Home made thicknessing sander if

[Cabbie]

Home made thicknessing sander if you have a lathe.

I wanted to cut some new deck planks for my Mermaid which i can do well enough,

but they would have a sawn face. So I started thinking about making a thickness sander, what did I have that spins horizontally?

The little Proxxon lathe, a little bit of thinking and came up with this item.

Its is a bit crude, just made up with bits in the shed.

The height adjustment is probably lacking in enough horizontal stability

The butt hinge is a bit loose in the pin.

And the cloth backed sandpaper is just hanging on to the velcro.

But that said, it did a pretty good job for a first up, bang it together fitting.

The lathe handled the load fine, the planks were put through against the spin.

I was only sanding a small amount each pass so holding the wood was no problem.

Certainly need refining, a dust extractor hood.

I trued up the dowel by running a file under it sitting flat on the bed.

Cheers Chris

[bruce d]

Looks good to me. I'll be interested to hear how you get on with Velcro. It might actually be a good thing to have a bit of 'squish' in the process provided it squishes consistently across the width.

 

Bruce

[Cabbie]

33 minutes ago, bruce d said:

Looks good to me. I'll be interested to hear how you get on with Velcro. It might actually be a good thing to have a bit of 'squish' in the process provided it squishes consistently across the width.

 

Bruce

That's about it in a nutshell Bruce, I don't know if hard roller would work. A bit of squish is good to have.

The problem with the velcro is that it only just hangs on to the paper. I think a spray glue is available to hold the paper directly on

to the wood that would let go when you wanted to change the paper, but that means a hard roller.

Will fiddle with it, I am good at that.

Hooroo Chris

Edited June 30, 2019 by Cabbie

[Griphos]

Might try a spindle sander shaft arrangement, perhaps with a threaded rod. You can still support the free end, but a nut and washer between the support and the rubber sleeve would tighten a spindle sander tube onto the rubber. You’d need to buy a few spindle sander tubes and a rubber sleeve of an appropriate size and a threaded rod of the same diameter as the spindle shaft. You could set up the free end support similar to the bed adjustment to true the sleeve to the bed. 

[Jaager]

I made a machine using NRG plans - in the '70's  ?  

The platten was Hard Maple -  The square stock was glued to a 1/2 cold rolled steel rod and the turned by a professional woodworker.  I did not and do not have a full size lathe.   At the time, the only media that I knew of was the 11x9 hardware store sheets, so I had the platten sized to take that = 11 inches long and 9 inches circumference.  I used Weldwood contact cement.  It was/ still is a bear to change.  Mineral spirits and naptha denature it,  but the paper backed media -- awful to remove.

 

I have since discovered cloth backed sanding media - it is much better.

Do over =  I would keep the diameter the same -  I would make the platten 12"   I would allow for 2 inch thick stock.

My  imagination sees a thick platten as producing a better surface.

 

Why 12" ?

Klingspor makes long rolls of open coat Al oxide in 3" and 4" widths.

With 12 inches, I could have 4 inches of 80 grit,  4 inches of 120 grit, and 4 inches of 220 grit.

A rubber platten is almost certain to be out of round.  Commercial sleeves - vampires on your wallet.

A soft platten  - Velcro = heartache.

I am pretty sure that if you use cloth backed and coat both the media and the platten with rubber cement  - it should hold.  It has a thinner/solvent and it is a magnitude easier than contact cement to use -  easier application -  a no contest for removal..

You will need to buy it in quarts.

 

A dust hood is vital.

I made one.    It is an open box with a 2.5"  shop vac connection on the top.

I made it by Titebond III  gluing 3 layers of Amazon box cardboard together and using that for the 4 sides and top.

It is good quality cardboard and with two layers of PVC - it is strong and light weight.

The inside corners have 1/4" x 1/4" Pine sticks  and also at the top to take the screws for the shop vac hose socket.

Covered the outside with duct tape.

Keeping it in place and having no weight/ force from the vac hose is the most difficult chore. 

 

Jim Byrnes unit is 6"  - friction clamp - easy to change --  Klingspor 3"  two pieces

 

 

 

Edited June 30, 2019 by Jaager

[TBlack]

Chris, not a bad idea. I might copy. It's not patented is it? Sawdust must be a problem.

Tom

[druxey]

Please consider dust collection and control. Fine dust in the air is injurious to your health. Also, under certain conditions, a flash fire or explosion may occur. Sawmills have been destroyed and folk killed this way.

[Cabbie]

Morning to all and thanks for replying

Griphos, yes certainly has possibilities.  Will the rubber tube stay flat when tightened or squeeze out of shape a bit?

Might be a bit too much to set up in my little proxxon lathe

 

Jaeger Some good ideas there thank you, but 2" stock is way overdoing unless you are talking about scaled sizes😀

the max thickness i will be putting through is about 2mm. Yes the platten and paper fixing is an open question.

I might not have very good velcro hooks. I did think of a longer one, but that means a bigger hood. In its current

configuration it takes very little effort to change to a different grit.

 

Tom, no patent, go for it.  And Druxey, YES  the dust will be a problem I wore a mask testing yesterday.

It will need to have a hood made for it, even just positioning an extractor hose in the right

spot would make a big difference.

 

This little unit is not going to do a lot of work, just meant to be there for the occasional small use.

When I start scratch building and machining a lot of wood sometime in the distant future I will buy a Byrnes type machine.

 Thanks to all Chris

 

[Griphos]

The rubber sleeves on my spindle sander are quite dense, and are certainly true enough for this sort of operation, and the sanding tubes are themselves fairly thick. You don’t need to crank down on them. Just a slight tightening holds the tube in place, and the tubes are quite stiff and do not deform. The may be expensive. I don’t know.  I’ve yet to have to buy replacements. A rubber sanding stick has cleaned them well and they still serve. A light touch sanding and the oscillation keep them from wearing much. Without the oscillation, they might wear more quickly. 

 

Here's something like what I had in mind. Not cheap, as it turns out. 

 

https://www.mscdirect.com/browse/tnpla/81251803?cid=ppc-google-New+-+Machinery+-+PLA_sTtF8HGSz___291757062200_t_S&mkwid=sTtF8HGSz|dt&pcrid=291757062200&rd=k&product_id=81251803&gclid=EAIaIQobChMIy_-fh-yT4wIVTb7ACh3-RAv5EAQYECABEgK62PD_BwE

[bruce d]

Chris, did you see this earlier thread?

 

[TBlack]

On 6/30/2019 at 5:32 PM, Cabbie said:

 

Tom, no patent, go for it. 

 

Great! Thanks Chris; got my patent this morning. You're in violation. As royalty. I'll take all the 1/32" pear you can crank out!

Hugs, TB

[Cabbie]

No worries Tom, but don't hold your breath on the pear. I don't have any and not likely to.

I did see somewhere else a suggestion for using double sided carpet tape to hold the sandpaper.

Maybe other tapes would work, but I didn't want to make it hard to change the paper.

Which could be ok it would still have a little bit of the squish that Bruce likes.

Probably got too much squish at the moment.

I have been thinking of putting some springs each side of the adjusting screw to help

keep the table even, where to find them around here is another story.

 

Edited July 3, 2019 by Cabbie

[lehmann]

I have two of these sleeveless drums from Lee Valley Sleeveless sanding drums.  The picture on the web page doesn't show the method for holding the sheet of sandpaper, but it works very well.  There is a slot in the drum to insert the two ends of the sheet and a simple, but effective locking method.  No problem getting the sheet tight around the drum. 

 

I see that they are also sold at https://woodworker.com/1x3-w-14-shaft-sander-sleeveless-drum-mssu-815-895.asp.  The picture there gives some idea of the slot and design.

[Cabbie]

Thanks Bruce they look like a a top quality drum. I am a bit restricted by diameter

up to about 35mm. And i like it also being held by the tail stock.

But you prompted me to go looking again and come up with the links below.

The first one is I thought might be able to be adapted, it has a blow up drum.

The second one and bottom link is supposed to be made for a lathe using

the attachment. A bit pricey but would last a long time, not sure if it

can be held both ends though.

 

https://www.amazon.com/gp/product/B017ZE6DM2/?tag=ezvid02-20

 

https://hopewoodturning.co.uk/sanding-items/sanding-tools/69/hope-drum-sander

https://hopewoodturning.co.uk/jig-s/threading-jig/49/2mt-cutter-holder-draw-bar

 

Edited July 4, 2019 by Cabbie

[bruce d]

Have you seen this one?

https://www.ebay.co.uk/itm/Axminster-Sleeveless-Sanding-Drum-25mm-x-75mm/351794312321?epid=1279424135&hash=item51e8933481:g:9PcAAOSwfKRc0svT

 

HTH

Bruce

[Cabbie]

Another good looking one too Bruce.

But I don't think any of the ones above can be held both ends.

Thanks Chris

Edited July 4, 2019 by Cabbie

[iMustBeCrazy]

G'Day Chris,

 

You've inspired me!

 

As I don't have a lathe (yet) the power plant comes first (Aldi special today):

 

It's supposedly 150 watt but stalled when shaping the pulleys, so I will gear it to about 2:1 and see what happens. Drive belt/s will be sewing machine. One either end will give me about a 150mm sander but I'd like 200mm so maybe two belts at one end.

 

It will also hopefully power my yet to come DIY lathe/disk sander.

 

[iMustBeCrazy]

Some progress. The drum is going to take some sanding, I have to take about 1mm of most of it.

 

Motor still stalls, may need a bigger pulley on the drum. One belt handles the load.

 

[Cabbie]

Looking very good Craig, interesting to see different ideas to achieve the same result.

[iMustBeCrazy]

More progress:

The drum is round, I finished up taking it out after I marked the ends and used a plane to get it closer. Still required a lot of sanding. Final sanding will be against the platen (tilt table?) to make sure it's parallel.

 

[iMustBeCrazy]

More progress,

 

It turns wood in to dust! But only just

It will only just take 0.25mm (0.010") of a 135mm (5.25") wide piece of cedar (western red if it matters).

 

I need to gear it down again, I'll try a 100mm pulley on the drum next.

 

Height adjustment is by pushing a wedge under the platen, this will be done with a bolt or some threaded rod when finished.

 

That and dust extraction will happen after I sort out the gearing.

 

Sandpaper is attached to the drum with spray on adhesive and the ends are tucked in to slots cut with a hacksaw (see pic), seems to work.

 

 

 

[Bob Blarney]

That's a classic design for a shopbuilt sander.  The key points are to set the plane of the platten exactly parallel to the axis of the lathe, so as to ensure uniform thickness (or displace it to make beveled planks).  The second point is to feed the stock at a rate that cuts steadily without boggind down the motor - this is determined by experience with the grit and the wood species. 

 

I think an interesting idea would be  to make a 'gravity-drive' sled to carry the stock.  I would attach weights to pull the sled through at a constant speed so that the results are more uniform.

 

From the 'Days of Old' (PM, June 1958) here's a scalable design that I really like. The construction is very robust and the fineness of adjustment is excellent and easy.  It needs a dust shroud, however.  Again, I would add a gravity-drive sled.

https://books.google.com/books?id=KN8DAAAAMBAJ&lpg=PP1&pg=PA191#v=onepage&q&f=true

 

 

 

[iMustBeCrazy]

G'day Bob,

5 hours ago, Bob Blarney said:

The key points are to set the plane of the platen exactly parallel to the axis of the lathe, so as to ensure uniform thickness

I glued some sandpaper to a board and fed it through before putting sandpaper on the drum.

 

5 hours ago, Bob Blarney said:

I think an interesting idea would be  to make a 'gravity-drive' sled to carry the stock.

Interesting thought, I dismembered a laminator the other day to see if I could use the heating elements for something and I thought one of the feed rollers could be used to draw the stock out. The tilting platen makes this hard.

 

6 hours ago, Bob Blarney said:

From the 'Days of Old'

Interesting. Physically less compact but the double taper (wedge) height adjustment would make fitting an out-take roller easier. A threaded rod parallel to the taper could be used for finer height adjustment.

[Bob Blarney]

45 minutes ago, iMustBeCrazy said:

 

 

Interesting. Physically less compact but the double taper (wedge) height adjustment would make fitting an out-take roller easier. A threaded rod parallel to the taper could be used for finer height adjustment.

The dimensions of the sander can be changed for width & height.  A 1:8 taper will give a good compromise between length & adjustment range.  E.g.  1.0mm horizontal displacement will give a 0.125mm thickness adjustment. It's not too difficult to make a direct reading scale (and a vernier) if the taper is not 'perfect' - that could be discussed later. 

For a threaded rod adjuster, you could savage a handscrew clamp for one of its screws and its pivot barrel nuts.  

Btw, here's a thickness sander that I made years ago.   I think the PM version is better.  (I think the link still works):  http://www.mimf.com/old-lib/hammond_sander_lathe.htm

Edited July 16, 2019 by Bob Blarney

[Bob Blarney]

A word of caution about these designs:

 

It's best to stand to the side when feeding stock, because if your fingers slip (fine dust acts as a lubricant) then the stock can be ejected at high velocity.  A 6" x 36" guitar side-rib blank once slipped through my fingers and flew across the room and shattered when it hit the wall.  That was an expensive bit of lumber that was ruined, and then there was the issue of the orphaned bookmatched other side-rib.  

 This is one reason that I would make a gravity-driven sled that carries the stock through.  

Edited July 16, 2019 by Bob Blarney

[iMustBeCrazy]

18 minutes ago, Bob Blarney said:

Btw, here's a thickness sander that I made years ago.

Nothing new under the sun is there

5 minutes ago, Bob Blarney said:

This is one reason that I would make a gravity-driven sled that carries the stock through.

The only issue I can think of with a sled is that the stock tends to bow slightly as the side being sanded get hot. May not be a problem but....

 

 

[Jaager]

This has drifted a bit.   For where this is now,  I add the following:

at minimum a 1/3 HP TEFC motor  with a final sanding drum rotation of 1700 rpm

If more than a few passes are contemplated per session,  as much air circulation around the motor as can be had.

[Bob Blarney]

1 hour ago, Jaager said:

This has drifted a bit.   For where this is now,  I add the following:

at minimum a 1/3 HP TEFC motor  with a final sanding drum rotation of 1700 rpm

If more than a few passes are contemplated per session,  as much air circulation around the motor as can be had.

Efficient dust collection is important,  and it may obviate the need for an expensive TEFC motor.  I agree about the 1/3HP,  but light cuts shouldn't overheat a motor.  Hmm,  I wonder if anybody has thought about roughing the wood down with a handplane first - it might save a huge amount of time and airborne dust.  

[iMustBeCrazy]

Minor update:

 

As is usual for this sort of project, it reaches a point where to test it you need to use it for the job you built it for and if it works you don't need it and progress stalls. So it was with this project.

 

However, as I can see a need in the near future I have done a little more work including safety guards and some steps towards dust extraction.

No chance of the belt hitting me in the face now.

On another note, I picked up this at a market for A$20 (US$14) new in box but I'm not sure I got a bargain. It is the worst kind of Chinese product, the drill press used to drill the pulleys and sanding disk wasn't set square so they wobble, the bearings for the axle driving the belt and disk are fixed to sheet metal not the nice solid casting - if you raise the belt to vertical you tilt the disk, if you want to swap belts to a different grit you need to undo 10 screws (holding the dust cover/guard) and loosen 3 bolts. I'm sure it will be useful....... eventually.