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Bridgeport R8 head skimming

Posted: Sun Feb 10, 2019 3:24 pm
by gunt
bridgeport r8 for skimming heads and blocks metal and alloy , either that or recommendations for where to buy and or make ,

cheers

Re: Bridgeport R8 head skimming

Posted: Mon Feb 11, 2019 8:41 am
by Dave Koehler
As far as making your own you can certainly do that.
Google will be your friend.

Here are a couple places among many that come to mind.
https://www.subtool.com/st/fcs_fly_cutter_sets.html
https://www.pinnacleflycutter.com/

Re: Bridgeport R8 head skimming

Posted: Mon Feb 11, 2019 11:42 am
by bill jones
---the R8 shank that fits into the quill is pretty small and not very sturdy---so there would surely be some distortion trying to happen at every hit of the cutter.

---having a multiple head cutter such as 6 cutters would allow each cutter to take 1/6th of the cutting load if they were adjusted pretty decent---so the distortion at cutter would be greatly reduced.

---this link below shows a couple of pictures of how I built my cutter head for my #30 taper quill---which is a much stronger snout design.

---it takes some effort to get the cutters dialed in perfect or even to within a couple of thou---but this cast iron flywheel has worked for me since 1996.

---I felt the cutter diameter needed to be pretty large to get a nice sweep---so my cutter diameter ends up at 9.8".

---I have my mill head tilted precisely up on the trailing edge .0015" so the trailing cutters don't leave a waffle pattern as they come across over the freshly milled surface.

---the joint between your R8 mandrel choice for the adaption of your cutter head really needs to be 100% secure and failure proof.

http://ryanbrownracing.com/Bill_Jones_Page_1.html
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---this link has a little more about my way of thinking on the cutter head operation.

https://www.speed-talk.com/forum/viewtopic.ph ... 7&start=30

Re: Bridgeport R8 head skimming

Posted: Mon Feb 11, 2019 4:34 pm
by gunt
Hi

I'v long read all your items , thanks for the imput , that was always one thought i had as to why not use the multi tip cutters somonlly seen , also any views on stone as i have heard of several who using the big name machines ruin an expensive head over " there must have been a hard / soft spot and the cutter dug in " , this could be a myth too.
Bill I haven't used this mill yet I'm trying to get a semi retired guy in and build from there , but no point in having a guy and no tooling , are you saying i can mount your setup to my head eliminating the R8 or you are using a mill with a different head , would you consider making another cutter ?

Thanks Dave , I had seen these and forgotten again , looks like what i'm thinking, I like the mounting plate as it should suit the majority of engines i work on


Anyone any thoughts on this

http://jamisonequipment.com/machine/cbn ... e-machines

Re: Bridgeport R8 head skimming

Posted: Mon Feb 11, 2019 5:39 pm
by bill jones
---My stuff fits a #30NMTB spindle---which has a larger taper and larger diameter at the large end of the taper.

---I just showed it because it's what I built---because I didn't have $1300 for something like the Jamison cutter and I know nothing about running a single high speed cutter.

---the R8 maximum diameter of the largest end of the R8 piece inside the quill is only something like maybe 1.250"---so the cutter plate can't be real sturdy is you making it with a 3/4" shank to fit into an end mill holder.
---so you need some special R8 part that is solid and protrudes down to mount your cutter plate to---maybe something with a circular threaded flange or like large #4 Morse taper with a key and a single mounting bolt---then build your own hub to fit your large diameter cutter head plate.


---my deal made out of a Chevy flywheel is pretty crude but it works really well with no problems.

---the large diamond wheel needs to be run easy on the cut depth---it's best purpose is on cast iron diesel heads that have the hardened "pre-cups" to deal with.
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---personally I would not use steel for the large diameter cutter plate---I'd rather make it out of cast iron to eliminate any vibrations or harmonics getting onto the surfaces being machined---so a simple cast iron flywheel seemed a good choice to me.


---I had to machine a couple of the critical mounting surfaces of my #30 hub adapter for the Chevy flywheel---and I did those machining processes on the hub right on the mill from underneath with the cutter's mounted in the mill vise.


---I really don't have any plan for what it would take to build an R8 cutter plate.

---if I had to do mine again I would probably use a larger diameter flywheel that the SBC one I used---to get another 1" or so cutter diameter---but there's really nothing wrong the diameter I'm using now--so far.

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---I also have about a 6" diameter flywheel CUP stone mounted on a different mandrel---that I use for when I need to do a flywheel or like the SBC & BBC rear main cap pad where the oil pump sits.

---this cup wheel is really coarse but it actually leaves a pretty nice surface on cast iron---don't think it'd try it on aluminum though.

---------------------------------------

---I have several other multi-tip cutter heads that I use like for milling intake flanges of intake ports where the valve cover rails protrude along the top---one cuts about a 6" diameter and the other cuts about a 8" diameter.

Re: Bridgeport R8 head skimming

Posted: Tue Feb 12, 2019 1:20 pm
by JRice
Get one of these.
I use one on my DCM Machining center and it works good. Can get a 14-18 RA finish on a LS Cylinder Head. I spin it 850rpm and around 7in a min.

http://bigflycutter.com/site/mobile?url ... e.php#2756

Re: Bridgeport R8 head skimming

Posted: Sun Feb 17, 2019 3:38 pm
by gunt
Just remembered i had a few dvd's from these guys, any one have one or a basic yes or no would help , seam like good guys at it a long time

https://www.precisionmeasure.com/produc ... ture-only/

Re: Bridgeport R8 head skimming

Posted: Mon Feb 18, 2019 1:39 pm
by gofaster
I use a Precision Measurement Supply 8" fly cutter with the 1" stub arbor. It's a slow process but it leaves a nice finish that looks better than factory stock.

Re: Bridgeport R8 head skimming

Posted: Mon Feb 18, 2019 3:24 pm
by gunt
Hi
Thnaks , I seen only 1 left so i went with it , for what it is its gona come in handy either way ,

Cheers

Re: Bridgeport R8 head skimming

Posted: Mon Feb 18, 2019 5:11 pm
by In-Tech
JRice wrote: Tue Feb 12, 2019 1:20 pm Get one of these.
I use one on my DCM Machining center and it works good. Can get a 14-18 RA finish on a LS Cylinder Head. I spin it 850rpm and around 7in a min.

http://bigflycutter.com/site/mobile?url ... e.php#2756
404 (Page Not Found) Error

edit, I backed up and found it on the home page http://bigflycutter.com/ , that cutter looks nice. What are its drawbacks? I haven't looked at it close enough, is it big enough and/or capable of doing interrupted cut such as an alum deck with sleeves? LS?
Thanks

Re: Bridgeport R8 head skimming

Posted: Mon Feb 18, 2019 7:26 pm
by jeremyinlinepro
I have the big fly cutter and use it in a Cat40 cnc mill. I bought a pcd bit and the finish is the nicest I have ever seen on aluminum cylinder heads. Iron blocks have been fine. Aluminum blocks with stock sleeves I have been able to get an ok finish on but I have not been able to use it with aftermarket ductile iron sleeves in an aluminum block. I tried tons of different bits, speeds, and feeds and I just can’t get it to work right. I think the cutter may not be stiff enough for the ductile iron.

Re: Bridgeport R8 head skimming

Posted: Mon Feb 18, 2019 8:09 pm
by In-Tech
Thanks for the reply.

Re: Bridgeport R8 head skimming

Posted: Mon Feb 18, 2019 11:43 pm
by JRice
jeremyinlinepro wrote: Mon Feb 18, 2019 7:26 pm I have the big fly cutter and use it in a Cat40 cnc mill. I bought a pcd bit and the finish is the nicest I have ever seen on aluminum cylinder heads. Iron blocks have been fine. Aluminum blocks with stock sleeves I have been able to get an ok finish on but I have not been able to use it with aftermarket ductile iron sleeves in an aluminum block. I tried tons of different bits, speeds, and feeds and I just can’t get it to work right. I think the cutter may not be stiff enough for the ductile iron.
I’ve ran into the same issue on aftermarket sleeves. I also have a 12in steel body cutter that came with my DCM that I use for the sleeved blocks. (Just don’t like installing the heavy son of a gun In the spindle)