slipjoint ?: liners pushing together at top

[ashwinearl]

this project is getting comical. If there is a mistake to be made, I've been making them all.

So now I've got my bolsters JB welded to the liners, and my scales super glued (gel) to the liners.

Holes are drilled, and I was fitting it together, and now the liners are squeezing together at the top. So instead of the opening between the liners being the same thickness as the spring, it is smaller. And hence the blade tang scrapes on the liners and won't open or close smoothly.

If I put the bottom of the assembly in a vice and squeeze the liners together between the spring, it tends to open up the space some more.

Will the peening accomplish the same thing

Any ideas for why they are squeezing together at the opening like that?

[Ray Rogers]

It would be difficult to say with certainty why that problem exist but I have some ideas about things you could check.

First, are the liners flat and true? I'm guessing they are.

Second, if the liners are flat then check to see that the holes you drilled for the blade pivot and the spring pivot are perpendicular to the liners. I'm guessing the are not.

If they are not perpendicular, did you drill them before you mounted the bolsters and scales or after? In this case, I would guess you drilled before you mounted the bolsters and scales and the presence of the JB Weld and gel under them has allowed the to set at an angle to the liner.

If they are perpendicular, then check your pins. If the pins you are using are currently set in some kind of assembly jig then the pins may be bent or they are not perpendicular to the face of the jig.

Lots of guessing going on here..........

[ashwinearl]

I JB welded the bolster to the liner, then drilled the pivot hole through the hole already in the liner

I super glued the scales to the liner and with the scale on the table, drilled through the existing hole in the liner.

I also tried flipping the scale/liner over and drilling. So with the liner flat on the table drilling through the scale and into the liner. Hoping that that would straighten out the hole if it got skewed when drilling it the first time, with the scale on the table and drilling through the liner.

The sides of my spring arent totally flat and uniform either. And I am thinking I ought to do a new spring anyway for some other reasons. Let me try that and post the result.

[george tichbour]

Just a shot in the dark but did you deburr the holes after drilling?

A slight raised burr can keep things from seating properly even though you glued everything up before drilling.

[michael vagnino]

Ash, don't know if there is a maker close to you that makes slip joints. But if there is I would contact him and ask if and how much he would charge for a day or two of class time. If he would and the price is in your budget then do it. It will save you more time and a lot less frustration in the long run. Making a slip joint that works well is not a easy as you might expect.

Michael

[ashwinearl]

I've actually decided to cut my losses and give up.

It has become this vicious circle, where one piece gets messed up, and after fixing it, the result becomes that the other pieces need to be modified because of the first piece.

For now that is. going to make a table or something. At least that way I can start and complete a project and get that good feeling inside.

If I can't find a maker nearby for some lessons, at least I am going to get a slipjoint kit and use that as my template.

I will make one piece at a time, and fit it into the kit to ensure that it works, before putting the complete knife together.

[michael vagnino]

Ash, why don't you check out the tutorial section on the forum. I believe there is one on slip joints.

Michael

[ashwinearl]

The tutorial is wonderful. And I've been following it as close as I can.

However Chris is so good that he makes it look easy. There are so many things that can go wrong,as I've found out.

I also made the mistake of doing my own design from scratch as opposed to using the template he provided. I should have done that to start off with.


AA

[Saint Mark]

Just a couple of thoughts.

1) Take a break and when you come back use the templete from Chris's tutorial. It is basic and makes a great knife. When the slip joints get to me I work on a fixed blade for a while and then come back.

2) Holes are very important. One thing that I did not know when I first started was to take a level and make sure the my drill press plate was level. If this is off it can mess you up. You may have to place some shims underneath it. I then take a st. edge and make sure the drill bit is in streight. Small things - but they can add up.

3) You can make a slip joint without one, but a st. remmer gives you a perfectly round hole.

4) Do not use expoxy on your handle materials as it usually dries and tends to bend the liners

Hope this helps.

[ashwinearl]

Thanks for the tips.

I put a small engineering square on the drill press table and sighted it on the drill bit. It looked square.

One problem I think in drilling the holes for the scales, was that I assumed that the scales were flat. I think I need to drill the holes for the scales, with the bolster indexed onto the top of a drill press vice or something like that. That way all the holes will be referenced from the same piece(the bolster) flat on the drill press table (or drill press vice)

When you say st. remmer do you mean a Reamer?

What size reamer do you use for each pin size. I've tried to figure out what hole to drill for what pin size. I have all the numbered drills and used a bit that was just slightly oversize of the pin stock.


Thanks again.

[Saint Mark]

Go ahead and check the level of the plate - you would be surprized how often they are not level. I am not a precision person by nature - but you have to learn to be for slipjoints - precision is EVERYTHING.

Yes I did mean Reamer - I just can't spell :-) I got mine from one of the knife supply places and they come in the standard pin sizes. I usually drill using the drill bit that matches the pin and then use the reamer to get a rounded hole - drill bits do not make a true round hole.

Chris Crawford and I were talking about the handle material and liner thing the other night and he suggested takeing a piece of metal and putting wax paper on it and then glueing the handle material to the liner with the liner on the wax paper - clamped to the metal. I hope that made sense. This way the liner stays flat while the glue is drying. Since you have already drilled holes in the liner - when all is dry you only have to drill thru the handle material using the holes in the liners as a guide.

Others may chime in here with better suggestions.