I need to graduate to a drum dryer so I can handle a higher volume of rods. Been using the PacBay Multi rod unit until now. Unfortunately, there isn't much available commercially.

One concern I had was difference in rpms. I've always turned rods at 6 rpm. Moving to a large disc that holds 8 - 10 rods - a 6 rpm motor is going to have what impact on rpms with the actual rod rpm, etc...

I'm sure certain pulleys will work (Roger - here's your chance!!!) but really not sure what/where.

Also thinking about the type of motor I should use and I'd like to put a timer on it as well.

Any thoughts appreciated!

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One of the earlier RodMakers had a home built drum unit I think.

[www.rodbuilding.org] Did a Quick Search here ya Go

There's photos of one with a pulley set up on the photo page under my name.

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Yeah thanks... I had searched and looked at the photos before posting. That gave some good ideas but really didnt answer the questions I had. I liked Tom's idea coming from the ceiling since it uses "unused" space. I'd planned to go high up the wall, but wonder if hanging wouldn't be better.

The big question being the change in RPM going to a big ol' disc on a X rpm motor. Also, if there was a different "best practice" rpm on a drum. Also best motors, timers, etc.

I didn't see one in the rodmaker spreadsheet... but I could have missed it. I'll check again.

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Mine was used for repair work, only. It had a final drum speed of 10rpm which seemed to work fine with any epoxy I used.

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Alex,
When I built some drum dryers last year, I built an extra set of drums. If you have any interest, I could sell the drums at a reasonable price.
Do a search under my name - roger wilson - and you can see the pictures of the drums as well as the dc motors that I used to power the dryer.

I use a square tube for the dryer main rod so that there is no issue about the drums turning on the rod. One end of the tube has a rod in the end to go into a bearing to support that end. On the opposite end of the tube, I insert a threaded rod on which I screw a drill chuck. Then, when it comes time to attach the tube to the motor, I simply mount the motor on the opposite end of the drum and then use the drill chuck to attach the tube to the motor.

[www.rodbuilding.org]


Drop me a line - at
hflier@comcast.net
if you have any interest in the drums or any more information.

Since finishing the drum dryer I have used it to dry many many rods and it works very well.

I use my power wrapper to get the finish on the rod and to get everthing smooth and perfect. When I am ready, I simply move the rod to the dryer for long term drying.
With a drum dryer, you have to have the rod in good shape before you move the rod to the dryer, because with multiple rods n the dryer, you really can't do anything to the finish to clean it up . So, do your finish application as well as the perfecting of the finish with respect to clean edges, no bubbles etc. before transferring to the drum dryer.

I typically use a 12 volt 6-10 rpm gear motor that is powered by a 12 volt plug in power supply to power the drum dryer. Inexpensive on the big @#$%& site and it works very well.

Roger

Thanks Roger - I like some of the things I saw. I'll get my thoughts together and shoot you an email. I'll add that am looking to make this a permanent mount.

To your point... once a rod comes off my power wrapper for finish - there's nothing to touch up. It's ready to be left alone.

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I recommend that you get up to 10-12 rpms minimum. My experience has been that the 18 rpm's work best. I dont like the 6's.

OK Alex, time to fish or cut bait!

How many rods do you want to do in house at a time?

Best way to guess at size of drum dryer.

Circumference of a circle equals 3.14 x Diameter of Wheel - Skate board, tricycle, bycycle, Unicucle or humongous.

Consider rods and types and establish distance between centers to assure ease of placement without bumping.

Example: Wheel size is 24 inch diameter - on 3" centers you can get approximately 24 rods on and off at while under rotation.

The rpm of the wheel is determined by the distance of the circumference from the center by the following.

Most are set at 18 rpm.

[hyperphysics.phy-astr.gsu.edu]

Remember the best option!

Sell more rods - make more money!

Keep what you got - enjoy life - we will contract build, in the USA, to your specifications using your components.

[www.swamplandtackle.com]





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Edited 1 time(s). Last edit at 09/12/2010 11:21AM by Bill Stevens.

Bill.
I read your post with interest.
I do agree 100% with the physics equations with respect to circumfurence, angular velocity and tangantial velocity.

But for the case of a rod dryer, you really don't care about these components of rotation. The only thing you really care about for a rod dryer, is 1. i.e. how many total rotations will the rod make in a given amount of time.

Lets say that you have a single rod dryer that turns a rod at 6 rpm. So, if you put a mark on the top of the rod, or look at the first guide on the rod and count the number of times that the guide would be vertically upward in a minute, you would find that you would have that event occur 6 times in a minute. i.e. the rod is turning at 6 revolutions per minute.

Now, then, lets suppose that you put a drum of variable diameter around the rod blank - much as is the case of a drum dryer on a single center shaft turning a drum containing rods on the circumfurence of the drum.

Lets suppose that for argument, that the diameter of the drum is 4 inches and you only have one rod mounted on the drum. You also align the butt guide on the outside of this drum, in line with the butt guide of the center rod on the inside of the drum.
When you turn on the motor, you will find that the center rod turns exactly 6 rpms. Or, the center rod has a drying speed of 6 rpm. Now, if you look at the rod that is mounted on the circumfurence of the 4 inch drum, you will also count the single butt guide exactly 6 times in a minute. i.e. you will see no difference in the total number of times that the rod that is mounted on the outside of a 4 inch turning, compared to the turning of the center shaft of the drum.

Now, expand the drum to 12, 24, or 36 inches. You will still have exactly the same thing happening to the drum that is mounted on the circumference of the drum. i.e. if the center shaft rotates at 6 rpm, you will find that each of the rods that are mounted on the outside of the drum will also rotate for the very same total of 6 revolutions per minute.

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Having said that, your physis equation do bring up an interesting point. i.e the equations discuss angular as well as tangential velocity. So, now you start running into a "slinging" effect as you go to larger and larger drum diameters. i.e. in addition to the rod simply rotating, the rod itself is experiencing a linear velocity as a result of being mounted on the non center of a rotating drum. If you think about it, there is a possibility that this linear velocity could have some --- epoxy running -- effects if the rpm of the center shaft is increased too much, or if the diameter of the drum dryer is increased too much.

A simple example of this is to take a towel, drop it into a tub of water to get it nice and wet and start slinging it around your head. If you have a long length of towel, you will find that the slinging effect of the towel, and hence the water in the towel, is much greater, than if you have a very short length of towel that is being slung around. i.e. the water in the towel, will be slung away from the towel much further from the long piece of towel.

So, the best speed for the drum dryer, is really dependent on the finish being applied, the wishes and desires of the epoxy applier and the overall diameter of the dryer.

But, for the low speeds that we are speaking, whether it is 6 rpm, 10 rpm, or 18 rpm, there will generally be a very small component of linear , angular or tangantial velocity that will have any effect on the flowing characteristics of the epoxy finish.

Take care
Roger

Roger the individual rods mounted on the circumference of the wheel are not rotating at the same speed about their center axis as the wheel. The other factors are worthy of consideration.

I will defer to the people who formulate epoxy finishes and design drying units units for production companies to come up with a proper rotational speed for epoxy finish drying units..

If you care to make a visit to see a properly designed drum dryer I will be happy to arrange it. We can simply use a stop watch to check out the speed without slinging water from towels.

Open this link and scan down to the finishing room picture.

[www.castawayrods.com]

Bill,
I would be curious if you would simply send me an e-mail with your stop watch measurements of your large production dryer.

i.e. put a mark on the center shaft. Count the number of revolutions in a minute.

put a mark on one of the spots where a rod rests, count the number of revolutions in a minute.

I have yet to figure out how the two numbers could be different.

One revolution is one revolution. Sure, you have other factors, but when you consider a single rotation of the rod about its axis, I have difficulty in seeing how the two numbers could be different.

Thanks for your help.

Roger
hflier@comcast.net

They're the same.

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The Castaway shown in the above link is 12 rpm

Roger try it for yourself. Cut a circle out of paper-cardboard whatever, put a pencil in the center , make a mark from the center to the outer edge. Turn it one complete turn Do the lines start and stop at the same point

I do know all those big works

Bill - willierods.com

Bill,
Yes they will!!!!!!!!!!!!

Mike (Southgate, MI)
If I don't want to, I don't have to and nobody can make me (except my wife) cuz I'm RETIRED!!

They will arrive at the same time ,but,the outside will have travelled faster to get there at the same time because it traveled a farther distance.I think that is what Bill is saying,and by traveling faster will have more tendency to sling the finish.

Sling finish ??? Your not turning it at 200 RPM

Look at the link Bill gave you It does not work ??? And I am sure you are not making one that large

Bill - willierods.com



Edited 1 time(s). Last edit at 09/13/2010 01:21PM by bill boettcher.

A drum dryer turning at 10RPM will not sling finish.

Not unless its many, many feet in diameter. Far more than what we're talking about here.

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