Axminster AWFS18- vibration help?

[GarF]

I'm new to scrolling and have probably less than two hours use on the machine. So last night I was working away trying to stick to my lines or else maintain a fair curve where I drifted off line. I was beginning to wonder if perhaps the blade was beginning to dull as I seemed to be deflecting it a bit more than before, and perhaps had run into a tougher patch in the wood when something evidently gave way as there was now substantial oscillation in the blade and noisy vibration below the table.

The blade is intact.

The noise is caused by the end of the lower arm catching on the safety guard.

Moving the lower arm up and down by hand, the tip appears to follow a diagonal path rather than vertical which accounts for the oscillation in the blade.

Incidentally the plastic bushes on the tension lever have also succumbed in the commonly reported fashion. I presume this reduces the blade tension somewhat, but I don't think this is responsible for the shift in 'tracking'.

Could anybody with experience of this machine give me a troubleshooting list to work through in order to get the lower arm working vertically again- I'm assuming this occurrence is not novel, and haven't yet had chance to make a detailed study of the mechanism.

I have read on here about people replacing the (cheap) plastic bushes on the tension lever with bearings from router cutters and would also be grateful if somebody could advise at the the spec required.

Many thanks in advance, I hope a relatively straightforward fix of which I'm sure I am capable with the right information, otherwise a warranty claim to Axminster.
G

 

[John15]

Hi Garf,

If the machine is still under warranty it's worth giving Axi a call.

John

 

[Alexam]

Hi GarF,

what size timber were you cutting at the time? With thicker timber (2"), sometimes the blade guide will interfear and often it is removed, but then you need to feel comfortable in holding the work down. Also have to checked that at the lowest speed, the blade is vertical from the side and from the front. It is important to make sure you have a dead vertical cut, (use a small engineers square).
Malcolm

 

[Claymore]

Any chance of some photos to show what you meaning? I have the same machine and trying to work out just where its out of line etc. Also the plastic rollers are a quick fix, I bought some plastic ones from Hegner when mine wore out and they seem to last ok so far, I will probably get some bearings when they fail)
2" is maximum thickness I would use on any scroll saw, as for the vibration my own saw has none and isn't even bolted down etc so if yours is vibrating then something must be faulty... give Axminster a call and see what the tech guys say... they are usually very helpful and you should soon be back in action.
How old is the saw? they are superb saws and yours is the first i have heard having vibration issues.

Cheers
Brian

 

[GarF]

Malcolm- I was cutting 3/4" pine-- some old futon slats

The blade was vertical to begin with- I tweaked the table when I got it using the cut a block of wood, flip it around and blade fits into kerf technique.

Will see if I can get some photos which show the deflection
Cheers
G

 

[Alexam]

Did you also check the side vertical? The blade should not be tilted and the block of wood check only gives 90 degrees from the front.

With work of only 3/4" it should not be a problem at all. I might have expected a problem with 2". Perhaps others can help, or take it back and get a new Axminster Trade Ex16 which have just come out.

 

[martinka]

Check the bolts haven't come loose in the link arm that connects the motor to the lower arm, or that the link itself hasn't broken.

 

[Claymore]

could the plastic rollers be twisting the actual blade holder? have you removed all of the plastic rollers so the metal sits level?, just been out to check mine and its hard to tell how you could get it out of line unless the arm has bent but i'd be very surprised if it was bent.

 

[martinka]

I agree, Brian, it seems something drastic would have to happen for the arm to be noticeably out of line. If the arm didn't bend, which is unlikely anyway, that leaves the rear pivot bolt and bearing, just as unlikely, and the motor and its connection to the arm. Going on GarF's description, I am going for the link arm cracking and a bearing coming loose, or the link arm bolts coming adrift. Another possibility, though again unlikely, is the motor coming loose.

GarF, if you take the left hand cover off, below the table, you can get a much better look at the link arm, and possibly get some photos.

 

[GarF]

Thanks for the advice so far. I have removed the metal guard from the left of the machine and by turning the drive wheel I have established that the tip of the lower arm describes and elliptical path being closest to the motor side at the bottom of the stroke and closest to the casting supporting the table just before the top of the stroke. Measurement is awkward but I found about 2.5mm from the casting at the top versus about 4.5mm at the bottom. The picture shows a 2.5mm allen key snugly held with the arm near the top of the stroke.

Using a square I found that at the top of the stroke the blade is near enough perpendicular to the table, but at the bottom substantially off - reflecting the deflection of the lower arm of about 2mm towards the motor at this point. After purchase I had to tilt the table somewhat to the right to get the blade perpendicular so the indicator arrow below the table is currently pointing to about minus one and a bit.

I haven't disconnected the link arm from the motor drive wheel to check tightness there, yet. All other bolts appear tight. Any more clues in amongst this lot? A message to Axi in the morning methinks
Cheers
G

 

[Alexam]

Suggest that you don't mess about with it, but return it to |Axminster to sort out. If you start trying too solve the problem and can't, then you may well have invalidated yor guarantee. Phone Axminster.

Malcolm

 

[GarF]

Indeed. Message sent. In the meantime I disconnected the link arm from the motor drive wheel, to find not altogether surprisingly that the thinner of the two washers on the motor side of the bearing had fragmented. Not having another of the same size to hand I reassembled without it to see what would happen.... Lo and behold normal operation resumed, though I did have to adjust the table back towards it's original starting position to achieve perpendicular.

This operation allows you to alter stroke length between 10 and 20mm (10 being factory setting from what I can see), which I assume has some bearing on speed of cut and length of blade engaged, possibly at the expense of vibration? The manual doesn't go into much detail.

For now I intend to seek a replacement washer and keep an eye on things. If Axminster offer to inspect the saw I will take it along to North Shields which I always find dishearteningly quiet- it's nice to have the staff always ready to assist but I do worry that they won't do enough trade and the company will wind it up.

 

[Alexam]

I hope that they will still be happy with the guarantee, as you have made changes. Think carefully about using it because if it now went wrong with a washer removed, it could be left to you to sort out. I doubt this would happen with a firm as good as Axminster, but other firms may soon cancel a guarantee if you had done that. That washer was there for a purpose. Better to take it in and let them sort it out as other damage may have been caused by the washer disintergrating.

Malcolm

 

[martinka]

On my Hegner, and on the Axminster and Hegner diagrams, there is only a thick washer in that position, with a thin washer and spring washer at the outer side of the bearing.

When I went to check the washers on mine a couple of hours ago, I noticed a noise at certain speeds and it turned out to be the bottom bearing. Luckily I had a couple of spares the same size and was able to change it. I only use the saw at full speed where there was no noise, so I hadn't noticed it until now.

 

[GarF]

Martin, Isn't that interesting? Mine has spring washer, thick washer and thin washer on the outside, then missing thin washer and thick washer on the inside. I couldn't really see why there would be two washers either side in addition to the bearing since washers themselves make fairly lousy 'bearings'. Although on reflection, perhaps this is intended as a sacrificial bearing surface which would only really have any effect in the event that the actual bearing failed. Engineers don't generally add components without reason which either makes the thin washer a deliberate feature or an accidental inclusion during assembly.

It hence does seem that the bearing could be at fault. Or perhaps the washer failed because it wasn't supposed to be there in the first place.

Malcolm, Don't fret (Ha!) from now I'm waiting to speak with Axminster before doing anything else. So far I haven't done anything to the machine which isn't detailed in the manual except running for a couple of minutes without the washer that fell out. Given that the blade is better aligned without it I need them to both check the bearing and verify the washer from their drawings one way or the other.
G

 

[GarF]

Just spoken to Axi and we're in agreement with Martin's diagnosis. The disc washer which isn't on the machine diagram appears to supernumerary and it's loss resulted in slop at the lower end of the link arm. Then with things tightened back up the alignment of the lower arm is corrected. Off to the Hegner site to get some new bushes for the tension lever...

 

[martinka]

Glad you got it sorted. There's so little to go wrong with these saws that it had to be something silly like that. Mind you, it doesn't say much for the quality of the steel if a spring washer broke up.

 

[GarF]

After I posted my last message I went to the Hegner website to order spare bushes for the tension lever, a quick release clamp and a couple of spare retaining springs for the table insert, etc. Probably finished the transaction by about 11am yesterday. Was impressed to find my order sitting in our kitchen when I got home from work this evening. Excellent service from Hegner!

 

[Claymore]

a couple of spare retaining springs for the table insert........ what are they for? holding the round metal doodah in? didn't know you could get them for the Axminster saw?

 

[GarF]

No, on reflection I'm not sure either, but if I can compress one enough to insert in the hole in the table which looks to be designed to receive it then it would stop the insert rattling. Will report back.