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Main Boards => The Bowyer's Bench => Topic started by: Bighornangler on April 21, 2013, 12:18:00 PM

Title: Lam grinding jig
Post by: Bighornangler on April 21, 2013, 12:18:00 PM
In Feb. of 2010 there was a post about a lam grinding jig using a Ridgid bench top oscillating sander. I just recently discovered this post and tried to contact the originator, but was unsuccessful. Does anyone out there have a similar jig setup using a Ridgid oscillating sander? If so, how is it working for you?
Title: Re: Lam grinding jig
Post by: Walt Francis on April 21, 2013, 02:01:00 PM
I built one for my Rigid and it worked, but when it was all said and done I disassembled the parts and materials and used them for other projects.  The biggest issue was consistency, without a reliable and consistent feed system the quality of the lams were not comparable to those you can get from Kenny or Troy.  Around 25% of the lambs were serviceable and I used them in bows with good results, but I wasted a lot of time and materials to make them and definitely didn't save any money.  The quality and consistency of anybody's bows will not overcome the use of sub-par materials. I finally found a used Delta thickness sander on Craigslist and have had excellent results making lam's with it.

My experience is, unless you have a lot of spare time and quality material laying around, you are better off to buy quality lam's from one of the sponsors.  If you are a novice with glass bows don't attempt it, you are adding a extra variable into the design matrix that will cost you a lot more than you save.
Title: Re: Lam grinding jig
Post by: Bighornangler on April 21, 2013, 04:39:00 PM
Walt. Thanks for your thoughts. I was just about to go purchase the materials for the jig, but you have made up my mind for me. I will take your advise which makes a lot of sense.
Title: Re: Lam grinding jig
Post by: jsweka on April 21, 2013, 06:34:00 PM
Yes sir, Walt makes some excellent points and that has been my experience as well.  My father has a Jet drum sander and I've made laminations for three bows on it.  They all resulted in shootable bows, but I still wasted a lot of wood.  I'm not mass producing bows, and I've come to the realization that it well worth it just to order from Kenny.
Title: Re: Lam grinding jig
Post by: LC on April 21, 2013, 09:26:00 PM
X what ever it is. I totally agreed with Walt. Been there done that. I presently have a Delta drum sander. I can't add anything that Walt hasn't already put in words.

I also agree with jsweka your way ahead to just buy lams for Kenny! The only reason I grind my own is I have this stupid idea of only making bows with wood from my local area only. Gheez after reading that it sounds pretty stupid of me spending hundreds of dollars just for that reason. If however you have this desire to buy exotic wood and grind your own lams cheaper than you can buy you should maybe rethink it. JMHO
Title: Re: Lam grinding jig
Post by: LittleBen on April 22, 2013, 08:15:00 AM
I recently made a lamination grinder from a 1/4hp motor, a 3x3 drum and a  bunch of 3/4" ply. It works reasonably well, but that's after hours and hours of screwing around with it, truing everything up 25 times ... and going really slow. Just getting the the point my sleds are working properly, and I can do acceptable tapers.

It cost me maybe $100 ... probably should have bought and converted a rigid edge sander ... at least then I'd have a spindle/edge sander too.


It seems to be so dependent on feed rate ... my next one will be a delta as stated here.
Title: Re: Lam grinding jig
Post by: Docdevin on April 22, 2013, 10:25:00 AM
My cousin and I were about to make a short trip to go get some mesquite to start drying for laminate material. Are there spsonsors on here that already have mesquite laminates produced?  The reason I am asking is he and I can build about anything and we usually do if we have time and can build jigs but that doesn't mean it is the best way to spend our time, like you all already pointed out.  But we are each wanting to make a laminated recurve using local wood.  When I say make a trip to get mesquite we only need to drive an hour or so to get some really nice pieces.  We have plenty of Osage Orange and walnut here handy and want to make these from our own areas materials.  But like I said if there are guys that already have material ready to go we can go for a drive and say see that is what our bows are made out of, LOL and have saved a lot of time.  Who has mesquite?
Title: Re: Lam grinding jig
Post by: Troy D. Breeding on April 22, 2013, 07:49:00 PM
You can bet if I could find it I'd have it in stock. I've used it in the past and really like it.

Troy
Title: Re: Lam grinding jig
Post by: kennym on April 22, 2013, 08:01:00 PM
I don't have a supplier for mesquite either!  :(


"It seems to be so dependent on feed rate ... my next one will be a delta as stated here."

Feed rate is key, it is super nice to have a conveyor system.   :thumbsup:
Title: Re: Lam grinding jig
Post by: heartlandbowyer on April 22, 2013, 08:28:00 PM
Bighorn I posted my rigid sander lam grinder set up  a couple months ago. I've had decent luck grinding lams with my setup. I think the thread was "redneck lam grinder". I have found that I need to grind one side then flip the lam end for end and grind on the same side just in case the table is not perfectly 90 deg to the sanding edge. I seem to get pretty good results that way and usually have less than .001 difference from edge to edge measuring with my reloading calipers. I've ground lams down to .035 without having a backer board behind the lam. Consistent feed rate is important but its a bit of a challenge by hand.

I do know when I can justify a thickness drum sander with belt feed I will be investing in one. Until then I will grind what I can and have Kenny grind the rest.

Cory
Title: Re: Lam grinding jig
Post by: heartlandbowyer on April 22, 2013, 08:52:00 PM
http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=009460
Title: Re: Lam grinding jig
Post by: Buemaker on April 23, 2013, 06:46:00 AM
I beleive this to be a good machine, they have more expensive ones also. Too bad  The USA and Europe have different voltage.
http://youtu.be/CP_65VCjuTg
Title: Re: Lam grinding jig
Post by: Roy from Pa on April 23, 2013, 07:22:00 AM
Ifin you boys made real bows, yunzs wouldn't need all that high tech electricial equipment:)  :laughing:
Title: Re: Lam grinding jig
Post by: LittleBen on April 23, 2013, 08:19:00 AM
I'm using mine for laminated wood bows roy ... just like your beloved tri-lams. I mainly use it to taper the core and sometimes the other lams before glue-up. I could probably do it close enough for wood bows with a table saw or band saw but it's alot more practical to keep a small lam grinder in my apartment than a big saw.
Title: Re: Lam grinding jig
Post by: Roy from Pa on April 23, 2013, 08:24:00 AM
Well that's cheaten then:) LOL
And don't tell no one that I just bought an edge belt sander either:)
Title: Re: Lam grinding jig
Post by: BenBow on April 23, 2013, 09:34:00 AM
Roy ifin I didn't drink sooo much coffee I'd  try making one of them thar real bows    :knothead:
Title: Re: Lam grinding jig
Post by: Docdevin on April 23, 2013, 02:11:00 PM
Troy, if you are talking about the mesquite, I have only heard that once you try it, it will be your favorite.  We have multiple grinders and sanders and access to planers and jointers so I guess we need to go get the wood and start drying.  If anyone does hear of anyone having any ready to go please let me know and if there would be an interest as long as we are gathering we could try to gather more for others.  You all from other parts of the country realize with mesquite the answer to the question of can we cut some mesquite off of you property is usually...if you take it all.  My wife grew up surrounded by it and it is nasty stuff on just about everything but bar b q and bows and if you are brave enough gun stocks.
Title: Re: Lam grinding jig
Post by: LittleBen on April 23, 2013, 03:53:00 PM
Man I was just looking at some mesquite rifle stocks and that looks killer! That could make some awesome veneers.

Roy, yes it is definately cheating ... no doubt about that one bit. Once I can shake off this city life and get back to the country and get my own place (hopefully 16-18months) I'm gettin me one of those 35hp edge sanders too ..... and a 35hp vacuum to go with it.
Title: Re: Lam grinding jig
Post by: Roy from Pa on April 23, 2013, 06:42:00 PM
Ya you need ah high octane shop vac when running them edge sanders..
Title: Re: Lam grinding jig
Post by: Bighornangler on April 23, 2013, 07:26:00 PM
Cory. Checked out your post of a few months ago. I really like your idea. I am only building wood bows not glass bows and I don't build more than one or two a year. I recently made a lam bow with a piece of IPE I had on hand. This bow also had some tapered pieces of osage which I ordered from Kenny. The IPE I had to taper myself using a band saw and belt sander. If I had a jig such as yours I could have done a much better job on the piece of IPE. Not only did I have the IPE on hand, but I couldn't find any sources for tapered IPE. Not only is the cost of materials to make the jig miniml, but I already have the Ridid sander so I will be giving it a second thought.
Title: Re: Lam grinding jig
Post by: heartlandbowyer on April 23, 2013, 09:19:00 PM
http://www.mesquitevalleywoodcrafts.com/lumber.html

Troy, Devin,
Looks like this place sell Mesquite detention lumber via phone or email guys. It's located in Waco TX.

Gerald, sounds like the jig I built would work for you, you would just have to build a taper board with the taper you need.

Good luck,
Cory
Title: Re: Lam grinding jig
Post by: Bighornangler on April 23, 2013, 09:52:00 PM
Cory. In order to build a taper board with the taper you want, I would assume you would first buy a tapered lam and then glue it to a flat board of the same length or just press the tapered lam against the board and bush it thru the jig with the lam you want to taper. How do you do it? When you bush the lam thru do you just grab it with the other hand on the far side and pull it the rest of the way?
Title: Re: Lam grinding jig
Post by: heartlandbowyer on April 23, 2013, 10:35:00 PM
I bought my taper board from Kenny, it starts out about 3/8 and tapers .002 per inch, Kenny will custom grind one for ya if ya wish. I just lay may lam against the taper board and push them through, then flip both and run em through again to make sure of square. I just work one side of the lam until I have a good grind and all of the saw marks off, then I grind the opposite side down to my desired thickness.

I do push on the one side until the lam is through far enough to pull the rest of the way.
Title: Re: Lam grinding jig
Post by: MoeM on April 24, 2013, 03:14:00 AM
Another way to get your first tapersled is use the leafes/sheets(?) of a feeler gauge and doubele sided tape.
Take two straigt boards and fix the feelers(?) with same spaces along the board to the desired taperrate. Then put the other board on it and run it throug the sander.
(hope this is understandable...)
Title: Re: Lam grinding jig
Post by: Bighornangler on April 24, 2013, 07:42:00 AM
Cory. I got it. Ordering a taper board from Kenny sounds like the way to go.

Moe. I get the idea.
Thanks guys I appreciate your input.