Aereopiccola Vibro 2000 saw problem

[rogerj]

Hi all..This is my first post so I'll introduce myself first. I'm a retired electronics/broadcasting engineer living in Cornwall. I do some woodwork as a hobby but generally it 's not very classy stuff - although I have a reasonably well equipped workshop. The problem is that I have a good friend who does some very nice fine work in his and has been making good use of his Vibro saw - which has now stopped working. So he has brought it to me to try and fix. He is wrongly convinced that I can fix anything !

Unfortunately, this time, I'm stumped and I am at a bit of a disadvantage in that I've never seen it working. On switching on it makes a furious buzzing noise, the blade is pulled downward but only vibrates a very small amount - probably only 1 tooths worth and it will not cut at all. I am wondering what the correct "stroke" should be - and whether resonance of the spring plate and or the upper spring provides the means by which useful oscillation occurs.

It's very simple construction and everything about it looks OK. There is a pad of foam on the central magnet pole but I assume that's original. The maximum possible downward deflection looks about 5mm so I wonder if the "stroke" should be 10mm ?
I also wonder if there could be a diode in the circuit that reduces the pulse rate to 25HZ. I can't see any sign of it only that one could be situated under the magnet. If there is it's now a short circuit. That maybe a flight of fancy though !

Enough rambling....I wonder if anyone has an idea what might be wrong...and a happy new year to all...Roger

 

[powertools]

I have done a forum search and there is little mention of the vibro saw so it would seem that few if any members have one.
It may be a good idea to search on model boat builders forums as those guys seem to use them to cut out the boat kits.

 

[Bryan Bennett]

Welcome Roger to the site,we have some very clever members who may be able to help you.I am sorry that I am not one of them.I hope that it will be fixed soon.

Bryan

 

[ChrisR]

Roger.

Welcome to the forum.

Sorry I don’t know anything about the vibro saw, only thing that may be of help, is that the blade stroke would be a minimum of five to six teeth, I would think.

Take care and a happy New Year to you and yours.

Chris R.

Just an after thought, a number of scroll saws limit the blade stroke to cut thin material ie(veneers), on my saw it is achieved by changing a cam setting, as it is motor driven, maybe on the Vibro saw, it is achieved electrically and a switch setting has moved. Just a thought.

 

[martinka]

No idea on this one. I'd love to be able to help, but each time I tried to buy one of these on ebay, I was outbid.

edit: I posted this some months ago, if it's of any use. https://www.ukworkshop.co.uk/forums/download/file.php?id=17749&mode=view

 

[rogerj]

Ok..I do appreciate the replies...and to Martinka..it was your post that led me to this forum. It was the only useful net content I could find. (the other was a youtube video of a guy cutting out a star)

All the other posts equally appreciated.

I've spoken to the owner again and he reckons the "stroke" may have been about 5mm. That seems reasonable now I look at the construction again. Unfortunately I've now managed to break the blade which limits further tests until I can get a new one. He tells me it would cut 5mm mdf perfectly. Tomorrow I'll take and upload some photos of the machine. Out of interest if nothing else..Roger

 

[rogerj]

I'll get a new blade soon and continue looking for a solution. Meantime, as this machine seems quite uncommon I've uploaded some images so ypu'll know what to expect if you are ever successful on eBay !
I haven't included one fully assembled as a 9" table can be easily imagined.
I transcribed the instructions from martinka's photo but soon found that pdf's and open source docs are not allowed here.

edit: I'll just add that when I spoke to the owner last night I asked if the problem came on abruptly or not. He said he put it away in the attic for a year and when he got it down it wouldn't work. Something strange going on in that attic maybe

A new years resolution is to assemble and make use of the S/H DeWalt radial arm saw I bought two years ago. If I get stuck with putting it back together I now know where to come for advice !!



Roger

 

[martinka]

Cheers, Roger. Do a screengrab of the pdf and upload as a jpeg, or as plain text.

I still look on ebay occasionally for one of these. I don't need one, I just fancy one. The missus would like me to buy a Dremel Motosaw as the Hegner frightens, her but she wants to have a go. It'd keep her out of my garage as well.

 

[CHJ]

No knowledge of the machine but going by the description I take it that it is just powered by a vibrating solenoid.
If this is the case I suspect it has gained some corrosion or solidified dust between the steel core and the brass? coil core tube whilst inactive in storage.

Assuming the above see if you can dis-assemble the solenoid and polish the brass? bore and iron piston.

 

[rogerj]

No knowledge of the machine but going by the description I take it that it is just powered by a vibrating solenoid.
If this is the case I suspect it has gained some corrosion or solidified dust between the steel core and the brass? coil core tube whilst inactive in storage.

Assuming the above see if you can dis-assemble the solenoid and polish the brass? bore and iron piston.

There may be some confusion in interpreting the pictures..The coil core is a laminated iron "E" core similar to that used in "E & I" transformers. The steel plate is pulsed by the alternating magnetic field formed across the two outer poles and the inner one. The yellow that I think you might have thought to be brass is the glued remains if the foam rubber pad that I removed for the bottom picture..

The more I think about it, given such a simple mechanical arrangement, is that the problem is electrical. ie not enough strength in the field. This could only be caused by shorted turns in the winding. With no means of knowing what the resistance and inductance of the coil should be I can't follow that up. There is a warning on the body saying "not for prolonged use" as these types of coils always start to heat up. If it had been allowed to over heat then shorted turns could possibly result.

As suggested, I ve added a jpg of the instruction sheet. You can see that it's not complete - as in the original..

Roger

 

[CHJ]

If you bridge the E laminates with a piece of iron/steel does the coil heat up rapidly or smell of burning, if the device was working when put in storage then can't see a winding short being a problem, would expect to see some heat damage to the plastic bobbin as well.
Does the travel of the mechanism rely on the characteristics of a foam spacer ?

 

[rogerj]

If you bridge the E laminates with a piece of iron/steel does the coil heat up rapidly or smell of burning, if the device was working when put in storage then can't see a winding short being a problem, would expect to see some heat damage to the plastic bobbin as well.
Does the travel of the mechanism rely on the characteristics of a foam spacer ?

I'm reluctant to try anything that may cause it too heat up in case I damage it -when no damage presently exists !There is no sign of overheating on the outside surface of the coil..
You are right to question how it could have been working right up to putting into storage - and now suddenly not. I am really clutching at straws (hammer)
The foam pad is about 7mm relaxed and there is 6mm between the underside of the plate (armature) to the poles so I assume it is a damper. It must also prevent the plate from reaching the poles and ( and making a very loud racket). Most probably the downward maximum deflection is only about <3mm making the stoke about 5mm as was suggested in an earlier post and confirmed by the owner. The foam has deteriorated with age but I don't hold out any hope of getting a replacement.

I'm not giving up yet but if I do I'll ask him if he would like it made into a hot wire foam cutter :idea:

Roger

 

[Geoffrey]

Hi I think if i remember right the stroke Is ajustied by moving the weight with the wing nut on the top arm :idea:
Geoff .

 

[rogerj]

Hi I think if i remember right the stroke Is ajustied by moving the weight with the wing nut on the top arm :idea:
Geoff .

A good point ...but. Some light rusting on the top spring arm shows whee the weight had been probably for most of it's life..I did try moving it though and with no effect. Until the blade broke. I may get a new one today and experiment further. I'll get back when I've done it. Roger

 

[rogerj]

I think I can put this subject to rest. I've got the new blade and reassembled the saw after the complete disassemble for the photos.
But this time there was one small, supposed insignificant, difference - I left out the thin bits of leather cloth the owner had put under the ends of the vibrating plate....

The steel plate has "U" shaped pieces of rubber across each end which are clamped down by the angle plates and screws you can see in the top picture.
The bits of leather cloth raised the plate by about 1mm and may have had an effect on the rigidity of the plate ends fixing.

I assumed they had been in position when the machine was working and, anyway, I didn't think they were significant, so every time I tested I had them in position. The owner had put them in he said because, without them, the machine was horrendously noisy.

It would seem that he has not actually used it very much (he has a couple of other more conventional machines) and when he did last use it the noise bothered him so much he added the leather cloth. He ran it - the noise was reduced - and he put it away without cutting anything. he didn't tell me that :roll:
Now, without the leather cloth, the machine saws.
I've informed the owner diplomatically what the problem was !
However if Martin, or any of you, are tempted to buy one on eBay etc I would say, don't bother. The racket it makes has to be heard to be believed and it doesn't cut very well because of the small stroke. not 5mm but nearer 2mm. I'm not surprised they are no longer made. Roger

 

[Geoffrey]

Glad you got to the cause of the problem and saved some one some money =D>

Geoff.

 

[martinka]

Good to hear you got it sorted, Roger, and thanks for the tip.