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Need help....

R

robo hippy

Joined
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Well, I am inventing again.... Long term goal, from some time ago, is a flex shaft sanding system to go on an articulated arm (did a video about that), and it is run off of a mini lathe, and is capable of running 5 inch discs. I am needing 3 axis rotation for the sanding mandrill, and trying to figure out how to do it. I had thought some of the carving stands might work well, but they seem to be pretty much 2 axis control. I am thinking some sort of ball and socket type fixture and I would be able to tighten up the ball and socket joint. I am sure that there is some thing out there that would work, but I can't find it. I did find a flex shaft system that should work, from King Arthur tools, but their motor system is 3200 rpm, which is way to fast for bowl sanding. Vertical axis will be post/bolt through a loose joint so it pivots, and the ball and socket would control the up/down placement of the sanding mandrill as in sanding at or below center for the outside of a bowl, and being able to be slightly above center for the inside of the bowl. I have found 2 right angle attachments for drills, one from Milwaukee, and the other from Milescraft called Drill 90 +. Seems that no one makes any other than 90 degree attachments. I know there are things out there, but I can't find them.... I will not make this for sale, only for personal use. I know it is possible, just hit a road block....


robo hippy
 
I have used these as way of getting around the issue of locating a small crown wheel and pinion plus the associated machining work . 90' attachments are available but as a small gear box and so they are cumbersome overly large. I have considered as I said machining up a small housing to encase a crown wheel and pinion set up. But again ran into issues of quality parts, fully machined parts are very expensive and the most common are cast like the right drive in your jpeg so longevity is a major concern. So far mine is ok but I have only used it a couple pieces none of which are hardwood
The down side of using the small drill right angle drives is that they are not well made and tend to wear our although Milwaukee make something that looks a quality tool, but again its rather bulky. But then as some folk have suggested to me maybe I should learn how to turn better so as not need to sand so much. :D lol I use mine for the inside work and outside I use the inertia type sanders. In fact I use the inertia sanders both internal and externally and actually market a version of the internal with an extension allow for 400mm penetration in to a hollow vessel, with that a much smaller sanding head 30-50mm I find less than 30 there is a heat build up issue.
 

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robo hippy said:
Well, I am inventing again.... Long term goal, from some time ago, is a flex shaft sanding system to go on an articulated arm (did a video about that), and it is run off of a mini lathe, and is capable of running 5 inch discs. I am needing 3 axis rotation for the sanding mandrill, and trying to figure out how to do it. I had thought some of the carving stands might work well, but they seem to be pretty much 2 axis control. I am thinking some sort of ball and socket type fixture and I would be able to tighten up the ball and socket joint. I am sure that there is some thing out there that would work, but I can't find it. I did find a flex shaft system that should work, from King Arthur tools, but their motor system is 3200 rpm, which is way to fast for bowl sanding. Vertical axis will be post/bolt through a loose joint so it pivots, and the ball and socket would control the up/down placement of the sanding mandrill as in sanding at or below center for the outside of a bowl, and being able to be slightly above center for the inside of the bowl. I have found 2 right angle attachments for drills, one from Milwaukee, and the other from Milescraft called Drill 90 +. Seems that no one makes any other than 90 degree attachments. I know there are things out there, but I can't find them.... I will not make this for sale, only for personal use. I know it is possible, just hit a road block....


robo hippy
Click to expand...
As far as speed goes Harbor Freight makes a speed control for about $20. Use it on my router table for several years.
Pat
 
Well, this is the flex shaft I got from King Arthur tools:

www.woodworkingshop.com

King Arthur's Guinevere Flexible Shaft

Klingspor's Woodworking Shop is full line distributor of woodworking tools and supplies from respected companies like Klingspor Abrasives.
www.woodworkingshop.com www.woodworkingshop.com

I found out you can simply mount it in a jacobs chuck on a mini lathe, no problem, and there is a mandrill on the end for mounting any sanding mandrills and/or carving bits. I needed a lathe with both forward and reverse, because most of the time I will sand with the head going counter clockwise. Building a small rolling stand for a Rikon mini lathe as my old Jet 1224 mini lathe did not have reverse on it. More to come.....

Oh, the inertial sanding things I never considered using. Mostly because they don't work when the bowl is not spinning. I have found it to be really helpful to spin the bowl by hand for the first couple of grits.

robo hippy
 
I haven't seen those scuff balls, but don't think they would be practical for lots of bowl sanding. I did try it out last night, for one bowl. For sure, it works, but lots of 'different' things to experiment with.

One is that the size of the yellow handle/holding part is much smaller than the angle drills, so I have to learn how to hold it all over again. This part might be simplified if I make a mandrill to hold the drill. This might be simplified by making a big sleeve to go over it. Figuring out which angles I am going to need will be helpful. Putting a mandrill on a vertical post, that would rotate rather than be fixed would be simple, but that is about half of the problem. Some times I like sanding above center, some times I like sanding below center.

I did find out that my rpm is about 1000, which surprised me. It could be that I am using a high speed drill rather than my slow speed one. It is convenient to have 'dial a speed'. It is not convenient to have to turn the lathe off and on to change interface pads. I do experience a little bit of 'wobble' when on the inside and using the edge of a 3 inch disc, but that can be controlled by learning how to use it.

I do find the shaft to be a bit short. This is mostly due to getting the mini lathe close enough to where I am working, but not being in the way. May have to drill some holes in my sanding hood and move the lathe to the back side of the lathe.

For sure, if you want to use the carving bits, this shaft system would easily hook up to a mini lathe with a jacob's chuck fitting into a #2 morris taper. Max speed on the mini Rikon, well 12 inch Rikon, is 3200 rpm, which is the speed of the drive motor from King Arthur tools. Not sure if any of the other small lathes go higher than that or not.

A work in progress. Might have to get my video guy over, because, a short video would explain a lot of things better than my typing....

robo hippy
 
Mark Jundanian said:
I think I'm getting a better idea where you're going with this. You could run that flex shaft off of a corded drill, if you find using a lathe to be cumbersome. Also, have you considered using these scuff balls?

Buff & Polish Balls Products - Klingspor's Woodworking Shop

www.woodworkingshop.com www.woodworkingshop.com
Click to expand...
GobletBuffing.jpg
The 2 buffs at about 4" shown are ones I bought from a industrial salvage store about 1998 and I found that they worked on these thin walled goblet forms. The goblet has a wall thickness of between 20 and 30 thou or .7 to 1MM so hand sanding or steel wool are out of the question. I tried Watco danish oil to see if it will block the darkening that eventually happens with cherry but the DO does raise the grain and the buff does work good on that. The buffs I have are too big to reach inside or under the lip on the outside so I Googled Scotchbrite and could not find anything but I now see that Klingspor has 2" and 3" buffs.
 
Tim, thanks for the reference, I bookmarked it. I should have said that Dremel does sell doughnut shaped buffers, which I do use, but these look better.

I wish that I could find a small diameter ball/sphere shape, though.
 
Well, I am running the system off of a mini lathe. While a drill press would work, most are not variable speed, which I consider important for bowl sanding. I did add this to the chuck on the end of the flex shaft.

www.milescraft.com

Drill90PLUS™ - Milescraft

The Milescraft Drill90PLUS™ is a versatile right angle drill attachment and a must-have for your next remodeling or construction project. Get yours today!
www.milescraft.com www.milescraft.com

It is far easier to sand with than the straight shaft that is standard with the flex shaft. For now, I am putting more work with it on hold because I have my only show that I still do coming up and need to sand a bunch, and at present, the angle drill still works more efficiently.

Take aways for now.... I think this flex shaft would have no problem running 3 inch discs over the long run. The drill 90 is pretty good and easier to hold, but there is some loss of efficiency by adding another thing to the set up. I have noticed that if the flex shaft is bent too much I get vibration. When I am able to figure out how to add it to an articulated arm, that would make things far more stable. Perhaps a more stout flex shaft would account for less loss of efficiency. Figuring out how to rout the flex shaft to the sanding head would help too, to avoid any over bending. Finding a little gear box to change the angle of the head would be nice. The drill 90 worked great for that. I may be able to take the chuck off of the flex shaft and direct mount the drill 90 to that. I may want to make my own set up for a motor and variable speed drive for this set up, rather than using a mini lathe, but the mini lathe works great.

There is always some thing to invent....

robo hippy
 
'There is always some thing to invent' ain't that the truth, it seems every time I start a new project there is something that need modifying or inventing, still whats life without a challenge?
 
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