So this evening after the Committee meeting, Myself, @Chris_Wischkowsky, @BobKarnaugh, & @mikeglass looked at the Colchester. I was reported in the meeting that there were several issues with it. We cleaned up the Gib’s on the compound & cross-slide. We did find incredible backlash on the compound. After dis-assembly of the compound, we found the compound nut/arbor extremely worn. So badly word that we decided to remove it from service. So until we can replace the compound arbor nut, no one will be able to use the compound. We are following through on several different solutions which include buying a replacement arbor nut, or machining one. This nut is made from copper, so it takes all of the wear. Under inspection of the compound screw, it is still in great shape. So please bare with us as we work on getting this machine back up as soon as we possibly can. I have updated the Tool status board to reflect this as well.
Whats the bolt head diameter and thickness and the bolt diameter.
Could use a copper grounding bar for thread portion and upset the top to create the head.
If bolt available much faster to buy. If someone has a p/n and link, send me the link and I’ll order.
Either we order a new part or more than likely we could machine one.
The only challenge is the ACME thread, it appears to be a 1/2-10
We can either press in one of these:
Or find a tap that is cheaper than $200 or make one from existing ACME thread.
Other than the ACME thread it is a very simple part.
Order a new part if it has and acme thread. While it is makery to make a part - if the part impacts accuracy, I suggest getting a replacement parts.
Part no. is 73070-O
20 Chars
Bob is/was going to check the avenue of getting pricing/availability from Colechester. It’s probably 7/8 in diameter by 2.25 in long. It is a simple part. I can drop my Acme threaded rod by so we can make a tap from it.
Andrew is correct. We did have to trim the gibs as well. They were sticking about a half inch too long on the thin side. We believe that it was due to that, that the compound and cross feed would periodically lock up or get loose. Bob cut a spacer on the Sherline to give us the ability to tighten the gibs. He used some 12L14 rod he had laying around. I tig welded a 3/16 rod to it to keep the tension on the gib that was receded to far to lock.
Do you know where to order it? A link?
@BobKarnaugh has the contact information to get parts. He said last night, or I thought he said, That the folks pulled the contact information from their website & that he still has the number.
Once I have it I’ll order it.
This guy may be a worth while to ask. I don’t have the serial number with me though.
https://www.fdk3co.com/lathe-parts.html
I should be there today. I think I had trouble finding a serial number before. Model Number yes.
I’ll look again.
I kinda cringe when I see this… I found it on Practical Machinist
I had a badly worn cross-feed nut on my '63 Colchester and ended up buying a 3/4-5 ACME threaded block from McMaster_Carr. It was half the price of a tap. After a little machining to round it over, it worked well. My ACME rod wasnt very worn so i didn’t feel the need to replace it.
Just sharing this as a possible solution to someone.
(You do need to tap a hole downward for the attachment/oil feed nut. I couldn’t find the correct tap so i used a 7/16 fine and bored the bolt out.)
BTW, Clausing quoted me $1400 for the nut. They have a blueprint for many of their vintage parts and sub the job out to a machinist. I laughed and said i paid less than that for the whole LATHE!
Good luck!
I just asked Frank of FDK Co. (the Owner) to send us a quote for the topslide nut (PN 73070-D) and a topslide gib. Relates to Serial No: MCHNO5/0014/11241DD. He said that he would email me with the quote today or tomorrow.
I gave Clausing Industrial the same request but no one there has actually answered me as of yet. Of course, if we get a quote on the nut for $ 1400 every can get a good laugh about the nut quote from a nut.
The quotes are in from Houston area dealer, FDK Co. :
Topslide nut - $1016
Topslide Gib - $970
So we better develop our aptitude at making parts for our machines! Good thing that the automotive parts industry isn’t this ineffective, or no body could afford to maintain an auto.
For this part it is all about the acme thread job, that is where our attention needs to go next.
I dropped an acme threaded rod off that we can make a tap out of. We have the right sized brass in the teachers cabinet to create the new one. I will not be able to work on this as I will be not able to come back to the space until at least Friday.
Bob can you machine a duplicate part out of the brass stock in the teachers cabinet? I can convert Tim’s ACME rod into a tap.
It probably does not need to be very hard. Steel > Brass
Frank is right, It doesn’t need to be hardened. Considering its (hopefully a one off). Will it make it more difficult, probably. But its doable in brass or copper.