Drum sander sled for trueing parallel edges on one piece DR longbow

[dbeaver]

Hey all, first post here. I have to set aside another post sometime to really thank all that contribute I can't say how thankful I am for the free knowledge and multiple viewpoints.  I am building my fifth bow, from kennym's modified DR and I want my process to start getting a little smoother and reliable

Let's get to the real inquiry, I clean up the boogers from squeeze out on my 6x80 grizzly at 36 grit(I've had this machine for the last bow and the one I'm currently on).  I have an older model jet 10-20 drum sander I have used to taper my own lams for the past two setups. 

I know myself to be an overthinker so I am asking if melamine alone would suffice as a flat sled for the drum sander? Something in my head wants to put a few aluminum u channels screwed underneath for a bit of long term stability.   With such length I don't want the melamine bending out from the bow on the extremes of infeed and outfeed.

My idea is to clean up boogers with the belt sander, lay a pretty flat bow on the aluminum based melamine sled, and run a few lines of hot glue down the limb lengths, or some permanent blocking that fits the bows, get a flat side then flip and true it up.

Let's hear it fellas, it's appreciated

[Mad Max]

I used chip board/plywood because I had it.
I have a Baby Drum sander Grizzly 12" (with the hook and loop removed many years ago) so my chip board was 11" wide and longer than the bow 8" or so both ends.
I ran the chip board threw many time flipping it over and over, and then laid my bow on it and ran it threw keeping my hand on the bow at all times. The snipe on the ends doesn't help you find center at the tips so I don't do that anymore.
I like the edge sander 6" x 80" and stop as soon as the epoxy is gone off the sides, slowly sand and look, sand and look over and over.
Also I make sure my glueup form is straight end to end.
I think the form is the most important part of the process .
This is a 1/8" x 1" strap I bolt threw the form on both ends and the push it back in the center and I have a 6 foot straight edge to check it. I also use angle iron on some of them.

[dbeaver]

Okay so a no frills sled worked 'okay'. The aluminum wouldnt help with snipe anyway. And I am left with having to align tips to true center with a string because of the snipe you mentioned? 

So if i can get to relatively squared up trying not to go through the epoxy squeeze out but right up to where the wood begins, and the riser and pretty close to parallel, mark my centers and move on. 

I am open to hear about various sled experiences

[Mad Max]

Yes the plywood being wide put more of a even pressure on the belt unlike a narrow one.

Just using the edge sander only---I get most of the glue off the riser first then sand from fades to tips. I'm not worried about the riser that much.

[dbeaver]

Nice touch on the form, didnt catch that.  That dimension of my form is dead on. I believe im going to re route the top face.  My initial setup for routing has improved and i believe the surface could be a little better. Time to pop off the formica and get a truer surface before the next glue up.

[Mad Max]

Nice touch on the form, didnt catch that.  That dimension of my form is dead on. I believe im going to re route the top face.  My initial setup for routing has improved and i believe the surface could be a little better. Time to pop off the formica and get a truer surface before the next glue up.

I've when back resurfaced it too.

[Kirkll]

I’ve been using the same melamine sled for over 10 years with no problem.

Look at these photos and note that after knocking the boogers of the edge coming out of the form both sides pick one side on each limb and check them closely for 90 degrees from butt to tip befor running them through the drum sander… this is critical so you are not building a twist into the limbs.  Of course you riser needs to be perfectly square on the limb pad section for this to work.

https://photos.app.goo.gl/naVE25uNZ5pJZ8yL6

For a one piece bow it’s very important to check the limbs for 90 degrees too, and the limb profile always goes from center line.  Use a string or a straight edge to measure to center. I use a 6’ door level myself. Even just a string works well too.

[dbeaver]

Good notes Kirk, I can see how the riser being off would translate to both limbs being wonky on the z axis if you will. Those pics are super helpful and I understood immediately. Big box store has a 11"×72" melamine closet rack if checked for flatness should be good? Or is it recommended to pickup from a sheet supplier for ensured flatness

[Kirkll]

Quite honestly…. I wouldn’t mess with a 6’ sled for a one piece bow. Just knock the boogers off and get one side straight,   and check for square then run the bow through the drum sander for parallel… then get a center line on it, and go from there. I don’t own a long sled. No reason for it.

With that being said… I don’t build a large volume of one piece bows any more. Just my Flatliner long bow, and I trust my form on that one for twist and straightness. I build my forms from 1.75” LVL material now, and slowly replaced my old plywood forms that constantly needed adjustment. But  I really liked that 1/8 strap steel adjustment with the bolt in the center showed above. That would work nicely.

Having a 6-7’ work bench that has a very flat surface with no twist is very helpful with one piece bows. I have a granite countertop I used to use for one piece recurves years ago, but I gave up building them. I stick to TD bows pretty much these days. Ya miss draw weight, ya build more limbs.