People often start threads about sash cramps, wanting to find something which works but doesn't cost as much as a commercial offering from Bessey, Record etc. I recently bought some nice cramps secondhand and thought I'd share details in case anyone fancies having a go at making them.
This article in the Woodworker in 1902 shows how to make a simple version. It's the second design I'm talking about - with a notched batten, a strap and some wedges.
There is a more elaborate version as well, which has a wooden screw instead of the wedges. I felt sure that I had some instructions somewhere on how to make them, but despite hunting through quite a few old books, I've not been able to find any old instructions. I found some modern illustrations. This is from Salaman's Dictionary of Woodworking Tools (1974)
and this is from Graham Blackburn's book "Woodworking Handtools Instruments and Devices" (also 1974)
but they are both frustratingly light on detail. So, let's have a few photos.
One four foot cramp and two at two foot.
The little ones are beech, with brass fittings, proudly made by Mr Fennimore
The fixed end has a nice captive pressure pad so there is no need to fiddle about finding scraps of wood when glueing up.
The sliding foot has a tongue which fits into a corresponding groove on the top of the bar.
The joint at the head is suitable and has lasted well - I don't know a name for it, but it's like a combination of bridle joint and through tenon, with the tenon being wedged.
The main stem is about 1 3/4" x 7/8". The fixed end is from 1 3/8" thick wood. The threaded part is 3/4" diameter, 4 1/2 tpi.
The bigger cramp is possibly older - it has three different owner's names stamped on it. It's made of oak, about 2 1/2" x 7/8". A couple of extra holes suggest it could well have been from scavenged materials.
At the head, the wood has been thickened up a bit by glueing on some extra slices, so that it can have a similar joint to the other one, with a tenon in the middle and bridle joint outer tongues.
The tenon doesn't go through - maybe it's fox wedged? The joint is reinforced with screws, which I have no intention of ever removing!
The movable stop has an inserted tongue
and straps with spare holes and rivets made from sawn-off woodscrews. They haven't given up yet!
The threaded rod is bigger in proportion - 1" diameter, 5 tpi. The end has a nipped off nail making an exposed spike. I don't know if there would have been a pad as well, or whether the spike was an easy way to get everything tightened up without any slipping. If it was for use on doors or windowframes, I guess the minor damage would pass unnoticed.
Having had a good look at these, I scouted round to see if I could find any other images that might be helpful to anyone making some.
This image is from an amazing historical catalogue that has been discussed on here before - see http://pudl.princeton.edu/viewer.php?ob ... 8/mode/2up for the whole thing. It's Austrian and dates from 1869.
It shows the triple joint, with the outside tongues let into the sides of the main beam.
This last image is from a 19th century French catalogue, Feron & Cie, Paris, which was made available at the Lost Art Press blog
At least one of the designs on this page has a simple spike on the end of the threaded rod.
So there we have it - cheap, lightweight and strong cramps for projects large and small. Is anyone going to have a go at making some? Or do you have some more pictures of similar designs?
This article in the Woodworker in 1902 shows how to make a simple version. It's the second design I'm talking about - with a notched batten, a strap and some wedges.
There is a more elaborate version as well, which has a wooden screw instead of the wedges. I felt sure that I had some instructions somewhere on how to make them, but despite hunting through quite a few old books, I've not been able to find any old instructions. I found some modern illustrations. This is from Salaman's Dictionary of Woodworking Tools (1974)
and this is from Graham Blackburn's book "Woodworking Handtools Instruments and Devices" (also 1974)
but they are both frustratingly light on detail. So, let's have a few photos.
One four foot cramp and two at two foot.
The little ones are beech, with brass fittings, proudly made by Mr Fennimore
The fixed end has a nice captive pressure pad so there is no need to fiddle about finding scraps of wood when glueing up.
The sliding foot has a tongue which fits into a corresponding groove on the top of the bar.
The joint at the head is suitable and has lasted well - I don't know a name for it, but it's like a combination of bridle joint and through tenon, with the tenon being wedged.
The main stem is about 1 3/4" x 7/8". The fixed end is from 1 3/8" thick wood. The threaded part is 3/4" diameter, 4 1/2 tpi.
The bigger cramp is possibly older - it has three different owner's names stamped on it. It's made of oak, about 2 1/2" x 7/8". A couple of extra holes suggest it could well have been from scavenged materials.
At the head, the wood has been thickened up a bit by glueing on some extra slices, so that it can have a similar joint to the other one, with a tenon in the middle and bridle joint outer tongues.
The tenon doesn't go through - maybe it's fox wedged? The joint is reinforced with screws, which I have no intention of ever removing!
The movable stop has an inserted tongue
and straps with spare holes and rivets made from sawn-off woodscrews. They haven't given up yet!
The threaded rod is bigger in proportion - 1" diameter, 5 tpi. The end has a nipped off nail making an exposed spike. I don't know if there would have been a pad as well, or whether the spike was an easy way to get everything tightened up without any slipping. If it was for use on doors or windowframes, I guess the minor damage would pass unnoticed.
Having had a good look at these, I scouted round to see if I could find any other images that might be helpful to anyone making some.
This image is from an amazing historical catalogue that has been discussed on here before - see http://pudl.princeton.edu/viewer.php?ob ... 8/mode/2up for the whole thing. It's Austrian and dates from 1869.
It shows the triple joint, with the outside tongues let into the sides of the main beam.
This last image is from a 19th century French catalogue, Feron & Cie, Paris, which was made available at the Lost Art Press blog
At least one of the designs on this page has a simple spike on the end of the threaded rod.
So there we have it - cheap, lightweight and strong cramps for projects large and small. Is anyone going to have a go at making some? Or do you have some more pictures of similar designs?
