Jump to content

Making lever arm grommets


Recommended Posts

Hi all. Just making my first batch of lever arm grommets out of some fairly stout thick leather belt (3mm-ish). Am I missing something or is it fiendishly difficult? Firstly I tried punching some small circles and piercing them with a leather awl. Couldn't get them on the lever ends. Then I tried holding them in small pliers and drilling them, difficult to get the hole central. I've now abandoned the circles in favour of drilling holes along a thin strip, then slicing into pieces. I end up with grommets about 5mm square and 3mm thick. I reckon the flat edge is probably better to glue onto the samper than the tangent of a circle (but then I would say that, wouldn't I?)

What do others do? (apart from buying them for 0.12p!).

Seeing as my concertina hours work out considerably less than the minimum wage, it costs me hardly anything to make them :)

Andrew.

Link to comment
Share on other sites

Andy

 

Here's a photo of the tool I use and some grommets made with it.

 

First I punch a whole load of 4.5mm diameter blanks using a normal hole punch out of 2mm thick belt material. Then I use this device to punch a 1.6mm dia hole in the middle (if I'm lucky) in the blank.

 

It helps to fill out an evening. You have to either be really determined to be completely self-sufficient or to mean to not to pay 12p per grommet; this is not a mechanised process!

 

I understand that one can get a tool which simultaneously punches the blank and the centre hole but I've never seen one

 

Alex

Link to comment
Share on other sites

Andy

 

Here's a photo of the tool I use and some grommets made with it.

 

First I punch a whole load of 4.5mm diameter blanks using a normal hole punch out of 2mm thick belt material. Then I use this device to punch a 1.6mm dia hole in the middle (if I'm lucky) in the blank.

 

It helps to fill out an evening. You have to either be really determined to be completely self-sufficient or to mean to not to pay 12p per grommet; this is not a mechanised process!

 

I understand that one can get a tool which simultaneously punches the blank and the centre hole but I've never seen one

 

Alex

Alex, I like the look of your hole punch, where did you obtain it!

The concertina seems to have many, many jobs that "fill out an evening"! I've just been cutting bellows papers out of sheets. ;)

Andrew

Link to comment
Share on other sites

Andy

 

I'm struggling to remember where I got it. This appears to be a similar item (http://www.craftworlddirect.com/acatalog/screw-punch.html) and you can get even smaller hole bits which could be handy from here (http://store.falkiners.com/store/product/5655/Japanese-Screw-Punch/). I'm sure I didn't pay that much though

 

Best of luck!

 

Alex West

Link to comment
Share on other sites

Andy

 

I'm struggling to remember where I got it. This appears to be a similar item (http://www.craftworlddirect.com/acatalog/screw-punch.html) and you can get even smaller hole bits which could be handy from here (http://store.falkiners.com/store/product/5655/Japanese-Screw-Punch/). I'm sure I didn't pay that much though

 

Best of luck!

 

Alex West

 

Thanks Alex. I love the Falkiners one but it is a bit expensive!

Link to comment
Share on other sites

If you have a drill press, the best method I have for consistently making a lot of grommets is using the press to drill a bunch of holes in an old belt, then chucking your leather punch in the drill press, leaving it off and using the leverage of the press to punch out the outer circle. Assures that both hole and outer wall are parallel.

Link to comment
Share on other sites

If you have a drill press, the best method I have for consistently making a lot of grommets is using the press to drill a bunch of holes in an old belt, then chucking your leather punch in the drill press, leaving it off and using the leverage of the press to punch out the outer circle. Assures that both hole and outer wall are parallel.

 

Thanks Chris. I'll try that method. I think there really isn't any point trying to drill the holes after the punch as I first attempted!

Link to comment
Share on other sites

If you are using hand tools drill the small hole and then use a punch and centre it by eye. About 1 in 5 will be off centre by too much to use. If you only need 30 then it s small job...

That's what I do...

...though I've tried Alex West's way as well.

/Henrik

Edited by Henrik Müller
Link to comment
Share on other sites

  • 2 weeks later...

Has anyone else ever tried using pieces of silicon tubing for making the grommets?

 

I did this on a poor little Lachenal 20-key I use for notorious experiments in concertina repair. I think it was 3mm outside diameter, 2mm inside diameter tubing that I used. It fits pretty tight on the threaded ends of the key levers, so no glue is needed to attach them. Then I used a tiny drop heavy-grade plastic cement to attach the tube to the leather samper disc on top of the pad.

 

Working on the keys is a bit faster this way, for instance if you need to replace the bushings, you can just pull off the piece of tubing along with the pad, and then get at the key. No need to pry off glued parts and re-glue them.

 

Also, the silicon tube is very flexible and stays that way for much longer than a leather grommet I imagine. Besides looking ugly, I can't really think of any downside to using it - I think it does the job better than a leather grommet. I don't think it flakes off notorious substances or anything, since this is the stuff they use for medical equipment, and also for fuel transfer in RC airplanes.

 

It's not that the leather grommets are too expensive to order or too difficult to make, but shouldn't one strive to make the best possible repairs for the instruments we have, even if it isn't traditional?

 

Anyway, if someone knows of a specific reason not to use the tubing, I'd like to hear it before I apply the technique on something more valuable!

 

 

Cheers,

Jori

Link to comment
Share on other sites

Has anyone else ever tried using pieces of silicon tubing for making the grommets?

 

I did this on a poor little Lachenal 20-key I use for notorious experiments in concertina repair. I think it was 3mm outside diameter, 2mm inside diameter tubing that I used. It fits pretty tight on the threaded ends of the key levers, so no glue is needed to attach them. Then I used a tiny drop heavy-grade plastic cement to attach the tube to the leather samper disc on top of the pad.

 

 

This sounds like a useful development, but does depend on finding a glue that will bond reliably to silicone rubber. Most glues wont, so I'm interested to know specifics of the glue you used.

Link to comment
Share on other sites

Has anyone else ever tried using pieces of silicon tubing for making the grommets?

 

I did this on a poor little Lachenal 20-key I use for notorious experiments in concertina repair. I think it was 3mm outside diameter, 2mm inside diameter tubing that I used. It fits pretty tight on the threaded ends of the key levers, so no glue is needed to attach them. Then I used a tiny drop heavy-grade plastic cement to attach the tube to the leather samper disc on top of the pad.

 

Working on the keys is a bit faster this way, for instance if you need to replace the bushings, you can just pull off the piece of tubing along with the pad, and then get at the key. No need to pry off glued parts and re-glue them.

 

Also, the silicon tube is very flexible and stays that way for much longer than a leather grommet I imagine. Besides looking ugly, I can't really think of any downside to using it - I think it does the job better than a leather grommet. I don't think it flakes off notorious substances or anything, since this is the stuff they use for medical equipment, and also for fuel transfer in RC airplanes.

 

It's not that the leather grommets are too expensive to order or too difficult to make, but shouldn't one strive to make the best possible repairs for the instruments we have, even if it isn't traditional?

 

Anyway, if someone knows of a specific reason not to use the tubing, I'd like to hear it before I apply the technique on something more valuable!

 

 

Cheers,

Jori

 

Hi Jori, I'm with Theo on this, I'd like more details of the adhesive. I guess silicone sealant would stick well to it! There is an adhesive lined heat shrink tubing( polyolefin, not silicone) so that must stick. I have some silicone heat shrink here so I'll try some different adhesives on it.

Andrew

Link to comment
Share on other sites

  • 4 weeks later...

Hi Jori, I'm with Theo on this, I'd like more details of the adhesive. I guess silicone sealant would stick well to it! There is an adhesive lined heat shrink tubing( polyolefin, not silicone) so that must stick. I have some silicone heat shrink here so I'll try some different adhesives on it.

Andrew

 

Hello, and sorry for the long wait. It's G-S Hypo Cement I've been using. To tell you the truth, I can't say anything about how it will hold after 10 years of constant playing, since lately I've barely had the time to squeeze the experiment box at all. The instructions that come with the tube advise against using it on a porous surface (such as leather), but the leather samper has held pretty nicely to the piece of silicon so far...

 

Cheers,

Jori

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...