Drum sander project started.

[xy mosian]

Great, I like home built machines, using basically whatever is to hand. Normally good fun, in the end, too.
On the lift mechanism. Your tubular nut is going to be some diameter. How about a rod welded to opposing sides of a nut?
As you are planning a clamping arrangement of the adjusted feed table there should not be a great deal of force on the adjustment mechanism.
xy

 

[sploo]

Yep my intention is to slot the sides and make up 6mm threaded rod with turned knobs to lock the table. What I was going to do was tape a pencil to the feed table and raise it to mark a piece of thin card, transfer that to mdf, cut out on scrollsaw to make template for router guide and cut the slots. Bet there's an easier way I don't know about. #-o

Sounds pretty good to me. You could calculate the arc, drill a hole at either end and hack out with a jigsaw; but your template and router method will give a much nicer looking result.

 

[Lons]

Had an hour spare this morning to cut the mdf disks ready to be glued up, also a couple of 25mm ply ends but not happy with those so will revert back to hardwood. What I have done though is take comments about the drum to heart and I think might just drop the idea of the pipe and stay with mdf / hardwood ends. Might change my mind again of course which has been known. The mdf if I give it a couple of coats of varnish or sanding sealer will be hard enough after all.

I can't heat my workshop, too high and too many draughts and it was just below freezing this morning so it will have to wait.

 

[Lons]

Ok decided definitey to accept advice and ditch the pipe idea so glued up the drum this afternoon, used 30mm ash for each end and epoxied a key on to flat on shaft but forgot to cut the section to hold abrasive #-o so that will be a multitool job later.

Drilled and tapped a bit of alloy rod to make the barrel nut for 12mm threaded bar so that's the lift mechanism started. Onwards and upwards.

 

[Lons]

Great, I like home built machines, using basically whatever is to hand. Normally good fun, in the end, too.
On the lift mechanism. Your tubular nut is going to be some diameter. How about a rod welded to opposing sides of a nut?
As you are planning a clamping arrangement of the adjusted feed table there should not be a great deal of force on the adjustment mechanism.
xy

Using some 12mm threaded rod I unearthed and a bit of 20mm alloy rod which will comfortably sit withing the table thickness.
Hopefully that's ok with a metal plate under the base and a plate recessed into the base top surface. I've found a decent length of alloy angle for the underside of the feed table so will be well supported.

I know what you mean about home builds, I find them fascinating as well even when no intention of having a go.

cheers
Bob

 

[xy mosian]

Sorry Lons, I'd missed the diameter of the adjustment bar being 12mm. I brought to mind the larger diameter threaded bar.
Everyrhing is looking good so far
xy

 

[Lons]

Sorry Lons, I'd missed the diameter of the adjustment bar being 12mm. I brought to mind the larger diameter threaded bar.
Everyrhing is looking good so far
xy

If I'd seen Cols' router lathe build earlier I might have splashed out on some ACME bar. I did look at 16 and 20 threaded bar but the 12mm seems pretty strong and if not I can always change.

Gives a real buzz and so far not a penny spent on materials so can't lose as if it's cr*p I cal reclaim the important bits anyway.

 

[sploo]

Gives a real buzz and so far not a penny spent on materials so can't lose as if it's cr*p I cal reclaim the important bits anyway.

That is a good feeling

I have a 3hp induction motor I've been keeping for years; intended for a bandsaw build, but I suspect I may build a drum sander first. I'm sure 3hp wouldn't be overkill... would it :mrgreen:

 

[AES]

Also watching with interest - book marked, thanks for posting.

Somewhere up above (sorry, only just seen this thread) somewhere asked about bearings and housings. One good source I found (I'm sure there are others) is Arc Eurotrade in UK. The have a wide range of "Plumber Blocks" and "Bearing Blocks" in different sizes and geometries. Many feature self-aligning bearings (i.e. the ball race is housed in a spherical housing, so that within quite broad limits, you don't have to worry too much about alignment of the shaft at each end). Good on line and paper Catalogue (lots of "general engineering" small tools and machines too). Prices seem reasonable to me and I found their service excellent.

Usual disclaimers. There's a link to them (and others) in the sticky at the top of the separate Metalworking section here.

HTH

AES

 

[Lons]

A bit more progress this afternoon:

Drum is solid and ready for the abrasive slots to be cut, (wish I'd remembered before gluing!) so got to work on the lift mechanism. Was a little unsure 12mm would be strong enough but seems fine. There is a small amount of movement due to slip at the base end / barrel nut but it isn't much and as I'll be fitting clamps to the side of the table, I'm sure it will work. Certainly the operation is smooth enough though I got tired of winding by hand without a handwheel and resorted to a drill. :lol:

Pics are self explanatory, threaded rod is held captive through the alloy angle which fits to the underside of the feed table, by a nut, drilled through, pinned and ground roughly round, I stuck it with epoxy for good measure. Angle is sanwiched between washers and another nut under drilled and held with cotter pin. This is as tight as I could while still allowing the rod to turn.

Main base was slotted and alloy angle rebated and fixed from underneath to form durable sides, I then fitted a sub base of melamine covered ply, (offcut of bathroom wall board) and extended the front of the baseboard around it (had made it too short, dozy git ).

Cut a slider plate out of 3mm polypropylene which brought the top of the barrel nut level with base surface for a good fit once the top alloy retaining plate was fitted.

Not the prettiest job but hopefully functional.

Won't get anything done tomorrow, babysitting a lively 3 year old granddaughter sees to that. :lol:

 

[xy mosian]

That's coming along well. I like the 'using stored treasure' approach as well.
Am I right assuming that the slot around the lower mount of the adjustment bar is to avoid a flexible joint at the other end? Clever!
You have fired up my 'can I ?' brain bits now. I find myself wondering if I can mount my 4" belt sander as a thicknesser. Not very wide but useful for some jobs in the near future. Unless I change my mind of course.
Have fun, ain't that what it's all about if we are lucky.
xy

 

[Lons]

Quite a bit of progress today so not too far off now. Waiting for pulleys, belt and abrasive roll to be delivered then I can get it running and the drum trued, sort out dust extraction and electrics plus cut some slots in the drum to hold the abrasive and I'm there. \/

* I modified the sides so removal of 8 bolts allows me to take out the drum complete with bearings.
* Cut slots for the side clamps, rebated alloy angle to the feed table drilled and tapped to take 6mm rod (epoxied a nut behind for good measur, turned knobs for handles.
* Made a handle for the lift rod
* Mounted some abrasive on a sub table ready to true up the drum.
* Cut a couple of 10mm thick spacers for the drum shaft out of srbp sheet.
* Made a hood, just locates into holes via 4 plastic dowels. Still have the hole and connector for dust extraction to sort.

A lot of cleaning up to do especially around the slots for side clamps which are rough despite using a router but all seems to work well so far.

 

[Lons]

More photos

 

[Lons]

I find myself wondering if I can mount my 4" belt sander as a thicknesser. Not very wide but useful for some jobs in the near future. Unless I change my mind of course.xy

I'm sure I've seen a youtube video doing exactly that.

 

[murphy]

Lons, when you are trueing up the drum take VERY light cuts to start with, otherwise you will get vibration and it will make the drum go off round and will be hard to get it round again, I had this problem years ago when I used MDF discs, mine was 22" wide and had 1" steel rod through the middle, (as your's is not as wide it might be okay) and found the only way was light cuts, once the drum was trued I covered it with self adhesive velcro and velcro sandpaper which worked great and I still us velcro now on the metal drum I got on ebay, this is the sandpaper I use and find it lasts a long time http://www.ebay.co.uk/itm/SAIT-5mX115mm ... Swa~BYPZDI

 

[AES]

Lons, I haven't yet even started to build a drum sander, but just yesterday I was watching a Youtube by an English lady, Susan Gardener, who seems pretty good, and about truing up the drum, she said exactly the same as murphy has above (very light cuts to start with).

HTH

AES

 

[Lons]

Thanks for the links and advice guys, I'll take that advice. I'm hoping the solid ash ends will help keep the soft mdf in check.
Bob

 

[Lons]

Got a bit more done yesterday afternoon so very close to the finishing line now. Should be operational bey the end of the week. \/

* Sorted electrics though probably swap for a NVR switch at some stage. * Dust ext. port cut * Motor mounted * Drum trued up * whole thing screwed together and put on a mobile base 'cos it's bl**dy heavy.

It runs very well with hardly any vibration so the drum seems well balanced and I'm pretty happy with it so all that's left to do is cut slots in the drum, fit abrasive and make a cover for the pulleys / belt and see how it works.

 

[AES]

Great, well done. Still following with great interest.

I don't have a planer/thicknesser but as I don't usually use girt big lumps of rough sawn timer I'm thinking a drum sander (to go with my drill press sanding drums) would be a big help for the smaller stuff such as toys which is my usual fare.

Will you be fitting self adhesive Velcro or perhaps thin rubber/plastic sheet to the drum as an "underlay" to the sanding sheet?

I read somewhere that provided the "underlay" is not too soft, this helps with the overall finish of the sanded job off the machine. Any comments?

AES

 

[sploo]

Very nice - looking really good now.

On the subject of "underlay" - pretty much any commercial machine I've seen uses a metal drum, with paper wrapped directly around it and held with clips.

I guess there are cost factors that drive the design of commercial machines, but if underlay or velcro backing was a good idea I assume you'd see it in at least the more expensive machines (which I haven't) - so personally I'd just go for the raw drum and clip decent sandpaper to it.