Thread: Powered Feed Drum Sander

The recycling option I have taken is to buy a second hand supermarket check out counter and pull the conveyor out to use as a feed conveyor for my yet to be built drum sander. Counter cost was $50AU with the rest of the counter providing materials I will readily use for other projects. All the electrical equipment had just been recently checked and tagged as requiring next inspection in 2008. Frame encloses everything so easy for me to install into what ever table I set up. Belt width 450mm (18") and speed 0.26m/s (52fpm unless I converted wrongly). I may have to buy a second unit for the future wider sander. I will look at other devices to use as a variable speed drive. Still researching this at this stage.

Nick

NickJ

Good find. I looked for some type of belt like that. The cloest thing I could find was a treadmill belt and rollers. Most of these balt are to long and narrow. How is that belt joined together. Is it laced together to glued? Can it be shortened ?

Well I made a little prograss on the conveyor. To make the rollers I made a Jig to turn them down. This Jig has two side with just a little taper on both ends. Here is a Pic of the Jig




Here are the rollers ready to get turned.




and the finished roller. I attached one end of the roller to the motor I going to power it and them moved the router slowly along the Jig.

Ok and one more. Hopefuly I can get this to work. Here is a Video cap of a video I made of the conveyor running. The plate the sandpaper rides on is not mounted high enough so the belt sags a little. I need to work on that.



and this is a Link to the video ( 2.5m ) on my web page. Sorry about the sound. The motor is a 58 RPM Bodine, and the speed control is running about 90%. Now I need to work on the mounting for the plate, the motor and two braces under the power feed for the car jack.

If the video or Pic will not show, the bandwith was exceeded, tray again next day.

http://members.cox.net/yoterry/sound/mvi_1150.avi

Originally Posted by junkboy999

NickJ

The closest thing I could find was a treadmill belt and rollers. Most of these balt are to long and narrow. How is that belt joined together. Is it laced together to glued? Can it be shortened ?

Treadmill on rollers was exactly what I was looking to use and agree too long , too narrow and I wasn't sure if they would be strong enough long term. Being from the food industry it was spliced using a proper vulcansing system. I have organised and watched enough splices to know I would need the right materials and practice to do it myself. Shortening the frame wouldn't be to hard but I would loop back the belt on another idler rather than cutting it. I am watching your development with envy.

Nick

That powerfeed looks fantastic, you came up with quite an idea. The jig for machining the roller is is almost identical to mine, only I mounted the roller in it's final position and built the jig over it. How did you get that slight taper on the roll?? Is it convex or concave? If I had more ambition I'd try something like that, but guess I'm getting lazy in my old age and leave "well enough" alone.
By the way, that black knob is, as you rightly mentioned, is to tighten the threaded rod to keep it from working it's way down. Probably not necessary, but I'm the type that wears a lifejacket in the bathtub, haha.
I really enjoy being able to exchange ideas with all you nice folks in Australia.
Long may your Big Jib draw

The Jig has a slight convex curve to it. I made this by drawing two lines alnog the side 2 mm apart, clamped a little block to both ends of a side on the lower line and use a long flexable ruler to make a curve up to the other line, then marked it. I cut it out with a band saw and snaded it on my edge snader ( both sides are stuck together with dubble stick tape ) , I routed a rabbit on both out sides of the boards and broke them apart, swaped sides so rabbits are on the inside now. This Jig wokred ok but my snading was a little off. I did notice that one of the ends of the roller was smaller them the other. No big deal , I just floped the roller end for end in the jig and made another pass..


Bad News. I went to take it apart today to work on the a mounting brace, I could not resist puting the motor back on it and giving it anther go a round, just to giggle with amasement that it really worked. But NO ! the belt started to cut back in to the side again. The tracking problem came back. After removing the belt I saw that my idle roller broke in 2 places and the drive roller broke in 5 places. After talking with my dad and aonther woodworker I found that the MDF had a high moister content. I can see this now by sanding an edge of some scrap MDF and some scrap from more another sheat of MDF from another store. One peice of MDF stayed light color form the saw dust and the other peice after 3 hours turned dark on the edge, and the saw dust caked up on it, kinda sticky-like. this can be seen in the Pic's in the fact that the saw-dust caked up in the bottom of my jig and on the roller. So it is off to the lumber yard in the AM to get some play wood. I needed Ply any how to make the main drum. Now instead of 50 circles for just the drum I need to cut 94 to include the 2 new rollers Guess it is good that this whole thing is still in Mock-up stage

Hi Terry, thanks for explaining the setup for milling the convex contour, pretty ingenious.
About tracking problem with the belt. I'm not sure by looking at your drawing whether you have a tracking adjustment on the idler, something like you see on beltsanders. That's just a thought.
Like the video.

Terry,


Sorry to here about having the start again with the rolls but thanks for the information. I'm going to use your system of machiing the roll sarface to check my rolls. What was the reason for abandoning the PVC pipe as a roller? If you felt it was too smooth did you consider sanding the surface? I was thinking maybe it was infact problems with tenstioning equally on each side. How did you cap the end of the PVC? How did you decide on the dia of the rolls for the drum sander itself and the surface speed? Again I am looking to recycle using a 700mm (28") piece of aluminium tube (dia 90mm or 3 3/4 "). I am doing this to hopefully keep the motor power demand to just turn the drum to a minimum (my theory may be wrong and maybe I actually need the inertia stored ion the drum.) While scavenging for materials I came across a desk with electric controlled rack and pinion systems for raising and lowering the desk top - dial up a height between 600 and 730mm (2' and 2' 5") and push the button for it to drive to that position ($20 for this one). For fine adjustments I will have to use a screw system the same as everyone else.

Breslauer
The the idler roller has about 2 1/2 adjustment. This is a alot but allows me to play with different size rollers.



This is the simple adjustment, just a washer and wing nut. The block on top is the wrong one. I made a longer one to give the full adjustment. There will be a small block to the left of this assembly with a nut int it, and a bolt runing out of of it. unscrewing the bolt will push there assembly forward to adjust the belt, them just tighten the nuts.

Nick J
If you turn your rollers like I did just flip them from end to end on the last pass with routher set at same depth, to make sure thay have the same taper. ( only for rollers for a power feed. if you turn your sanding drum this way, make sure your jig is FLAT, no convex).

PVC- I made a plug out of MDF to fit inside of the end. I and used 4 screws to hold it in place. Problems- if the plug was to loose, when the screws where tigthened it pulled the PVC out of shape. if the Plug was to tight it flanged the end of the PVC outward. Then there is the problem of getting the hole in the middle too, so the whole thing is not off centered. As for it being to slick I was going to roll the whole roller in a rubber sitck on weather seal.

Dia for rollers - I desided to make the rollers 4" round. this was to alow the motor to be placed inbetween the feeder belt and hide it the middle on the feeder. This would of worked out well but I forgut about the table that the sand paper has to slide across, and to support the wood DUH!! ( I still might try this and just route out the space in the plate for the motor. the plate is 3/4 MDF with formica glued to the top. )

Making a bigger roller also makes the feeded shorter. I'll probly rebuild the feeder one day after I break down and get a job so I can buy that welder I want.

Dia for sanding drum - I just took a S.W.A.G at the size of the sanding drum. I looked at .pdf files from Jet tools and grizly and other drum sander makers just to get an ideal of what thay where using. most 1700 rpm motors and drum spinning about same speed and a little slower. A heaver and bigger drum can spin slower, lighter and smallers drums should spin faster. I have a 4" and a 3.5" aluminium tube 1/4" thick wall and both about 36'" long from my local scrapyard.

hope this helps..

Ps. post a pic of that desk thingy . I would like to see that.

Pss SWAG = scientific wild ass guess

Well is has been a week and I allmost finished with the power feeder.


I spent 2 night reading Tec pages for companies that sell and maintain conveyors to see if I could get any ideal about my tracking problem. After reading and reading I found a page with some very good info. It looks like small wide belts need to have flat rollers with no taper at the ends. To track these typs of belts the idler roller rock left and right, this in done but touch sensors, optic sensors or small rollers on the underside of the belt. Touch sensors and optic sensors all control a drive device to rock the idler as required. These are uasly for faster belts. The slower belts have rollers or fingers under the belt touching it on both side at a 45 deg angle, casuing the belt to cup. Humm

I took the feeder apart and returned the rollers. I only took off enough to make the roller flat and still try to keep close to 4" dia. I needed the 4" dis to still keep the motor hiden in side the unit.

When I put it back together it still track badly. . But with the flat roller I was able to see that the right side of the unit was out of aligement with the left side about 2 mm forward I took the screw from the right side and slid it back and just clamped the two sides to the table top. It works. It still wanted to track the the right, but it takes about 80 turns now, instead of 10 for the belt untill it hits the right side. After I get it all together I'll see if I can fine tune it better.

First Pic - is jut a view of the feeder.

Secound Pic - is of the motor and chain. The sprocket needs a set ( grub ) screw hole drilled in to it, so for now it is just temp attacked. Once it is
attached right I brake the chain and make it shorter.

Third Pic - This is the tension take up. realy hige tech here. I have to make a better ones. there will be a block to the left of the tension TU with a bots screwed in to it, as you unscrew the bolt it will push the unit to the right applying tension to the belt.


A got a new AVI up for all to see ( 3 meg )
http://members.cox.net/yoterry/sound/mvi_1241.avi the AVI in post above has been removed