As I anxiously await my shipment from Binghams - I've been scouring the various build alongs that you fine fellers have contributed to the bench. I feel very confident in the process, my design and layout at this point. Yet one recurring theme that many "greenhorns" such as my self seem to battle is sliding lams or risers during glue up / baking.
I'm just curious to hear your favorite way of preventing this. Any input is greatly appreciated!
I saw a video from Kirk Lavendar where he drilled holes in the lower form and threaded zip ties in there. The zip ties when over the pressure strip. I have done that on the last few bows with success.
-Chris
I just hold them in place and wrap packing tape around from the bottom of the form and go over the top all the way down the length of the form and have never had any problem with em sliding. Kennym drills a shallow hole at the corner where the lams and riser come together and uses a piece of toothpick to hold them in place. This method is very helpful if you are using a powerlam...
Here is Kirks youtube video
http://youtu.be/uAMsgze0u7Y
To keep the lams from sliding side to side- I use washers (drilled offset) that I roll up to prevent slippage. I also use strapping tape and on recurves zip ties to get everything onto the the form.
(http://i290.photobucket.com/albums/ll259/truxturning/Short%20Bow/ShortBow012.jpg)
I saw a video from Kirk Lavendar where he drilled holes in the lower form and threaded zip ties in there. The zip ties when over the pressure strip. I have done that on the last few bows with success.
-Chris
If you do the above , as I do its important, IMO to remove the zip ties after about 15 - 20lb goes in hose . I have seen the ties leave a bump in the limb when left on and 65PSI is used.
I made plates from 1/8" thick metal. They are 3x3" with a notch cut out halfway up the center. This notch fits over 3/8" lag bolts that are screwed into the press in positions like Trux's washers above. The plates' heights are adjustable due to the notch. I lay up the stack, put plastic over everything, then put the plates on and raise them until they are flush wih the top of the lams. Impossible for them to move out of position.
I might add I use side plates as well. I've had one move in the form and it was a hard lesson.
I have forms with slideplates and others with washers. I like the plates best. If you do use washers use thick ones. Those wimpy fender washes can flex when tightened.
True on the fender washers, but I loosen whatever I put on after full inflation and a few minutes pass. If too tight, you can pinch the glass against the washer or whatever and it won't lay down, making a bump in your limb. Not good!!
I've used plywood pcs, metal pcs ,and washers, they all work, just take your time and if you use a power screwdriver, don't forget to loosen a bit and retighten by hand!
One other one that works is having an extra pair of hands like a son or son in law or a buddy, to hold em while you tape em, thats been the best for me
Wow ~ some great ideas. Seems that plates or washers are a popular choice. This obviously prevents latitudinal movement (side to side), does any ever have problems with longitudinal movements? (tip to tip)I can picture this being a problem with risers and aggressive r/d forms.
QuoteOriginally posted by NYArrow:
Wow ~ some great ideas. Seems that plates or washers are a popular choice. This obviously prevents latitudinal movement (side to side), does any ever have problems with longitudinal movements? (tip to tip)I can picture this being a problem with risers and aggressive r/d forms.
Refer to my post from earlier. I misread what you were asking the first time and answered for what I do for longitudinal sliding :)
I do the same with riser as limbs, that is use a tie to hold it to form. This tie can stay there when hose is inflated as it will not indent the riser and that part is removed during shaping anyway. I use tape where the lams run up the fades so then it is all held together longitudinally.
Here is my best friend during glue up. A clamp I made from 1" steel straps and long bolts. After all the back lams are glued up and the riser is in place, clamp all the pieces together. This really helps hold those slick pieces in place while you finish up the belly glass. Get the bolt holes just far enough apart that they don't interfere with the hose or top form.
(http://img.photobucket.com/albums/v78/mikebaker/000_0173.jpg) (http://smg.photobucket.com/user/mikebaker/media/000_0173.jpg.html)
My shipment finally arrived! Time to start a build.
Hey Mike, I know the bow in that form!!!! My favorite "cross" bow!!!!! She's a dandy!
For those that use washers or wood or side plates of some kind, how do you keep the lams from sticking to them? Since they would be right up against the lams it would seem to me that would be hard place to get plastic to cover and as epoxy squeezed out it would get all over the washers/plates.
I just lay plastic wrap over the form before glue up. Some wax the form, I never get anywhere near my lams or form with wax, I am certain I would get it somewhere I shouldn't.
Plastic over the form... then build the bow up... then plastic over the bow... then pressure strips... then side plates.... then hose... then top of press.
I saved this thread, just incase I ever want to make a glass bow:)
:biglaugh: :biglaugh: :deadhorse: :deadhorse: