my new lam grinder jig

Pennsyltuckey pete · January 09, 2010, 06:54:00 PM

I had built a lam grinder that was supplying decent laminations until I tried to do some really thin ones. I was having problems with the slight inconsistencies in the sanding drum. Not too long ago I bought a new Rigid bench top oscillating sander. As I was using it I started eyeballing it as a potential lam grinder. I thought about it for a while and this is what I have come up with.

This first photo shows the lam sled guide set as far away from the sanding belt as possible. it also shows the feather board set where it gives a nice pressure to keep the lamination against the sled guide. Note that the lam sled guide is resting directly on the bench grinder table which is square to the sanding belt.

This second picture shows how the lam grinder attachment is attached to the bench grinder. Three C clamps. It is simple and secure. The thickness adjuster is a 1/4 20 screw that is threaded through a piece of oak that was glued and screwed to the base. I did tap the oak and then smother the threads with cyanoacrylate (CYA) and then tap them again. on the right side of the photo you can see the 1/2 inch dowel that I used as the lam sled pivot.

This last photo shows the lam sled adjusted very closely to the sanding belt. I still have to make my lam sled but using the grinder as it is is very simple. As always the key is to push the laminations at a smooth and steady pace.

pete

AALLFAB · January 09, 2010, 07:05:00 PM

Nice creative solution. Did you see something like this or just totally make it up. Jim

bjansen · January 09, 2010, 08:28:00 PM

Ingenious solution Pete. I am impressed.

Pennsyltuckey pete · January 09, 2010, 10:20:00 PM

Jim,

I made this one up all by my lonesome. Took what I liked about my other one and got rid of what I didn't like.

I have finished my sled and will get the pics posted tomorrow.

pete

Dmaxshawn · January 09, 2010, 10:48:00 PM

That's pretty slick. I have the same sander. Hum that definately gets the wheels turning.

Shawn

Steve Kendrot · January 10, 2010, 11:13:00 AM

Can you show it in use? Having never seen such an operation, I'm not sure how you feed the lam through. Is this just for parallel lams or will it do tapers as well?

Looks pretty cleaver. I have one of these sanders too. Wish my shop was heated so I could work through the winter!

Pennsyltuckey pete · January 10, 2010, 11:07:00 PM

Steve,

Here are a few shots that should help you understand why/how this thing works. First one thing missing in the previous shots is the sled. It is a key piece. The sled is the piece with the dowels sticking up from the top. The dowels are to give you a good grip to control the feed speed. The sled is run through the grinder to make the face of the sled perfectly parallel to the grinding belt. In this picture you can see the sled and a lamination positioned for grinding. This setup will give you a parallel lamination.

In this next picture my finger is touching a tapered lamination that is placed directly against the sled. This is a lamination that I bought from a supplier that was already ground with a .002 inch per taper. (one hint, You can see the writing on this lamination. I write all over them so I don't accidentally grind one or use it in a bow.) By placing a parallel on top of it and then running it through the grinder you will duplicate the taper. Note the stop that is glued to the end of the sled to stop the laminations from kicking back.

In this next photo I am pointing to the lamination that will become a tapered lamination when it is run through the grinder because of the taper that is positioned against the sled. Note that the stop is thick enough to catch this lamination also.

One last thing I would like to point out is that I have made a new feather board that is the full height of the laminations. This should work better than the 3/4 inch piece that I had built originally. I will try and get some video posted tomorrow while I am actually grinding laminations.

pete

4est trekker · January 10, 2010, 11:28:00 PM

Very clever! I love a good jig, and this one might just be my next project. Thanks for sharing!

Dmaxshawn · January 11, 2010, 08:30:00 AM

Thanks for the pics Pete.

Shawn

cobbow · January 11, 2010, 09:55:00 AM

I have the same sander and was thinking about doing something like that. The only concern is the up stroke of the sander. Dose it cause the lam to rise up?

Cant wait for the video.
Cobbow

ChristopherO · January 11, 2010, 03:01:00 PM

cobbow,
It looks like he is using the belt sander, not the spindle sander. I don't have the Rigid, yet, but my guess would be that the belt sander doesn't move up and down as it spins, as the spindle sander attachement does.

BTW, great idea and ingenuity!

metsastaja · January 11, 2010, 03:18:00 PM

The belt does go up and down

AkDan · January 11, 2010, 05:10:00 PM

you could always add a featherboard to the top of the lams to keep them from shifting up and down as the belt is moving up and down. You're template lams will have to be made the same width as the lams you're grinding, or you'll want to make the lams your grinding wider then the template lam so the featherboard rests on it.

I have the same machine pretty sweet rig. I definatly wished the belt didnt occilate to the point I'd give up the occilation on the spindle also!

Pennsyltuckey pete · January 11, 2010, 06:05:00 PM

First, Thanks for the interest and the compliments.

As far as what I am using,it is the belt sander. Yes it does oscillate up and down. The oscillation is no problem at all. IT is actually a benefit. The fact that the belt oscillates evens out the slight imperfections of the belt that would be ground in to the lamination. I do not set the grinder up super aggressive. I use many passes to remove wood. This practice of using "Light pressure" eliminates the issue of the lamination trying to shift up or down.

Another reason I am using the belt sander is because the roller on this end is hard plastic and has a truer surface than the rubber rollers. I have actually had the rubber rollers give me a slightly concave surface on my previous grinder. I will try them and check which gives me a better lamination.

dinner then video session. I hope to post later tonight.

AkDan · January 11, 2010, 08:19:00 PM

lookn forward to it Pete!

Pennsyltuckey pete · January 11, 2010, 09:18:00 PM

AUGHHH

I can't get photobucket to load the video!

I am going to keep trying. It may have been too long. I will do some single shots. I have since learned that the spindle gives a nicer finish than the belt. SURPRISE< SURPRISE!

Pennsyltuckey pete · January 11, 2010, 10:20:00 PM

here is a little clip of the thing in action. I am still in the learning curve with this toy so I will leave you with this and pick up again tomorrow.

with what I have done so far I am happy with the results.

pete

AkDan · January 11, 2010, 10:44:00 PM

looks good Pete, I may have to try that one, already have some lams from omc as templates for tapers.

I was wondering why there isnt a feather board on the outfeed side holding the sled to the fence face like on the infeed side? Do you think I'd need one? are you running acrossed just the wheel end or the hole belt?

tommy6 · January 12, 2010, 04:02:00 PM

that looks great! I have the same sander and Ive been trying to figure a way of doing the same thing. I have had some problem with a little play in the belt sander when I push wood up against it. It usually results in the bottem part of the wood being sanded a little less than the top, resulting in an uneven thickness. Have you run into this problem with your Rigid? Oh and I have checked the table and it is perpendicular to the belt.

Steve Kendrot · January 12, 2010, 08:46:00 PM

Pete. Thanks for entertaining all our questions. Especially my dumb ones!! What exactly does the feather board do? It seems like it would just get ground off. How did you make it?