Mini lathe amadeal cj18a help needed

[Neil Mccarthy 1Participant @neilmccarthy1]

Hi all could anyone help me as I am not technically minded on motors but I was using my lathe and turn the motor off when I went to use it again the motor sounds like it is going around but it is not turning the belt around to make the chuck spin. I’m wondering is there something inside the motor that would need replacing or will it be a new motor.

any help would be greatful

thank you in advance

[Neil Mccarthy 1Participant @neilmccarthy1]

[Martin CargillParticipant @martincargill50290]

If the motor sounds like its rotating then it probably is. Check the belt to see if its snapped or has come off. Check the pulleys to make sure that they are properly attached to their shafts and are not spinning on them. Many small pulleys use a grub screw to secure them to the shaft, make sure that they have not come loose.

[Former MemberParticipant @formermember19781]

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[Neil Mccarthy 1Participant @neilmccarthy1]

Hi the motor sounds like it is turning but the pulley is not turning the belt if that makes sense it’s as if the pulley has snapped inside if that is how they work

thank you

[Martin of WickParticipant @martinofwick]

If the motor sounds as if it is running then it probably is OK. Check by taking of the backgear cover and look at the small pulley on the motor shaft.

Most likely the belt is not under sufficient tension and is slipping or the small motor pulley is loose on the motor shaft and needs the retaining grub screw tightening.

It is also possible that some teeth have been striped from the belt (if the lathe has had significant use, so give the belt a visual inspection.

Strongly suggest you take of the motor cover at the back of the lathe so all is easier to see and do a thorough inspection. Even if the issue is inadequate belt tension/alignment you will still need to do this to get at the adjusting screws and bolts etc.

If it is anything like mine was when it came out of the box, expect to find that you will need to completely re align and re tension the belt by adjusting the position of the motor with respect to the headstock. Expect this to take 2 or 3 hours of knuckle skinning frustration with small spanners and sockets and will probably need the front electronic control box removing to get at the motor lock bolts.

Unplug the lathe from the mains before proceeding.

[Neil Mccarthy 1Participant @neilmccarthy1]

Thank you looks like I will be busy for a while now swearing away trying to fix it

thank you for the advice I will have a look it’s only 4 months old with little use so should be under guarantee

thanks

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Neil Mccarthy 1Participant @neilmccarthy1]

Hi yes that’s sounds a good idea I will do that

[Neil Mccarthy 1Participant @neilmccarthy1]

Just took the back off and the motor spindal is spinning and there is a grub screw missing and the other grub screw is not holding the plastic wheel on so hopefully if I can find a grub screw small enough hopefully that fixes it

thank you

[Iain DownsParticipant @iaindowns78295]

The motor has a cog on it with a plastic key which is designed to break under load. I've had this happen a couple of times when doing an interrupted cut.

The solution (for me) was to replace the gear with this

AMA-SP-CJ18-148RB

Motor Pulley for CJ18 (part #148)

From Amadeal. Hugh is back from Xmas tomorrow so you should get it quite quickly.

Iain

[Neil Mccarthy 1Participant @neilmccarthy1]

Thank you

[Neil Mccarthy 1Participant @neilmccarthy1]

I have just ordered 2 so I have a spare

thank you for all of your help with this

[Neil Mccarthy 1Participant @neilmccarthy1]

Posted by Iain Downs on 29/12/2019 16:44:26:

The motor has a cog on it with a plastic key which is designed to break under load. I've had this happen a couple of times when doing an interrupted cut.

The solution (for me) was to replace the gear with this

AMA-SP-CJ18-148RB

Motor Pulley for CJ18 (part #148)

From Amadeal. Hugh is back from Xmas tomorrow so you should get it quite quickly.

Iain

Thank you I got the part you said to get today and I have my lathe back working

thank you very much

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Neil Mccarthy 1Participant @neilmccarthy1]

I ordered one of the below which is a plastic one and fitted it used it for 20 mins on and off only on delrin and it’s happened again it’s stopped the chuck spinning so looks like it’s broken again looks like it’s a design fault maybe waiting to hear back of the company

AMA-SP-CJ18-148RB

Motor Pulley for CJ18 (part #148)

[SillyOldDufferModerator @sillyoldduffer]

Posted by Neil Mccarthy 1 on 14/01/2020 11:47:59:

I ordered one of the below which is a plastic one and fitted it used it for 20 mins on and off only on delrin and it’s happened again it’s stopped the chuck spinning so looks like it’s broken again looks like it’s a design fault maybe waiting to hear back of the company

AMA-SP-CJ18-148RB

Motor Pulley for CJ18 (part #148)

That's surprising – can you describe exactly what you're doing with the lathe? Takes a fair amount of force to break them, such as a jamb, interrupted cut, forcing a blunt tool, or a dig-in. The last might be due to something as simple as the tool being at the wrong height and overhung, causing excessive force to be applied when the tool springs.

Apologies if you're a retired master machinist and know exactly what you're doing, but it took me a while to learn how to drive my mini-lathe properly. Being self-taught I've become expert on how not to do it, and learned not to assume anything! Pictures are good if you have the technology.

Dave

[Neil Mccarthy 1Participant @neilmccarthy1]

Hi I’m a beginner but all I was doing was reducing the size of a piece of delrin rod by doing 1-2mm off at a time and all of a sudden it stopped I am presuming it was the same thing happening again I will check it later on again. The lathe has only been used a few times for light work that is why I can not understand why it has done this. I got 2 off the plastic bits when I ordered one last time so if it is that again I will replace and see if it does it again. I have emailed amadeal when it first happened and got no reply and I have emailed again last night so see if they reply when I was looking to buy it they where very responsive with messages I just hope they get back to me now

thank you for your reply

[Ron LadenParticipant @ronladen17547]

Neil, unfortunately I dont have an answer to your problem other than to suggest you check the drive train from motor through to the chuck. It sounds as if the work you were doing at the time you lost drive was light duty and assuming there are no faults within the drive assy its strange that the motor drive pulley has failed yet again, it could be a faulty pulley of course but I wonder..? Have you checked the motor pulley to see if that is where the problem is..?

When I had my CJ18 I stalled it twice whilst parting off and the second stall broke the plastic high/low spindle drive gears inside the head. It was quite some force as it broke off some teeth and split the main body of the gears and yet the small plastic motor drive pulley was fine including the moulded in key.

Have a good look at the motor pulley and the rest of the drive to see if you can identify any problems which could cause the motor pulley to fail (if it has of course) it could be that the problem is elsewhere.

Edited By Ron Laden on 14/01/2020 16:12:34

[Iain DownsParticipant @iaindowns78295]

In fact my earliest lathe damage was when I broke the high low gears and replaced them with metal – no issues since. That was because of a jam (and highlights the dangers of unidentified bits from the scrap yard).

The motor gear has gone twice, both times when I was doing interrupted cuts. What I did notice is that it's difficult to line up the plastic key which is cast in the gear with the keyway in the motor spindle. It's possible that pushing the gear on damaged the key – I think that was an influence on the second breakage which happened soon after the first.

But I'm surprised that you broke it on delrin. Perhaps a picture of the gear?

 

Iain

Edited By Iain Downs on 14/01/2020 16:53:17

[HollowpointParticipant @hollowpoint]

It's quite possible to break a gear even cutting delrin, you just need the right circumstances. You said you where taking cuts of upto 2mm which is quite alot imo. A sharp pointed tool and a jerky hand movement could easily dig-in. At high speed the shock from the abrupt stop would destroy a plastic gear or pulley in no time.

[Howard LewisParticipant @howardlewis46836]

It seemed to me that 1 – 2mm depth of cut, even with Delrin, was a deep cut for a small lathe.

If you are continuously breaking gears and things, the machine is being overloaded in some way.

If the motor is 500W or less, I would start to think in terms of 0.5 mm depth of cut as a maximum.

Could be cheaper and more convenient that way.

I know that many folk exceed the advice given in the Operator manual for the C2 and C3 mini lathes and exceed the recommended 0.25 mm roughing cut in steel, and get away with it.

You wouldn't expect a 850 cc Mini to haul a 40 ton load would you?

Howard

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Iain DownsParticipant @iaindowns78295]

Neil – my experience with Amadeal (specifically Hugh) is that they are good with phone calls but not so much with emails.

I think they're a bit overloaded and the emails get caught up when they can. Try calling.

Iain

[Neil Mccarthy 1Participant @neilmccarthy1]

As you say I have always had good correspondence from them and I received a reply today they are sending me the part out free so a good service from these yet again I would buy from them again. Saying that I keep buying other parts for the lathe cutters threaders etc so without a doubt a good company to deal with

thank you everyone

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