A different style boring head

[marksbug]

I have some of those trees in my yard. I once worked in a prototype shop, programing&running the cnc mills off prints and out of my head. many times the prints were rong...especilay when the owner (engineer,machinist etc) did them.... or when they were done by a engineer that did not know basic real life things like...bend raidi changing locations when things are machined then bent and different thickness material alters that also... aerospace, defense engineering ****.....sometimes I wonder weather they can get thier zippers down before or during or after the peeing down their own leg process begins.( male&female, engineers). those sure are pretty pictures(cad) I dont do any of that stuff hear at home...the only place I work any more.I probably should. be eazer to remember stuff than paper.

[Frank S]

Well I am off to plan "C" the idea of placing a set bolt in the center would only work for up to about a 1/4-20 without having to cut into the center shaft that goes in the collet and I feel that anything less than a 3/8-16 would not do much if I ever needed to use a longer boring bar cutter like for going into 3 " or so, and should I go ahead and install the 3/8" diameter bolt the relief area required for the head would require me ot mill away a notch that would remove nearly half of the shaft which would weaken it too much for comfort. So I will have to install 1 or 2 set screws at angles to the original lock.
Another thing I noticed after grinding the plates and trying the boring head again was as long as I force myself to take very tiny cuts it works great, however I noticed that I have quite a bit of slop in the quill bearings so I am going to have to deal with those soon.

[marksbug]

a real good quality1/4 or even 5/16 grade 8 with a hardened wavy washer under the head.will do a lot more than most people think torqued at only 14~18 pounds on that short of a bolt. as far as the 2 extra set screws, either use a "puck","key" something to keep from making an impression and making adjustability a chore. of coarse hardening the entire thing would also be a good way to keep brinelling&deformation ( boogering up)to a minimum. I tend to get impatent and dont like a lot of little cuts....thus..I sometimes swear a lot when something gets cut toomuch...., my worst thing seems to be making a new tool and not marking it for what it is and...sometimes it gets grabbed thinking it's a drop or whatever and... turned into annother tool...with out realizing it. especialy on round stock Ive made to hold something inpaticular to machine that part......and when Im done...ferget to mark it for what it is. sometimes scraps... are not realy scraps. I do repourpose a lot of stuff, like engine parts...forged piston tops are sweet for oh somany things. camahafts are great for many things too, but be carful if you try to cut the lobes off with a lathe it will beat the **** out of the lathe, those lobes are hardened. I started using a chop saw to cut the lobe's down before sticken in the lathe. keep on making and posting good stuff.we all need new ideas. even just seeing something gets our minds to wandering on something we havent thought of that isant the same but might have just 1 part that will set things in motion. as for the quill bearings....that tree your having lunch under is on a path that has no end.....

[Philip Davies]

Another really interesting thread, thank you, Frank and Mark. I walk that path daily. Haven’t even mastered carpentry, or ever really stated machining metal, what a lot there is to learn!

[Frank S]

This thread is old enough now that I guess it needs an update. Some of my observations after I made it and used it several times. #1 it is not as easy to index for bore diameters as a dovetail head would be. #2 after through drilling it from the bottom part into the top part and threading it for a 5/16-18 clamping bolt it did help with stability #3 the range of adjustment as I made it was a little lacking This could have been overcome by making the whole thing a larger diameter with slightly more eccentric offset and if I were to make another one like it, I would make the eccentric stem longer for stability. However, if I were to make another, I probably wouldn't use the eccentric design at all just take the extra time and make a dovetail boring head, the problem with that though is I still don't have any dovetail cutters.
Ther is a consolation to a design of this type though. For someone with limited tooling or experience a boring head such as this would be an easier build and with some careful measuring you can achieve satisfactory results for about any bore you need to make providing you take your time. I am a little too impatient at times when it comes to running a mill, I just want to hog my way through the initial cuts and do a single final cleanup like I can do on a lathe, which is not a good practice especially with smaller machines I'm a T50 or MT7 type guy. The concept of an ER11 collet is as foreign to me as a bb gun would be to a gunner's mate on a battleship

[marksbug]

dove tail cutters are great.hell use a fly cutter as a dove tail cutter, but go slow and if possiable one side of the tail at a time. my brother hits a lot of swap meats..oops meets. Ive been to a few with him there are always guys there with old machining tools&tooling. he has been buying the big lather indexable holders (1"square and larger,mostly about 1.250 to 1.500 shank size, and he mills a slot in them and then dove tails them and adds a stop screw for hight adjustment. to used them directly on the quick change fixture on his lathe, no need to buy a bunch of holders. I was quite impressed when I saw what he was doing with them when we got back to the shop. and he only pays 2-$5. each for them many times a lot less when he offers to but a whole pile of them and other things ,he go's buy early and looks, them late he makes the offer "Ill give you$$ for all that stuff and you wont have to pack it up and haul it back home just to toss it..... and it works every time. and his offer is usually less than what most would pay for 1/5th of it. he has so much tooling and machines now that I doubt he will never be able to use it all.
As for me....I've stopped buying stuff, I have realized that my limitations and my wants and Ideas, and what I will actually get to do are 5 different things. my days of most of that are over. my mind wants to do it all,sees how it all needs to be.... but my body & drive just aint into it. as well as memory. 1 min it's all there 2 min later its' gone outa my head.

[marksbug]

Another really interesting thread, thank you, Frank and Mark. I walk that path daily. Haven’t even mastered carpentry, or ever really stated machining metal, what a lot there is to learn!

carpentry is easy.. well for me it is. as long as it's building buildings, Im not into cabnet work.those are easyer to buy on clearance and stick them in.work benches&storage yes thats easy, like building building. my 24x34 shop 6' from my bedroom back door took my about 2 months to build by my self(I did have somebody else do the concerate after I did all the form work to make sure it was square&level. it's fully sheet rocked,central ac&heat, bathroom,kitchen,engine build room, blasting&porting, grinding room too. then I built a 12x12 for my 4 wheeler&dirt bike&wood worken stuff, then about 2 years ago ai built my 11x16 2 story barn, with ac for storage and my wood worken tools will be in there as well as painting ****. all that stuff is eazy to do. especialy if you have atleast half a brain( witch is more than 90% of the guys doing it nowdays) I always over build everything. extra huricane straps&brackets & more. I kinda like building stuff with wood nowdays it's lighter and easyer to clean up than the mechning stuff.....and more relaxing too. well it was befor all the price gouging started 2 years ago . ****ing $6.48 sheet of osb now $50.I have a lot I want to do but not at those prices. Im done.

[Frank S]

As far as carpentry goes I try to avoid it, That's not to say I can't do it I just prefer to burn wood rather than work with it

[Floradawg]

also with the indexable inserts&bars there are somany different grades, you might just find one that will cut without dystroying it. rough cut, rotate insert,final finish cut.
as for the mill speed, look at building a jack shaft& extra pully&belt to get the speeds you want, you have the brains&capability to do so!!! I too need a slower speed on my BP....well BP clone, 1979 millport 9x42 ,I did have a small auxzillary motor off the side of my small 1975 enco mill for slow speed stuff.But thats sitting un powered and in the way....along with a lot of stuff in the way.

Everyone calls you Marksburg. I kinda get a kick out of it.

[WmRMeyers]

This thread is old enough now that I guess it needs an update. Some of my observations after I made it and used it several times. #1 it is not as easy to index for bore diameters as a dovetail head would be. #2 after through drilling it from the bottom part into the top part and threading it for a 5/16-18 clamping bolt it did help with stability #3 the range of adjustment as I made it was a little lacking This could have been overcome by making the whole thing a larger diameter with slightly more eccentric offset and if I were to make another one like it, I would make the eccentric stem longer for stability. However, if I were to make another, I probably wouldn't use the eccentric design at all just take the extra time and make a dovetail boring head, the problem with that though is I still don't have any dovetail cutters.
Ther is a consolation to a design of this type though. For someone with limited tooling or experience a boring head such as this would be an easier build and with some careful measuring you can achieve satisfactory results for about any bore you need to make providing you take your time. I am a little too impatient at times when it comes to running a mill, I just want to hog my way through the initial cuts and do a single final cleanup like I can do on a lathe, which is not a good practice especially with smaller machines I'm a T50 or MT7 type guy. The concept of an ER11 collet is as foreign to me as a bb gun would be to a gunner's mate on a battleship

Sounds like you need a small shaper. They say you can make anything but money with a shaper, but there are some things you can't do with anything else, and the cutters are pretty cheap.

Bill