Swing mill builders

[tjhammer]

ready to start on my blade arbor,I looked at fire bass's post and can't make out the demensions,what matieral did you use for the hub,what do you think of stainless,did you key your hub or drill and tap the hub and arbor together,sorry for so many questions,just want to be safe,got my gear box and timing pulleys coming,I talked to a shop instructor at the local trade school he will help all he can,after I get my centers I can order the belt,is the balance hard to get on the swind,would it help to move the arbor further away from the gear box
tjhammer

[tjhammer]

firebass



got all my parts from mcguire bearing,I'm working on my arbor and I'm wondering did you machine your hub from a 5in peice of 4140,I looked at your post on the arbor could not make out any numbers at all,looks like you have two shoulders on the shaft,I though about turning a 4.5 in flange but not sure how thick to make it,do you think two shoulders would be better.

tjhammer

[Firebass]

I made a flange that the blade bolts to.  then I machined down the shaft leaving a shoulder to act as a stop so the flange could be heated up and slid down the length of shaft from the opposing end to the sholder.  This made it so it could not come off the shaft.  I then used a series of 3/8"' set screws drilled into the face of the flange between the two to insure the flange wouldn't come loose and work its way back up the shaft.  This is how I got away without welding the 4140 alloy shaft and screwing up the temper of the material.

 I once did a bunch of work for a local saw mill where they would weld up large air cylinders to get by but they never lasted long once they were welded.  Once you've seen a broken 2" shaft it makes you think twice about welding on something that could cause death if it breaks.   Welding on high carbon steel can become so brittle that even a blow with a hammer can cause it to break.   

Firebass

[bandmiller2]

TJ,why not use the  rear axle out of a rear wheel drive auto, that gives you a forged one piece axle and flange,you trust it at 70 MPH in you car it  should hold saw blade.

[pitotshock]

For my dimensional sawmill build I am currently cutting a shaft / hub out of a rear drive axle from a 4x4 chevy as bandmiller2 is suggesting.

Mine is going to be a 1.250" diameter shaft and 4" diameter hub with 5 countersunk screws and a 1.000" pilot to hold the 18" blade in place (flush on outer face like a swing mill). All I have to say is the lathe work is demanding. This forged and hardened piece of steel requires C6 carbide tool to cut it (High Speed Steel need not apply!) and the depths of cut in each pass are very small. I don't think you could use the axles I have seen without modification.

When it is done, I think it will be the most robust design possible with no bolted joints or welds to fail. 

[scrout]

TJ,

I purchased Tinman's materials for the swingmill, but have not started my build yet.  I am just putting on the finishing touches to my sawshed so I can get my Linn based bandmill out of the shop.
The electric motor I have is a 10hp 3 phase, and it is a monster.  I like Dangerous Dans design, very simple, I think he uses helper springs to offset some of the weight.
I am trying to figure out if I can use my bandmill track for the swingmill and just build the carriage, but I think it might be too narrow.  Since I am fairly local to Firebass, I think I will have to go up for a visit and see his machine first hand before I start, as it looks very robust.

[tjhammer]

firebass


In my younger years I have had some bad deals with welders and high corbon steel saying this I am very cautious in building anything that has adanger about it,I have been very timid about this saw build because I want to build a safe saw that works right so this is why all my questions,I guess I would feel a little better if I could just see a swing saw,Pitotshock I have an truck axle 2in on the bearing flat but lost faith after toting it all the way home and a chop saw would barely scrach it,I got a 3 ft long 2in bar of 4110 to make my arbor,found a 1.35to1 curtis gear box and bearings like fire bass used also a set of 24 touth timing pulleys from mcguire bearing,I shopped and they had the best price as a whole,I would like to use my axle if I could machine it.I am planning a saw like firebass machine only I'll use a 1 3/4 arbor I haven't decided on the swing yet,Ihave mocked up a modle out of plywood and doles to get my machanics.I'm sure glade this fourm has opened up I was beginning to wonder

tj

[tjhammer]

scrout


I was wondering what happened to tinman,,I feel bad for tinman firebass said he had to side line the saw because of a extra family members coming,hope you finish up the project maybe tinman will beable to start again soon

tj

[Firebass]

I would think truck axles would be a great swingmill arbor..  Wish I would of thought of it.  I think it all boils down to whats in your bone yard ... Funny how things are reverting back to the old days.  I love it.... kind of feels like were reverting back to the days of  a common sense approach to make things work without wasting our hard earned money when we don't absolutely need to ..

Steve

[pitotshock]

My truck axles were 1 5/8" at the outboard bearing and to cut them on the chop saw (I don't think a bandsaw would do much to them) I didn't clamp it in, just kept rolling back and forth to open a new face to the blade. Only took about 40 seconds to cut through this way.

Here are some pics before and after... still have to machine a slot for the pulley key and the holes for the blade screws. I have a 1 7/16 bearing for the blade side, 1 1/4 bearing on the opposite end. The pulley hub is 1 1/4 also.


 

[fishpharmer]

Pitotshock, your arbor really turned out well.  Are you trying to make work for a specific blade that you already have or have in mind?  Are you going to cut down those concrete blades? 

[sigidi]

I seem to recall the problems with good or bad welds is why Lucas have always used a single hub and driveshaft.

Great lookin gear there pitoshock - here is Oz we'd say "that looks like the ducks guts" or just right to do the job

[tjhammer]

pitotshock


good looking shaft,after looking at yours I think I will try on my lathe,I have a set of carbides,after the chop saw wouldn't cut it I didn't even try it on the lathe,as it was the axle was to long for my bed without cuting it,think I will torch off the end extra long as to get it in my lathe and see what happens wish my hub was flat,its concave and may be a problem,I have some heavy channel laying around it may make a good swing frame.

tj

[pitotshock]

fishpharmer: this arbor is for my own blades which are going to be made out of the concrete saws

think I will torch off the end extra long as to get it in my lathe and see what happens wish my hub was flat,its concave and may be a problem

make sure to grind off all that torch slag... tough stuff on the lathe to cut through

This shaft was cut out of the one on the right (not the flat faced one). It too had a concave center, but there was so much meat on them, there was room to machine this out of it.

[tjhammer]

hey pitotshock

tried rocking the shaft it cut fine but not in seconds,the shaft was to big for my swing so I had to cut the bolt flange from the back side,the shaft was like a foot ball was wondering if a 1 3/4 shaft was in there some hard stuff waiting on my bearing to show up to finish the shaft,I don't know what kind of truck it was out of bet it didn't go to fast as out of round as it was.If I can figure this upload out I'll post a couple pictures.

tj

[Firebass]

Pilotshock

Thats one fine looking piece of art.  I like the fact that theres no gearbox incorporated with the saw arbor...Exactly why I built mine that way.   I would expect a standard gearbox rated for the Working RPM and HP too hold up far longer than if you had a big old blade hanging off it. 

One note about automotive axles... I believe the material is a high carbon steel but its not 4140.  That doesn't mean it's not a High quality steel just its not the super quality of 4140.  4140 is like twice the strength of a mild steel shaft of the same size.  Axle shafts if I remember right are made out of medium carbon steels with a bit of chromium for toughness................. Guess thats some perfectly worthless information.......  Keep up the good work...

Firebass

[bandmiller2]

All of the automotive rear axles with flanges i have worked with[mostly jeep] have been more gummy than hard.Possibly you guys are getting into larger truck axles that are made of harder material.I have shortened axles and welded them, being forgings they took a weld well.I would think a standard axle out of a rear wheel drive auto would be plenty strong for the arbor.Frank C.

[pitotshock]

Firebass

from the knife building guys on the web: auto axles are "Listed as SAE 4140 in many junkyard steel lists our industry experts claim most are SAE 1050 and 1541H." This axle was hard enough for the needles of the outboard bearing to run directly on the shaft without an inner race.

So I think your comment about medium carbon steels is probably correct. But I am working this in the fully hardened form and going to be using it as such. Trust me, the pile of broken carbide lathe bits and milling cutters contest to the shafts toughness.

With the 4140, is it being cut and used in the annealed form? Or is it machined, heat treated and ground?
dug up on the web from a steel manufacturer on 4140
4140 Annealed state Tensile Strength 95 KSI, Yield Strength 60 KSI min. tempering at 600 F gives a tensile strength of 225 ksi while tempering at 1000 F will give 130 ksi

Strengths listed on efunda site for the 1541H range from 40ksi to 273ksi depending on the heat treatment

 

[tjhammer]

pilotshock

hows the shaft coming,for your bearing fit are you going to make a tight slip fit or a  lite press fit or maybe I should ask what type bearings are you using.

tj

[tjhammer]

firebass


on your machine I noticed a counter weight on the swing,I would think your swing is quite heavy,wouner if a gas strut would do the same

tj