Boring machine questions

[Mad Professor]

I'm picking up a complete working boring machine this week.  Not sure of brand but pictures looked good and price was right ($110), I'll post pictures later this week.

I had been roughing out my mortices with an auger and/or hand brace, slow work in hardwoods.  I got a chance to try a boring machine a couple months ago and was impressed. 

Anyway what size bits do you suggest I acquire?  Any tips on maintaining it (grease vs oil) ? I think I'll be giving Jim some used tools business soon...............

[Dave Shepard]

You'll need a bit for each size mortise you want to bore. I am using 2" for pine right now, and have 1.5" for hardwoods. There has been some discussion of thread pitches as well. Hardwood bits have more threads, and therefore a slower feed rate.

[moonhill]

With a slower gear ratio and a fine thread on the feed screw you could bore 2" holes hardwood, you would want a metal framed machine for that though.   There is a lot of combinations to choose from.   I have been using a modern 1-1/2" bit which cuts very well, a nice clean hole, for hard wood that is what I would go for.    Tim

[Mad Professor]

Thanks for the replies. I'd not thought about feed rate/pitch.

So I take it that most of you bore the full width of the mortise?? I was wondering if it would be better to go ca. 1/8" smaller and clean out with the slick/chisel.

[Greg]

Thanks for the replies. I'd not thought about feed rate/pitch.

So I take it that most of you bore the full width of the mortise?? I was wondering if it would be better to go ca. 1/8" smaller and clean out with the slick/chisel.

Full width IMO. Cleaning up that last 1/8" is what kills you. Let the bit do the work.

I'd say get a good couple of 1 1/2" bits and use them almost exclusively. Boring 2" out of anything requires alot of muscle power, besides I doubt they are very many joints that require a 2" tenon, unless you are working with VERY large timbers.

Just curious what type of woods are working with. Hardwood/softwood? Green/reclaimed beam?

I learned my lesson after wasting lots of time, money, blisters and sweat - I wouldn't even bother with boring machines for hardwoods or reclaimed wood...

Greg

[Mad Professor]

Greg,

I'm using mostly white ash I mill/hew myself .

If you think the boring machine is slow, consider using a hand brace or T-auger, even 1" is slow.

Using the brace sure gets you ready for drilling holes for ice fishing season though

[Jim_Rogers]

Mad:
We've been selling bits for boring machines for several years now. And some people like, as Dave has mentioned, to use a 2" bit on a 2" mortise, and 1 1/2" on 1 1/2" mortises. But some people like to use a bit a sixteenth or more undersized then the mortise.
It could be just as simple as personal preferences.....
Like riding down the road in a Chevy or a Ford.....

Whatever works for you is ok, as long as the job gets done...

[moonhill]

My preference is a diesel powered something going down the road. 

As for the bore hole in a mortice, I don't mind a bit of over lap on the side of the mortice.  It cleans out better and doesn't effect the way the mortice works.  I don't cry if I am over the line with the bit.  I have lately taken to marking the feed screw location in the mortice during layout and this speeds things along.  I have also been drilling pilot holes, 1/8", which makes it real easy not to miss.    Tim

[Jim_Rogers]

In this older story/post/thread https://forestryforum.com/board/index.php/topic,29052.0.html
there is a photo of one of my drawings that shows how I layout a mortise for boring with a boring machine and bit.
We usually do the two end holes first and then the middle holes. This way the ends are correct and the overlap between the middle holes don't matter that much.

Here is the picture again:




Basically, we draw a center line for the bit tip and then mark off with a pencil where the bit will start. Then I use a carpenter's awl to make a dimple into the surface of the timber so that the bit tip will sit down into this starting dimple and bore the hole in the right spot, hopefully in the center of the mortise and not to close to the ends.

It is important to not bore into the end of a mortise that is a bearing point for another timber, such as a tie beam or brace pocket. Boring into a bearing end of a mortise will cause the load bearing timber to squash the fibers of the mortise bearing end and this may move the timber off its intended location.

Tim:
Right now diesel is kind of expensive  :D

[routestep]

Like Greg said, go with full diameter.  But make sure the drill is vertical to the beam or as close as possible. And as moonhill stated lay out where you want the bore hole to go. I use a nail punch to start a hole for the lead screw. It helps on getting the bit on target. My 2 inch bit is a fine thread lead screw but I use it on both hardwood and soft as I don't know any better.

I have a couple three T-augers. They're pretty slow too. Real slow, but you can drill at any angle that you can hold it to. (Some nice boring machines will tilt also)

[moonhill]

Yup, they changed sulfur content which means it cost more to refine.  I just like the sound I guess. 

I have have been boring brace pockets from the bearing end with the angle reaching into the pocket to make up the difference.   I stay a 1/16 or more from the bearing end on the brace pockets and pare to the chiseled score line, the sides are of a lesser concern for me.    Tim

[Mad Professor]

I picked up the boring machine tonight.  From the pics Jim has posted on his tools for sale it appears to be a Swan.  Wood frame is in excellent condition as are the gears and mechanicals.  Seller knocked of $10 so I got it for $100.

The only problem is he also had a really nice planer/molder with ripsaw and dust collector attachments for sale too..........................

[Raphael]

The only problem is he also had a really nice planer/molder with ripsaw and dust collector attachments for sale too..........................

         :D :D :D
I tend to suffer from that problem as well...
I start hunting for bits, and wind up with planes.

$100 is a great price for a working machine.

[Mad Professor]

O.K., TAD (timberframing addiction disease)has set in. 

I ordered bits from Jim and just brought a Boss double eagle in good shape at good price..........

I'll do a comparison and put another post up soon.  Will have to mill up some beams for a small project.......