Drum/ Thickness Sander

[vtsteam]

Take as long as it needs, Simon. 

[RobWilson]

I have an Oldham coupling  going spare if you need it Simon .


Rob

[S. Heslop]

I have an Oldham coupling  going spare if you need it Simon .


Rob

I think I'll be fine, but thanks for the offer. I want to try build this thing with as many easily available things as possible.

[S. Heslop]

It's finally done. Well maybe not finally but it's done enough to make a video.

I had an interesting problem where the off switch stopped working for the speed controller, and on investigation it turned out the little heat sink got so spicey that it melted the insulation on the two switch wires, which were touching it, and they shorted out. I guess the little box will need better cooling but i'll sort that out some other day.

Also the epoxy on the hose didn't hold up so I went with the double jubilee clips. In fact there were a whole bunch of problems, like the sandpaper not lining up when wrapping it on (which was simple to fix but required taking the drum off), and I managed to wire it up wrong the first time, so it's been a busy day.



I also had a kickback and was glad I'd decided to stand to the side of the thing because the block of wood really shot out. I guess the moral of that story is that if i'm going to sand small parts, I should secure them to a larger board first. I'm also kind of glad I caught this on camera though, even if it highlights my stupidity. Kickback is so mythical it's like getting a photo of bigfoot.


It's left a fairly rough finish, which could be due to the 80 grit sandpaper, but i've seen on other people's sanders they like to use the velcro sandpaper. I imagine the soft cushion from that probably leads to a smoother finish. But the price of that sandpaper is insane.

[vtsteam]

Congratulations Simon!
Looks like the video isn't quite up yet.

The sanding marks probably were from the coarse grit, though they aren't evenly distributed. Maybe there are ridges under or the paper isn't even?

Sanding semi cross grain as it looks like you did will definitely raise the grain much more than wth the grain.

I'm sure you'll work things out! 

[micktoon]

Hi Simon , looks like you are making good progress in the right direction, just a case of ironing out the problem areas now hopefully. I bet you were glad that kick back did not hit you in the nuts mind 

  Cheers Mick.

[vtsteam]

I had a wooden boat shop back in the 70's in a former mill with a bunch of other craftspeople. In a neigboring woodshop one of the employees, a woman, was ripping a board and holding with her hands while pushing it with her belly. A one inch by 6 foot strip of the rip waste broke off at a knot and the blade sent the piece right through her. They got her to the hospital in time and she survived,.

Kickback is real, and body position is extremely important to consider with woodworking machines.

[greenie]

Good to see that you will be posting that piece of film showing the timber being kicked back out of the sander and sanding both sides of that bit of timber.

Apologies from those that said it wont happen, might be excepted.

80 grit is very severe on any surface finish, 120 grit will give it a far better finish, or if your after a good smooth finish, then 180 will be the grit you need.

So, are you going to fit any more rollers to the machine to add downward pressure to the timber on the movable belt to stop the kickback happening ?

[S. Heslop]

Good to see that you will be posting that piece of film showing the timber being kicked back out of the sander and sanding both sides of that bit of timber.

Apologies from those that said it wont happen, might be excepted.

80 grit is very severe on any surface finish, 120 grit will give it a far better finish, or if your after a good smooth finish, then 180 will be the grit you need.

So, are you going to fit any more rollers to the machine to add downward pressure to the timber on the movable belt to stop the kickback happening ?

That isn't what happened. The piece was just able to tip over, raising the back end into the drum, encouraging it to tip over further until the whole thing escaped with alot of momentum. At the time of it jamming the feed belt momentarily stopped moving, because there was alot of downwards force with the piece. I'm lucky it didn't tear the feed belt when it shot out. I'm also not sure if you're aware but the feed belt moves very slowly.

Anyways that small part would've probably done that feed belt or not. If i was standing behind the machine pushing it through like you suggested with some sticks then I would've been right in line to lose a few teeth.

As for the grit, yeah it's a given that a lighter grit would leave a smoother finish, but I went with the 80 since I want this machine to level wood fairly quickly more than produce a good surface. A regular bit of hand sanding and scraping would smooth out the surface quite easily.

And for the rollers, I did draw up a quick system for attaching some if necessary when thicknessing veneers (which may warp a fair bit after cutting), but for most stuff it's probably preferable if it isn't trying to be forced flat to the table.

[S. Heslop]

I hate editing audio. Had just under an hour of raw commentary to cut into clips. It's bad enough talking for an hour, but having to then listen to it all in detail is beyond tedious.

The funny thing is that despite all the effort, I still get alot of comments on my videos of people saying they can't understand me. Since I'm mostly reading from a script it wouldn't be too hard to add subtitles to the video, i'm just reluctant to do it since something doesn't feel right about subtitling yourself.

At least people assume i've got a Thick Accent, and don't realise that I really just talk like an idiot.

In other news, I had a go at sanding those hexagons I made a good few months ago. I'm going to pretend I left them that long to let the wood stabilize.


They came out nice and flat, which was good to see. Hopefully I won't get sidetracked again and manage to make a banjo after about 2 years since I started the project.

[vtsteam]

I can understand you fine. Others need to learn. Don't make incapability easy for them, Simon.

[RobWilson]

Good to see you have the sander up and running Simon 


Rob

[Meldonmech]

 
   Hi Simon, were the problems on the speed controller, associated with the feed motor?

                                                                               Cheers David

[S. Heslop]

About damn time.

I gotta be honest I didn't have alot of fun editing this one. Two months worth of big long boring video clips of me sawing stuff to sift through. It took me quite literally all day from 9 till now. I'm not a big fan of multi-part videos but if I ever end up doing a big project like this again, i'll probably go back to that format just to keep it manageable.

[vtsteam]

That was definitely worth the wait Simon! 

[dsquire]

Simon

Like Steve said, "definitely worth the wait Simon! "

If there were a video of the month selection you would be my first choice. You probably spend as much time or more taking photos and editing them as you do making the drum sander.

Thanks so much for taking the time too do this and share this with the members.

Cheers 

Don

[RussellT]

I liked the video, and the machine.

Well done.

Russell

[S. Heslop]

Thanks for the comments!

I forgot to add a thanks to Bluechip/ Dave in the video for helping out with the electronics. I added one to the video description.

There's probably some other people I aught to have thanked too but this project took so long my memory has gotten hazy.

[RobWilson]

  Well done Simon , 


Looks like it works a charm 


Rob

[NormanV]

Excellent! Well done, and I could understand you.

[micktoon]

Hi Simon, top marks for the sander and the video too, good editing and film work.Thanks for taking the time to record it all, it was a ig enough project to do without having to film it all too.

 Cheers Mick

[Bluechip]

Thanks for the comments!

I forgot to add a thanks to Bluechip/ Dave in the video for helping out with the electronics. I added one to the video description.

There's probably some other people I aught to have thanked too but this project took so long my memory has gotten hazy.

All very nice to be publicly acknowledged, but where do I send the invoice ...     

Now, about your sizzling MOSFET. What is driving it ?? ie Where does the 12V come from?

If it is not too well regulated, the voltage may well be dropping when the motor is driven on under load. If this happens the drive to the MOSFET could be insufficient to switch it in a sharp fashion and it will run warmer than necessary.

Scope the supply and see. 

If it is, the quick and dirty way is to shove a diode in the supply to the '555 circuit ....

See attached:

If you do this the drive to the MOSFET gate should always be close to the full 12V and it will be driven on pretty damn quick, as the motor cannot drag the 12V to the '555 circuit down. C1 can only charge from the supply, it cannot discharge into the load, D1 prevents this.

This does assume that is the cause ... what MOSFET are you using anyway ??

Dave

PS C1 should be 220uF ... 

[Will_D]

Many thanks for an excellent thread and brill. video.

[millwright]

well done Simon,

  I have followed and enjoyed the thread from the start. The icing on the cake must be the video and seeing it all come together. a great job.

                                                           

John

[S. Heslop]

Thanks for the comments!

I forgot to add a thanks to Bluechip/ Dave in the video for helping out with the electronics. I added one to the video description.

There's probably some other people I aught to have thanked too but this project took so long my memory has gotten hazy.

All very nice to be publicly acknowledged, but where do I send the invoice ...     

Now, about your sizzling MOSFET. What is driving it ?? ie Where does the 12V come from?

If it is not too well regulated, the voltage may well be dropping when the motor is driven on under load. If this happens the drive to the MOSFET could be insufficient to switch it in a sharp fashion and it will run warmer than necessary.

Scope the supply and see. 

If it is, the quick and dirty way is to shove a diode in the supply to the '555 circuit ....

See attached:

If you do this the drive to the MOSFET gate should always be close to the full 12V and it will be driven on pretty damn quick, as the motor cannot drag the 12V to the '555 circuit down. C1 can only charge from the supply, it cannot discharge into the load, D1 prevents this.

This does assume that is the cause ... what MOSFET are you using anyway ??

Dave

PS C1 should be 220uF ... 

That's a clever solution. Although to be honest i'm really sick of this project at this point. I'll save all this for when the thing fails. Thanks for it though.