Pits in drum
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
-
Topic author - Posts: 167
- Joined: Mon Jul 29, 2019 1:49 pm
- First Name: John
- Last Name: Burgett
- * REQUIRED* Type and Year of Model Ts owned: 1924 Touring
- Location: Camargo Illinois
- MTFCA Number: 29590
Pits in drum
I have decided to use kevlar linings. Is this band too pitted to use. I was originally going to polish it.
John
John
-
- Posts: 6496
- Joined: Fri Jan 04, 2019 9:37 pm
- First Name: Steve
- Last Name: Jelf
- * REQUIRED* Type and Year of Model Ts owned: 1923 touring and a few projects
- Location: Parkerfield, Kansas
- MTFCA Number: 16175
- MTFCI Number: 14758
- Board Member Since: 2007
- Contact:
Re: Pits in drum
Get a better drum. Taking off enough material to remove pits that deep is a bad idea.
The inevitable often happens.
1915 Runabout
1923 Touring
1915 Runabout
1923 Touring
-
- Posts: 1057
- Joined: Thu Feb 21, 2019 1:20 pm
- First Name: Joe
- Last Name: Bell
- * REQUIRED* Type and Year of Model Ts owned: 24 Fordor
- Location: Tiffin Ohio
- MTFCI Number: 24066
Re: Pits in drum
You have a really nice gear on that drum, I would replace the drum with Dave Noltings and it would be perfect balanced and new, you have it down this far what is another couple hundred dollars. If my own engine is down that far I would replace at least the reverse and low speed drum, they get all the abuse!
-
Topic author - Posts: 167
- Joined: Mon Jul 29, 2019 1:49 pm
- First Name: John
- Last Name: Burgett
- * REQUIRED* Type and Year of Model Ts owned: 1924 Touring
- Location: Camargo Illinois
- MTFCA Number: 29590
Re: Pits in drum
Thank Steve and Joe. That is what I thought. I have 2 of Dave’s drums and they are very nice plus he is great to deal with.
John
John
-
- Posts: 1414
- Joined: Sun Jan 06, 2019 11:57 am
- First Name: Adam
- Last Name: Doleshal
- * REQUIRED* Type and Year of Model Ts owned: ‘13 Touring, ‘24 Touring, ‘25 TT dump truck, ‘26 Tudor, ‘20 Theiman harvester T powerplant, ‘20 T Staude tractor
- Location: Wisconsin
- MTFCA Number: 23809
- MTFCI Number: 1
- Board Member Since: 2000
Re: Pits in drum
Measure it first! I’ve seen plenty of “junk” drums that are oversize enough that they clean up nice at close to standard. Particularly ones out of early to mid twenties engines. I have a suspicion that during periods of high production demand that drums may have been turned and ground to a larger spec to reduce machining time.
Turning the drum .040” undersize (which is a .020” cut) results in the band ears being 1/8” closer together than they would be with a stock drum. The correct stock drum diameter is 7.500”. I would not use a drum machined to less than 7.460” which is a .020” reduction in designed wall thickness, plus there are a whole lot of other considerations and judgment calls. The drum casting must be very concentric, can’t be “too thin” (there are apparently some design and/or mould variations), the drum should be verified to be free of cracks, shouldn’t require any further reduction of material (such as balancing), etc. The “payback” on machining a drum undersize is thrift at the potential expense of longevity.
I highly recommend a new ductile iron drum from Nolting Machine. They are made from billet, not a casting and are machined all over which makes them very close to balanced when installed and generally require very little additional balancing if you are doing a full balance/blueprint job.
Turning the drum .040” undersize (which is a .020” cut) results in the band ears being 1/8” closer together than they would be with a stock drum. The correct stock drum diameter is 7.500”. I would not use a drum machined to less than 7.460” which is a .020” reduction in designed wall thickness, plus there are a whole lot of other considerations and judgment calls. The drum casting must be very concentric, can’t be “too thin” (there are apparently some design and/or mould variations), the drum should be verified to be free of cracks, shouldn’t require any further reduction of material (such as balancing), etc. The “payback” on machining a drum undersize is thrift at the potential expense of longevity.
I highly recommend a new ductile iron drum from Nolting Machine. They are made from billet, not a casting and are machined all over which makes them very close to balanced when installed and generally require very little additional balancing if you are doing a full balance/blueprint job.
-
- Posts: 4095
- Joined: Tue Jan 08, 2019 1:39 pm
- First Name: Norman
- Last Name: Kling
- Location: Alpine California
Re: Pits in drum
That drum might be ok for wood band linings. It would just cause a slight groove in the wood without much of a problem. However, any fabric band such as Kevlar, cotton, or Skandinavian would be a potential to snag the material and cause fibers to get stuck in the oil lines or other parts of the engine or transmission. If you don't want to spend for new drums, use wood lining.
Norm
Norm
-
- Posts: 979
- Joined: Mon Jan 07, 2019 5:42 pm
- First Name: Stan
- Last Name: Howe
- * REQUIRED* Type and Year of Model Ts owned: 2
- Location: Helena, MT
- MTFCA Number: 19133
- Board Member Since: 1999
Re: Pits in drum
Every damn time I try to post something and don't save a copy I get a screen that says "the site is down," it dumps my post and wastes my time!! I've about had it!!!!!!!
It has now dumped it three times in a row!!!
So this is what I wrote. Or close to it.
Like all of this it depends on what you are doing. If you are doing a cost is not object gonna drive it a thousand miles a month want it perfect -- yeah I'd buy a new one.
If I had a better drum I'd put it in. But what I probably would actually do is set up my tool post grinder on my lathe, put a fine stone on and true it, set up a drip so I was wet grinding and grind about 10-15 off of it and see how it looks; probably use it. A few small pits wont hurt it.
Your mileage, may vary, guarantees are between seller and buyer, vehicles under $1000 selling price are not eligible for return or refund, this notice conforms to UCC 612, etc., etc.
It has now dumped it three times in a row!!!
So this is what I wrote. Or close to it.
Like all of this it depends on what you are doing. If you are doing a cost is not object gonna drive it a thousand miles a month want it perfect -- yeah I'd buy a new one.
If I had a better drum I'd put it in. But what I probably would actually do is set up my tool post grinder on my lathe, put a fine stone on and true it, set up a drip so I was wet grinding and grind about 10-15 off of it and see how it looks; probably use it. A few small pits wont hurt it.
Your mileage, may vary, guarantees are between seller and buyer, vehicles under $1000 selling price are not eligible for return or refund, this notice conforms to UCC 612, etc., etc.
-
- Posts: 988
- Joined: Tue Jan 22, 2019 8:16 am
- First Name: Richard
- Last Name: Gould
- * REQUIRED* Type and Year of Model Ts owned: 1910 touring, 1912 roadster , 1927 roadster
- Location: Folsom, CA
Re: Pits in drum
I used a brake drum with a larger pit than yours. I was concerned that the band material might catch and fray so I used a dremel tool to smooth out the edges of the pit. Worked fine.
-
- Posts: 3923
- Joined: Sun Jan 06, 2019 8:00 pm
- First Name: John
- Last Name: Kuehn
- * REQUIRED* Type and Year of Model Ts owned: 19 Roadster, 21 Touring, 24 Coupe
- Location: Texas
- MTFCA Number: 28924
Re: Pits in drum
That’s a good idea about smoothing out the holes or pits. You can do the same thing in Babbitt rods too. Use to do that in IR Rand large air compressors at the air base where I worked.