Thread: Leg Vise help

Thanks Derek and rustynail for you suggestions. I will be having a tensioner for clamping parallelism so a rear wheel on top of the guide is not possible as per Derek's vice. The last suggestion from Derek re the front wheel has merit and I may end up doing that (or a recessed spring loaded jockey type) wheel under the chop. I like the look of the long chop. It will be mostly invisible and the spring can deal with the floor / screw alignment.

However, I was fundamentally flummoxed by the fact that most of these LV's do not have wheels. So I tried another screw as mentioned last night - no difference. Then I opened up the mortice vertically a bit more to follow Will Myers instructions of ¼" now about 7mm. Made no difference from the 5mm I did yesterday. Whilst doing this I noticed that the front left bottom of the mortice was polished. I hadn't though about this as theft / right gaps when at rest looked parallel. Will said that there should not be much play left to right. The guide should move freely, which it did, but not be sloppy to minimise left to right racking. So whilst I had the back off I took a couple of thin parings with a chisel at the shiny spot probably say ¼mm for about half up the 70mm mortice.

Wait for it.... drum roll... the vice is now working as expected - unbelievable. At full extension 400mm I can feel the weight of the chop but in at 200mm or closer I can spin the T bar as fast as I want going in. Coming out its a bit stiffer so may still be binding on the opposite corner of the mortice. I guess the screw when running pushes the guide off left or right by a fraction and 300mm down the chop this became a wedge in that direction. The wheel and other slide bits under the chop were lifting it just enough to prevent the binding. Here is a pic, that is the total gap now.

IMG_2099.jpg

Doesn't visually look different from the before the parings. The top of the mortice is now messier and chipped (dry tuart chips easily) due to impatience when enlarging it but as I say below this is not fine furniture. I have only made furniture before with no moving parts so I guess my tolerances were too tight. This is work bench not a fine joint. So it turned out is was the guide jamming just left to right not vertically - another learning as always.

Many thanks for your help and as I said above I might include a wheel at the front of the chop just to take some of the weight / wear off the screw at big extensions. Just need to put my tensioner back on and see what effect that has on the slightly changed arrangement.

I agree with Derek,

The bottom line is, the farther out the screw is (the more you open the jaws) and the more weight you have in the chop, the more "camming" and "jamming" and so an increase in friction in the action of the vise which translates to that stiff feeling.

To get around it, you can reduce the amount of weight in the chop, but your chop doesn't look too heavy as it is.

More beneficially as Derek has done, put a couple of wheels in there to help mitigate that friction. Wheel UNDER the guide bar at the front and a wheel OVER the guide bar on the rear, to counter the "racking" of the guide bar.

Take note of Derek's clever slots on the wheel mounts, that allow for him to adjust the preload of the wheels upon the guide bar. As Derek has done, use 2 screws to ensure the wheel mount remains vertical and secure.

With the wheels, you can leave a little space on the upper and lower sides of the mortise, as the wheels are what hold the guidebar in place.

You will notice that your guide bar will expand a little during the humid months of the year and increase the friction in it's action. This is why id suggest a little space on the upper and lower sides of the mortise, that way any expansion in the guide bar only affects the friction had on the sides of the mortise.

The reality is, with any workbench like this especially when timber components are used it is impossible to have a silky smooth vise with zero play.

But that is the nature of it, and the beauty of it.


Cheers,

Siggy

Thanks Siggy and my experience lines up with the comments all have made. I find it interesting that with the exception of Derek's vice and a picture at the English Woodworker site no other leg vice has mentioned or has wheels. Maybe it's because a lot of them have the expensive metal hardware for screws and the traditional ones just get used to the vagaries of this design.

Rex Kruger has a video on YT about an old woodworking firm replacing the leg vice with twin screw vice (moxon like) on their production benches. Until this bench I have been working with two B&D Workmates which I like a) because they fold flat to put against the wall and b) they are a twin screw vice with great holding power for the size. The disadvantage is they are low in height and light so move around a bit when planing anything taking thick shavings. I just need to get used to the leg vice once I finish the details like adding wheels .

Hi Tony

My offer stands - you are welcome to come over (weekends only) and collect the wheel I made. Also to examine my bench and set up. Beer thrown in.

Obviously if convenient. I am in Rossmoyne.

Regards from Perth

Derek

Hi Derek

Sorry for the late reply, was out for a long weekend . Thanks as always for your very kind offer. I think I understand the arrangement you have from a) my visit there when we were shaving the wiggly Tuart and b) the excellent write ups on your web site.

I have done a bit more fettling and used some homemade paste wax (beeswax / mineral oil soft mixture so it dries more slowly). I can turn the screw easily and it doesn't stick. Just a bit stiffer on the way out compared to in.

Will just finish oiling these parts ie the chop, the back and nut and add some chop grip either a bit of cork tile or some thin leather. Will play and see what I like best. Then oil the rest and the bench will be done.

If I am not satisfied I may take you up on your offer with plenty of notice.

TTFN

Tony