Need help for a Lesto/Bosch jigsaw

[nali]

Hello.
I think I need some help.
I had for quite cheap (5$) a vintage Lesto Jigsaw model GEB4 from circa 1958.
It's in very decent condition, I even thought it was much younger.

My plan is to use it to build a small bench jigsaw.
Of course I did my work, found some information about those saws, but have problems with the blade retaining system.
I have read that you have to insert the blade, then turn it 45 or 90° and hold it with the screw on the bottom.

I can turn the screw for hours, it never get tight. If I insert a rod or anything from the bottom (blade side), it doesn't seem there's any effect from the screw above.

Since I plan to use a really small blade instead of the original one, I won't mind modifying the original system to hold it. But before destroying a (maybe) working tool, I'd prefer fixing it

A schematic of what is inside the shaft would be very helpful, I couldn't find any.
Thanks a lot.

You may also enjoy my brand new battery charger

 

[neophyte]

Do you have the proper type of jigsaw blade? I believe some of the early Lesto/Scintilla jigsaws may have used a different type jigsaw blade than the current T-Shank type.

I'm not certain about this since I haven't used a Scintilla/Lesto jigsaw if that age, but there is a type if jigsaw blade that has a longer shank with two crossbars. The catalogues from MPS Sagen and Wilpu, both of whom manufacture jigsaw blades in Germsny show the type of shank and list them for AEG, Metabo, and Bosch jigsaws. All the current jigsaws from these companies use T-Shank blades so I presume these are for older models, and Bosch is the owner of Scintilla/Lesto. The blade shank can be seen in the two below catalogs.

The Wilpu catalog shows the blade shank on page 11.

http://www.wilpu.de/fileadmin/user_upload/Produkte/Katalog_2016/KATWilpu1617_web_gesamt.pdf

The MPS Sagen catalog shows the shank on page 38.

http://www.mps-saegen.de/fileadmin/mps/medien/Katalog/Stichsaegen.pdf

I believe I've seen Starrett blades with the same shank as well, and Bosch may still manufacture them, at least for some markets.

 

[neophyte]

The blade type I'm refering to is sometimes called "double tang". If you google doubke tang jigsaw blade you may be able to find some for sale. I found one or two listing on Amazon in the USA.

https://www.amazon.com/gp/aw/d/B000...ng+jig+saw&dpPl=1&dpID=21CPPszI7mL&ref=plSrch

 

[Mintgrun]

a photo or two of the blade clamping mechanism might be helpful.
the older jigsaws I have seen do not use the T-shanked blades, but have a straight tang, which is simply clamped by the screw. In an old saw I have, there is also a small metal tab which the screw presses against, to clamp the blade. I have never seen a vintage saw made by bosch though.

Could it be that the threads (in yours) are simply stripped?

 

[nali]

Thanks for the replies.

In fact I'm now sure the mechanism is dead. This explain why the saw is in so nice shape, it may have been broken early.
Even the foot has only minor scratches.
On the top side of the shaft there's a screw, and a retainer for the blade on the bottom.
Both are mobiles and turn freely, so I have problems drilling through.

I'm trying to build a homemade EDM to remove them