Lam Grinder

[Tommy D]

I have been using a modified sander to grind my lams. The curved piece of plywood added to the side is to stiffen up that roller section and keep it parallel at all times.

I had tried using a bolt at one end of the piece of plywood attached to a hinge to raise and lower the thickness, but the plywood isn’t stiff enough, so it creates a bow and this was leading to poor lams.

I now simply add spacers under the lam I am grinding to adjust the thickness. I do tapers by supergluing the lam to a tapered lam and running it through the machine and then separating the glue. It works ok ... but sometimes you get a few waves/ dips/ half rounds...

I am now wondering if there would be any down side to adding a fitting to allow one to pass the lams over the top/ flat part of the sander.

I was thinking if one bolted a roller where I am holding the ruler, I might not get the divits that I sometimes get now because you are grinding the lams on a larger flatter surface?

[willie]

seems like if the lam were to be ground all along the length of the platen, it might be harder to control the finish of the cut. 

With your existing set up, have you checked to see if there is any runout in the drive roller (out of round) or any play in the hinge?
The spacers under the lams, might they be what some would call a sled? How thick are they?

[Tommy D]

seems like if the lam were to be ground all along the length of the platen, it might be harder to control the finish of the cut. 

With your existing set up, have you checked to see if there is any runout in the drive roller (out of round) or any play in the hinge?
The spacers under the lams, might they be what some would call a sled? How thick are they?

I’ve never measured if it is out of round, but it doesn’t wobble - it’s just the whole thing is a bit unsatisfactory- firstly the fact that it is only attached on one side (so you can remove the belt) and secondly that it is quite a small diameter drum makes me think it’s not a prefect solution in any case.

But the flat part grinds things much nicer and smoother, so I don’t see why putting a “bridge” (for want of a better word) over it to feed lams through and thickness them would it work. But maybe others have tried it and know enough to tell me not to bother.

The “sleds” I use are simply bits of plywood of various increasing thickness that I stack to get a lam of the thickness I am after.

Again ... not perfect ... but still easier than a hand plane!!

[willie]

But the flat part grinds things much nicer and smoother, so I don’t see why putting a “bridge” (for want of a better word) over it to feed lams through and thickness them would it work. But maybe others have tried it and know enough to tell me not to bother.

seems like a plan



Over on the glass bow site, guys have posted quite a few different setups that seem to get the job done,  google

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lam grinder site:https://www.tradgang.com/tgsmf/index.php?board=68.0
If your bows are all wood and going to be tillered some after glue up, then you can get away with less thickness precision than the guys who are glueing up between two pieces of glass.

[Tommy D]

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lam grinder site:https://www.tradgang.com/tgsmf/index.php?board=68.0
If your bows are all wood and going to be tillered some after glue up, then you can get away with less thickness precision than the guys who are glueing up between two pieces of glass.

I thought mentioning glass bows on Primitive Archer was sacrilege Willie - you might get my thread banned    - but I sure do appreciate the link!

[bownarra]

I just remembered I said I'd grind you a set of lams and it completely slipped my mind.....If you still want some help just give me a shout!

[BowEd]

Have you ever checked into these hand power planers?Reasonably priced and a lot cheaper than a drum sander.Tapering is easily done with these power planers.

[Tommy D]

I just remembered I said I'd grind you a set of lams and it completely slipped my mind.....If you still want some help just give me a shout!

I would never turn down such a kind offer. Thank you