Official Luthiers Forum!

Solely owned and operated by Lance Kragenbrink
It is currently Tue Jul 17, 2018 11:42 pm


All times are UTC - 5 hours


Forum rules


Be nice, no cussin and enjoy!




Post new topic Reply to topic  [ 142 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Author Message
PostPosted: Thu Jan 11, 2018 8:31 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Sun Mar 30, 2008 8:20 am
Posts: 2587
" But I’m 100% convinced any thickness could be used"

I know 6 inch will work - You just rip it to 3" and it works every time. bliss


Top
 Profile  
 
PostPosted: Thu Jan 11, 2018 8:38 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
So, clay, what ur saying is only one thickness can ever possibly wrap a particular drum?


Top
 Profile  
 
PostPosted: Thu Jan 11, 2018 11:51 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Mike OMelia wrote:
So, clay, what ur saying is only one thickness can ever possibly wrap a particular drum?


Mike, in the ultimate showing of Brad has too much free time...

Here are a couple videos where I do the patented roll paper test with both 2 1/2" and 2 3/4" paper. Hopefully this shows what I mean and if you can come up with some way to not have to cut the paper that is great. Or better yet, if you come up with a way where it will work for all drum widths, even better! :)

Plus it was fun to learn how to use my son's GoPro.

http://www.youtube.com/watch?v=_DPCIHDj ... e=youtu.be

http://www.youtube.com/watch?v=Sx9gO8sT ... e=youtu.be

Sorry about the dust collection hose getting in the way. Also, I could have done better with angling the camera. Maybe next time! [:Y:]

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob



These users thanked the author bcombs510 for the post: Mike OMelia (Sat Jan 13, 2018 12:02 pm)
Top
 Profile  
 
PostPosted: Fri Jan 12, 2018 10:17 pm 
Offline
Contributing Member
Contributing Member

Joined: Fri May 09, 2008 2:25 pm
Posts: 1739
First name: George
City: Seattle
State: WA
Country: USA
Focus: Build
Status: Amateur
Clay S. wrote:
Tape is your friend ... My old fingers can't work those stupid clips that don't really hold the strip in place at the far end of the drum. I usually just run a piece of strapping tape around the last inch or so of the sanding strip and drum. You don't have to worry about where the strip ends. Unless you really need that last bit of width it could be a non-mathematical solution.


I'd like to hear more about this idea. You just tape the final edge of the roll to the drum, instead of fighting to insert it into the clip? Brilliant! Fiddling with those stupid clips has taken the fun out of my workshop time on more than one occasion.

_________________
George :-)


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 9:27 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Sun Mar 30, 2008 8:20 am
Posts: 2587
"I'd like to hear more about this idea. You just tape the final edge of the roll to the drum, instead of fighting to insert it into the clip"

It does work, but you lose an inch or two of sanding width. I use strapping tape or cellophane tape and wrap it completely around the drum and edge of the sandpaper (sometimes more than once). You have to stick the ends down good so it doesn't peel off when the drum is spinning. It is a little easier on the fingers, and when the end that goes into the clip tears off and leaves the strip an inch too short it allows you to continue using it.


"So, clay, what ur saying is only one thickness can ever possibly wrap a particular drum?"

No, actually if you don't mind a small portion of the end of the drum not being covered by sandpaper, you can cut an angle on the opposite (inner) side of the strip so it can slip into the clip.



These users thanked the author Clay S. for the post: George L (Sat Jan 13, 2018 12:37 pm)
Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 12:06 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
bcombs510 wrote:
Mike OMelia wrote:
So, clay, what ur saying is only one thickness can ever possibly wrap a particular drum?


Mike, in the ultimate showing of Brad has too much free time...

Here are a couple videos where I do the patented roll paper test with both 2 1/2" and 2 3/4" paper. Hopefully this shows what I mean and if you can come up with some way to not have to cut the paper that is great. Or better yet, if you come up with a way where it will work for all drum widths, even better! :)

Plus it was fun to learn how to use my son's GoPro.

http://www.youtube.com/watch?v=_DPCIHDj ... e=youtu.be

http://www.youtube.com/watch?v=Sx9gO8sT ... e=youtu.be

Sorry about the dust collection hose getting in the way. Also, I could have done better with angling the camera. Maybe next time! [:Y:]


Very interesting. Nothing like a video example to illustrate the problem. I looked at the manuals for the 16 and 22 inch drums. They provide the same info. The paper diagram shows a 15 3/4" taper, and is based on a 3" width of paper. Let me get my pencil and calculator out. Thanks Brad. Excellent work.


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 2:26 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
I have a formula to test. Maybe, Brad, you can try? It defines the straight length along the edge to determine the taper. Use it to mark the paper, draw a straight line across the paper, and then use a straight edge to mark the taper from there to the corner. The rest is as you did it before. If it works, I will explain more:

This assumes a drum sander with a 5" diameter. The Jet 16" is 5". L is straight edge length of taper (not the angled length)

L = sqrt(w^3/(DL/nwraps - w))

w is paper width, nwraps is what you see on drum with 3" paper, counted from taper cut point to taper cut point. I see 7 on my 22" drum. DL is drum length. Everything is in inches. For my sander, I get around 15.5" for 3" and 7.5" for 2.75". 5" for 2.5". You will need to do your own calculations for 16" drum. The square root and possibility of a negative number limits things. This means for wider paper, number of wraps is reduced. Kind of makes sense.

My length of 15.5 is precisely correct based on manual. sqrt(3^2 + 15.5^2)=15.78 (close enough to 15.75)


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 2:35 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
I just noticed something in the equation. Drum diameter not there. So it will work for any diameter as long as you know the number of wraps for the paper it was designed for. (3")


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 2:37 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
I will give it a try later tonight. I’ve got half a dozen things going on in the shop today. :D


Sent from my iPhone using Tapatalk

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 3:02 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
Me too. You got me stuck on this. Dang it. U might ask why 15 3/4 works for 10-20, 16-32, 22-44. Good question. I think 3" paper width drove design lengths. There appear to be other tapers that work. Also turns out that the numbers I calculated above for 2.75" (7.5) will work on your drum. For 2.5", same thing.

Maybe. There will probably be a downside to this in that some of the end of the drum will be unusable.


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 3:18 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Mike OMelia wrote:
Me too. You got me stuck on this. Dang it. U might ask why 15 3/4 works for 10-20, 16-32, 22-44. Good question. I think 3" paper width drove design lengths. There appear to be other tapers that work. Also turns out that the numbers I calculated above for 2.75" (7.5) will work on your drum. For 2.5", same thing.

Maybe. There will probably be a downside to this in that some of the end of the drum will be unusable.


What I noticed was that the number of wraps with 3” paper was always drum length - 1 / 3. So for my 16” it was 15 / 3 so 5 wraps.

Same for 22” drum - 21 / 3 = 7 wraps.

Any idea where that 1” consistently gets lost? The paper goes edge to edge so why is it consistently drum width - 1?


Sent from my iPhone using Tapatalk

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 3:35 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
I don't know. What I do know is this is based on "wrapping efficiency". The ratio of the drum area to the paper area. For the 2.75 and 3 paper, there is only 5 and 7 wraps possible (on 16 and 22)

For the 2.5" paper, on your drum. there is 5 and 6 wraps possible. 5" edge, 11" edge.



These users thanked the author Mike OMelia for the post: bcombs510 (Sat Jan 13, 2018 6:51 pm)
Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 5:28 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
I take it all back. This problem does not appear to have a (good) solution. Other than Abranet making proper widths. There appears to be one where you make a longer (MUCH longer) taper, but who wants to do that?



These users thanked the author Mike OMelia for the post: bcombs510 (Sat Jan 13, 2018 6:51 pm)
Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 7:04 pm 
Offline
Cocobolo
Cocobolo
User avatar

Joined: Mon Jan 14, 2013 3:25 pm
Posts: 113
First name: Tony
Last Name: Thatcher
City: Bozeman
State: MT
How many luthiers does it take to wrap a sanding drum.......

_________________
Tony Thatcher
Montana


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 7:47 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
It is a surprisingly difficult problem. One that does not appear to have a simple solution without leaving gaps. What makes it really hard is ending up at the right location where the clips are. Jet sanders are ubiquitous. Why would Mirka make a width jet sanders cannot use?


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:32 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
I think I’ve figured it out. 2 3/4”. What u think?


You do not have the required permissions to view the files attached to this post.



These users thanked the author Mike OMelia for the post: bcombs510 (Sat Jan 13, 2018 8:36 pm)
Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:37 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Looks good. What’s the formula?


Sent from my iPhone using Tapatalk

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:48 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
No formula Brad. 15 3/4” taper as per manual. But, ignore the 3” clip off end. Use only half or so of the clip width. Apparently that’s the key. Have no idea if this would work for 2.5”. Maybe you could verify?


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:51 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Wow, that is really surprising! I will give it a try.


Sent from my iPhone using Tapatalk

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:51 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
The clip channel is 1.25” wide. I noticed on all my current rolls I was only using 0.8”. Got me thinking. Maybe the idea of that width is for some flexibility on width.


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:52 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Mike OMelia wrote:
Jet sanders are ubiquitous. Why would Mirka make a width jet sanders cannot use?


The Abranet is not marketed for drum sanders. It’s for Mirka’s palm vac sander.


Sent from my iPhone using Tapatalk

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:53 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
Please do Brad. I feel awful for spending my whole day on this. Lol!!


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 8:59 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
bcombs510 wrote:
Mike OMelia wrote:
Jet sanders are ubiquitous. Why would Mirka make a width jet sanders cannot use?


The Abranet is not marketed for drum sanders. It’s for Mirka’s palm vac sander.


Sent from my iPhone using Tapatalk


Not true. That was the whole point of this thread. Abranet makes drum rolls. Or at least, it was one of the points.


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 9:18 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6192
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
Brad, how did u figure out 2 1/2 would work?


Top
 Profile  
 
PostPosted: Sat Jan 13, 2018 9:46 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 1163
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Mike OMelia wrote:
Brad, how did u figure out 2 1/2 would work?


Because I was focused on the number of wraps. At 2 1/2” each wrap was 1/2” short of where 3” paper landed. Since the 16” drum took 5 wraps and each wrap was 1/2” short it left me with 2 1/2” or one more full wrap.

I know what you mean about Mirka selling Abranet on a roll, but I don’t think they are targeting that for drum sanders. Their palm vac is 2 3/4” wide and it’s pictured on the wrapping for the roll.


Sent from my iPhone using Tapatalk

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 142 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next

All times are UTC - 5 hours


Who is online

Users browsing this forum: powdrell and 14 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com