lyman trimmer cuts at an angle...anyone else?

[mozeppa]

i get 7 to 10 thousands of end run out with it.

when i put a .223 case in it and lock it down...it does NOT line up with the spud.

[mozeppa]

i hate the lyman "universal" case gripper thingy on the lyman because it lets go sometimes.
went ahead and ordered a hornady case trimmer that utilizes actual shell case holders and a central mandrel to keep the case tight.


i got the lyman used ...and bubba'd .....no big loss.

[farmbif]

ive got 2 of those Lyman universal chucks on a manual and motorized trimmer, never had a problem with them till they sat in not so ideal conditions and got rusted.
problem now is trying to get parts from Lyman

[beshears]

Try slipping spud in then then locking down the head

[country gent]

a quick check would be to pull the bearings from the base and check for wear or dirt. also under the universal shell holders shoulder. Something is out of square here.

When the cutter is turning it is critical that everything be square and parallel since the cutter will cut on its plane. When the part is turning With the cutters being square isnt as important it wont cut even but will cut square as the part turns on its center line. you may get a cone shape and one tooth may cut heavier or before the others.

Im betting the cutter shaft has gotten bumped out of square. .007 on a case mouth dia .244 is a lot out of square. It can probably be fixed with a good cleaning or re setting the bushings though

[metricmonkeywrench]

You may need to disassemble and clean up the chuck. Also check to see if the cutter shaft/bushing is worn/loose adding to the alignment issue. My first one when starting out was bad on both the chuck and shaft ends and i just was careful and tried to cancel out the alignment issues when putting in the case and accepted the results.

I subsequently moved over to a Forster case trimmer seems to be more true with less effort, and the Lyman Universal now lives up on the shelf in case some odd round comes my way (it does come with a pretty decent pilot selection)

[Mk42gunner]

And people wonder why I loathe trimming brass for readily available cartridges.

Otherwise, I do as beshears does: slip the pilot into the case mouth before tightening the case holder.

Robert

[243winxb]

Loosen nut , rotate shell holder. . Shim if needed so a locked down case mouth alligned with the pilot.

Sounds like a new, sharp cutter head is also needed. Or slow the feed rate. Less pushing on the handle.

I clean cutter head every 3th brass with a toothbrush & BREAK Free CLP.

[GARD72977]

I have a power Lyman trimmer. The cutter wobbles. It has set on a shelf for a couple decades.

[mozeppa]

just to follow up.... it has no bearings to clean or adjust.

took the mandrel out of the chuck and put it into a lathe...yes it has about 4 thousandths run out ....reversed it into the lathe got the same run out.
quality control at lyman is non existent.

the clamping teeth inside they wobble 8 to 20 thousandths.

i'm not even sure that the bore for the cutter is true to the bore for the chuck.

i know this ....i have a desktop clock makers lathe and i can put a case in it and turn it down perfectly (almost) with only 1 to 2 thousandths run out from one side to the other of the mouth.

so here is my challenge to you guys (million dollar invention...of which i'll only take 1% of the profit)
make a small lathe that will center the brass and spin it up against a stationary cutter bit that has micro adjustment capabilities with a mounted dial indicator.

[Three44s]

Problem solved!

LE Wilson! The cutter moves and case stay stationary but the result is .0005” to .001” runout .... on length. Even less on angle.

Three44s

[country gent]

.001-.002 across the 243 dia mouth is a lot to be out. angle wise. A good lather or mill would cut this to very low 4 place decimal.

What you want can be easily dine with a mini lathe and a set of er collets. You could set it up with one collet that held wilson shell holders for their trimmer. Here for the ut most accuracy the collet / collets would be shimmed open and lightly bored for body taper to the spindle of the machine. This would take care of run out and square the bore true to the machine. The emergency soft collets were made for this to be bored for odd sizes or trued for accuracy above drop in.

When doing high precision parts in the tool room the first step of set up was to true the chuck if needed or collets. A 3 jaw chuck will run very close if cleaned and properly lubed then ringed and ground in to the spindle. other wise expect .002-.004 run out. Most shops have large numbers of chuck jaws vise jaws or collets so they can be trued up in this manner. Jaws collets and such are now considered consumables.

The problem isnt making the super accurate trimmer factories buy make them every day for jobs, the problem is people wont pay for the time and skill for that level f accuracy. How many are going to pay the price required for the machine made to truly do this. a small mini lathe can run from $400.00 up to well over $1500. Ine of the small 3 x 12 tags would be ideal for this. the ER collet set and mount in high precision would be $200-$300 for it. a dial indicator 1" range another $100-$150. mounting would need to be made still. A read out would work as well. cutters could be a HSS lathe bit hand sharpened and honed. Once all the pieces parts were acquired then the er collet chuck mounted and checked if run put was excessive then bored true. the collet shimmed and bored true with body taper. A stop would need to be installed in the collet chuck. Then the cutter ground up and honed sharp. the indicator mount made and installed or read out. The process is daunting to most let alone the cost. The little tags with the solid beds are very good machines and very accurate. the above set up would when done be capable of holding length around .0005 and squareness of around .0002 on you .243 dia. very accurate but will also be considerably slower than most on the market now.

[1hole]

I've happily used my Lyman Universal Trimmer since the early 70s; I love it. No, it isn't watchmaker perfect. But it really doesn't need to be because the supposed value of a perfectly cut mouth is greatly over estimated.

Thing is, at the moment of ignition the thin case mouth quickly expands until it stops hard against the steel wall and the bullet is completely released. At that point any small case mouth unevenness effectively becomes a meaningless tiny part of the chamber wall and the emerging bullet will never notice the difference.

Redding's hand cranked case trimmer turns the rotating case against a stationary cutter; if the user is careful the finished mouths will be perfectly square. IF I were concerned about mouth squareness that's the trimmer I would use.

[MostlyLeverGuns]

Like Three44s - L E Wilson -I've tried others, but the Wilson is the most accurate. For bulk I have a Little Crow Power Trimmer that indexes of the shoulder.

[salpal48]

trimming sometime Is like going to the dentist. put it off as late as possible. was Looking @ a power one. Price and extra chucks well Not for me.
Them I found DAcAM power pods
quick , easy , pleasent

[onelight]

And people wonder why I loathe trimming brass for readily available cartridges.

Otherwise, I do as beshears does: slip the pilot into the case mouth before tightening the case holder.

Robert

I don't wonder , I know I feel the same way , same with my forester .
And same solution . Frustrating to have a big pile of cases and not be getting good clean trims.

[jmorris]

https://www.youtube.com/watch?v=LaBON6F1LlQ