are rarely simple and you always find something you don't expect.    BUT   You improvised and overcame the difficulty and was successful!    Now we go to the next problem!
Congratulations!
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Offline AlexS

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #39 on: January 19, 2024, 11:52:04 PM »
Well, I have read about twisted casting before started on this replacement. Other option was to get a second hand casting, but there you also not very sure if also has not the twist. For now it is wat better then before, so little vibrations. And with VFD controlled way more fun and earlier to work on the machine.

New shaft between 19.14 - 19.17 mm.

After reaming pulley side 19.20 other side 19.30 mm. 0.06 - 0.13mm play

Offline steamer

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Re: Myford Countershaft Stuck With New Bearings And Shaft
« Reply #40 on: January 21, 2024, 02:11:41 PM »
Well, I have read about twisted casting before started on this replacement. Other option was to get a second hand casting, but there you also not very sure if also has not the twist. For now it is wat better then before, so little vibrations. And with VFD controlled way more fun and earlier to work on the machine.

New shaft between 19.14 - 19.17 mm.

After reaming pulley side 19.20 other side 19.30 mm. 0.06 - 0.13mm play

That should work just fine Alex.   Just keep it lubricated, and it will be fine.    You got this Alex! :ThumbsUp:
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

 

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